I'm curious if it would be possible to glue a belt to the aluminum v-slot and use it as a rack and pinion to reduce the belt stretch error and apply greater torque?
So... how do you couple the motor to the belt without loading the motor bearings so they last longer?
That's a good question and one that will most likely bring you back to a belt and pinion system or looking at aluminum or steel racks that slide into the slots or mount to the sides so that it can handle any real load. With the stiffer rack or wrapping the belt around the pulley there no need to extra force to keep the teeth in the groove.
Here is something similar to this concept that may help http://builders.reprap.org/2010/07/changing-game-and-using-kapton-tape-as.html
That's Mike Everman's design, cool guy who builds cool stuff Check out his blog http://mikeeverman.com/ and his company page http://bell-everman.com/
I have thought of a few ways to replicate the servobelt system. But not something I could sell or let others build, as it is patented by him. But it is an amazing system.
So it looks like servobelt glues the belt to the aluminum, as I suggested, and then uses another belt to couple the motor to the glued belt. So just buy 2 belts and some glue, then move the motor and belts over a little. I wouldn't let someone's self-interested-information-withholding syndrome, such as a patent, shut down the conversation. I think we can probably do better anyway. I like the idea of using 2 sprockets to couple the motor to the belt and just let the motor sprocket wedge between them. By playing with the gears you could get some really precise movement and high torque.
yeah that might work. I was also thinking of maybe a a tank tread. I think the 2 belt solution has pros and cons. By just having 1 belt glued down you could get a really precise rack. The solution with 2 gears and 1 motor sprocket seems logical. I think you would have some mechanical wear. That being said, If you wanted to get a stronger system it would be just as easy to glue down a bicycle chain and use a sprocket off the bike as a metal rack and pinion capable of ungodly torque, lol.
This is making a lot more sense the more I think about it. Tape a toothed belt into the groove of the v-rail. With super strong tape. Come up with a bulldozer double side track arrangement for the drive side. This could really keep the costs down and not dedicate the track to rack drive only. A CNC Mogul type approach where all the electronics and motors are on the gantry, that you can move from table to table depending on how you're going to use it. Just slide it off one and on to another. Woodworking to Plasma. It would make a CNC really portable. Need a longer or shorter table? Tape down belt into the groove of shorter or longer rails. The bulldozer could first used to align and tape down the belt into the channel. I could imagine that with bulldozers on the top and bottom of the v-track it may be possible to get enough contact and stability using a couple of motors to do some vertical arrangement. Lots of possibilities here Might be enough to get me going
That's looking good! And it would probably work fine, but I like to complicate things So a couple of more things. From reading other forums where people glue down the belts in tracks, the sprockets don't stay seated so well on the belts and they tend to skip. I was thinking more bulldozer track being on the motor side. The belt wrapping around a real belt drive pulley, this drive belt being double sided, and a couple of guide pulleys extending down into the track to give several inches of belt to belt traction. With V-wheels stabilizing the whole thing. That would keep the torque where it needs to be This could be cheap enough you could duplicate it on the bottom for more belt to belt action. Good for a Z. Possibly a Z of feet long. 3m VHD tape instead of glue. Instant, same thickness throughout, and gives a little cushion. It can have a little down pressure on the belt to belt interface.
You could assemble the carriage and then use it to press the belt down while gluing. Just roll it back and forth a few times every couple minutes until it sets. Anyway this would eliminate belt stretch with higher torque. As for slippage I dunno. Maybe a bulldozer wheel track would solve that but now you have a belt spinning. What if you do 2 wheels like in my drawing and add another toothed wheel to the motor... so there's always 2 points of contact on the motor gears and on the belt?
What about something like this down in the track and fastened at each end. No need for glue & no belt stretch, same company that makes synchromesh wirerope. http://www.asahi-intecc.com/industrial/product/cablerack.html
Interesting wire gears. I'm not too fond of the synchromesh as it has proprietary drive gear. It also being a belt like solution needs a certain percentage of the belt/wire circumference covered to be effective. I'm not sure it has any advantage of sticking down a standard belt. For the nylon/wire gear. It looks good. I'm not so sure how wire and nylon can adhere together. Seems like if you tightened the wire the nylon would want to separate from it? It may not be a problem at all. I'd still probably want to glue/tape to keep it from racking in the slot. Pricing and availability?
It maybe just be a hole that the wire slides into, and if thats the case we could just try a plastic rack without the wire. Not sure
You guys might want to check out this thread along the same lines http://www.openbuilds.com/threads/attaching-rack-to-v-slot.172/#post-704
I'm pretty new to the whole belt and pinion idea for movement, but what significant advantages does a rack and pinion have over a belt and pinion system? The belt and pinion system sees to be fairly elegant solution to me
Pros Belt: Quick to setup Quick to adjust Cheap compared to rack Cons Belt: Can stretch possibly more sensitive to dirt Pros Rack: no Stretch Can be very accurate Cons Rack: more expensive then belt more intricate setup
Belting is accurate as it gets and works for almost everything from foam to aluminum. When we start talking about rack and pinion is when we are dealing with extremely large forces like cutting steel or turning steering wheels on cars. At that point you either need to go to a chain, rack, or one of those belts you see on harleys.
Hi, as soon as i watched the vid on page 1 i knew i wanted to replicate this...somehow. After watching and reading a little on Bell Everman it seems that they do not attache the lower belt to the profile, other than clamping. Why do i think so? Looking at their product site one always sees a kind of stopper at the end of the bosh alu profile, and in some pics you can make out that this seems to act as a stetch/clamp/holder for both belts. Yupp seems like KISS. Also they state that there is limitless scalability... so if the belt was to be glued to each section of the profile how would you correctly lineup the "Toothing" of the belt(s) of each section... so it seems that both belts are put on after building your correct lenth. That means for me that we could simply put two belts face to face onto an OX cnc and clamp them both at once. Two (temporary) hold-downs could surely beeing inserted if the original setups would not work. To try, all one would need is a spare length of belt and a re- setup of the belt.... attache one side of the belts( interlocked), stretch lower belt to desired tension ( same as used on origainal setup ) and having it kept there (somehow i.g wife), feed upper belt through arrangement, back onto lower (interlocking again) and clamped tight at the other end Not having an OX myself i would like to ask: Anyone willing to try?? greets Flo
LOl well, i am not a native english speaker. Anyway someone has already done it - check it out: (aprox min 1:30) on my next build i will definetly do this... greets flo
Oh it's totally do-able. It's actually patented so you can do it at home but if you or openbuilds were to try to sell it, they would get sued. SO that's why we've been trying to come up something even better than that. How about a v-slot wheel with helical nylon gears and a rack with helical nylon gears that fits into the v-slot? I believe you can 3D print nylon...
