New to me Clausing 8520

gajunkie

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Picked up a gently used Clausing 8520 the other day. Spent a couple weeks disassembling, cleaning, and painting it. All-in-all I think its a pretty nice little milling machine in pretty good shape after really digging into it.

It's got some problems, however, and most of you might spot one or two in the pics, but wanted to use this thread to ask some questions and get some help getting her up to snuff.

Probably the biggest thing is the motor. After finally getting it installed and running, I've noticed that it has almost no torque. It gets up to speed quickly when no pulleys are attached, but once I rigged up the drive pulleys and belts, I can slow it down just by putting moderate pressure on one of the pulleys...kinda bogs down and then kicks in a little power, then bogs down again...rinse and repeat. Not sure that its wired correctly, I just put it back together like I found it, as I'm not really familiar with wiring these kind of motors up. Hopefully I can attach the video of it for better understanding of the issue.

Its also missing some Gib screws on the front X-axis?? I believe I can make the screw parts, but I'd like to find out what kind of nuts those are. The have almost a bare steel finish and a bit wider diameter, and thinner profile with a flat part on the machine side...probably a common type but I haven't found them yet. 1/4x20 thread.

This is my second 8520. I bought my first one a few years ago and always intended to restore it, but never wanted to take it out of service just in case I needed to make a part or something during the resto. I found this one recently and it has the 4" riser extension which will really help my Z-axis issues. Once I get this one up and running, I'll start in on the resto of the other one.

Currently into a DC motor conversion and actually have it mounted up and running, but the motor controller I have won't keep a constant speed with application of a load. It really bogs down just like the AC motor, so i'll have to look into the setup a bit more. I'm basically copying what I see people on youtube doing, without actually knowing what Im doing lol. The last two pics show the DC motor mocked up with the pulleys, but it was just to get things turning and see what happens...as I suspected, it bogs:confused:

More soon...




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Beautiful job.
That’s a very popular mill for us fellow hobby folks.

You suck dude. :)
 
The ac motor is probably miswired or has an internal problem, can you post some pics of it's data plate?
What type of controller are you using with the treadmill motor? Simple types have no torque compensation
-Mark
 
that looks nice. Straighten that plate for covering the carriage slide... too much swarf gets in there.
You have a feed on that... YOU SUCK! :grin:

since you already have an 8520 in the back, why not spend some time and plumb this for oiling? I hated that oil hole in the back, and really hate the front one too. If I had a second machine I would drill the table and slide for fittings and tubing. A one shot would really be nice.

I can't help on the motor. Not like others who are really knowledgeable.
I have wanted to replace the quill brake with one like the BP.. if I had a second mill, I could fill and re-drill the casting. I hate the lock with a passion.
I look at the BP guys and a flick is all it takes, I wish.
 
The ac motor is probably miswired or has an internal problem, can you post some pics of it's data plate?
What type of controller are you using with the treadmill motor? Simple types have no torque compensation
-Mark
The controller is a small/simple one you can see it clamped to the motor mount plate in the last couple pics, I bought it and the motor a long time ago with the intention of mounting it to my first 8520. I don't remember any model numbers and I'm pretty sure now it doesn't have the torque compensation feature lol
MC1Y1FajSPGKa%Y92Dfn2A.jpg


link to yt video of motor running



My other one has that bend too, although it is much more angular and a bit shorter. I figured that's the way it is supposed to be, but did wonder why...might yank it back out and straighten it like you say...makes sense. Yes a feed did come with it, but it is a bit worn in places...have yet to take it apart, clean it and go through it. may just put the handle back on for now.
 
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I bent mine once too. It's from being high on the knee, and trying to lower it with the Y all the way back.. the cross slide acts like a brake finger and it bends there. just don't lower it with the cross slide all the way back at the top.. or pull the slide toward you before you do. After you straighten it you may need to file or grind it to slide nicely .. I had to. Nice little baldor there.. you suck again...
 
First observation: The motor pulley is quite large- why such a severe step-up ratio? Is that stock?
Certainly that would put a heavier demand on the motor
-M
 
First observation: The motor pulley is quite large- why such a severe step-up ratio? Is that stock?
Certainly that would put a heavier demand on the motor
-M

Thats the stock pulley. it has a smaller pulley underneath far an "A" and "B" range from 180 to 3250 rpm. 3 speeds per range.

The motor wiring was removed for clean and paint and put back the way I found it...actually the motor had each wire number stamped into a collar on the wire (1-8), and somebody had previously marked the wires coming from the switch so I know I put it back the way I took them off, but the switch wiring diagram on the inside of the switch cover was unreadable. Forward, reverse and stop works like its supposed to, but there is one thing thats weird about it...when I move the switch from forward to reverse without letting the motor come to near complete stop, the motor just keeps running in the same direction. not sure thats correct.
 
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