Thread: for mini carver users

Sorry, never looked. Will have to look next time ( if there is one ).
Thanks for the advice on thin CA.

Terry

just finished the 5 day wood sculpture workshop,
12 students, 7 mini carvers being used a lot of the time, (maybe 8-10 hrs)
I replaced 5 belts with the 0 rings at the start and they all survived

note:...the 0rings seemed to slip a little more than the originals ( might try 75mm next time) but didn't seem to affect the cutting ability and didn't show any undue wear when inspected.
I still reckon the original is the better product but the difference in price makes these alternatives very interesting.
cheers John

Good news! You have already answered the next question I was going to ask, whether you had taken into consideration the elasticity of the O ring rubber compared with the non-elastic belts. I shortened the belt for the sanding discs driver after finding it slipped, like you did. I did not measure the minicarver belt, but if that 80mm is the diametre of the ring, that is, a circumference of 251mm and that is the length of the belt, if the material is the same as the one I have tested, you could probably go down to 70mm. A good opportunity to test whether CA holds on such a small surface. Slipping less might mean snapping more, experimenting should hopefully produce a satisfactory compromise.

I'd assume the bands would be sliced at an acute angle for the glueing. Correctamundo?

Originally Posted by movay_2008

I'd assume the bands would be sliced at an acute angle for the glueing. Correctamundo?

Wrongville. The rubber guy did it for me cutting straight down, and I did it the same way when I shortened it. The logic being, I think, that you present 2 identical round surfaces that are very easy to line up, while one's chances to cut two exactly matching diagonal surfaces are Buckley's, I suspect.

I agree with you that if you managed that the joint would be stronger, though, and for a belt perfect continuity is not as important as for a sealing ring, which could be the sole reason why the rubber guy did it that way.

With many of today's adhesives, though, the joint is stronger than the jointed material, so maybe that is not a problem anyway. My approach for the small belts of the minicarver will be to do it the easy way, if the ring/belt then breaks on the joint I'll try as you say.

BTW, I have made a flat belt with a strip of ribbed rubber matting that way, because I did not think that I could get a good enough joint by butting the thin flat base. When I find a moment to mount it on the old Workwheel to see if it works, I'll report the findings.. My only problem is that I have 100 things going at the same time.

Thnaks for the info on the O rings, Undie. For what it is worth I found this on a USA forum, see below.

To all users of the arbotech minigrinder. If the drive belt breaks it is far cheaper to replace it with an O ring rather than a new belt from arbotech which is about eight times more expensive The diamensions are 53mm dia x 2,5mm wall thickness. The wall thickness is critical as the ring slips if it is thicker.

Hope this helps.

Very interesting, Inventor. Unless there is some more mundane reason, ie different size machines or the guy can't talk metric the discrepancy between the dimensions given by that source and Underfoot's basically satisfactory experience is so large that there must be some glitch somewhere. My guess is that because the difference in area between 2.5 mm and 3 mm diametre is 44%, the length has to be so much shorter because 2.5 is so thin that it strecthes much more. The question then is whether 3mm slips because it is larger or because the source used an inapproprate (and undisclosed) length: I doubt that it could be 53 mm diametre if Underfoot used 80 reasonably successfully. Pity I have already bought the 3mm cord, though.