View Full Version : Taig slowed up after stepper replacements

10-05-2007, 10:57 AM
Hi all,
I have a problem with my Taig. After I replaced the small stepper motors on the 3 axis' with larger 425 oz motors the max feed rate went from 60 inches to 12.5 inches.
Does this sound like a power supply issue?

Thanks in advance for any help.


Stepper Monkey
10-05-2007, 06:06 PM
It sounds like a stepper motor problem - they are not really appropriate for the machine. Higher oz/in numbers sound good, but if they work with the same driver - i.e. they are rated at the same number of amps as your previous steppers, then something has to give, in this case inductance. Higher inductance motors can have, say, twice the torque rating but will then run at less than half the speed. The numbers also may start high for holding torque, and low speed, but the strength will drop off very quickly as RPM increases, probably leaving you with actually LESS power at the speeds you really use than the smaller motors did, and at slower speed to boot. Especially with the Taig screw pitch (20:1), as opposed to many machines running at maybe 5:1 where motors like yours would be more appropriate.
Regardless of cost, some of the best setups for the Taig, giving the best performance, tend to be in the 150 - 250 oz/in range. No kidding.

Motors need to be matched to the drivers, the power supply, and the machine. No motor, no matter what rating is on the nameplate, will work well if it is not a good match for the rest of the setup. What are you running right now? What voltage and driver type? What was your old motor type? What speeds and type of material cutting do you do?

I have a feeling you might be better off with your old motors and a higher voltage driver, but lets see what you have to work with first!

10-05-2007, 07:27 PM
The original motors were, I believe 116 oz with a 269 for the Z.
The Box is a Xylotex from Jeff. The feeds originally were 50 to 60 but the small motors would skip especially the X at even very slow speeds of 5 ipms.
Going to the larger steppers stopped the problem but slowed the max feed down to 12.5.
The load on the table was way too much for the little steppers. Aluminum stock 1.5 x 2 x 12 inches. I guess when I jumped to larger steppers I jumped too far....

I just purchased a much larger machine for the heavier stock and probably should change my little Taig back to smaller motors. Your suggestion is 269s ?

Thanks for your input,


Stepper Monkey
10-06-2007, 08:27 PM
If you want to stick with the existing Xylotex, then 269's all around would work nicely. I'm thinking the 116's are not going to cut it for X and Y, but do work very nicely for rotary axis applications and the like so hold onto them as they still are quite useful. 269's are an all around good match for the Taig given the voltage and power range limits of the Xylotex controllers. You can actually get a surprising amount of work done with that setup, it seems to pretty much be the standard nowadays.
If you want to upgrade in the future, controllers capable of higher voltages and/or current output would be needed to see any real benefit from larger motors.

10-06-2007, 08:48 PM
Thanks again,
My plans were to build a small gantry style machine for the 116s and maybe use the original Taig spindle for it.

I'm ordering a new set of 269s for the Taig. I'll let you know how it goes.


10-06-2007, 08:51 PM
i would check out the keling web site,buy some 40-50 volts drivers and supply
and those motors will run great for you,the keling drivers are like geckos and cheaper

10-07-2007, 01:00 PM
Did you adjust the Vref settings for the new motors? do the motors stall out when trying to run faster? do they garble really bad? Could it be a resonance issue? Xylotex are really bad about that! Also it needs to be noted that with larger motors that doesnt mean you get more speed. just more torque. 269`s are a good (Even over kill) for the Taig sized machines. I have the 269`s on my maxnc 15.

If resonance is an issue causing the stalling, then your first order of buisness is to make some dampeners!!!!!

10-07-2007, 02:43 PM
Thanks Guys,

The settings are good, the added weight on the tables were my original problem. The 425s took care of that but cost me the speeds.

Do you have an address for Keling? I wouldn't mind being able to keep the 425s.


10-08-2007, 11:45 PM
i dont have the link handy,but they are on this site all the time,ill find the link and post it

10-08-2007, 11:49 PM
try this link, www.kelinginc.net