X3 Motor Problems

[Westy]

Hello all

I need some urgent assistance, so any help would be much appreciated.

We have just finished the conversion to CNC of my X3 mill using CNC Fusion kit with adapted Nema34 motors - the CNC side works very well indeed. The only problem is, I now have a problem with the actual mill motor.

When used at slow speeds, it seems ok, although if you watch closely, when the cutter has to do any serious work, the speed jumps irratically. When turned up to anything above 50% speed, there is a distinct electrical burning smell, and sparks in the bottom of the motor.

Does anyone know a direct replacement motor for the stock job - possibly slightly more powerfull but just straight swap, or the actual current of the standard motor so I can source a replacement locally.

Any help would be much and greatly received.

Cheers
Westy

[beliefdrive]

you can find motor here
http://www.kelinginc.net/NEMA34Motor.html

b.r

[Westy]

Hi

Thanks for the quick reply, but its not the stepper motors that are the problem, its the actual drive motor for the mill.

Cheers
Westy

[jalessi]

Westy,

Arc Euro Trade has the OEM motor in stock.

http://www.arceurotrade.co.uk/Catalo...ll-Mill-Spares


X3-224 X3 #224 Motor £89.95 In Stock

Jeff...

[Westy]

Hi Jeff

Yes, I have seen that, I think it is probably the best and quickest solution to the problem. I just thought that while I am in this prediacment, I could take it as an opertunity to upgrade the motor. The original one, although 2 years old has done hardly any work and is as clean as clean can be.

Thanks for the post though. If anyone has any ideas on a reasonably priced upgrade without much work involved, please feel free to post.

Cheers
Westy

[jalessi]

Westy,

I forgot to ask if you checked the brushes on the motor.
A good cleaning and polishing the commutator may help a lot.

See instructions below:

The commutator should remain a polished surface.
Blackening may indicate rough or eccentric commutator.
Occasional wiping (power off) with dry canvas or non linting
cloth may suffice. If rough or excessively dirty,
smooth with very fine (00) sandpaper lightly with
armature rotating. Never use emery cloth. Never allow the
brushes to wear so short that spring tension is lost. The
resultant sparking will damage the commutator.
If frequent dressing is required, the cause should be
found and corrected. A very rough commutator should be
turned in a lathe, at high speed, with a sharp tool. Do not
remove more copper than necessary. The mica should be
undercut if necessary.

On a separate note, you may start looking for treadmills that people discard.

On garbage day you may find them in the trash for free.

Most of them have 1-2 horsepower D.C. motors and a controller too.

Lots of Zone members have retrofit them onto there mill.

Jeff...

[Crevice Reamer]

Hi Westy.

Jeff has given you good advice:

http://www.reliance.com/prodserv/motgen/h7000ch1.htm

CR.

[Westy]

Thanks guys - most helpfull.

I have stripped the motor down and found the copper to be very dirty in areas.

Placed it in the lathe and used the non abrasive side of some abrasive cloth to clean it of to polished finish.

The contact surfaces of the brushes were a mess, so I have lightly cleaned them with fine sand paper.

On first assembly, the motor failed to work - so I am going back out this morning to have another go - but I am sure you hit the nail on the head.

Cheers
Westy

[Crevice Reamer]

After you replace the brushes, you must wear them in to their correct, commutator-fitting shape. You do this by mechanically (No power to motor) turning the motor (with an outside power source like a drill, or motor shaft chucked into lathe) until they wear in.

You can start this process by wrapping sandpaper around commutator and sanding brushes (sideways) to rough shape.

Make sure the brushes go all the way down into the sockets and actually CONTACT the commutator.

CR.

[Westy]

Hi Guys

Thanks for all the help and suggestions. I removed the brushes, cleaned up the copper and refitted the brushes having bedded the in without power first.

The motor works 95% good - I have ordered a new set of brushes and a new drive belt as this wasworn out too.

Cheers
Westy

[Crevice Reamer]

Good job Westy! Well Done!

CR.

[skullworks]

Now might be a good time to start searching for neglected low hour treadmill that could serve as a donor for a motor transplant. Getting the complete treadmill allows you to utilize the matching speed control unit.

Usually treadmill motors will put out more usable power but will also put out more heat and will require a fan be fitted. Also they tend to be more open framed so protective covers might be needed to keep chips out.

YMMV