Any rack you make, even if machined perfectly will have some backlash. It is unavoidable. Belts have zero backlash if you use the belt the way it was designed -- the belt moves
If you want to use a belt, contact the sale engineers at https://www.sdp-si.com/ or at least read the technical article on their web site. They have a lot of good engineering advice and real data SDP/SI is *the* place to buy this kind of stuff. If I were building this I'd use either V-track or round rails. Chips can not build up on a V or a round. Then pull the carage with a long belt. IF you do you calculatins right (or ask for help) belt streach is a none-issue. But does it matter? Maybe for wood cutting a 1mm tolerance is OK? On Sat, Apr 27, 2019 at 8:08 AM Leonardo Marsaglia <[email protected]> wrote: > > > > Cutting your own racks, while doable is a heck of lot of work for the > > lengths you are talking about, even if you make it in short sections. If > > your time is worth even a fraction of minimum wage you would be better > > off using off the shelf rack and pinions. > > > I know it sounds like a pain in the ass but I can get some really nice and > squared 6061 aluminum profiles to make the racks. And I'm planning to mount > them on the turret of the Mazak and use a fly cutter on a shaft between > centers to machine the racks in a serial way. That way I can make them in a > easy way. I already have the jig to mount them so it's only a matter of > program the job and start to cut. I need to make some holes and registers > to mount the racks but still I think it's not that big deal. > > It's just that gluing the belt sounds cheap and/or not at all a secure > option for me. But it's just the way I see it. > > El sáb., 27 abr. 2019 a las 12:01, Leonardo Marsaglia (< > [email protected]>) escribió: > > > With any rack or rack-like drive a gantry can have zero racking problems > >> by connecting the drive on both sides with a shaft. > > > > > > Gregg, sounds you don't trust too much on having two motors driving the > > gantry. I've seen too many machines working this way but I would like to > > hear your opinion about that matter. I have zero experience with gantries > > so I like to hear all the opinions. I have to say I do like more the two > > motors approach but I would like to know what do you think about it. > > > > El mié., 24 abr. 2019 a las 11:16, Les Newell (< > [email protected]>) > > escribió: > > > >> > >> > 10m, 35mm width T5 for $60 > >> > > >> > https://www.aliexpress.com/item/10Meters-T5-open-ended-timing-belt-T5-30-W-30mm-T5-timing-belt-polyurethane-with-steel/2051875939.html > >> > >> > >> That's a good price. Two of those would do both sides of a 4M machine. > >> That is steel cored which is stiffer than Kevlar. Pity one reel isn't > >> quite enough to do a 2.4m machine. Of course it would be enough for a > >> 'tank track' style mechanism. Must...resist...temptation... > >> > >> Les > >> > >> > >> > >> _______________________________________________ > >> Emc-users mailing list > >> [email protected] > >> https://lists.sourceforge.net/lists/listinfo/emc-users > >> > > > > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > -- Chris Albertson Redondo Beach, California _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
