FILENAMES: treadmot.dxf treadmot.zip treadmot.bmp treadmot.plt treadmot.ps treadmot.gif treadmot.pdf URL for TDA1085 datasheet http://www.mot-sps.com/books/dl128/pdf/tda1085crev5f.pdf DESCRIPTION: These files all contain the same image in different graphics formats. The image is of the schematic of the speed control electronics for the 2 HP DC treadmill motors that many people have purchased from the Surplus Center in Lincoln, NE (1-800-488-3407). The dxf file contains an AutoCAD version R12 dxf copy of the file. The zip file is just a compressed version of the dxf file. The bmp is a bitmap version loadable by Windows Paint and other programs. The plt is an HPGL file for pen plotters and some programs that inport HPGL. The ps is a postscript printer file. Thanks to Don Foreman and Wayne Cook for posting these files. Wayne deserves special credit for helping figure out how to work with these controllers. Don provided the following description: ============================================================================== Here it is, zipped, dxf format, AutoCAD R-12 flavor of dxf. I can save to R-13 or R-14 format also, but R-12 seems to be somewhat more usable by other platforms. ============================================================================== The following is discussion from the rec.crafts.metalworking newsgroup about the modifications made to improve the speed control. ============================================================================== >Don: > >I'd be interested in a copy, too. But why not post it on the Metal Web >News page? If I recall correctly, didn't Wayne come up with a >modification to start the motor at its last speed? > >- Bill > I didn't come up with it but I became the central com for spreading the messages. In fact I think it was Skipper that sent that mod to me (I'm not positive on that though and my archives are on another computer at the moment). The speed control mod is pretty simple. You just remove transistor T3 from the board. The other mod was a collaboration between myself and another (basically he suggested it and I confirmed it). What it entails is to cut the trace to pin 6 of the chip and then solder a jumper from pin 6 to ground (pin 8). This mod was the most important for me since it allowed the motor to have the power I required out of it. What it does is removes the slow soft start feature (it's still fairly soft just not extremely). This allows the controller to respond to sudden heavy loads such as the cutter engaging the work on a lathe in power feed without lagging so much as to let the motor bog down. >Don Foreman wrote: >> >> No problem. I got it from Wayne Cook in Shamrock, TX -- thanks and credit >> to him for tracing the circuit. >> It's in .dxf format, if you have a CAD package that will open that. If >> you can open Word documents, I can imbed it in that and send it -- those >> turn out pretty well. HTML usually doesn't turn out so well. By all means post them to the dropbox. I haven't done it mainly cause I've not had enough time to write a good explanation out for the box and the fact that I can't convert the image to something more universal (I've only managed DXF and Postscript so far without loosing to much resolution). ============================================================================= on 29 May 1998 the following was in the rec.crafts.metalworking newsgroup ============================================================================= I just called Surplus Center (800-488-3407) and got the item number for the 2hp motor. It's item number 10-1572 and is $39.95 I also talked to a tech there (Jeff) and he said that the current draw is about equivalent to an honest 3/4 hp induction motor. There goes my idea of converting my drill mill to variable speed drive. I just ordered 2 of them, and there are only about 2,000 left, so don't you guys be greedy and buy all of them before I figure out if I need any more of them. -- Dick Brewster ============================================================================= on 19 May 1999 the following was in the rec.crafts.metalworking newsgroup ============================================================================= There's a full schematic of the controller and modifications that can be done to it in the dropbox at metalworking.com. They are in the 98 retired files and under "treadmot" (I think that's right). But it doesn't include the hookup schematic. It's fairly simple to hook up with the small tach wires from the motor going to TA1 and TA2. The motor goes to M1 and M2. A 10K pot should be hooked up to P1,P2, and P3 with the middle leg of the pot hooked to P2. The plug for 110V should be hooked to N and L on the board. Wayne Cook