Belt Grinder 2x72" and 50x2000 mm

[Boyan Silyavski]

Have almost finished the 3 grinders. There were some details that slowed the process, now more or less everything is clear.


Welding the motor mounts, trying to keep things on one same plane:




Grinding away the spot welds, drilling holes, making stronger weld...only on one of them. Too much works and then i had to make it flat. So i decided to stop there and the other 2 only were reinforced where necessary.
Next time as i know now which weld first where and how, i will just do all pproperly.





Then some painting:




Too much paint mixed at once? No problem some but not all that was upgraded at home:





Now the blackening, heating the steel at around 300C. Then brushed in olive oil when cooled down. The oil made them even darker after some time. Very happy with the result, last 2 pictures.





Now why its called prototype, and why as Dean said it is good to be done one by one. I knew it could happen and was sure that i have avoided it but...as i have not designed the future 2 attachments, it happens that belt would interfere with one of them





This is what took me most time. Deciding on the spring, finding the proper spring, tension, length and how to fit it on the machine correctly so it willnot mess with the belt and the future attachments. Main problem being is- this is the shortest spring i was able to find at that rating.
I finally was happy with the result, so version .01 was born On right picture is Jeffs grinder, we left his motor as he does not need it for making knifes so no future attachments.



Finally mounted the handle, at the end it happens upper side of the arm is best and easiest. Then the VFD and motor. Cut some scrap belt and started the machine to program the VFD. Boom. The fuse goes down at home. Again, and again. Half day later after some research i went to the conclusion -"leak current" from input capacitor filter. Bloody hell, so i started reading the manual. Good old Toshiba. have made a switch on the VFD that can deal with that changing the capacitance. clicked the switch and all is working.

No vibrations. Super quiet. Not so when i mounted the old belt which is quite bumpy, the connection where is spliced. The belt tracked easily though but makes some noise.But as machine is heavy even that introduces no vibrations.

I am quite happy. Worked from first time. Tracking is perfect, speed is right. I dont see that machine without speed control though, i can not stress enough on that. Did some test grinding today and is super important to control exact speed at every moment.

The other important detail is that the 2 rollers at the front are fixed by spacers and shoulder bolts. So these 2 holes were drilled on the mill and hand tapped. That could not be. The must be machine tapped. hand tapping M10 is you could make it straight or not. Had to redo them a couple of times. As i have no M10 machine tap i bought yesterday. Next time will make tapping fixture similar to drilling holder, where shaft passes through a bearing and use driver to spin the shaft, so its clutch does the job of releasing when too much resistance.Though if needed, may be its the time for tapping head.

The video is a bit shaky but you could get idea what happens