Bridgeport btc 1 Servo carbon Brushes

[BOB F]

Hi Guys,

My Bridgeport BTC 1 cnc milling machine have worn servo brushes for both motor and encoder. The Z axis bound up as it went wiggling past the home limit; this could maybe due to worn brushes. Please anyone tell me the source I can buy these items.

Bob F.

[Al_The_Man]

Originally Posted by BOB F Hi Guys, My Bridgeport BTC 1 cnc milling machine have worn servo brushes for both motor and encoder. Bob F.

Bob I assume you mean tach, as encoders don't usually have brushes. In some cases Bridgeports had motors made by S.E.M. of the U.K., If you cannot find an online source for these you may want to try the local motor repair shops that carry brushes, try and make sure to get the same grade carbon if possible, too soft and it wears fast, too hard (a high degree of copper content) and it wears the commutator away fast.
Have you checked the brush length?
Al

[BOB F]

Al the Man,

Thanks for the tips Al. Yes you're right not the encoder. My tach commutator are worn and the brushes of motor and tach are too short. I hope will be able to find these items the web.

Bob F

[Jonp]

Bob, I have brushes for the BTC1 servo motors if you still need them, also am curious did you find any brushes for the tac. generator ? I could use some. email if you need the motor brushes , Jon P.

[Bloy2004]

Just a thought...
I too am looking for brushes for a motor... leisurely, but I thought it might be nice if there were a repository here for numerous sources for brushes.

[Al_The_Man]

One of the biggest suppliers for US & Canada is helwig http://www.helwigcp.com/products_services/brushes.cfm
Al

[BOB F]

Thank you Jon P
I was able to buy for all 3 tachs from local supplier here in LA. One motor has now new brushes and have decided to replace the rest because they are quite short.
Will inform you on how it is going when back in line. I got busy with another Kasuga cnc mill which is intended for heavier stuff. It had a burnt Y servo motor. I'm ready to install motor after it was rewound. These servo motors have a set of gears for resolver, one of these sets is worn out. Hoping someone has this gears. The gears are for count compensation because it is a 5mm pitch ballscrew.
I plan to retrofit this Kasuga mill with new up to date controls when its running and major mechanical components back to good tolerance.

Bob F.

[machintek]

I believe the BTC-1 used a POWERTRON motor.
The home switch on the Z axis is set up so a "F" drill can slide between the top of the quill and the ball nut. This is critical so the ground plane can slide across the grove in the top of the spindle during the tool change.
Maybe you had an encoder failure or bad connection.

George

[BOB F]

George you're so knowledgeable on Bridgeports, I feel encouraged to begin exploring the tool changer again. I gave up on it. The computer seems to recognize the carousel up to 12th or the 13th slot, after that the carousel begins to spin and cannot be stopped unless the E-stop is depressed.

[Jonp]

Usually when the BTC tool changer starts spinning out of control it is because it has lost track of where it is, this is usually because of lack of signal comming from one of the five switches on the cam plates below the tool carousel plate. These switches have a habit of going out every now and then, they appear to be standard micro switches but they are not, they have no mechanical contacts , they have a hall effect sensor in them, any how there is a +, -, and signal terminal, monitor the signal terminal to see witch one is not working. Usually it is the switch but I've seen the little brass roller on the end worn just enough so they only need adjusting. In the rare case that all the switches are good then you need to go to the board , if I remember right they feed opto-isolaters, slim chance you have a problem there, Good Luck , Jon P.

[machintek]

Note that the switches for tool carosel position interface to the XTC board on K-9, pins 19,10,9,8, and 7. this is shown on page 7 of the machine wiring schematic. Although the discussion in the maintenance manual shows micro switches with little rollers, the schematic shows prox (hall effect) switches. I have seen both on a machine.
Note that carosel position 14 has all the switches made, and position 24 has all open.

George

[vebers]

I have recently rescued a couple of these machines from the scrap yard. The both will fire up, but neither will move in any axis. Upon further inspection I found that a couple of the boards have been smoked. The XTC board for one and the board inside the operator interface has black marks as well. Does anyone know of a source for these products or will I have to try to repair them myself?

Vince