Motor heat and vibration

[dahui]

Hi all,

I'm still having significant problems with the motor points sticking. I bought some new US made capacitors and that didn't seem to help much. I'm currently looking for some 15,000 ohm/2 watt resistors to put on the caps. I hear this should help a lot. Has anyone here tried this?

I also got an email from a fellow that suggested using a MOV and capacitor combo across the motor points to help dissapate the surge. Has any one tried that?

The point of the post though, my lathe motor gets pretty warm. I'm not too worried but with my other motor problems I'm looking out for other potential faliures. I can put my hand on the motor can for about 3-5 seconds before it gets too hot and I yank my hand away. I haven't run the mill enough to compare. Any thoughts on how hot is too hot?

It also seems like the lathe motor vibrates a LOT more than the mill motor. Often I fire up the lathe motor and it makes kind of a nasty vibrating sound that goes away if I push on the motor can, but touching the stand, I can still feel a significant vibration. That said, the problem is intermitent. I thought maybe it was just vibrating against the mounting pin so I hammered in a little wedge of wood to no effect. Anyone else have this vibration issue?

thanks,

DaHui

[PoppaBear10]

I had these identical problems with the stock moters, and I would start and stop them over and over until the ran normally.......... I got sick of it, and so I upgraded to a variable speed 2hp DC moter and drives.
I wish I had a better answer, but I chased the problem like you are currently doing, and had no luck of over a year....

S.

[Jasonixo]

The lathe motor on my ElDorado is starting to complain too... I have a pair of Leeson DC Motors from American Scientific that I hope to use- I just have to learn how to properly control and power them... Poppabear10, did you retrofit your machine using your own knowledge, or did you use a reference to do so?

Jason

[PoppaBear10]

Jasonixo,

I did it myself, and you can too, it is not that complex. I used "KB Electronics", DC drives they can drive upto 1.5hp on 110v, OR 2hp on 220 on the models I have. (They make drives that can drive MUCH more), but for me I use 2hp DC moters from Lessen as well, max rpm is 3400.

The drives come with a good manual on how to hook stuff up. I would also HIGHLY recommend a DC feed back tack for each moter. (don't confuse this with the Mach3 feed back tack for spindle speed). The DC tack is 0-7volts, and this allows the controller to have precise RPM control even under variable loads that responds much quicker. (obviously this is more inportant on the lathe).

Mach 3 controls both my lathe and mill moter in the following functions: On/off, cw/ccw, and rpm, I am also considering an mach controlled "Enable" run through my DL06, but that will probably be down the line.

Further I think Automation Direct has some reasonably priced DC moter drives as well. Depending on what spindle drive you use and what cnc control, (I am assuming your running Mach3), you want to make sure that the Drive you pic is compatable with what mach can control. The Drives I used are all analog stuff, like switches for on/off, forward/reverse, enable, and a reostate for spindle speed. Using perifial boards like relays, and a digital to analog spindle speed controller board (CNC4PC, Bob Campbell, Peter holman, PMDX all make one). you can control your moters completely via your Mach3.

This biggest hurtel will be making the custom motor mounts for you new moters, the mounts for the Tachs (both for the Drives and Mach), the pulleys and (coolent Shields I put these over the moters especially the lathe moter, the mill moter really doesn't get hit by splash). But hey!! you have a shoptask so get to makin parts!!!!!

scott

[Jasonixo]

I re-checked the equipment on my shelf-

-2 Leeson 2hp 0-160VDC motors. Fabricating mounts will be fun.
-1 Danfoss Cycletrol 150 Controller: 240VAC 0-180VDC output. Includes speed control knob, and on/off/jog control.

I need to mount the motors and find a proper power transition setup. Toothed belts/pulleys? The controller has a signal output for an analog tachometer.

Am I set?

[PoppaBear10]

Yea, you are set.

Power transition should NOT be a problem, since most of the DC motors like the lessons, will do about 3400rpm. In all reality you should even need more than this. On my lathe I just used ONE pulley set, to put the max RPM about 2k, (this is to maintain power at low speed settings), same on the mill.
It is said that the bearings in the ST, are good to about 6k.

Truely, the machine is NOT rigid enough to do more HP than this, standard cuts with 2hp can only cut about 15"/min, (given a 3/4" mill, depth .125, AL), rpm 4k.

All that you said, can be controlled via Mach as well.

[Jasonixo]

I am having little luck finding a good, clear resource for pulleys and belts for the DC retrofit- is there a good place to start?

Jason

[PoppaBear10]

I got my pulleys from "tractor supply", but home depot and Ace, carry some as well. Belts from tractor supply, are in many different sizes. Northern Equipment also usually carries them.

if none in your area, they all have a online presence to order them.

S.

[Jasonixo]

Thanks for the reply Scott-

I take it you used V-belts and pulleys?

Outside of price, is there any reason you chose V-belts over toothed belts?

[PoppaBear10]

no reason, they where available, cheap, and I haven't had any problems with belt slippage, especially if you keep the belt tension where it needs to be.

see my pics of poppas machine, and look at the mill moter pulley set up