This project is not specifically for my DIY router, but it is leveraging the information I've learned so far in trying to build my own from this forum subsection, so I thought this would be a good place to post it. If there is a better place, please let me know.

This 'machine' is a simple 1 axis traversing 'do-dad' for my company. After researching DIY routers here, I thought it might help solve a problem at work and also let me experiment with someone else's money! Its purpose is just to get to positions along 1 axis. The load is less than 2 pounds.

I constructed it using an 8020 frame, 3/4" linear rail/ball guides and a 16mm rolled lead screw with a 5mm pitch (spec says 0.002"/12" accuracy) with an anti-backlash ballnut. The electronics are from Keling and include the C10 BOB, a 4030 stepper driver and a 270 in/oz stepper motor. The PC is an old Pentium 4 running XP 32 bit, using the parallel port. The software is Mach3 and the parallel port passed the driver test with 'excellent' at 25khz. It also passed at 65khz with an 'excellent' but I'm running Mach3 at 25khz still.

The issue I seem to be having is that I'm not moving as far as the PC thinks I am. For example, if I make a move from 0 to 40", I only move 39.95". I would assume that if everything is working properly together, it should be much closer than 0.050" off. This was measured with a 72" vernier caliper, so I believe the measurement is accurate.

In Mach3, my motor tuning specs are 8128 steps/unit (inches; The driver is set for 1/8 microstepping). I have the max velocity set to 50IPM. The results seem to be very similar even if I use a feed rate of 10IPM as well.

The machine does repeat very well (i.e. when I go back to 0, it is there within 0.001" every time), so I doubt the coupler is slipping. I'm not sure if I'm losing steps, the screw is way out, my configuration is off or what. The stepper motor is very hot to the touch (guess 120-130 deg F).

Any help troubleshooting is greatly appreciated. I'm sure I've left out a few key pieces of data, but I'll be glad to fill in what I can with more information as needed. I do suspect it is user error on my part, but I'm not sure what additional steps to take to resolve the issue.

Thanks for the excellent forum and any help that can be provided. It was pretty cool for sure to see this thing move the first time. I can't wait to finish my own router!

Sandy.