Bridgeport Turret Mill series 1 X axis power feed

[Nick BoylandParticipant @nickboyland99108]

Changing the PCB

[Nick BoylandParticipant @nickboyland99108]

Hi folks, I've just come across a DC speed controller on Amazon for a little over £12 It claims to accept AC or DC input up to 110v with an output of 110v DC up to 10A. As I understand it, the original power feed motor on the Bridgeport is 4.6 amps at 110v DC. Would this cheap little gizmo replace my burned out Erskine PCB? know it won't be a simple job to wire my variable resistor to this unit, but I think I can manage that probably at the sacrifice of the fast reversing cycle. Can any of you highly knowledgeable electrickery types have a quick look at this doohicky and tell me if it would have a shot.**LINK**

Thank you

[Thomas DyeParticipant @thomasdye26707]

That thing scares me a little. As a cheap hack to get power feed working again whilst a proper solution is found it might work. One thing to check first is the creepage and clearance required at the voltages you wish to use.

**LINK**

If you buy it then maybe you could get someone to check the insulation resistance i.e. to the heatsink, since that should in some way be open to air and could therefore cause a safety issue.

My advice is not to buy that board.

As to a more permanent solution, someone called john fletcher says he has a copy of the Erskine PCB layout with all the component values: **LINK**

I can imagine his knowledge may be useful too, in checking what caused the fault. Don't want to buy something only for that to burn out too, because something else on the machine caused the fault.

Hope this helps.

Tom

[Clive FosterParticipant @clivefoster55965]

The Bridgeport-Mill Yahoo group **LINK** has a pretty comprehensive set of data on the Erskine boards in the member files including a typical circuit diagram and typical component lists. Members only access so you will need to sign-up. Which may take a day or three depending on how grumpy Yahoo is feeling when you ask to join!

Sorted Machine Sales do an exchange service **LINK** . Base price is £109 but VAT and delivery to go on top.

Unless you are an electronics person with reasonable experience and some knowledge of older style motor control electronics its probably best to bite the bullet and splash nearly £150 on a known good, properly sorted unit. I have some electronics expertise and ought to be able to fix one but, after a quick look, decided that life was too short for DIY.

Clive.

[john fletcher 1Participant @johnfletcher1]

Hello Nick, and to Tom it was me. Nick if you send me a PM with your email address I will send you a circuit diagram together with a list of all the components and location on the on the board. I had a well used, poor copy of the circuit diagram which I sent to CR Foster and he made a smashing job of updating the drawing.I might be able to scan it and send you it as an attachment, which will be quicker than the post Before spending a lot of money have you check the motor. Its a shunt wound 110 Volt DC.Check the brushes, have a careful look at the armature commutator, does it look OK and is there any sign of solder or burning. Then check the field coils using a Ohm meter for continuity and to the frame (Earth).Also have you checked the speed pot which is mounted on the end of the table.​The motor can be run using a site transformer and a bridge rectifier, be careful here and have a second person in attendance. Some thing caused the board to burn it need locating. John

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