Cut Motor Safety Sparks & Dust Collection

[Digitalwoodshop]

I am cutting my last sign tonight, a group of 5 and as I watch the machine cut I had a thought about the Cut Motor....

My Muffler is about shot and was thinking on my options...

I see a few users run the exhaust of the Cut Motor into a dust collection system or down draft. I had a though about all the sparks the Cut Motor Brushes make.... And the thought of sparks getting sucked into the dust collection dust....

This is really a "s t r e a t c h" but last year a Wood Shop on Sawmill Creek had a Sunday Shop Fire after being closed since noon on Saturday. Started in the Dust Collection a day later....

The Cut Motor cooling fan draws air from 2 places. The one I am concerned about is the air sucked into the back of the Cut Motor near the Brushes and the air passes through the Stator and Rotor area and out the muffler.

So far we have all been pretty lucky. I have one motor here that I bought off a user for the case paying the core charge. It had a burnt wire inside and it looks like some windings in the stator shorted causing a increase in current. I measured the Ohms on the Stator and a good one and there was a difference in the bad one. Measured like some turns were shorted. The Wire has a coating that lets them wind the turns on each other.

This is a rare case.... The Stator might have been dropped in the factory.

As our machines age and the brushes get shorter, they spark more...

I am rethinking my Muffler Idea..... I may just make something like a metal can with a metal mesh screen.... Like a Kitchen Exhaust Fan uses....

May be over thinking this but I would re evaluate dumping the muffler into a dust collection....

Notice all that nice inside the cut motor....

When I do my Wall Mount for 2 of my machines, I am going to mount the Cut Motor outside the machine above the machine on a wall bracket. I will Exhaust it outside through the wall. It will just take extending the wires for the Cut Motor Power and Motor RPM Sensor. I will mount the motor 90 degrees from the way it is now so there will be less stress on the Flex Drive.

Just my 2 Cents....

AL

[Kix]

Tuned racing pipe with Intercooler?

[CarverJerry]

Hey Al, seeing that you have these cut motors out, and you knowing so much about the CW/CC, is it very hard to change out the brushes in the cut motor. Something that is done with only taking the top cover off. I have also asked the approx. time for a set of brushes, does anyone stock these besides LHR?

CJ

[Jcpb321]

When I do my Wall Mount for 2 of my machines, I am going to mount the Cut Motor outside the machine above the machine on a wall bracket. I will Exhaust it outside through the wall. It will just take extending the wires for the Cut Motor Power and Motor RPM Sensor. I will mount the motor 90 degrees from the way it is now so there will be less stress on the Flex Drive.

Al,
I think this is a great idea!
When I first started looking at the CW one of the first things I didn't like was the cut motor being inside like it is, I would think it should be like a couple of my die grinders hanging up above and the flex shaft is straight. Will be looking forward to seeing how this works out for you.
John

[bjbethke]

Al,
I think this is a great idea!
When I first started looking at the CW one of the first things I didn't like was the cut motor being inside like it is, I would think it should be like a couple of my die grinders hanging up above and the flex shaft is straight. Will be looking forward to seeing how this works out for you.
John

I do not think that would work the motor needs a solid base. Hanging on a hook, I think it would go airborne.

[PCW]

Another thing to consider is air flow. Cut motors has two fins inside just to move air via the duct work of the machine.

The cut motor I believe is designed to keep air flow moving around the electronic components by sucking air in the bottom cover vents for cooling purposes as well as keeping the board sensor clean by blowing air across it.

If the cut motor is moved out of the machine you may have to consider replacing the air flow by other means.

Just my thoughts.

[Digitalwoodshop]

I agree that if the Cut Motor is moved outside the unit then I would plumb a hose from the dust collection to keep the electronics cool.

I agree that the motor needs to be solidly mounted to not twist.

I tried to replace the brushes once while the motor was still installed. I fussed with it and reaching under the motor pushing the spring and cap without seeing it was frustrating. I found it simpler to remove the motor with just a few screws and do it on the bench. I would highly recommend that when changing the brushes you open the motor and blow the dust out. Remember the case screw in the inside of the muffler hole too, not easily seen.

Cut Motor brushes should be replaced after 250 hours. If they become too short and the motor stalls then you can snap a $40.00 bit.

AL

[CarverJerry]

Always nice to get professional answers, even if the questions are sometimes a bit stupid. And the pointer about the screw inside the muffler port will sure help when it comes time to replace the brushes. Know of any one who sells the brushes, or if any member stock piles these. If not I'd be willing to do so to help on shipping costs.

CJ edited: I just looked at the carvewright web page to see the price on brushes.....couldn't find it. anyone know what it would be under?

[PCW]

Jerry,

I was at a Do It All hardware store the other day and they had like a couple dozen sets of brushes in stock. I have a spare new motor sitting on the shelf that I will take the brushes out and try to match them up.

I live in a rural area and don't get to the bigger town but a couple times a month but will due that if no one beats me to it.

[Digitalwoodshop]

I measured them and hit up about 5 web sites selling carbon brushes and had no luck finding a match since it is metric. Did find one that was close with a longer spring and tether wire but I did not think it would have worked and was 5 times the price of the LHR Brush set.

I recommend ordering it from LHR.

With the longer tether, the metal of the brush could reach the copper commutator of the Armature damaging the motor beyond repair. The Tether acts to conduct the voltage from the carbon from the cap to the brush AND acts like a Dog Leash and CHOKES it from reaching the spinning parts.

CB001 Carbon Brush Set of 2. My Jan 2009 Price was $5.00 for the set.

AL