# 2x72 Belt Grinder/Linisher/Sander Project 50x1830



## richardkirkman (9 Jun 2018)

I was offered an extra qualification at college called EPQ (Extended Project Qualification) where I could make something.
My College is new and meant to be practical oriented.
So, I decided that a belt grinder would be fun to build.

I went about my research then made a CAD model on Solidworks












I wanted to make it quite versatile, so I made the 30mm bar long enough to allow the use of 1500mm belts up to 2000mm long belts.
This meant that I can buy what ever is most widely available.
For my use 1500mm will probably be best as I don't foresee doing too much grinding and they are cheaper than longer ones.

I found a 3 phase 2hp motor with inverter set on inverter drive supermarket that should have been plug and play 
https://inverterdrive.com/group/AC-Inve ... 2800RPM-3/ 

When I bought it a year ago it was only £240 and I'm taking advantage of my college being newly opened, so it's on them, as are all of the other components and metal.

The spring in the CAD was a 3.25mm diameter 100mm long spring from eBay which cost £5

I made an order list from the CAD file and found a local supplier. I used bright mild steel as there is no scale so you can weld it with minimum prep. The wheels were made from aluminium so I added them to the order too. The steel cost just under £100 and the aluminium was £60.

The drive wheel was 6 inches to allow me to get a big enough SFPM with the max speed of the motor, although after building the thing I've found that I can push it as far as I want and it grinds fine, so i could have probably used a smaller wheel.
The tracking wheel is 3 inches and the two idler wheels on the platen are 2 inches







Once all the metal arrived i began marking out all of my pieces and proceeded to drill and tap some of the holes.
The Taps at college were the cheapest possible quality so really struggled to tap the steel. This was a pain but I managed to get everything done.

Then I had to teach myself how to weld :shock: 
This was a fun but challenging part of the project. Not sure how much unsupervised welding I really should have been doing at college, but no one said anything, so I kept practising

The hardest part, and the worst part of my design was the tubing that i had decided to create for the main bar to travel in. 4 pieces of 5mm bar wrapped around a 30mm bar with some cut up aluminium can for spacers. First of all, clamping was impossible. Secondly, I didn't use thick enough spacers, so once I welded it the bar didn't want to budge. Finally, 5mm is not thick enough.
Anyone building a similar product I would recommend either using tubing or using 10mm thick steel and bolting it together.
I also managed to get it to warp which created even more problems later on (which were only solved with a grinder).







After that I proceeded to drill, tap, weld, mill and turn my way to a functional product.






Then came the wheel turning. I was fortunate that my college has CNC machinery with a technician/teacher from industry that knows his stuff.
I gave him all of my solidwork drawings for the wheels and the metal and he produced all of my wheels for me to exactly what I gave him.






The motor I bought had a keyed shaft. This meant that I had to find some way of creating a keyway in the motor bore. 
I decided to try doing it on the lathe, as a makeshift shaper.





This would have worked alright but i was far to eager with my passes and the hss tool ended up digging in and twisting in the tool-post. 
It was use a regular piece of hss set in the tool-post at around a 5 degree relief angle and around a 30 degree cutting angle.
Another problem was that I had a significant amount of stick-out so it was probably not the best.
I did my best and finished it of with a file. It fit on the motor alright, especially with the bolt and end cap that I had turned. Having an m8 internal thread on the motor shaft was very useful






Tracking Wheel- I used bearings with 12mm ID so i could use m12 bolts. I found this to be sufficient and would not bother to use 15mm bolts or half inch.







I also found some online files for knob handles and printed them out on the colleges 3-d printers. This was a nice touch to the grinder and saved me a job. The print quality was not the best, but they work.









Then I assembled everything. There were a few issues that required adjustment, mostly because of my shoddy welding and the tubing issues.
Initially I thought that the motor and VFD was going to pull more than 12 amps, but luckily it didn't so I was able to use a standard 3 pin plug.


















If you want to see a quick video, here is a link
https://photos.app.goo.gl/3U96uUjdxb1xDKQQ8

That's a 60 grit aluminium oxide belt running at 1500rpm

I plan to paint, create an enclosure for the VFD ( because it's only IP22 rated) and make some guarding. The pictures are the sander only running at half speed, so once i put some guards on i'll crank if up fully and take some more pictures. I did purchase some 24 grit ceramic belts, however they were really efficient at removing metal and didn't make many sparks so the pictures didn't look too good, although they do work better at faster speeds so I may need to try again.
I'll post updates if anyone's interested.

I would recommend that anyone making their own tracking wheel looks at this web page as I made my tracking wheel badly and found this after. I will also try and improve that at some point.

http://www.beltlink.com/technical-docum ... y-Crowning)


Anyway, I hope this interests someone and that they find it useful in the future.

I'd say one of these tools is useful for anyone, they're just fun to play with, not sure how much I'll use it, but having received an A* for the coursework and build one free of charge I'm pretty happy.


----------



## MikeG. (9 Jun 2018)

That's brilliant, congratulations. There's some serious engineering in there, too. Getting all those axles parallel is no mean feat.


----------



## TFrench (10 Jun 2018)

Thats really good, well done! (not in a condescending way at all!) Nice to see a college teaching actual practical skills.


----------



## richardkirkman (10 Jun 2018)

MikeG.":2b1z8xtf said:


> That's brilliant, congratulations. There's some serious engineering in there, too. Getting all those axles parallel is no mean feat.



Due to the issues with my tubing it did create some problems with everything being parallel, but I managed to just try and weld it up square enough. The belts have some give in them so not everything has to be perfect.

Thanks


----------



## Lons (10 Jun 2018)

Great project and nice write up, thanks for posting that.

A useful machine for knife and tool makers especially I would think, it's on my to do list. Does need the guarding though so I for one would be very interested to see your updates in due course.


----------



## richardkirkman (10 Jun 2018)

TFrench":1357m6wf said:


> Thats really good, well done! (not in a condescending way at all!) Nice to see a college teaching actual practical skills.



Thanks, it wasn't condensing at all, I'm very proud of what I've made.
However there was almost zero teaching input, I just did it all in my free time. The only thing the actual qualification was concerned with was the writing about it, so the research, product development and diary. I don't think half my teachers knew what I was doing, If they had, I would have probably needed to be supervised. The college is new so it's just building up Steam, I was the only person to actually make anything in the first two years of it being opened!

Thanks


----------



## richardkirkman (10 Jun 2018)

Lons":qtw4if9h said:


> Great project and nice write up, thanks for posting that.
> 
> A useful machine for knife and tool makers especially I would think, it's on my to do list. Does need the guarding though so I for one would be very interested to see your updates in due course.



From my research I found that since the belts are so light, if they snap they don't have much momentum, so it's not too dangerous (providing you're wearing your PPE). 
But I will be putting just a small guard over the tracking wheel. I'll be the only one using it and it'll be up against a wall, so I don't think I'll need any more.
Updates should be around the week of the 25th
Thanks


----------



## AES (10 Jun 2018)

+ another 1 to all the above congratulatory comments, well done Sir! And as also already remarked, nice to see at least 1 "school" teaching (or allowing) such stuff to be made.

That should last you a lifetime and you'll look at it with pride - quite rightly so - every time you use it.


----------



## Sideways (10 Jun 2018)

Excellent piece of work Richard. I'd be very happy if I could match what you've done.
Next step is to take your 3D CAD through the CAM and cut the aluminium yourself. CNC machines are cool toys to play with. Don't let your teacher / technician have all the fun


----------



## richardkirkman (10 Jun 2018)

That sounds great, however the CNC machines are industrial bits of kit which take years of learning to use as they only take code. I would have tried to do it myself, but the machines don't take the CAD files or any type. This is probably a big flaw for the college, but ensures that further years will have to learn how to do it properly through coding. But then there's not enough time to teach every student how to comprehensively use these large and potentially deadly machines.
I did stick around while he did them, so i was able to watch, but the machines are very complicated and it just turned into watching him write code then run simulations. This was interesting for the first wheel but took a while.
If I were to do it again I would do it manually myself as the parts are not too complicated and the setup time on the CNC parts for one off production wasn't ideal. I would have tried to do them manually, but we did not have to correct tooling for the manual lathes.

Thanks


----------



## flh801978 (10 Jun 2018)

Richard
Yours looks a great machine
I built one earlier this year
And its had a lot of use so far...i got rid of 5 other grinders/sanders 
I’ve built lots of jigs to sharpen chisels and gouges and knifes accurately
I’ve made a small contact roller attachment so from 10mm dia to 50mm
And a toolbar holding a 250mm contact wheel
And a shaft for polishing mops like here driven by a 50mm wide flat endless belt





Ian


----------



## richardkirkman (10 Jun 2018)

Yeah, I saw your post before I was about to do mine, inspired me to get it done and do a good job.
Your's looks great, that buffing attachment looks really useful. I think I'll look into further upgrades once I've built my enclosure for the VFD and done some final overall improvements. I could probably do with a coat of paint too.

Thanks


----------



## Fitzroy (10 Jun 2018)

Awesome job, well done!


----------



## DTR (11 Jun 2018)

Very impressive, well done =D> =D> =D>


----------



## Brandlin (11 Jun 2018)

richardkirkman":8yt86clh said:


> MikeG.":8yt86clh said:
> 
> 
> > That's brilliant, congratulations. There's some serious engineering in there, too. Getting all those axles parallel is no mean feat.
> ...



The best engineering approach is never to try and make it perfect. Make it adjustable instead.


----------



## richardkirkman (11 Jun 2018)

I very much agree. It just so turned out that the only bit I didn't make adjustable went badly, probably lack of hindsight : )

Thanks


----------



## richardkirkman (22 Jun 2018)

Update

Today I finished my A levels, so i'm free from college(Finally)

I decided that instead of making a metal box I would buy a purpose made dust proof one. There will be another update for that

However today I decided to add a small guard just in case my belt snaps it should help absorb some of the impact. 

It's very simple, just a piece of 3mm bar bent over, drilled and then the frame tapped m6. Then I deburred everything and made it all smooth with the belt grinder.

I still need to paint it, but its finally been brought home so i'm free to work on it whenever.
Control box update probably within the next week or so.


----------



## AES (22 Jun 2018)

Very nice Richard, well done Sir! As I remarked before you have now (almost) finished a tool that will last you a lifetime.
Excellent. =D> =D>


----------



## richardkirkman (25 Jun 2018)

Update
Box arrived so I got to work on the components and drilling some holes. Everything fits beautifully, I'm quite proud. I'll post some final pictures once it's all finished, keep reading to see why its not.

I have now found an issue, which I think I may have caused myself.
Before this I had been using a large potentiometer that my teacher had had lying around. This potentiometer is a 1M ohm one and the manual for the VFD suggests between 1Kohm and 10Kohm. So I ordered a 10Kohm one. 
Today when fitting the box i decided to finally solder up and fit the new potentiometer. Once I finished everything and tried it, It didn't work and I don't know why.
I think I may have broken it by soldering through the holes instead of using the tabs, I don't have much experience with electronics
Are potentiometers particularly delicate?
Can anyone provide a second opinion for me?
And Finally, what are the two connectors on the bottom for, the other potentiometer didn't have any on?
Thanks














This is the new pot, I soldered through the holes as you can see, not the tabs.


----------



## TFrench (25 Jun 2018)

Pictures not working for me?


----------



## thick_mike (25 Jun 2018)

Me neither


----------



## AES (25 Jun 2018)

That's funny!!

I saw the post about 2 or 3 hours ago, complete with very nice clear pix. Now it's come again ("View New Posts") and there are just greyed out "no Entry" road signs, no pix at all.

No clue why that happened.


----------



## richardkirkman (25 Jun 2018)

They're still here for me, even when not signed in. 
Don't know whats going on....

Does anyone have an idea about the POT?
Thanks


----------



## richardkirkman (27 Jun 2018)

Final Update (Maybe...)
New potentiometer arrived, so I have soldered everything up.

Its all working perfectly, I must have broken the last one doing something.


----------



## AES (27 Jun 2018)

Pix not showing again, sorry.


----------



## richardkirkman (5 Aug 2019)

Quick update

Finally made a quick mount for my tormek jigs, seems to be doing a fantastic job so far.
Much more versatile than the tormek since I can change belts to speed up removal of material if i want to regrind any of my tools. Not water cooled however so I need to be careful overheating the metal


Pictures should show properly now as i'm uploading them instead of linking them from the url


----------

