HS233 Herbert Junior Mk2 surface grinder Part 6 - static converter
Вставка
- Опубліковано 23 жов 2024
- A series on restoring my latest machine - a Herbert Junior Mk2 surface grinder.
The channel I mention building a static converter with a Supco APR5 potential relay is Chris Z • How I made a simple st...
The corrected clip that green-screened at 19:10 can be found here • HS233 Herbert Junior M...
Great stuff Paul. I admire your tenacity!
A well presented video, I followed your progress through each iteration and it all made sense. I have a similar mindset, and don’t like to be beaten -even when it becomes a war of attrition!
The time and money spent should be viewed as an investment rather than a cost. We’ve both learnt something through your tinkering, and I’m grateful for that.
Looking forward to the next one. Matt
Yes Matt, I learnt "next time just buy an inverter". Cheers
I truly admire your perseverance with this and the only wisdom I can pass on is that genuine OMRON relays are the best.
Hi Malcolm, I suspected that Omron were a good brand being Japanese designed and once upon a time Japanese made. I learnt a lot. Cheers
Great video Paul, I've been in that situation many times. The worst is when you call in a co-worker or friend for help and they point to the problem in 30 seconds...lol.
Those potential relays were a fairly common item for us in the HVAC and refrigeration industry for single phase compressor starting.
Glad to see you've cracked it 👍
Cheers.....
Hi Dean, I shudder think of the layers of profit and tax on that potential relay. Production cost has to be less than $5 yet I paid $50. I've bought some building supplies recently - £25 ($32) for 25 insulation fixing nails. Surely all these layers cannot be sustained - often through end-customer borrowing. Cheers
Wow, what a mission, but the end result is what matters. Great detective work.
Yeh 'mission' just about sums it up Jon. Cheers
I totally respect your struggle. I am often bitten by the same affliction. Thank you.
Hi Don, it made no sense but I was committed to make it work or lose my mind in the attempt. Cheers
It is kind of nice to see someone else having the same type of problems I have😁. Glad you sorted it out in the end. When I built my rotary converter I noticed a hot smell coming from the circuitry. It turned out that i had switched it on so many times in a short period of time the start capacitor was heating up. It is ok in normal usage as it is only in circuit for a second, or so. Thanks for letting us see your journey.
You are putting me off building a rotary converter.
My knowledge is limited.
I have started to collect bits and pieces in readiness.
Can you help me understand ?
What is the relationship between the size (HP) of the pony motor and the driven motor ?
How much bigger can one be than the other ?
@Steve, I hope somebody will answer. I have no experience of those but there are quite a few UA-cams on it. But I imagine a rotary converter will always be better than static in terms of the output. Cheers
Paul I salute your perseverance, I personally stay well away from anything to do with electricity so to watch your quest for a successful completion was extremely entertaining. Well done mate and to all the electricians out there you have my admiration. 👍👍
Hi Paul, problem is with mechanical things more or less what you see is what you get but with electricity it's all a bit smoke and mirrors especially with heavier current (i.e. more than 5v or 12v electronics - but that's complex too if it's analogue). Cheers
Excellent video, thanks Paul! Videos that share the entire process of development, with all the problems you ran into and how you went about solving them, is invaluable.
Thank you Paul. As a presenter it's always difficult to know how to show the setbacks and still keep viewer interest. Thanks for your support. Cheers
Quite the journey, but that's the point. Nothing wrong with a little experimentation. Solving a problem like this can be frustrating, but it becomes worth it when you find a solution. Some who suggest that you should always just buy the thing, forget that there's a reason we have machine shops! It's often easier and cheaper to buy it, but where is the fun in that?
Hi Greg, it's a balance isn't it. I would not have missed that bit of experience. 🙄 Cheers
You did well sticking that out to the end. Well done matey.
Hi Richard it was massively frustrating but I'd got too far into it to quit. Cheers
Well done, a proper saga there Paul but I'm glad to see you made it through successfully
Hi Jason yes it felt like a proper saga. Numerous times I was ready to give up but I was too far into to it to just quit. Cheers
For those who have a lifetime interest in electronics and electrical engineering your videos are very interesting. I’m included in that. It also shows how far interest extends into many consumed manhours. Why do we do it?
Hi Geoff, it's good to get the experience but how and when I will apply it in the future I'm not sure. I can get experience banging my head against a wall - but is it useful 🙄 Cheers
@@HaxbyShed You could be underestimating the value being received by your followers. To those who are new to such machinery, it demonstrates how much time, learning, and determination is needed to get a result. To those more experienced it gives satisfaction to know we are not alone in our persistent and determined efforts. Learning from when things go wrong is very valuable for everyone. Personally, l used to study structural and mechanical failures to improve my own theoretical and practical knowledge. How about letting us know about your practical experience with solar panels - it’s on my todo list.
Hi Geoff, for solar panels start with HS196 and then HS217 for my observations after 6 months. I will do the 12 month comments in April 2024 (or maybe May - depends what else I'm doing at the time). Cheers Paul
I appreciate your honesty, this was one of your best episodes.
Thank you Joop. I'm always honest but the challenge is that honest does not always mean interesting or entertaining. Nobody wants to watch a 45 minute video and at the end I say "oh sorry it was a total fail and I just wasted your time - thanks for watching". Cheers
That was a saga, Paul. I don't think I'll try to make one, lol. You did well to sort all that out. Cheers Tony
Well Tony you understand as a UA-camr yourself the awful feeling when you have hours of video in the 'Can' and it dawns on your that the project may well be a total fail. Luckily I was able to pull it through but it cost me time and money. I think if I was not on UA-cam I might have quit earlier and just stuck the inverter on it. Or was it just pride and stubbornness that kept me going .... I don't know. Cheers
That was a good video Paul. If nothing else you have gained experience and knowledge. I understand the urge to know and understand. You were right about the cap, it was leaky. Always good to have cap measurement ability for this type of thing.
Cheers Carl. It was good to get it working in the end but it was very frustrating. I was off to a good start and thinking "this time it will all work just like those other guys on UA-cam", and you know the rest. Cheers
Hi Paul, I admire your perseverance and it works, well done!!
You explained the theory very well, be interesting to see if this produces any patterns or not. I'm glad you got off your chest at the end and it was a great video to watch.
Have a great weekend!!
Thanks David.
It is only when we push ourselves beyond our comfort zone that our knowledge increases. As an electrical engineer I would say you are a lot more competent than a lot of the people in the industry!! Steinmetz connection is not an exact art, and the only alternative fault I could think of was an earth fault on one of the motor coils! You worked through that logically and the only thing was the "that can't be faulty, its new" syndrome which catches everyone out! Capacitors are notoriously unreliable, You proved the fault using the equipment you had available! an ESR meter is something I have thought about, already bought a capacitance meter identical to yours, what an eye opener that was!! I was thinking along the lines of using a fridge start relay which uses the current flowing in the live condutor to hold the start winding in circuit and when the current falls, drops the start winding out. The relay coil carries the running current all the time, but when the start current is applied it operates the relay and pulls the start winding in. another form of the relay you are now using! I am really glad I have real three phase! Get a little woodburner for your workshop.
Another really enjoyable watch!
Thanks Paul,
Phil
Hi Phil, I know that house electrician and plant electrician are very different specialisms. I suppose we could say the same about automotive. I visited Bishop Burton Agricultural College not so long ago and the tutor said that tractors are now so complex they need to be maintained by 'system technicians' with knowledge of all systems, thus apprenticeships are getting longer. Cheers Paul
@@HaxbyShed I served my apprenticeship at Jeffersons in Driffield which occasionally did domestic work, mainly at the homes of industrial customers, but we did a full rewire at Sledmere Hall, a big domestic indeed! Also one in Cranswick in which we used copperclad for the first time, an installation which failed on testing and was all ripped out and redone! Beyond that it was all industrial, and three phase in flour mills, gravel pits and general factory plant and even East Yorkshire Printers. There were 11 electricians and 7 apprentices. Although i have also done quite a lot of autoelectrics and mechanics I don’t do auto work anymore, not even my own car, although i will be investigating my turbo which appears to be not boosting like it used too. Keep up the excellent standards you have set!
Phil
In the words of Pete Townsend, "It's all adding up to something. Something that can only be redeemed with fire".
Hi, I would have quite happily burned it. Cheers
Well persevered Paul, all way way over my head lol. I put an el cheapo inverter on my surface grinder, and whilst I do get some patterns on the grind, these are driven by the machine design in my case as there is no way to balance wheels. This is where the inverter is a real advantage as I can tune out the worst unbalance frequency for any wheel by altering the speed. If I run at 50Hz, I always get unbalance and marking regardless of wheel or size of wheel. I have found between 35Hz and 42 seems to be the sweet spot, and varying within this range depending on wheel size. Hopefully food for thought if you run into any further issues. Cheers, Jon
Hi Jon, I'm thinking of making a balancing collar ..... Cheers
I got a good chuckle from this. I spent my entire career designing industrial variable speed drives. Your experience was typical of many new designs I did. You get some really neat circuit design and it goes sideways. Track it down and you end up with logic races, power supplies with ripple on it, and a hundred other things you didn’t count on.
Hi Glenn, when I was maybe 18 or so it was all the rage to build your own electronic ignition from plans in Practical Electronics or whatever. So I did just that but with limited resources in my grubby bedsit I used a battery charger as the power supply. I could make sparks but everything was getting hot and after loads of messing I gave up. It was a long time later that I realised that the battery charger rectifier was selenium half wave. But for that it might have been a success and changed my life forever. 🤣
One of the best videos you have done. Thanks. ---Doozer
Thank you Doozer, I had no idea how people would respond. It was frustrating as hell for me. I thought the capacitor way would be much cheaper and easier than an Inverter - I was deluded. The inverter is on standby for a swap in case the grind finish is rippled. Cheers
@@HaxbyShed I am pretty interested in rotary phase converters. If you go back in my videos, you will see I have dual 6hp converters. Figuring out the caps and the potential relays are so interesting, because as you found, there are so many variables and problem points. I did not mention this before, but I run VFDs on all my grinders. I like to diamond dress my wheels at 10 Hz, so it actually rips out the grains of aluminum oxide, leaving a sharp and open, free cutting wheel surface. Also, varying wheel speed is a way to control how hard the wheel behaves and how easily the bond will break down. Super handy to be able to tune this, once you really learn grinding. But that was a side note to your static converter project. I admire your quest to learn how to make it work, and I learned a bit too. So thanks again for the good video. --Doozer
Thanks Doozer, I'm just now researching operating basics like wheel grit and bonding, dressing, wheel balancing and all that. Early on I was sure speed control was not required for a home surface grinder but now I'm realising it's something good to have. Anyway I will carry the static converter experiment through to a conclusion and try some grinds to see what I get. If my finish is rippled due to phase imbalance pulsing or harmonic vibration, or the machine lacks guts I'll switch to the VFD (which as you saw I already bought as backup anyway). Cheers Paul
@@HaxbyShed Great Paul. Looking forward to watching your journey into the grinding world. Next you will be wanting a cylindrical grinder. Myford makes a great little one. Temptation, I know HA! --Doozer
A great dose of detectve work and frustration. And al this because you cheerleaders were absent...
But still, it's a nice example of the meaning of the word "hobby".
As you know Michel, it's not a nice feeling as a presenter when everything is going South and you think you'll be left with nothing to show. I'm watching your leadscrew with interest .....
Wow, what a tale. Hats off to you for the long and arduous process to figure this out. A lot to learn in this video. I do not expect I will attempt a Steinmetz solution. I replaced the single phase motor on my milling machine with 3 phase motor and inverter. This was very simple since I use the controls on the inverter for start/stop and frequency controls. I keep pondering replacing the single phase motor on my metal lathe with 3 phase, but I know this requires a LOT of rework on the control box. I helped a friend do this on two metal lathes so first hand experience.
As you said air conditioners and heat pumps are common in the US. I have a 4Ton heat pump. Over a year ago it would not turn on. An internet search said it was likely the start capacitor. A special style with two different internal capacitors in the can. One for the pump and smaller one for the fan motor. This was an easy replacement, just change the wires from the old to the new then all worked again. Big relief. The old capacitor lasted 12+ years and was US made. Not a surprise it eventually failed. The new one is made in China, so only time will tell how long this lasts. At least this issue is easy to troubleshoot and easy to fix.
Well done with the surface grinder. We all hope the machine now works well.
Dave.
Dave I just read that by 2000 14% of US households had heat pumps. We are a long way behind that. Cheers
Well done, perseverance pays off, it's good to follow the full story. Also very helpful as a reference for future project I'm planning.
Oh good, if it's helpful then I feel better about it. Cheers
The adjustable relay came from my hometown, Allenwood is a section of Wall Township, which is where I live.
Hi Steve, I had a quick look on the map. Not too far from the beach. 😁
“…which is made in China. Not saying anything…”. LOLOL!!! We all know exactly what you mean. I enjoyed this video immensely. And no need to suffer the cold for the sake of more lighting - it’s your knowledge and experience that most of us are here for. I spent a fair amount of time in my shop today making some new parts on my mill. Watching your ‘fun’ makes me feel better about all the wonderful ‘fun’ I also get to have. It keeps life interesting.
Hi Russell, let's be honest so much is made in China regardless of the sticker, but when I was young everything cheap was made in Japan or Hong Kong (when it was still run by the British). The work moves to the cheapest place, and it will again. I tend to use my machines in cycles, no milling for months then it's all milling. I'm looking at the shaper for a task I don't think I can do any other way (and it's not an internal keyway). Cheers
This was very interesting but involved. You spent a long time on this and it is something we have done with other challenges once you get sucked in
Hi Joseph, I'm not sure what I gained in the end except maybe a better understanding of it all and maybe a working grinder. Let's see what the surface finish is like, when we get to that. Cheers
Well done Paul you didn’t let it beat you For someone who’s not an electrician (but sounds like one lol) that was some job thanks for your time
Hi Steve I do have some electrical and electronic knowledge from years ago but I'm not 'competent or qualified', so people copy me at their own risk. Cheers Paul
Hi Paul, I had a similar journey, not wanting to re-wire my M-300, which is very original, ended up going down the rotary converter build route, so I have a few spare capacitors now as well Your static converter (Steinmetz) plus an old motor as the jockey motor would basically make a rotary converter if you have any issues with surface finish if you fancy another side project 🙂. I just used a timer relay rather than the potential relay for my start capacitor to give a positive switchover. No 47 from the workshop practice series of books is a good read on 3 phase conversion, although a bit late for you now. Thanks for a good video on what can be a very dry subject, resolving the challenges made it more interesting.
The downside for me now is there is less of a threshold to picking up other 3 phase driven toys 🤫, although I justified it to my better half by letting her know she "needed" the inverter that came spare when the motor failed on her potters wheel.
Cheers Paul
HI Paul, yes the electrical stuff can be very involved and dry. Often it's not what people subscribed for. No spinning metal. If the grinder gives a poor finish I'll probably just fit the 'Plan C' inverter. Cheers
Whatever about all the work that goes into getting the machine going, and you put a lot if freezing fingered hours in, I find it torture to then edit a video of hours of failed attempts and dead ends. so well done! I have a big single phase motor that has a set of centrifugal weights that cancel the start cap mechanically! I think I posted a video about it.
The benefit of the inverter over a straight motor is that you can vary the speed of an old 3 phase motor. I thought about putting a single phase motor on my harrison 11" but then I would be limited to the gearbox speeds. The cheap inverter with none of the safety features used gives me the potential to vary speed.
It is the unusual position of time versus money, at this level, we have both, but we wouldn't learn anything if we went out and bought a new lathe, or grinder or whatever. craving a struggle!
Hi Owen, there is a very long list of benefits to inverters and I can't see any downsides except (re)wiring the control circuits, and needing one per machine. It's a story almost too good to be true. Cheers Paul
Plan N: Steam engine and line shaft!
Now your talking 👍
How long until we get to a hamster in a wheel? 😁
Well Yeh, we are still a way from proving that static converter is suitable. Let's see what the finish turns out like. Cheers
A thriller..., to the end !! I'd have done the same thing..., and have.
Hi Alan, goodness it was frustrating! I'll just buy an inverter next time. Cheers
Epic struggle!
well done for sorting it!
I have a dual differential probe attachment here should you ever need one....
Hi Bill, somebody suggested invert trace 2 and add. Seems obvious now 🙄
"It got personal". I suspect we have all been there Paul. I must admit that based on my limited electrial knowledge, a static converter is not something I'd want to play around with. It's the old getting something for nothing I suppose, there can be substantial trade offs.
Wikipedia tells me that the proverb "For want of a 'nail'", goes back to at least 1230 in Germany.
Hi Bill, I was watching a UA-cam documentary this morning and the same phrase came up "for the want of a nail the Kingdom was lost". I remember the nail bit but can't remember what the documentary was about now ..... 😁
@@HaxbyShed 🤣😅😅😩
Omron is a top quality manufacturer, assuming the relay isn't a fake?, a motor starter, or motor contactor would be more suitable for inductive loads, and handling back EMF, start current can be up to 10 x motor current.
Not sure, but there maybe a DC element on the circuit, this means the current never passes through zero on sine wave ( maybe someone can help here).
Very interesting trials and tribulations Paul, I did uild a static converter, as previously mentioned, cant remember the vagaries of it now, i used a timer.
Not sure on the capacitor testing, but always willing to learn.
Excellent video, thanks for sharing.
Regards john.😊
Some good pointers there John thanks. The capacitor was definitely breaking down but quite why it had that effect on the relay I'm not sure. I guess if the capacitor is 'shorting' L1 and L3 then it's going to pull up L3 and behave like that. Not 100% sure but it's working now ('now' being the last time I pressed the button anyway). Cheers
Good luck to you
Thank you Tony.
good video paul
👍 thank you.
One has to admire your persistence but i have to say wiring in the old machine switches into a VFD would have been a piece of urinary fluid in comparison.
One thought occurs, in all your testing there was no grinding wheel on the shaft, would the extra load alter your circuit settings?
Hi Chris, yes load does affect the coil balance but I selected the run capacitor for full load current (about 1.6 amps per phase). After the fact, yes fitting an inverter would have ben easier. I've wired remote control switches for inverters many times now. (and I maybe doing it again on a grinder you may be familiar with ... let's see).
Any reason why you didnt use the "Add" function on the scope and ch2 inv? That should have given you the difference.
Hi Robert, truthfully no. I did not even think of it. I can go 10 years without using a scope so I get very rusty. 'Invert and add', I won't forget that now. Thanks.
Robert, I have posted up a separate corrected clip where it green-screened and on that I've added a caption about 'invert and add'. Such a simple solution - would have saved me some work thanks. ua-cam.com/video/SR2lfUGbyDg/v-deo.html
A lot of great information. Maybe you could show the use of your Megmeter on a motor rebuild or something
Hi John, well sooner or later I'm sure I'll not get another machine and never have to meg a motor - so when that never happens then maybe. If the static converter proves suitable for grinding I'll have to get another machine to justify buying the Inverter, and the motor will need testing. 😁
u didnt test one of the other capacitors? a suspected bad vs a suspected good? enjoyed it, waiting out a cold snap here in Oregon. 😊
Hi Raymond, I tested the 20uF capacitor which was ok. The 60uF was leaky but most of all it was unreliable. One day it was fine but the next day it was breaking down. I know we don't really get cold here in the UK compared with the US - we don't get below 25F very often. But also we don't get too hot either. 100F would be very hot for us even on the hottest of summer days. It's all down to the moderating effects of the Gulf Stream running past our shores. Cheers.
Omron is a well known brand but unfortunately dodgy copies exist so best to buy from someone reputable. Glad you got to the bottom of it.
I think you are right. I managed to get a couple of old stock Omrons made in Japan. It looks like you have an interesting channel there Julia. Cheers
@@HaxbyShed top quality 😀 thanks let me know if you want to do a sticker exchange.
@@julias-shed Yes that would be good. Not sure how to reach you but my email address is in the 'About' section of my channel. Cheers
LOL, "a thousand % confidence and no knowledge" been there
Hi Ken, as a friend of mine used to say when managing his team, "when it comes to uncertainty and assumptions just accept that my statement is true until I say it's not true". The team was always aligned in the same direction, even if that direction changed a few times mid journey. It works. Cheers
To say that your not an electrician. Well you certainly probably know more than most electricians. I’m lost
Hi Brian, I know a bit about a lot of things but I'm an expert in none. Thanks for watching. Cheers
At the end of the video I went back to the beginning just to see if back then you had a full head of hair!
Hi Guy, 🤣🤣🤣🤣 LOL. Yeh it was very much like that. I was not sure of the reaction to this video because it's a bit hard going but people seem to like it (apparently). Cheers
Remind me again why you don't run a cheap VFD??
Hi Jagboy, it came to this because I did not need speed control and I thought the capacitor method would be cheap and easy. Of course I was wrong. And more so now that somebody has commented that they adjust the speed of their grinder to tune out vibration. So the story continues ...... Cheers
@@HaxbyShed That's what I put on my surface grinder. 70bucks, works perfect. A little tweak here or there with the hz can make all the difference! Mine has an automatic oiler. Fortunately, it was just 240 single phase. The trick was wiring up the switch. VFD's are like a woman, they want to control EVERYTHING. The trick is just let them think they are calling the shots. lol
@@jagboy69 🤣🤣🤣Well I'm sure we could have some fun talking about that.....
You could try a SSR instead of a mechanical relay.
Hi Mick, Solid State Relay - never thought of it. I see they are quite cheap maybe £15 ($18) but I'm not sure how to set the control voltage trigger point. Cheers
Typical good engineer's approach: too much logic and yet again too much sentiment (pride and need to solve the problem). An economist would have just bought the inverter... but where's the pride in that!!! Well done !
Hi SuperH, yes I pursued beyond reason but hey ho. All investigators (scientists, explorers, entrepreneurs) have to have obsession and sometime later the experience and knowledge comes together with some other experience and the light comes on. That's how we move forward. Cheers
@@HaxbyShed I absolutely agree, maybe my way of expressing isn't that good though. Many wouldn't have gone through the torment that you chose to go through, they would have gained a quickly running machine but they would have lost all the rest that you gained. Knowledge and satisfaction among these.
'Gone ahead'? Really?
👍
You lost me when my screen went green and you started telling me what I could see.
?
Ah yes Steve, that was a glitch when I exported the video from my editor and I did not spot it. Problem is if I upload the error-free version I will lose all my views and comments on the original video. UA-cam does not let me swap a video once it has been published. I was saying when the relay clicks over and the start cap drops out the two waveforms (L1 and L3) show the same voltage. I hope that explains. Cheers
@@HaxbyShedyou could upload the corrupt section as an unlisted video with a link in the description. It wouldn't show up on your main channel, but anyone sufficiently interested could click through to see it.
@Matt, that's a good idea. I'll look at that. Cheers
Hi, I've put a link to the corrected clip in the description, and also put a banner up on the Green-screen part flagging that. ua-cam.com/video/SR2lfUGbyDg/v-deo.html I hope that helps. Cheers