What's new
What's new

Strange slow fail on my Modular

Drstrangelove

Aluminum
Joined
Dec 11, 2012
Location
northwestdioxide northwest
So yesterday I was working on a part and had to shut down the lathe for an extended break. When I came back and started it up the spindle would only turn about 10% of the normal speed. Wide open gave me about 400 vs 4000 rpm. It ran this way for a bit, I was able to make a couple passes on the aluminum part I was making, then after I turned the spindle off while measuring I heard a faint pop in the contactor cabinet (I think) and no more spindle spin. I cycled power on the machine and now the contactor will not engage when I press the green button.

Any guesses out there from the learned?
 
Well it's been nearly a month and I just got a chance to dive into this. Fuses are good and so is the cap on T4. I located the source of the sound I heard it was the primary contactor reset switch tripping. I reset it and the lathe is back to running at 10% rpm. I'm going to run through the voltages on the list and see what I come up with.

If there are any other suggestions I'm all ears.

Thanks
 
I measured t5 with the spindle off but the main contactor closed and it measured just over 600 with the center at 310 ish. Spindle in forward both are out of range on a 600v meter. Something is amiss!! Let me get the rest of the numbers and I'll post them
 
Yep T5 is 600 VAC or more if the line is high. Do you have a dc current meter or a AC current meter
 
I measured t5 with the spindle off but the main contactor closed and it measured just over 600 with the center at 310 ish. Spindle in forward both are out of range on a 600v meter. Something is amiss!! Let me get the rest of the numbers and I'll post them
You are measuring the spikes from the thy. switching which can be way over range.
 
Ok I went back through some of the numbers I took and T4 shows 280 while the spindle is off but only 55 in forward.
There is your problem it is supposed to be Constant not varying I suggest you disconnect the SCR control leads and check again with the spindle engaged and off.
 
280 out of gear
56 in gear
I thought those were the leads you were talking about but I just wanted to make sure.
You will need to find what is loading that circuit down when in gear. Check the primary of t4 when in gear and see if it is 240 VAC
 








 
Back
Top