richardkirkman
Established Member
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.
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.
