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I have a delta 18x36 and the old belt wasn't as wide as it was originally... So bought a new one from supergrit. It has never tracked more than a minute or two no matter what I do to it. Put the old belt on and worked fine even though it was narrow. Then when it mechanically failed I went back to the supergrit one. Back to square one again and I have barely used the machine in two years.
It looks like the belt may be a little crooked when it was assembled. I might try cutting off a chunk chunk of the belt and see if it will track. If not I'll replace the belt again with a different one.
There are automatic tracking systems used in industry. I might do some looking at pics and see if it's feasible to build a system.
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Any chance you have a link to the youtube video you watched?
Thanks
Failure is simply the opportunity to begin again, this time more intelligently. "HF"
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Nothing useful to add to the conversation except to think how lucky I've been with my 16/32 sander. I bought it used from an estate. The conveyor belt on it was badly ripped and unusable as is. I spoke with a family member who said the original owner could never get it to work right. Had I read all these posts back then I probably would have passed on the machine, but I bought it, replaced the conveyor with an Industrial Abrasives belt and have had zero problems since. Getting the belt to track was indeed a finicky process, but I've now been using it for a couple of years and haven't touched the belt adjustment since I put it on. Better lucky than good I guess!
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(02-09-2017, 10:39 PM)Robert Adams Wrote: There are automatic tracking systems used in industry. I might do some looking at pics and see if it's feasible to build a system.
The ones I have seen are pneumatic. I looked at this because I wanted to build my own wide belt sander. If you over-tension one side, the belt goes towards the other side. So they have a pneumatic actuator that can pull and push on one side. Two photo interrupters drive a pneumatic solenoid valve. You have one that is always covered if the belt is tracking, and one that is only covered if the belt is too far to that side. Tuning might be an issue. On the wide belt sander, they actually twist the top roller, which is mounted on a large pneumatic cylinder in the designs that I have seen. Seems like a spring return cylinder would make this easier. The cylinder wouldn't have to have a very long throw, and I don't know how much force you really need either. If the belt was mostly tensioned through springs, a small offset from that would probably do the job.-
I wonder if the conveyor belt problems discussed on this thread aren't because the conveyor is twisted, or some other problem exists with the rollers. Obviously, if the belt is longer on one side than the other, it's gonna be a problem.
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The tracking idea I'm thinking is mechanical however the problem is that it would work but not on on a high tensioned belt. Now maybe if the rollers were rubber coated for friction. It's just one of those things I'll keep thinking about and eventually come up with something to build and try.
Or the easiest way might be to make a crowned roller and be done with it. Never understood why they weren't crowned as every other application with belts and pulleys are.. Unfortunately I don't have access to a lathe anymore. Would like one in the shop but metal lathes are quite pricey for something decent.
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02-12-2017, 08:00 PM
(This post was last modified: 02-12-2017, 08:03 PM by EricU.)
I guess I have seen lever actuated tracking devices that work off the side of the belt, now that you mention it. In my world, pneumatics and electronics are easy to come by, so I am not sure I would mess with mechanical.
I have a metal lathe, but I was cleaning up the electronics and seem to have screwed something up. Might need to get a new VFD. Not sure how much crowning the conveyors on one of these consumer machines could take.
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The kbvc-14 is an industrial 90vdc motor control made for the gear motors on these sanders. Usually runs about $40. For those with the delta you can add a dpdt switch and you will also have reverse.
Yeah would have to make a new roller which is simple but crowning it would be a pain if you can't offset the tail stock on the lathe. Then you just get a taper not a real crown. Cnc lathe would do it in a few minutes vs much time by hand and not as nice of a crown.
I'll be flying up to Cleveland next week so maybe I'll try drawing something up on the plane. I have a rough idea just not quite all the parts there yet.
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I sanded six rings yesterday for a bowl. Both sides. No problems. Again, the belt is tight on one side and loose on the other.
RP
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(02-13-2017, 08:37 AM)RPE1 Wrote: I sanded six rings yesterday for a bowl. Both sides. No problems. Again, the belt is tight on one side and loose on the other.
RP
Don't touch it then. I don't care what it looks like as long as it tracks.
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(02-03-2017, 10:23 PM)RPE1 Wrote: I called Jet. They would not talk to me because I didn't buy a Jet conveyor belt.
RP
That has just cost them a sell.
