The finer points and capabilities of a knife grinder are only realized thru detailed, solid engineering, trial and error and pure determination. Save the blue prints/drawings and the second (or more) will be a piece of cake (you may even decide to sell one or two) Keep up the good work!
Hi John, nice machine. I dont know if anybody else has mentioned it but your gas strut is upside down, the rod should always face down (or if at an incline with the rod the lowest point) as there is oil and a seal at the end of the tube section, if that seal is not kept in the oil, the seal dries out and gas strut loses its charge.
Congratulations! You not only joined the Super Friends Knife Making League by getting a nice grinder, you MADE your own really nice grinder. Like a Jedi knight making his own light saber. And yeah, those are mosquito larvae.
Awesome work guys! I built my own grinder a few months ago, and it was totally worth it! Tons of work, but really satisfying (and effective) once I got it working! Keep up the good work!
I could, but the new hole at the top works perfectly. I think different holes will give the strut more or less mechanical leverage, making it stronger or softer. But for now it just plain works.
Erik's used it more than I have, and he uses the vertical adjustment a lot. I guess it's one of those things, if you have it, you better use it otherwise it was wasted effort! Very few that I've seen tilt up and down like this, but I'm really liking it. Then table height isn't so important. Haven't used it as a horizontal yet because we don't have any rests for it, but I'm thinking it'll be pretty handy. I'm glad I incorporated both adjustments.
On the 4 link system, to lock it drill one hole for a pin through the 2 side plates, then have a series of holes in an arc on the linkage, so you can have a series of angles to choose from.
It's basically impossible to get the corner rounding tool to be perfect on both sides, so the way Erik was grinding just blends the two sides so they are uniform. Also, the mill leaves light milling marks on all edges, we want to sand them out.
Guys, this is awesome! I've just got into blacksmithing and props making, swords, knives bows and decorative things, and I need a grinder like this in my shop it would make my life so much easier! thanks for this video its the best one on grinders, now I have a much better idea of what to do to make one!, personally I don't have a milling machine, so mine will be plain and simple, but I hope I can make it half as good as yours! awesome guys! top notch!
Yep I wish I had the toys you have to make my own grinder. But once my shop is ready I will most likely take the CAD files for the EERF grinder to my local water jet company and start with that. Love the videos guys, keep up the great work!
Thanks for the reminder, I'll keep that in mind and get it done quickly. I think with that vfd it's easy to add external buttons, should be a fun little project.
Hi John & Eric, Man that Tormach really comes in handy in building tools for your shop. As usual you guys did a really nice job. I really enjoy watching your videos. I too am building my first DIY grinder for my shop. It will replace several tools in my shop and help me regain some valuable floor space. I have my basic build done and I am working on the various tool bars. My goal is to make each toolbar as versatile as possible by incorporating the most options into it. I am almost done with my new design Multi-Tool Rotary Indexing Platen. Some of the contact wheels are still in shipment and hopefully I will be able to get it together next week if all goes well. Thanks again for sharing your ideas and knowledge. John
We don't have a lot of need for flat grinding yet, but yeah I'll probably make a backing plate like that. All the holes on the top arm were originally intended as adjustable positions for the gas strut, but Erik drilled them all way too big and the strut ended up being too long anyways.
Awesome, thank you! I was primarily planning on using the 10" wheel for finishing (it matches my machined bevels perfectly), so this is good info to know.
I would highly recommend getting a half-inch 90° spot drill. It'll save your more expensive chamfer mills, and give you countersinks in one quick motion. They also last damn near forever in aluminum. Otherwise a good countersink tool will do the same with already existing holes, and also come in 82° for imperial screws.
It's hard to plan for everything, especially when building something for the very first time. This particular issue seemed to work in CAD but when applying real life spring pressure it didn't work. The other designs that I copied seemed to run into the same problem and made a hidden fix that I couldn't see in the pics. With the wheel, I knew I wanted a 10" wheel, so I got one. It just happened to be serrated.
I'd use a flat platen behind the belt for the knife scale flats, the wheel will always cause grooves and if used 90deg to the wheel would give your handles a hollow grind. I've heard some people are using toughened glass bonded to metal to reduce friction on the platen reducing the generated heat. Nice grinder though. Hoping mine will come out as nice.
I know Klingspor belts are really popular but I don't like them for the hand held belt sander. I was sanding an airfoil shape on a long piece of wood and went through four brand new Klingspor belts. They just blew apart at the seam after a few seconds of use. If you like klingspor that's fine, more power to you, but I have been really happy with Norton abrasives. We get our belts from a distributor in Texas.
Good to see your thoughts on building vs buying, appreciate that a lot. It used to be a simple choice, but seems like the time vs money equation is starting to sway the other direction.. a good problem to have in many ways I suppose.
The Serrations on the wheel just make it take material off faster, also they dont heat up quite as much, although the smooth rubber wheels have a nicer finish. Also great grinder I love it!
Ive always wanted a grinder like this I couldnt believe how spendy they actually are. Great job on yours though john making your own leaves you open to endless possibilitys for attachments.. awesome job guys
Hy, nice video. First I´m sorry for my English.... Second: About your question at minute 27: I´d say the striation of the wheel is therefore to get the air out to have a fully contact between the wheel and the belt. This is important espacially at high numbers of rotation. Greeting from Germany
Hello John! Serrated wheel helps take off material easier with coarse grit belts. It's really not good for finishing, for that a smooth wheel is much better. Serrated might leave a "jumpy" pattern.
Serated wheels are for rapid stock removal. Flat wheels are for fine finishing. Got information from Burr King. Good job on the grinder. Sorry your four bar linkage didn't work out, I can see what you where thinking. You where trying to get the top angle to change. I have a mechanism design for a tilting steering column that would work for the rear vertical link. Send me PM.
that's awesome man. been designing something VERY similar but with steel and not as crazy lol but from the tool arm slots up is exactly what I was planning in my head
One reason for tolerancing issues is the fact that stock is usually a few thou oversize. I have no idea if this has any relation to your issue however. But yeah. All the faces on the grinder that aren't machined could be 4-6 thou oversize which with so many parts adds up.
Nicely done. I have a suggestion though. I would stick the VFD into sealed enclosure and run a remote with a Estop. The grinding dust is going to ruin the vfd in no time and will most likely be an arcing fire kinda mess.
I know you've already fixed it but that spring can either be a link of a 3 bar linkage .. or a solid linkage can replace it and it will work attached between the opposite corners of a 4 bar linkage
I really like the fine trizact belts. They last so much longer. I've worked with norax as well but didn't get good results. It didn't seem to do too good of a job unless I was using the belt slack rather than the contact wheel As for klingspor, I've gotten very good results from their j-flex line. As advertised, it's good for contours. Seems to last longer than their standard AO belts too. I think you'd like them for finishing those corner rounds
Hey guys, that's a beauty you made there. I wish you had shown how you will mount the disk grinding plate to the drive wheel. Is there a way to extend the shaft to do so?
it's possible that close tolerances ARE the reason some of the parts don't slide smoothly. smooth, high tolerance mating surfaces result in a lot of surface area sliding against each other. AL isn't used for bearings; there's probably a good reason for that. a small amount of dry lube might help.
Are you not going to have a backing plate behind the belt for flat grinding? And what is the holes in the top plate/arm for? Was that going to be for the gas strut originally for adjusting the gas strut?
Hey John stick with the non serrated contact wheels, that's what most knifemakers use and prefer. Since you guys are newbies to grinding I would stay away from the serrated wheels. The serrated ones can be dangerous when using higher grit belts. If you put to much pressure on the wheel it can puncture the belt and send the blade flying. IMHO they're not worth the supposed cooling effect.
Machine looks great, simple design and well built. Now that you have had it a while, any other changes you would incorporate other than the ones you noted?
+Eric Helpenstell Great question Eric! Ummm, the tensioner is a little finnicky, I'm not sure what we did that others are doing differently or better, but it doesn't always respond the way I think it should. I probably would not use that VFD again, the buttons are breaking from being pressed so much, it's not dust proof, and Erik is constantly getting shocked (could be a totally different issue). The sealed ones that other knifemakers are always using is probably the way to go. Other that that it's pretty stout! I don't know if we've ever actually laid it down on it's side, a feature I spent so much time designing in! Then again, we dont do conventional grinding. I would like another grinder that runs 2 independently tensioned 1x72 belts for sharpening.
put 2 m10 nuts on your m10 bolt and use them as locking nuts, this will keep sanding belt on crown of wheel, also I sugest black pulley wheel make movable on a slotted arm to apply tension all the time to belt, but good job
To make it a 3 link instead of 4? Yeah that would probably work, if the top bar is long enough. I found a lot of areas that could be made way simpler and function just as well.
Big John,you should have made it out of sq tubing (as this is cheap and robust ). I Drew 1 in cad priced it out wheels and all with a standard motor (belt adj) 700.00 plus screws.. peace
I am not a machinist but I have been watching a lot of other machinists. I think the issue with tolerances comes from the fact that I don't think he faced off all of the components.
Why didn't you just move the lower strut pivot slightly to the right so that it locks with the wheel higher? What was the point of having the wheel pivot in the first place? My friend did this with some angle iron which he welded into a cuboid. He just put a pipe in the cuboid with a spring. The wheel was directly connected to the pipe. All vertical upward force.
Those bugs are mosquito nymphs. This video is a year old now but in the future dump the water some where that the mosquitoes can not continue to grow. Their life cycle is pretty short.
You need to let me come take a tour of your shop and play with all your toys haha. No but really what if i was to come down one day and you can teach me a bit on how to work a mill. Feed speed and stuff like that?
Hey John, what did you go to school for? I was enrolled in a mechanical design program where we started to do some CAD, but sadly I had to drop classes because of military orders, I really want to be able to do milling and such as well. Thanks ahead of time! Awesome video and wow! What a beautiful machine you have there!
I didn't go to school for anything. Everything I've learned I figured out either by trial and error, watching UA-cam, searching the internet, or asking key people how they do it. My way takes longer ;-).
screwed up coz I am using my phone to type this, can't understand why there is a problem and so a need to grind the backs of the blades on any grinder?
The finer points and capabilities of a knife grinder are only realized thru detailed, solid engineering, trial and error and pure determination. Save the blue prints/drawings and the second (or more) will be a piece of cake (you may even decide to sell one or two) Keep up the good work!
Hi John, nice machine. I dont know if anybody else has mentioned it but your gas strut is upside down, the rod should always face down (or if at an incline with the rod the lowest point) as there is oil and a seal at the end of the tube section, if that seal is not kept in the oil, the seal dries out and gas strut loses its charge.
Congratulations!
You not only joined the Super Friends Knife Making League by getting a nice grinder, you MADE your own really nice grinder. Like a Jedi knight making his own light saber.
And yeah, those are mosquito larvae.
Awesome bro, it the best feeling when you can make your own tools.
Awesome work guys! I built my own grinder a few months ago, and it was totally worth it! Tons of work, but really satisfying (and effective) once I got it working! Keep up the good work!
Genius Job done, John.....your work speaks a lot & loud...my best wishes.....
I could, but the new hole at the top works perfectly. I think different holes will give the strut more or less mechanical leverage, making it stronger or softer. But for now it just plain works.
Erik's used it more than I have, and he uses the vertical adjustment a lot. I guess it's one of those things, if you have it, you better use it otherwise it was wasted effort! Very few that I've seen tilt up and down like this, but I'm really liking it. Then table height isn't so important. Haven't used it as a horizontal yet because we don't have any rests for it, but I'm thinking it'll be pretty handy. I'm glad I incorporated both adjustments.
On the 4 link system, to lock it drill one hole for a pin through the 2 side plates, then have a series of holes in an arc on the linkage, so you can have a series of angles to choose from.
Very nice! I've been planning to build one and you've answered many questions I had. I'll be revisiting this video as I go.
It's basically impossible to get the corner rounding tool to be perfect on both sides, so the way Erik was grinding just blends the two sides so they are uniform. Also, the mill leaves light milling marks on all edges, we want to sand them out.
Exactly! As soon as Eric said "they're going to come out of the water and attack us while we sleep" I thought, "YES THEY ARE!!!"
Nice fix with the stop pin on the idler arm. Awesome machine.
Guys, this is awesome! I've just got into blacksmithing and props making, swords, knives bows and decorative things, and I need a grinder like this in my shop it would make my life so much easier! thanks for this video its the best one on grinders, now I have a much better idea of what to do to make one!, personally I don't have a milling machine, so mine will be plain and simple, but I hope I can make it half as good as yours! awesome guys! top notch!
Yep I wish I had the toys you have to make my own grinder. But once my shop is ready I will most likely take the CAD files for the EERF grinder to my local water jet company and start with that.
Love the videos guys, keep up the great work!
Thanks for the reminder, I'll keep that in mind and get it done quickly. I think with that vfd it's easy to add external buttons, should be a fun little project.
Hi John & Eric,
Man that Tormach really comes in handy in building tools for your shop. As usual you guys did a really nice job. I really enjoy watching your videos.
I too am building my first DIY grinder for my shop. It will replace several tools in my shop and help me regain some valuable floor space. I have my basic build done and I am working on the various tool bars. My goal is to make each toolbar as versatile as possible by incorporating the most options into it. I am almost done with my new design Multi-Tool Rotary Indexing Platen. Some of the contact wheels are still in shipment and hopefully I will be able to get it together next week if all goes well.
Thanks again for sharing your ideas and knowledge.
John
Thanks! I've thought about making a rotary platen too, just saw your design, love it!
We don't have a lot of need for flat grinding yet, but yeah I'll probably make a backing plate like that. All the holes on the top arm were originally intended as adjustable positions for the gas strut, but Erik drilled them all way too big and the strut ended up being too long anyways.
Awesome, thank you! I was primarily planning on using the 10" wheel for finishing (it matches my machined bevels perfectly), so this is good info to know.
Great job guys! I love how everything is engineered to the nth degree! Very impressive.
I would highly recommend getting a half-inch 90° spot drill. It'll save your more expensive chamfer mills, and give you countersinks in one quick motion. They also last damn near forever in aluminum. Otherwise a good countersink tool will do the same with already existing holes, and also come in 82° for imperial screws.
It's hard to plan for everything, especially when building something for the very first time. This particular issue seemed to work in CAD but when applying real life spring pressure it didn't work. The other designs that I copied seemed to run into the same problem and made a hidden fix that I couldn't see in the pics. With the wheel, I knew I wanted a 10" wheel, so I got one. It just happened to be serrated.
I'd use a flat platen behind the belt for the knife scale flats, the wheel will always cause grooves and if used 90deg to the wheel would give your handles a hollow grind.
I've heard some people are using toughened glass bonded to metal to reduce friction on the platen reducing the generated heat. Nice grinder though. Hoping mine will come out as nice.
Thanks for the tip, I briefly wondered about that but haven't given it much thought, will do!
I know Klingspor belts are really popular but I don't like them for the hand held belt sander. I was sanding an airfoil shape on a long piece of wood and went through four brand new Klingspor belts. They just blew apart at the seam after a few seconds of use. If you like klingspor that's fine, more power to you, but I have been really happy with Norton abrasives. We get our belts from a distributor in Texas.
nice job glad to see it coming together
Good to see your thoughts on building vs buying, appreciate that a lot. It used to be a simple choice, but seems like the time vs money equation is starting to sway the other direction.. a good problem to have in many ways I suppose.
The Serrations on the wheel just make it take material off faster, also they dont heat up quite as much, although the smooth rubber wheels have a nicer finish.
Also great grinder I love it!
serrations are for cooling.you use this kind of wheel for fast stock removal and coarse belts.flat wheels for fine work.
Ive always wanted a grinder like this I couldnt believe how spendy they actually are. Great job on yours though john making your own leaves you open to endless possibilitys for attachments.. awesome job guys
Super cool machine! Seems you could do so much more with a platen attachment. Pretty handy for flat work.
I thought about doing that, but it won't clear. Ideally you're right, it should be upside down, and have a seal.
John you will want to get an enclosure, or relocate the VFD before enough conductive dust gets in there to short it out.
Hy,
nice video. First I´m sorry for my English....
Second: About your question at minute 27: I´d say the striation of the wheel is therefore to get the air out to have a fully contact between the wheel and the belt. This is important espacially at high numbers of rotation.
Greeting from Germany
If you want, you can chase the threads in the hole with the tap with the imperial threads since they are very similar to m10 threads.
Hello John! Serrated wheel helps take off material easier with coarse grit belts. It's really not good for finishing, for that a smooth wheel is much better. Serrated might leave a "jumpy" pattern.
I would mount the strut with rod end facing down so that the strut self lubricates.
Really nice job.
I think I know what you mean, but I was able to lock the rear vertical arm and everything works great as-is.
I was actually thinking about Freya earlier today! Erik's liked that name for a long time, so I think it might stick.
Serated wheels are for rapid stock removal. Flat wheels are for fine finishing. Got information from Burr King. Good job on the grinder. Sorry your four bar linkage didn't work out, I can see what you where thinking. You where trying to get the top angle to change. I have a mechanism design for a tilting steering column that would work for the rear vertical link. Send me PM.
that's awesome man. been designing something VERY similar but with steel and not as crazy lol but from the tool arm slots up is exactly what I was planning in my head
One reason for tolerancing issues is the fact that stock is usually a few thou oversize. I have no idea if this has any relation to your issue however. But yeah. All the faces on the grinder that aren't machined could be 4-6 thou oversize which with so many parts adds up.
Your 4 link will work fine if you incorporate some stops to limit the movement to a point where at its max the belt will not slack. Sweet design!
Nicely done. I have a suggestion though. I would stick the VFD into sealed enclosure and run a remote with a Estop. The grinding dust is going to ruin the vfd in no time and will most likely be an arcing fire kinda mess.
I know you've already fixed it but that spring can either be a link of a 3 bar linkage .. or a solid linkage can replace it and it will work attached between the opposite corners of a 4 bar linkage
As far as belts, 3m cubitron belts run cooler, last longer, and cut faster than anything I've ever seen. That's all I'll use now.
Hell yeah man. Glad to see a grinder in a shop. Like the Norseman but don't like the noticeable steps from the cnc
I really like the fine trizact belts. They last so much longer. I've worked with norax as well but didn't get good results. It didn't seem to do too good of a job unless I was using the belt slack rather than the contact wheel
As for klingspor, I've gotten very good results from their j-flex line. As advertised, it's good for contours. Seems to last longer than their standard AO belts too. I think you'd like them for finishing those corner rounds
I recommend j flex belts for doing rounding of spines because they are very flexible.
You have to try the 3m trizac gator belts. They leave a great finish and they last a very long time.!
The serrated wheel is to keep the temperature down on the belt and wheel at high rpm and high forces against the belt.
Hey guys, that's a beauty you made there. I wish you had shown how you will mount the disk grinding plate to the drive wheel. Is there a way to extend the shaft to do so?
it's possible that close tolerances ARE the reason some of the parts don't slide smoothly. smooth, high tolerance mating surfaces result in a lot of surface area
sliding against each other. AL isn't used for bearings; there's probably a good reason for that. a small amount of dry lube might help.
I second Mike's opinion. Dump that water Eric, or they will come out and attack you.
You should make a flat platen and use that to flatten and remove the factory finish from the TI.
The Serrations I would say they are used to keep the work cooler and remove more material.
Are you not going to have a backing plate behind the belt for flat grinding?
And what is the holes in the top plate/arm for? Was that going to be for the gas strut originally for adjusting the gas strut?
Maybe make a device to hold the shell and put it onto the tormach using a grinding dischead.... if they have those?
I am sorry for asking about the corner rounding, I see now you wanted to blend the back of the blade to a complete radius
Trial and error...never fails.
For the wheel? Yes I did, but it's super duper simple.
Hey John stick with the non serrated contact wheels, that's what most knifemakers use and prefer. Since you guys are newbies to grinding I would stay away from the serrated wheels. The serrated ones can be dangerous when using higher grit belts. If you put to much pressure on the wheel it can puncture the belt and send the blade flying. IMHO they're not worth the supposed cooling effect.
Impressive man, I really like it.
you have done a great job
Nice job, just keep the power outlets away from the metal powder produced during grinding. It may end up a nice explosion... been there.
Machine looks great, simple design and well built. Now that you have had it a while, any other changes you would incorporate other than the ones you noted?
+Eric Helpenstell Great question Eric! Ummm, the tensioner is a little finnicky, I'm not sure what we did that others are doing differently or better, but it doesn't always respond the way I think it should. I probably would not use that VFD again, the buttons are breaking from being pressed so much, it's not dust proof, and Erik is constantly getting shocked (could be a totally different issue). The sealed ones that other knifemakers are always using is probably the way to go. Other that that it's pretty stout! I don't know if we've ever actually laid it down on it's side, a feature I spent so much time designing in! Then again, we dont do conventional grinding. I would like another grinder that runs 2 independently tensioned 1x72 belts for sharpening.
Good to know, wish I would have got the smooth one!
I bought the wheels like that from usaknifemaker website, made by beaumont.
All I got is "to excite, to stir up" from Wiki.
can I suggest using a HEPA filter and cyclone in the air removal?
put 2 m10 nuts on your m10 bolt and use them as locking nuts, this will keep sanding belt on crown of wheel, also I sugest black pulley wheel make movable on a slotted arm to apply tension all the time to belt, but good job
Hi john. You are highly skilled for sure. I have a fadec umc 10 and have the same rust you do around your spindle. Is that the only rust your getting?
To make it a 3 link instead of 4? Yeah that would probably work, if the top bar is long enough. I found a lot of areas that could be made way simpler and function just as well.
By the way, it's beautifully quiet, that's great!
Looking great John, very well done.
As for the name, have Eric look up "æsa"
the groves inthe wheel is for air to come in and cool the belt
can you cnc the knives then use the grinder to take off the levels from the cnc
Big John,you should have made it out of sq tubing (as this is cheap and robust ). I Drew 1 in cad priced it out wheels and all with a standard motor (belt adj) 700.00 plus screws.. peace
I am not a machinist but I have been watching a lot of other machinists. I think the issue with tolerances comes from the fact that I don't think he faced off all of the components.
That is one epic looking grinder! Have you guys thought of a name for it yet? I mean, you have to name it ;)
SuperGrit has some generic scotch-brite belts that I love to use.
that thing kicks ass
What if you just make more pins to stop the arm from moving. So basically you move it to the spot you want and put a pin in it
Why didn't you just move the lower strut pivot slightly to the right so that it locks with the wheel higher? What was the point of having the wheel pivot in the first place? My friend did this with some angle iron which he welded into a cuboid. He just put a pipe in the cuboid with a spring. The wheel was directly connected to the pipe. All vertical upward force.
great job guys. Just watch your fingers this thing can be dangerous.
No support for larger flat surfaces?
I haven't tried those ones.
Any reason not to just remove the linkage you needed to fix in place?
love it so much wonderfull job that give inspiration
Dexter and Breaking Bad... wow all that time watching tv... I told my mom letting me watch TV-MA would pay off. BOoom Beyotch! What now MOM!
Those bugs are mosquito nymphs. This video is a year old now but in the future dump the water some where that the mosquitoes can not continue to grow. Their life cycle is pretty short.
Those are mosquito larva. Watch out for the kids at home!
You need to let me come take a tour of your shop and play with all your toys haha. No but really what if i was to come down one day and you can teach me a bit on how to work a mill. Feed speed and stuff like that?
Hey John, what did you go to school for? I was enrolled in a mechanical design program where we started to do some CAD, but sadly I had to drop classes because of military orders, I really want to be able to do milling and such as well. Thanks ahead of time! Awesome video and wow! What a beautiful machine you have there!
I didn't go to school for anything. Everything I've learned I figured out either by trial and error, watching UA-cam, searching the internet, or asking key people how they do it. My way takes longer ;-).
screwed up coz I am using my phone to type this, can't understand why there is a problem and so a need to grind the backs of the blades on any grinder?
Hi guys
great job on the grinder. thaws bugs are mosquito larvae, you may wanna change the water lol
pro tip to erik, dont smoke too much pot before you use the grinder
bonjoutr
bravo pour cette machine
je suis entrain dans fabriquer une
merci pour cette video
eric
EXCELLENT!
I bought them like that.