Spindle Heat

[Hirearch]

Hi Taig users; little question for you:

Just starting to play with my new mill, engraving and then cutting out some sheet Aluminium to experiment with what works and what doesn’t. I notice the spindle is getting quite hot after a short while when doing the cut-outs.

specifically: 1/16 2 flute carbide endmill, taking 0.01" DOC into a 0.05" sheet of aluminium, this run was at 13IPM, using the fastest drive position (I am using a step down to get 110V so the motor runs a little slower than spec, and gets warm but not particularly hot) a little hand sprayed WD40 for coolant/lubricant

after only 5 minutes or so of cutting the spindle block is quite warm to the touch and the collet and nut are almost hotter than is comfortable to touch. I know these are not particularly quantitative temperature measurements, but I didn’t have my IR thermometer to hand.

So the question is, do Taig spindles generally get this warm, or if not what could the cause be?

Cheers

[cameraguy]

So the question is, do Taig spindles generally get this warm, or if not what could the cause be?

Cheers

Usually not -THAT- hot anyway. They usually run pretty cool. Could be the new spindle isn't seated in yet and it will break in and settle down once its run in for a couple hours, but likely not. You may have just gotten a bad spindle bearing or something. Check to make sure you don't have the belt massively overtensioned, but beyond that just run it in and hope for the best.

Taig is pretty good about replacing that stuff if it is actually a manufacturing issue. I had a bad Z carriage block on one unit a long time ago, it had one minor tolerance issue that kept the gib from seating correctly. They sent a new one out right away.

[lsces]

Hirearch
Personally I don't like the fact that Taig continue to supply 60Hz motors to 50Hz countries. In the UK I haven't actually shipped a Taig spindle with a mill for some years. We use the Kress 240V spindle and I have customers running that 6 or 7 days a week only requiring a regular change of brushes.

The motor WILL run hot as it's not pushing enough cool air through, and an additional fan is a good move to tubbocharge the air moving through it, but the spindle itself should not get too hot, and it sounds as if it has been preloaded a little too tight. I warm the cutters on the Kress up taking bigger cuts than you indicate, but normally only when they are getting a bit blunt, so I would be looking to check how freely the bearings in the spindle are turning without the belt on ...

[Hirearch]

Thanks cameraguy, I have tried the spindle by hand with no belt and it seems very stiff, give it a spin and it stops almost straight away, that seems pretty bad. Any idea how long it needs to run in, or if there is a way to check for bad bearings? It did travel a long way to get here, but seemed well packed so I’m guessing it’s not transit damage.

Isces; thanks I will probably stick a 12v pc fan on the top for a bit more air, would like one of those kress spindles, but haven’t seen a good supplier in Australia.

[Jeff-Birt]

After 5~10 hours the bearings will break in and the spindle will run cooler. If you are running it for long periods at 10K RPM it will run a bit warm to the touch.

[Hirearch]

Ok, it probably has been running for an hour tops, would it be sensible to hook the spindle up on a low speed and just leave it running for a few hours unloaded?

[cameraguy]

Thanks cameraguy, I have tried the spindle by hand with no belt and it seems very stiff, give it a spin and it stops almost straight away, that seems pretty bad.

Maybe, maybe not. Is it smooth and consistent friction, or is it jumpy and inconsistent drag as you rotate it by hand? It could just be a bit too much preload as mentioned earlier, but if its 'crunchy' or jumpy feeling it could be bad.
I would just go with running it in for a bit like you mentioned. Even after that, at 10k it may still get warmish after a long run, thats normal, but certainly nothing like what you describe now.

[Hirearch]

I tried rotating by hand last night, seems pretty smooth around the complete rotation, not crunchy or especially bindy bits. Have run it for a couple of hours on the low speed; no noticable change yet, will do some more tonight.

Can you give my your subjective guess at how freely it should spin? for example if you grab it by hand with the belt of and give the head a twist, would you expect it to keep turning for long after releasing it?

[cameraguy]

I tried rotating by hand last night, seems pretty smooth around the complete rotation, not crunchy or especially bindy bits. Have run it for a couple of hours on the low speed; no noticable change yet, will do some more tonight.

Can you give my your subjective guess at how freely it should spin? for example if you grab it by hand with the belt of and give the head a twist, would you expect it to keep turning for long after releasing it?

Turning some, yes. For long, no, not at all. Rotation should be glass smooth, but not so loose as to continue to spin on its own for long.