Messages

8321

General Mach Discussion / Re: BOARD PROBLEM HELP REQUIRED

« on: March 14, 2009, 11:15:17 AM »

Brilliant news about getting a replacement controller.

I doubt that this controller can handle the current necessary to satisfactorily run two motors wired in parallel. But it all depends on the torque required to drive the axis, maybe 1.25 Amps per motor will provide enough torque, maybe not. You would have to try it and see I suppose.

Tweakie.

8322

Show"N"Tell ( Your Machines) / Re: Laser cross hair tool position.

« on: March 14, 2009, 10:12:12 AM »

Just a note for anyone else wishing to add one of these laser pointers to their machine.

The positive supply of these devices is often connected to the metal casing so it is best to use a Delrin (or similar) clamping arrangement, as Budman has done on his mill. This isolates the device from the machine frame and will enable powering of the device direct from the BOB and switching it on and off under Mach control, as Greg has suggested, a lot easier to accomplish.

As I have used a metal clamp the body of the device is connected to ground or 0Volts therefor I need negative volts (-3Volts) to power it. This has been accomplished using the guts of a 3Volt wall wart (fitted inside my control box) which is in turn switched on and off under Mach control using a solid state relay which is directly driven by the BOB. This has resulted in more expense than would otherwise have been necessary but what the hell it's my hobby and you can't put a price on that can you ?.

Tweakie.

8323

General Mach Discussion / Re: BOARD PROBLEM HELP REQUIRED

« on: March 14, 2009, 03:18:32 AM »

If all else fails then you have nothing to loose by trying something radical. Thats my motto.

I am sure that if needs must that you could find all the necessary skills. Think positive.

Tweakie.

8324

Show"N"Tell ( Your Machines) / Re: Laser cross hair tool position.

« on: March 14, 2009, 03:12:57 AM »

You are certainly right there Jerry - It is never ever finished.

Tweakie.

8325

Show"N"Tell ( What you have made with your CNC machine.) / Re: Miser engine

« on: March 14, 2009, 03:08:16 AM »

I wish you good fortune with the job prospects.

Engine looking good.

Tweakie.

8326

Show"N"Tell ( Your Machines) / Re: Laser cross hair tool position.

« on: March 13, 2009, 11:15:17 AM »

Thanks Scott, you are a gentleman.

(I have now found the customization wiki which explains everything but will take some time to digest).
Thanks again and sorry that I am such a slouch.

Tweakie.

8327

Show"N"Tell ( Your Machines) / Re: Laser cross hair tool position.

« on: March 13, 2009, 10:03:32 AM »

I am being incredibly lazy here but I wonder if anyone would be good enough to help with the VB Script to turn the laser on and off as Greg has suggested.

Thanks,

Tweakie.

8328

General Mach Discussion / Re: BOARD PROBLEM HELP REQUIRED

« on: March 13, 2009, 09:58:09 AM »

Hi Stephen,

Unfortunately it may be the driver board as Hood has said (I hope it is not).
As it is only one axis at fault try testing the components associated with the failed axis - the 2 (large) current limiting resistors with a multimeter to make sure they are not open circuit, also check the 4 protection diodes to make sure they are not short circuit (low ohms in one direction and high ohms in the other - with motor disconnected of course). It would be a bit of tricky soldering but it is not out of the question to replace the TA8435 chip (cut off all the pins and remove them carefully from board one at a time then fit replacement to heatsink then solder pins). There is not really anything else on this board to go wrong.

Tweakie.

8329

Show"N"Tell ( Your Machines) / Re: Laser cross hair tool position.

« on: March 13, 2009, 03:00:24 AM »

Thanks Greg,

I will try that today and see how it goes.

Tweakie.

8330

Show"N"Tell ( Your Machines) / Re: Laser cross hair tool position.

« on: March 12, 2009, 03:13:04 PM »

Hi Dave,

I saw your excellent post when I was researching my project - it just took a while to locate the laser pointer.

I bought the polarizing film as a small sheet. It is laminated plastic and easily cut into the shape required with scissors.

Here is an ebay uk link which will work for a couple of days at least.

http://shop.ebay.co.uk/items/_W0QQ_sopZ10?_nkw=polarising+sheet&_sacat=0&_fromfsb=&_trksid=m270.l1313&_odkw=cnc&_osacat=12576

Tweakie.