On Thursday 19 November 2009, Chris Knowlton wrote: >> selection because I haven't a clue what to set them to. >> >> >> The L297-298 chipset doesn't to my knowledge do any microstepping, >> perhaps that is your problem? >> >> > I am using the default motor timings from the L297 default > ><--- Comprehension DAWNS! These settings have to do ONLY with the board! >Not the motors! Now I need some timing data on the board. The user manual >was rather interestingly brief. It does tell me though that these are >Toshiba TB6560AHQ chips. Perhaps I should grab the data sheet on them. >There are buffers on this board, though I have them set to the fastest >setting they have.
The Toshiba document is very complete, although they use some less than obvious names for some of the signals, there is enough there to design a pretty complete driver. And with 5 volts more headroom, and an amp more ability than the Allegro A-3977, it looks like a slight step up in power, plus the 16 step micro stepping will smooth it up a wee bit. Interesting chip, but would prefer the flat pack and a glued on heat sink. No idea which is in yours though and you are pretty well fixed by their choice. In either event, the more heat sink and fans, the better off you are. >I kinda need to make this work with this board if I can. Most of the > really nice parts in this build were scrounged. I don't have $350 for > another controller and this one was $90. > >But that conflicts with the 'aerospace' driver you mentioned above, and >which > >> I am not familiar with. Does it use this chipset? I tried to use them >> early >> on, but found they simply were not fast enough at switching, and the >> predictable result was converting a couple of them to slag, at which >> point I >> threw money at the problem and bought a Xylotex 3 axis kit. I've since >> bought a 4 axis too. Quite good drivers in this size range, for either >> the 262oz motors or the 425's. >> >> Generally, microstepping improves the torque, but at low speeds its by >> percentage points, not magnitudes. I actually lose torque at 1/4 step >> compared to 1/8 step. At midrange speeds, where the motors are still >> 'stepping' a step, then stopping till the next step, they will vibrate >> about >> the current step position, and at some speeds, this can actually cause >> the motor to forget which way its turning, or simply get confused and >> stall. An >> additional weight in the form of a flywheel with loose parts on the other >> end >> of the motor to absorb this vibration can easily extend the speed range >> to 2 >> or 3 times the original, un-damped stall speed. This is very important >> for full and half step lashups, somewhat less so at 1/4 step, and better >> yet at 1/8th. And I presume even better at 1/16th steps but mine quits >> at 8 microsteps. >> >> Ack! Learning curve wipeout. What is a lashup? I know about dampeners > >and I can probably get ahold of some brass and latex ones for the X and Y >axis because I only have two motors that have through shafts I think. > >>Leadscrews are 2 start 16tpi (so effective 8tpi?) for the two axes that I >> >> >have working now. >> > >> >Thanks for your attention! >> > >> >ChrisK >> >> -- >> Cheers, Gene >> "There are four boxes to be used in defense of liberty: >> soap, ballot, jury, and ammo. Please use in that order." >> -Ed Howdershelt (Author) >> The NRA is offering FREE Associate memberships to anyone who wants them. >> <https://www.nrahq.org/nrabonus/accept-membership.asp> >> >> "Well, it don't make the sun shine, but at least it don't deepen the >> shit." -- Straiter Empy, in _Riddley_Walker_ by Russell Hoban >> >> >> ------------------------------------------------------------------------- >>----- Let Crystal Reports handle the reporting - Free Crystal Reports 2008 >> 30-Day trial. Simplify your report design, integration and deployment - >> and focus on >> what you do best, core application coding. Discover what's new with >> Crystal Reports now. http://p.sf.net/sfu/bobj-july >> _______________________________________________ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/emc-users > >--------------------------------------------------------------------------- >--- Let Crystal Reports handle the reporting - Free Crystal Reports 2008 > 30-Day trial. Simplify your report design, integration and deployment - > and focus on what you do best, core application coding. Discover what's > new with Crystal Reports now. http://p.sf.net/sfu/bobj-july >_______________________________________________ >Emc-users mailing list >Emc-users@lists.sourceforge.net >https://lists.sourceforge.net/lists/listinfo/emc-users > -- Cheers, Gene "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. <https://www.nrahq.org/nrabonus/accept-membership.asp> CONGRATULATIONS! Now should I make thinly veiled comments about DIGNITY, self-esteem and finding TRUE FUN in your RIGHT VENTRICLE?? ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
