Several years ago I encountered this very problem. My complete oversight of the stud size resulted in a temporary tightening of the belt, and when the issue reappeared I cast the lathe into a dark corner where it sets to this day. Thank you for renewing my interest in this very handy tool.
A good tip to hold any thread section in the lathe chuck, is to lock a couple of nuts to the thread, so the flats align. The nuts then grip the thread without damage, and the hex of the nuts is gripped by the chuck very firmly.
I had exactly the same issue with my mini lathe, fixed it with a new lathe! only after doing virtually the same as you have just done, only I milled the surface around the two slots to make it level, so the motor would sit better also enlarged the two bolts to 8mm just to give them a fighting chance. I still use the lathe for little jobs as I do like it, and it's very handy. thanks for sharing, and remember, "Make Stuff, Not War".
Couldn't agree more. I spent some time getting mine in decent working order, and mine was well made by comparison to some I've seen. The best mod I've done is the drive belt reduction, which has given it much more torque, especially at low RPMs , without sacrificing too much high RPM speed.
So the wires are directional wires that turn the motor forward backward, or forward and reverse! Before someone complains! , I am not using it for a lathe but a different use! So I need to buy a variable peed controller for my use! Thanks for your help and support!
Love watching you work as it very soothing. I have done quite a bit of mods to my mini lathe. It is a Harbor Fright. All the bed castings are thew same. I have seen those mounts like you shown. They are a pain. You are also correct about the two bolts in the motor area. My lathe has an actual motor mount that has a pivot on it. If you download the HF manual, you can see how it works and probably make it. Very simple and holds the motor much better than the studs do. Keep up the great work my friend.
I see you're using the same Moore and Wright digital caliper as I am. I liked so much I bought a second pair, and a digital micrometer and a dial gauge also by Moore and Wright. Very happy with them. Way better than anything I've seen at that price. Not Mitutoyo, but for my purpose, as good as.
Good video, easy to watch. A few thoughts; did you consider just using stronger M6 studs and turn a bushing to fill the gap? Also, if you use a collet chuck they grab thread extremely tight without chance of damaging the thread. A very handy accessory I find. Cheers,
I think bushings could have worked, and a collet chuck would certainly have been better for gripping the thread. This video is about the quickest solution I could think of to get the lathe working.
@@AdventureswithaVerySmallLathe- On a quick look. A plate (3~6mm) with two paralel holes. Would make a fine replacement for those two dangling washers. Adding to the M6 and bushings already mentioned. It surely would make for a simpler, quicker and rather effective solution. Cheers
Repairing stuff is great, but unfortunately this lathe isn't old. It arrived new in this broken condition. Buying this lathe was an experiment to find out what you get when you order the very cheapest new mini-lathe off the internet.
As of yesterday I can claim, "been there done that". ;-) Your solution looks rather elegant. But a bit overkill. The original system in spite of being a pain in the "opposite side". 🙂It can and does work. It's neither elegant or practical, but it works. With that said on mine the first motor nut was becoming loose. Anyway basic improvements include. Adding some thread lock (Loctite) on those studs motor side. And replace the M6 regular nuts by M6 "Nylok" counterparts. Those two small details. Make all the difference. With no machining included. On my case I had both things at hand. So it was quick and really easy. The royal pain is by far. Fine tune the belt tension vs alignment. That was very time (patience) consuming. But an unavoidable absolutely important step. Cheers
Sounds like a nice simple solution, but how did you solve the problem of the slots in the casting being wider than the M6 nuts? Did you use a replacement stack of ordinary M6 washers, or use something else thicker to avoid bending?
@@AdventureswithaVerySmallLathe- Hi, I didn't replace or change the washers. I should, but my patience was running out. LOL 😂😂 The fact that the casting slots are wider. In spite not being elegant. It's not a deal breaker. After all, they are fundamental to fine tune the position of the motor (left-right axis) and respectively the belt alignment. Either case I believe the most important is to keep things tight. But not overdue. While metal it's kept under the "elastic phase" everything will be tight and secure (proper torque). But the moment metal enters the "plastic phase" it simply deform. And no longer play it's function correctly. Reason why the washers where bend beyond recover. A small M6 by it's own nature can't withstand much torque. And most important in this application, it really doesn't have to. ;-) What is absolutely fundamental in this case. Is to withstand vibrations so it doesn't come lose. That's where the elastic properties of the metal, along with Loctite on the threads and "Nilock" nuts. They all come together. ;-) Thousands of these mini lathes working with the same system. Many, or probably most. Are still using the OEM system. That should tell something. I hope this writing makes sense and can be of any help. Cheers.
Same issue on my mini-lathe. I suggest making a plate to mount the motor off of the lathe and bolt both down. The plate can slide to adjust tension. This lets you move to a larger/better motor easily.
Second that. I don't have a dog in this fight as I have a SHERLINE rather than one of these pieces from the PRC. All the same, were I faced with this issue, I think I would have gone with a plate of modest dimensions as it appears that the housing is cast and I have no love of cast metal and its inability to handle pointed stresses well. May I also add that I don't know the metalurgy involved, but feedback I have viewed about "chinesium" metal leaves me thinking about erring on the side of caution where one is required to trust it. FWIW.
Will tell you to take that speed control and remove from box, clean of all dust, and put in a plastic bag, or mount separate from the lathe itself in a dust tight box, with all connections coming in to it. Small bits of swarf and metallic dust will blow them up, and they are expensive to buy. You can guess how I found that out.
This isn't guaranteed, but I've done it a few times. Usually if a die has a large lead-in angle on one side, it often has a much closer cut on the other side.
What colour are the wires for neg or positive, as I have a 550w 6000rom mini lathe wires are white and blue! But I don't know which is positive can you help me out I would be grateful!
Check my video called "Reassembling the CJ0618 7x12 Lathe" at 8:35 where I did a close up of re-connecting the motor blue and white wires to the direction switch. This is all the info I have, and I simply re-connected it the way it was before disassembly.
I'm surprisely noting that your motor drives directly the spindle !!! Such a solution - as i know - is only used with step motors, while your one is a brushed, conventional one, as mine is ... but in my lathe ( a 7" x 12" ) there is an intermedium axis ( drived with pulleys and a toothed belt from the brushed motor ), which in turn moves a couple of gears, with the choise of two speeds, low and high, depending of which couple of gears is selected ... So i believe your spindle has not so much torque, or - in anycase - less than usual ... Did you go on with any modification ? Thank you in advance for your answer. My best greetings from Italy ...
This is the very cheapest and worst built Chinese lathe, so it's full of short cuts, and missing a lot of good features. It doesn't have the speed change lever and intermediary gears that other lathes have. I've been working on more improvement work, and have plenty more planned, so stick around.
To get my belt to the right tension I had to 3D print a spacer that fit between the motor and the slotted casting. Mine had no jacking bolts above the motor.
Nothing to do with what work you did on your mimi lathe, but it does apply to the DC motor, periodically check the carbon brushes. I recently checked ones on my Warco 180 and found they were worn down and needed changing.
I'm intending to watch your whole series "Adventures With a Small Lathe". I'd prefer to watch them in the order created but have yet discover that order. They don't seemed to be numbered in a obvious manner. Is there list somewhere?
I had same problem with mine. Fortunately the studs were reusable so I made a steel plate to replace the washers on the front side. I'm still thinking of a better solution but meanwhile the lathe is usable....
Hello Al, Nicely done, it was funny I was thinking about this lathe the other day and where it was on what I imagine is a rather large todo list Cheers. Paul,,
I bought this lathe from AliExpress, but unfortunately one component of the control board burned out on the 4th day. It turned out that it is a C6025L transistor that is not sold anywhere. I would very much appreciate it if you know another suitable board or what other transistor it can be used with replaced the one you show in a clip. My lathe is a 7x14 550w.
Good work! :) That motor mount "mechanism" seems absolutely horrible :) Sure there isn't supposed to be a cradle between the casting and the round shape of the motor? Also, one of the first things I would do (except the things on the bed you already mentioned) is to mount a support strut between the back left lower corner of the casting and the back left corner of the shelf for the headstock. The thin front plate of casting is all the torsional "rigidity" the headstock has - it must be twisting like an overcooked noodle under any type of load :)
Thanks for the suggestions! I've already been working with a friend on getting a 3d printed cradle made to sit behind the motor and make it more stable against the back of the casting. Glad to hear that makes sense to you too. The idea of a strut on the back corner sounds well worth looking into, as the back corner of that headstock does seem very undersupported.
@@AdventureswithaVerySmallLathe I haven't run any FEM analysis on it :), but by just a visual inspection it would seem you could increase the torsional rigidity manyfold with only a small strut strategically placed there. It might be a fun idea to mount a ground roundstock in the chuck and measure the deflection for say 10N of load 20cm out from the chuck... Doing that with/without a strut should be fairly easy :)
@@AJBtheSuede The way the back of the bed hangs unsupported has always struck me as flimsy, and potentially something that would exacerbate headstock vibration. However an obvious way to fit a strut with enough strength without interfering with the motor drive and the gear banjo hasn't presented itself yet. I'll focus on it at some point, and no doubt I'll work something out. The experiment to teste that deflection should make an interesting video.
I don’t know if you have watched Artisan Makes but he placed a steel spacer in the motor gap space on his mini lathe. I know you are trying to keep the repairs reasonably “stock” so removing the motor from it’s designed space is probably unappealing. But it’s hard not to look at the space beneath the head stock as a vast casam of flexibility. Perhaps a couple of 3/4 steel spacers with holes big enough to accommodate the motor and act as motor mounts themselves while supporting the lathe ways and the head stock? Admittedly since your channel is Adventures with a very small lathe I might be looking at this through the wrong lense failing meet intent.
I've watched quite a bit of Artisan Makes, and he does really great work. Sometimes I get inspiration for future work from there, and sometimes he does stuff I aready did, but haven't edited the video yet. There are lots of really good improvements for the motor mount that I've found on UA-cam, but I think my long term improvement will probably be to use a larger external motor. I haven't specifically decided how to set up the drive train yet.
@@AdventureswithaVerySmallLathe ooooh! It looks like I have something to look forward to. Perhaps a servo motor with an internal brake? I have a lathe that feels a bit under powered at low rpm so a motor upgrade, while not any time soon, is certainly a desire. I’m always looking to see good ideas for improving home shop machines. I’m looking forward to your upcoming projects.
This destroys the pleasure of machining new studs, however, what about drilling motor casing, tap it to M10, use M10 rod and file the slots in the housing to take the now much bigger rods? It might make the fix even stronger.
The motor housing isn't very thick. At 1.5mm pitch there would be little more than a single turn of engagement, and the housing curvature over the bigger area would make it even less.
@@AdventureswithaVerySmallLathe Thanks for the quick reply. How is this with the 6mm studs? Is there a nut welded in the housing where the studs are screwed?
Question: instead of threading the end of the new bolt, why not drill and tap for a long set screw? If your answer was that you didn’t have a tap, but you had the die, then bravo!
Rather than make a new part with multiple threadings on it, I would have simply replaced the studs with new non-bent ones and then turned a bushing to fit over them and fill in the slot...
Hola amigo tengo un torno exactamente igual al tuyo en estos días estaba realizando un proyecto y la correa se reventó y no se cuál es la referencia por favor ayúdeme a conseguir la referencia de esta correa
The belts should be quite easy to replace. They are multi-V belts, and all you need to know are the profile letter, the number of Vs and the length. The belts have 2 Vs, and the rest of the information is in the code printed on the belt themselves: PJ 330 and PJ 280. This means both belts are J profile, and one is 330mm long, and the other is 280mm long. PJ280 and PJ330 belts with two Vs should be easy to get from online sellers. I buy mine from online bearing retailers that carry this kind of supplies.
Can you go into why that would be an improvement? There isn't anything wrong with the existing holes. The motor wall isn't very thick, and bigger holes would mean fewer turns of thread engagement.
@@AdventureswithaVerySmallLathe Wall thickness is a consideration. It does seem as though when one puts a step or shoulder on a fastener t it creates a weak spot. But then again, we aren't talking about a heavy duty application here. I admit, I have not watched all your vids yet. Have you upgraded to the 750 watt motor at this point ?
@@oldhick9047 I haven't, but I have some upgrades in mind. I'm considering either an AC motor with VFD speed control, or an industrial sewing machine servo.
@@AdventureswithaVerySmallLathe MY CJ0618 HAS STOPPED WORKING AND I FOUND A ELECTRICAL WIRE NOT ATTATCHED TO ANYTHING BEHIND THE ELECTRICAL BOX AND DO NOT KNOW WHERE IT FITS CAN YOU HELP?
@@kennyhallford830 I posted the photo I have to the community tab of my channel. Hope this helps. Just click on my channel icon, and then select the community tab and view the latest post.
It's much more simple, and quicker, to remove the stator from the motor, drill out the existing 6mm stud holes in the motor casing to a suitable size for retapping to 8mm and use either stainless or high tensile studs cut from an appropriate bolt. This means you don't need to do any machining on the stud,, other than cutting them to length.
I can see why that might seem simpler, but it would have been very difficult to impossible with the equipment available to me. I only have a very small mill/drill machine, and could not have accurately drilled out the stud holes to that size. My custom studs may have seemed like a lot of work, but it was all very simple lathe work with easy setups.
The way I have described this alternate method is the way I changed studs on my motor and I simply used a hand drill and I lined up the tap using a small mill square. It really was that simple.
Wouldn't it have been easier to enlarge the motor screw holes and re-tap with fine thread? ... My next lathe up project is to make a plate where the motor mounts outside the lathe. On this plate I'll also mount double, floating belt pulley. The end result will be a two step reduction. The allows me to use larger pulleys on the motor, which give you more teeth on the pulley. It also give you a much slower spindle speed.
9,5mm is .375"...so Brooker rod of 3/8×24 UNF can be used, with a reduced 6 MA (6-1,0) stud section for motor body. Quicker Solution! DocAV...Binary Gunsmith...( Metric+Imperial)
Yes, it was intentionally loose at that stage. If you watch the full reassembly video for this lathe from a couple of years ago, the lead screw needs to be adjusted to make sure it is parallel to the movement of the carriage, which can more easily be checked once the carriage is installed.
The honest truth is that I used my other lathe. It would have been interesting to try it by wedging the motor temporarily in place with the old bent studs on the same lathe, but I went for the simpler route.
you should have added the alignment of the belt it should be running true to the main drive and motor, sorry its easy to find problems when one has already done the fixes
I went into more detail about adjusting the angle of the built in my earlier video, "Reassembling the CJ0618 7x12 Lathe". In this one I wanted to focus specifically on making the motor studs, and fitting those studs as best I could. Truing the belt seemed to be best done by adjusting the position of the pulley on the motor shaft, as it isn't really possible to move the motor along its axis.
The threaded rod is not stainless, judging by the colour it's galvanised. The reason it's hard to work with is probably because it's 8.8 grade, that means it has about twice the tensile strength of mild steel. Personally I like to build small parts that need to be strong out of 12.9 grade bolts that I can have in stock for relatively cheap compared to high strength bar stock. That being said it's even more tough to work with and is very demanding in terms of tools used, and machine rigidity and power.
I too, thought it looked galvanised, but most galvanised all thread or threaded rod is rather a low grade, 4.8, plating high strength fasteners is problematic, look up Hydrogen Embrittlement on plating.
@@bostedtap8399 Hydrogen embrittlement poses a meaningful risk starting at grades 10.9 and up according to reputable hardware supplier. These fastners and stronger grades can still be zinc coated by ‘zinc flaking’ which elimimates hydrogen embrittlement. The reason I think the rod in the vide might be 8.8 is because of the trouble the saw is having, or the blade might just be dull. In any case, 8.8 grade fastners can safely be plated.
@@shiro-r4m I stand corrected, I'm wary of any galvanising on all high tensile fasteners, yes, 8.8 grade fasteners can be hard to saw with standard blades, grade 10.9 will soon blunt any hacksaw. Have a great week. Regards John.
@@bostedtap8399 no worries, we all learn something every day. It’s not like I know affected grades off the top of my head but I do know where to look up stuff like that.
In general I prefer to make mods and improvements without modifying the existing parts if possible, especially not such a major part as the bed casting. It reduces the chance of me making a bad mistake I can't undo, and it ensures I have the opportunity to fix the problem with a better solution in future.
I think This old Tony had the same issue with his. It's a very common issue on these lathes, after beefing up the screws the threads rip out of the motor in most cases.
Some of then footage is from my disassembly and re-assembly video of the same lathe. The specifics of making the studs and the discussion of the solution are new though. I thought it was worth making a video specifically about fixing this problem.
The bandsaw has a warning on it not to lubricate the blade at all. I'm contrary enough to have tried it, and the blade came off immediately. I had to clean the drive mechanism thoroughly and degrease before it would run properly again. It's not a good bandsaw, and I'm delighted to have a much better replacement already.
A lathe can fix anything. I do wish I'd tried a way to fix this lathe with itself though. I took the easiest path, which was to use the other lathe which was already set up.
Yeah, the standard of manufacture of this lathe was really low. I don't have an example of a full price equivalent to compare to though, so I'm not sure if this is as normal, or if branded imports are significantly better.
Be aware the next thing that is going to fail is the threads in the motor. Keeping softer washers and the standard m6 grub screws helps to build in a failure point. Happens alot on these types of small lathes.
I learned most of what I know from Americans, and often I have no idea what the alternative terminology even is. I do my best to lean from as many sources as possible though, and am always welcome to new opportunities. What's the opposite of dismantle? Re-mantle????
@@AdventureswithaVerySmallLathe assemble. American English is to me either too cluttered or too stark. the worst and mosr annoying are issue and impact for cause and effect or problem and solution.
@@hrxy1 I'm not sure why nobody said anything earlier about this, but who exactly are you to police this man's vocabulary? It might have been a different story if this weren't widely used nomenclature, but it is. Get over it.
The time yoy took to take the many camera setups to show exactly what is being done is incredible. Thanks for sharing this!
Several years ago I encountered this very problem. My complete oversight of the stud size resulted in a temporary tightening of the belt, and when the issue reappeared I cast the lathe into a dark corner where it sets to this day. Thank you for renewing my interest in this very handy tool.
A good tip to hold any thread section in the lathe chuck, is to lock a couple of nuts to the thread, so the flats align. The nuts then grip the thread without damage, and the hex of the nuts is gripped by the chuck very firmly.
This is called‘double-nutting’.
Nice, but I have a better way. A collet chuck. A sound investment for any lathe.
I had exactly the same issue with my mini lathe, fixed it with a new lathe! only after doing virtually the same as you have just done, only I milled the surface around the two slots to make it level, so the motor would sit better also enlarged the two bolts to 8mm just to give them a fighting chance. I still use the lathe for little jobs as I do like it, and it's very handy. thanks for sharing, and remember, "Make Stuff, Not War".
These mini lathes are the equivalent of a casting kit. You do the final fettling and assembly after.
Couldn't agree more.
I spent some time getting mine in decent working order, and mine was well made by comparison to some I've seen.
The best mod I've done is the drive belt reduction, which has given it much more torque, especially at low RPMs , without sacrificing too much high RPM speed.
@@johnnodge4327
Bought mine almost two years ago. Still improving things on an almost daily basis,
You realise, of course, this one-ups Tony on mods for the "Manila The". Keep modding. We love you too.
So blue live is positive, and white is negative neutral! I found it helpful and informative!
So the wires are directional wires that turn the motor forward backward, or forward and reverse! Before someone complains! , I am not using it for a lathe but a different use! So I need to buy a variable peed controller for my use! Thanks for your help and support!
Love watching you work as it very soothing. I have done quite a bit of mods to my mini lathe. It is a Harbor Fright. All the bed castings are thew same. I have seen those mounts like you shown. They are a pain. You are also correct about the two bolts in the motor area. My lathe has an actual motor mount that has a pivot on it. If you download the HF manual, you can see how it works and probably make it. Very simple and holds the motor much better than the studs do. Keep up the great work my friend.
I see you're using the same Moore and Wright digital caliper as I am. I liked so much I bought a second pair, and a digital micrometer and a dial gauge also by Moore and Wright. Very happy with them. Way better than anything I've seen at that price. Not Mitutoyo, but for my purpose, as good as.
I'm glad to see you've made another video,. They're very informative, keep them coming.
Thanks.
Good video, easy to watch.
A few thoughts; did you consider just using stronger M6 studs and turn a bushing to fill the gap?
Also, if you use a collet chuck they grab thread extremely tight without chance of damaging the thread. A very handy accessory I find.
Cheers,
I think bushings could have worked, and a collet chuck would certainly have been better for gripping the thread. This video is about the quickest solution I could think of to get the lathe working.
@@AdventureswithaVerySmallLathe- On a quick look.
A plate (3~6mm) with two paralel holes. Would make a fine replacement for those two dangling washers. Adding to the M6 and bushings already mentioned.
It surely would make for a simpler, quicker and rather effective solution.
Cheers
I'm saving up for a minilathe and all your videos show me how I can improve it. thanks man. I'm excited for the next instalment 😀🤘👊
Nice fix, feels nice to tighten up an old piece of equipment and get that like new feeling back. Cheers!
Repairing stuff is great, but unfortunately this lathe isn't old. It arrived new in this broken condition. Buying this lathe was an experiment to find out what you get when you order the very cheapest new mini-lathe off the internet.
As of yesterday I can claim, "been there done that". ;-)
Your solution looks rather elegant. But a bit overkill. The original system in spite of being a pain in the "opposite side". 🙂It can and does work. It's neither elegant or practical, but it works. With that said on mine the first motor nut was becoming loose.
Anyway basic improvements include. Adding some thread lock (Loctite) on those studs motor side. And replace the M6 regular nuts by M6 "Nylok" counterparts. Those two small details. Make all the difference. With no machining included.
On my case I had both things at hand. So it was quick and really easy. The royal pain is by far. Fine tune the belt tension vs alignment. That was very time (patience) consuming. But an unavoidable absolutely important step. Cheers
Sounds like a nice simple solution, but how did you solve the problem of the slots in the casting being wider than the M6 nuts? Did you use a replacement stack of ordinary M6 washers, or use something else thicker to avoid bending?
@@AdventureswithaVerySmallLathe- Hi, I didn't replace or change the washers. I should, but my patience was running out. LOL 😂😂
The fact that the casting slots are wider. In spite not being elegant. It's not a deal breaker. After all, they are fundamental to fine tune the position of the motor (left-right axis) and respectively the belt alignment.
Either case I believe the most important is to keep things tight. But not overdue. While metal it's kept under the "elastic phase" everything will be tight and secure (proper torque). But the moment metal enters the "plastic phase" it simply deform. And no longer play it's function correctly. Reason why the washers where bend beyond recover.
A small M6 by it's own nature can't withstand much torque. And most important in this application, it really doesn't have to. ;-)
What is absolutely fundamental in this case. Is to withstand vibrations so it doesn't come lose. That's where the elastic properties of the metal, along with Loctite on the threads and "Nilock" nuts. They all come together. ;-)
Thousands of these mini lathes working with the same system. Many, or probably most. Are still using the OEM system. That should tell something. I hope this writing makes sense and can be of any help. Cheers.
Same issue on my mini-lathe. I suggest making a plate to mount the motor off of the lathe and bolt both down. The plate can slide to adjust tension. This lets you move to a larger/better motor easily.
Second that. I don't have a dog in this fight as I have a SHERLINE rather than one of these pieces from the PRC. All the same, were I faced with this issue, I think I would have gone with a plate of modest dimensions as it appears that the housing is cast and I have no love of cast metal and its inability to handle pointed stresses well. May I also add that I don't know the metalurgy involved, but feedback I have viewed about "chinesium" metal leaves me thinking about erring on the side of caution where one is required to trust it. FWIW.
Will tell you to take that speed control and remove from box, clean of all dust, and put in a plastic bag, or mount separate from the lathe itself in a dust tight box, with all connections coming in to it. Small bits of swarf and metallic dust will blow them up, and they are expensive to buy. You can guess how I found that out.
Very interesting Alistair. It’s an ongoing project which will reap just rewards in the end. Thank you for sharing. 👏👏👍😀 Andrew
Good video once again... Never thought to turn the die around to get a closer thread..
This isn't guaranteed, but I've done it a few times. Usually if a die has a large lead-in angle on one side, it often has a much closer cut on the other side.
Good to see some lathe work after some time!! Good fix. Would thin brass sheets on the jaws have helped with thread damage?
Yeah, brass shims would have been a big improvement. Unfortunately I did this work before I made the soft jaws which would have helped.
Great to you back 💫 waiting for your next project..
@ 11:02 would two rubber pads on the motor and the heads of the screws reduce vibration?
What colour are the wires for neg or positive, as I have a 550w 6000rom mini lathe wires are white and blue! But I don't know which is positive can you help me out I would be grateful!
Check my video called "Reassembling the CJ0618 7x12 Lathe" at 8:35 where I did a close up of re-connecting the motor blue and white wires to the direction switch. This is all the info I have, and I simply re-connected it the way it was before disassembly.
I'll be doing this mod to mine shortly!
It's well worth it. I've seen so many lathes of this types that have been delivered in a state which is nowhere near ready to run.
I'm surprisely noting that your motor drives directly the spindle !!!
Such a solution - as i know - is only used with step motors, while your one is a brushed, conventional one, as mine is ... but in my lathe ( a 7" x 12" ) there is an intermedium axis ( drived with pulleys and a toothed belt from the brushed motor ), which in turn moves a couple of gears, with the choise of two speeds, low and high, depending of which couple of gears is selected ...
So i believe your spindle has not so much torque, or - in anycase - less than usual ...
Did you go on with any modification ?
Thank you in advance for your answer.
My best greetings from Italy ...
This is the very cheapest and worst built Chinese lathe, so it's full of short cuts, and missing a lot of good features. It doesn't have the speed change lever and intermediary gears that other lathes have. I've been working on more improvement work, and have plenty more planned, so stick around.
Nice fix, These Chinese mini lathes need lots to adjust and upgrades from head to tail ,
To get my belt to the right tension I had to 3D print a spacer that fit between the motor and the slotted casting.
Mine had no jacking bolts above the motor.
i love it, i'm getting ready to dismantle the pratt & whitney ,so i need to get my mini lathe tuned up ,a bit
Nothing to do with what work you did on your mimi lathe, but it does apply to the DC motor, periodically check the carbon brushes. I recently checked ones on my Warco 180 and found they were worn down and needed changing.
I'm intending to watch your whole series "Adventures With a Small Lathe". I'd prefer to watch them in the order created but have yet discover that order. They don't seemed to be numbered in a obvious manner. Is there list somewhere?
If you go to the channel page, select the Videos tab, and scroll to the bottom and start there. That should be all my videos in the correct order.
Or you could make a bushing to go over the M6 and OD to fit the slot.
I had same problem with mine. Fortunately the studs were reusable so I made a steel plate to replace the washers on the front side. I'm still thinking of a better solution but meanwhile the lathe is usable....
Nicely done! Where do you get those drive belts?
Hello Al,
Nicely done, it was funny I was thinking about this lathe the other day and where it was on what I imagine is a rather large todo list
Cheers.
Paul,,
Hi Paul! The todo list for this lathe does seem to endlessly get longer. Chinese lathes are certainly never boring.
Al
good job Alistair
Thanks, Simon!
I bought this lathe from AliExpress, but unfortunately one component of the control board burned out on the 4th day. It turned out that it is a C6025L transistor that is not sold anywhere. I would very much appreciate it if you know another suitable board or what other transistor it can be used with replaced the one you show in a clip. My lathe is a 7x14 550w.
I used some 6mm thread and then used nylon busings the studs were 12.9 hardness
Brilliant repair.
I love your uploads.
Good work! :) That motor mount "mechanism" seems absolutely horrible :) Sure there isn't supposed to be a cradle between the casting and the round shape of the motor?
Also, one of the first things I would do (except the things on the bed you already mentioned) is to mount a support strut between the back left lower corner of the casting and the back left corner of the shelf for the headstock. The thin front plate of casting is all the torsional "rigidity" the headstock has - it must be twisting like an overcooked noodle under any type of load :)
Thanks for the suggestions! I've already been working with a friend on getting a 3d printed cradle made to sit behind the motor and make it more stable against the back of the casting. Glad to hear that makes sense to you too.
The idea of a strut on the back corner sounds well worth looking into, as the back corner of that headstock does seem very undersupported.
@@AdventureswithaVerySmallLathe I haven't run any FEM analysis on it :), but by just a visual inspection it would seem you could increase the torsional rigidity manyfold with only a small strut strategically placed there.
It might be a fun idea to mount a ground roundstock in the chuck and measure the deflection for say 10N of load 20cm out from the chuck... Doing that with/without a strut should be fairly easy :)
@@AJBtheSuede The way the back of the bed hangs unsupported has always struck me as flimsy, and potentially something that would exacerbate headstock vibration. However an obvious way to fit a strut with enough strength without interfering with the motor drive and the gear banjo hasn't presented itself yet. I'll focus on it at some point, and no doubt I'll work something out.
The experiment to teste that deflection should make an interesting video.
Nice video, Al. Very enjoyable.
And now up to the next fix :)
I don’t know if you have watched Artisan Makes but he placed a steel spacer in the motor gap space on his mini lathe. I know you are trying to keep the repairs reasonably “stock” so removing the motor from it’s designed space is probably unappealing. But it’s hard not to look at the space beneath the head stock as a vast casam of flexibility. Perhaps a couple of 3/4 steel spacers with holes big enough to accommodate the motor and act as motor mounts themselves while supporting the lathe ways and the head stock? Admittedly since your channel is Adventures with a very small lathe I might be looking at this through the wrong lense failing meet intent.
I've watched quite a bit of Artisan Makes, and he does really great work. Sometimes I get inspiration for future work from there, and sometimes he does stuff I aready did, but haven't edited the video yet. There are lots of really good improvements for the motor mount that I've found on UA-cam, but I think my long term improvement will probably be to use a larger external motor. I haven't specifically decided how to set up the drive train yet.
@@AdventureswithaVerySmallLathe ooooh! It looks like I have something to look forward to. Perhaps a servo motor with an internal brake? I have a lathe that feels a bit under powered at low rpm so a motor upgrade, while not any time soon, is certainly a desire. I’m always looking to see good ideas for improving home shop machines. I’m looking forward to your upcoming projects.
Thanks for sharing.
This destroys the pleasure of machining new studs, however, what about drilling motor casing, tap it to M10, use M10 rod and file the slots in the housing to take the now much bigger rods? It might make the fix even stronger.
The motor housing isn't very thick. At 1.5mm pitch there would be little more than a single turn of engagement, and the housing curvature over the bigger area would make it even less.
@@AdventureswithaVerySmallLathe Thanks for the quick reply. How is this with the 6mm studs? Is there a nut welded in the housing where the studs are screwed?
Question: instead of threading the end of the new bolt, why not drill and tap for a long set screw? If your answer was that you didn’t have a tap, but you had the die, then bravo!
Rather than make a new part with multiple threadings on it, I would have simply replaced the studs with new non-bent ones and then turned a bushing to fit over them and fill in the slot...
Congratulations and thanks for share this video !
Hola amigo tengo un torno exactamente igual al tuyo en estos días estaba realizando un proyecto y la correa se reventó y no se cuál es la referencia por favor ayúdeme a conseguir la referencia de esta correa
The belts should be quite easy to replace. They are multi-V belts, and all you need to know are the profile letter, the number of Vs and the length.
The belts have 2 Vs, and the rest of the information is in the code printed on the belt themselves:
PJ 330 and PJ 280.
This means both belts are J profile, and one is 330mm long, and the other is 280mm long.
PJ280 and PJ330 belts with two Vs should be easy to get from online sellers. I buy mine from online bearing retailers that carry this kind of supplies.
Dónde las consigo
Maybe re-drill and tap the motor for bigger studs ? I don't know.
Can you go into why that would be an improvement? There isn't anything wrong with the existing holes. The motor wall isn't very thick, and bigger holes would mean fewer turns of thread engagement.
@@AdventureswithaVerySmallLathe Wall thickness is a consideration. It does seem as though when one puts a step or shoulder on a fastener t it creates a weak spot. But then again, we aren't talking about a heavy duty application here. I admit, I have not watched all your vids yet. Have you upgraded to the 750 watt motor at this point ?
@@oldhick9047 I haven't, but I have some upgrades in mind. I'm considering either an AC motor with VFD speed control, or an industrial sewing machine servo.
How is the electrical conexion for mini lathe of 500w an 7x12
I don't understand what question you are asking. What do you want to know about the electrical connection?
@@AdventureswithaVerySmallLathe MY CJ0618 HAS STOPPED WORKING AND I FOUND A ELECTRICAL WIRE NOT ATTATCHED TO ANYTHING BEHIND THE ELECTRICAL BOX AND DO NOT KNOW WHERE IT FITS CAN YOU HELP?
@@kennyhallford830 I posted the photo I have to the community tab of my channel. Hope this helps. Just click on my channel icon, and then select the community tab and view the latest post.
It's much more simple, and quicker, to remove the stator from the motor, drill out the existing 6mm stud holes in the motor casing to a suitable size for retapping to 8mm and use either stainless or high tensile studs cut from an appropriate bolt. This means you don't need to do any machining on the stud,, other than cutting them to length.
I can see why that might seem simpler, but it would have been very difficult to impossible with the equipment available to me. I only have a very small mill/drill machine, and could not have accurately drilled out the stud holes to that size. My custom studs may have seemed like a lot of work, but it was all very simple lathe work with easy setups.
The way I have described this alternate method is the way I changed studs on my motor and I simply used a hand drill and I lined up the tap using a small mill square. It really was that simple.
faltou fazer um suporte para apoiar o motor
Wouldn't it have been easier to enlarge the motor screw holes and re-tap with fine thread? ... My next lathe up project is to make a plate where the motor mounts outside the lathe. On this plate I'll also mount double, floating belt pulley. The end result will be a two step reduction. The allows me to use larger pulleys on the motor, which give you more teeth on the pulley. It also give you a much slower spindle speed.
Not a good idea to be drilling/tapping in the motor case. Getting grime - let alone steel chips - inside the motor housing will bring dismal failure!
Possuo um muito parecido e novo, porém de fabricação brasileira, incrivelmente possui o mesmo problema...
Your voice is identical to Jeremy Wade, the guy who does the River Monsters show on TV.
I get that a lot. I've never seen River Monsters, but I choose to take it as a compliment.
I love your voice. You sound a lot like Alan Rickman.
9,5mm is .375"...so Brooker rod of 3/8×24 UNF can be used, with a reduced 6 MA (6-1,0) stud section for motor body.
Quicker Solution!
DocAV...Binary Gunsmith...( Metric+Imperial)
I love you too buddy!
Aww, thanks!
Bos,how many watts do you use?
Tapped out Brass split bushes would have been better to hold the 10mm screwed thread.
11:10 I guess you know but didn't say, but just in case, your lead screw is loose.
Yes, it was intentionally loose at that stage. If you watch the full reassembly video for this lathe from a couple of years ago, the lead screw needs to be adjusted to make sure it is parallel to the movement of the carriage, which can more easily be checked once the carriage is installed.
Should have made two spacers to fill in the slot and drill and tap larger into the motor housing
Do not allow any ferrous metal chips into the motor housing ! Take it from me and my sad experience in that area!!
So I need a working lathe to fix my lathe. Cool
How did you turn down the the stud with the motor removed from the lathe?
The honest truth is that I used my other lathe. It would have been interesting to try it by wedging the motor temporarily in place with the old bent studs on the same lathe, but I went for the simpler route.
@@AdventureswithaVerySmallLathe A lathe to fix a lathe.
Type of belt please?
This set up must directly transfer vibration from the motor to the lathe!
you should have added the alignment of the belt it should be running true to the main drive and motor, sorry its easy to find problems when one has already done the fixes
I went into more detail about adjusting the angle of the built in my earlier video, "Reassembling the CJ0618 7x12 Lathe". In this one I wanted to focus specifically on making the motor studs, and fitting those studs as best I could. Truing the belt seemed to be best done by adjusting the position of the pulley on the motor shaft, as it isn't really possible to move the motor along its axis.
Thanks for sharing 👍
The threaded rod is not stainless, judging by the colour it's galvanised.
The reason it's hard to work with is probably because it's 8.8 grade, that means it has about twice the tensile strength of mild steel.
Personally I like to build small parts that need to be strong out of 12.9 grade bolts that I can have in stock for relatively cheap compared to high strength bar stock.
That being said it's even more tough to work with and is very demanding in terms of tools used, and machine rigidity and power.
I too, thought it looked galvanised, but most galvanised all thread or threaded rod is rather a low grade, 4.8, plating high strength fasteners is problematic, look up Hydrogen Embrittlement on plating.
@@bostedtap8399 Hydrogen embrittlement poses a meaningful risk starting at grades 10.9 and up according to reputable hardware supplier. These fastners and stronger grades can still be zinc coated by ‘zinc flaking’ which elimimates hydrogen embrittlement.
The reason I think the rod in the vide might be 8.8 is because of the trouble the saw is having, or the blade might just be dull.
In any case, 8.8 grade fastners can safely be plated.
@@shiro-r4m I stand corrected, I'm wary of any galvanising on all high tensile fasteners, yes, 8.8 grade fasteners can be hard to saw with standard blades, grade 10.9 will soon blunt any hacksaw. Have a great week. Regards John.
@@bostedtap8399 no worries, we all learn something every day. It’s not like I know affected grades off the top of my head but I do know where to look up stuff like that.
@@shiro-r4m Good to know.
So, is the Proxxon PD 250/e worth the money, or is a Chinese lathe a better deal? 😇
I can't understand why you didnt simply file the slots 10mm.
In general I prefer to make mods and improvements without modifying the existing parts if possible, especially not such a major part as the bed casting. It reduces the chance of me making a bad mistake I can't undo, and it ensures I have the opportunity to fix the problem with a better solution in future.
Is this a reupload? I swear I saw this one...
I thought so too
I think This old Tony had the same issue with his.
It's a very common issue on these lathes, after beefing up the screws the threads rip out of the motor in most cases.
Some of then footage is from my disassembly and re-assembly video of the same lathe. The specifics of making the studs and the discussion of the solution are new though. I thought it was worth making a video specifically about fixing this problem.
Use oil with the bandsaw
The bandsaw has a warning on it not to lubricate the blade at all. I'm contrary enough to have tried it, and the blade came off immediately. I had to clean the drive mechanism thoroughly and degrease before it would run properly again. It's not a good bandsaw, and I'm delighted to have a much better replacement already.
I've scraped my lathe, practically everywhere. It's hard and tedious, but there is no other way...
Думаю болты с контр гайкой над мотором служат для дистанционного выставления передней бабки, а не для фиксации мотора !
Many people have made this comment, and it's not true. The screws align with holes in the headstock, and cannot have any effect on the headstock.
ขอบคุณ
اتمنا يوما ما املك واحد منه
TIL this version of the mini lathe doesnt have the high and low speed gearbox
Super Leistung !!!
Fixing a lathe with a lathe!
A lathe can fix anything. I do wish I'd tried a way to fix this lathe with itself though. I took the easiest path, which was to use the other lathe which was already set up.
I’ve never seen a mini lathe that was inspec! Tolerances of castings are so poor and runout is over 20 thousandths or more.
Yeah, the standard of manufacture of this lathe was really low. I don't have an example of a full price equivalent to compare to though, so I'm not sure if this is as normal, or if branded imports are significantly better.
Be aware the next thing that is going to fail is the threads in the motor.
Keeping softer washers and the standard m6 grub screws helps to build in a failure point.
Happens alot on these types of small lathes.
Cutting threats with a die is a pain in the a**. If possible I drill and tap a hole. Then just loctite a bolt there.
There is no point in watching this series further because the videos are not numbered and google does not present them in a sane order.
😊👋👋✔
Со своими вы......и резьбу прославился.
You Really ! Only ! Cheated ! Here !
we don't dissemble, we dismantle. we don't have chips, we have swarf. no new world order pls.
I learned most of what I know from Americans, and often I have no idea what the alternative terminology even is. I do my best to lean from as many sources as possible though, and am always welcome to new opportunities.
What's the opposite of dismantle? Re-mantle????
@@AdventureswithaVerySmallLathe assemble. American English is to me either too cluttered or too stark. the worst and mosr annoying are issue and impact for cause and effect or problem and solution.
@@hrxy1 AND TYPOS LOL
@@hrxy1 I'm not sure why nobody said anything earlier about this, but who exactly are you to police this man's vocabulary?
It might have been a different story if this weren't widely used nomenclature, but it is.
Get over it.
wow. you got a really bad example of the cheap chinese lathes