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Author Topic: Bridgeport Discovery 308 retrofit  (Read 23039 times)

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Offline Jeff_Birt

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Re: Bridgeport Discovery 308 retrofit
« Reply #10 on: June 07, 2007, 02:37:18 PM »
After talking with Brian the other day it seems that the best way to go on this retrofit is the Galil route.  Everything we need to do with the machien can currenty be done with the Galil and 64 I/O extesnsion board.  The cost diffrence between the two options is only in the $600 range with the Galil provideing the least complicated finished system.

I've downloaded all the Galil docs I can find and have been reading like crazy.  I was specing out the computer parts wich will be mounted in the same large enclosure as the original 80286 MB' this cabinet also contains the drives and other bits.  It occured to me that I'll need a way of securing the Galil PCI card and video card.  I've seen other have stripped an old PC case and used that.  I have an old case that I could use in the same way.  Does anyone knwo of anyother options?  Something like a mounting panel for the MB that has a riser to hold the cards?

Thanks,
Happy machining , Jeff Birt
 

Offline Chaoticone

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Re: Bridgeport Discovery 308 retrofit
« Reply #11 on: June 07, 2007, 03:06:18 PM »
Hey Jeff,
    As far as mountig the Galil, You should be able to bend the tab at the bottom and screw it through your panel you mount the MOBO to if the stand-offs aren't too long. I used 4-40 X 1/8 stand-offs to mount my MOBO.

Brett
;D If you could see the things I have in my head, you would be laughing too. ;D

My guard dog is not what you need to worry about!

Offline Jeff_Birt

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Re: Bridgeport Discovery 308 retrofit
« Reply #12 on: June 07, 2007, 11:37:03 PM »
I spent some time looking today and can't belive that no-one seems to make a simple MB mounting tray.  Check out the slide out MB tray in this small case: http://www.tigerdirect.com/applications/searchtools/item-details.asp?EdpNo=1800611&body=MAIN

That would be perfect, to mount a tray like that inside the enclosure.  It might be worth buying the case for the tray and power supply.
Happy machining , Jeff Birt
 

Offline Chaoticone

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Re: Bridgeport Discovery 308 retrofit
« Reply #13 on: June 08, 2007, 06:06:35 AM »
A good friend of mine just used one of those about 2 weeks ago on a retrofit, Cam Tech. I like that little case a lot. I just got my new cabinet put together with slide out panels. It works good but was a pain to wire. LOL Here is a link to mine.

http://www.artsoftcontrols.com/forum/index.php?topic=2994.10

I need to get some pics. posted of it all wired up. :P

Brett
;D If you could see the things I have in my head, you would be laughing too. ;D

My guard dog is not what you need to worry about!

Offline Jeff_Birt

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Re: Bridgeport Discovery 308 retrofit
« Reply #14 on: July 23, 2007, 04:49:10 PM »
Finally got the parts in the end of last week (had to wait until new fiscal year here at the University to buy stuff  :( ).  Got the Old unneeded stuff stripped from the control cabinet, the PC built and started to mount the new bits.  I bought a Ultra MicorFly case/mobo combo from TigerDirect.  After building the PC and loading Mach III, and a quick driver test (hey, even the built in graphics work good!), I took the case back apart.  The removable mother board tray was pulled (you can see the Galil card in the pic).  The tray will be mounted on the bottom-left side of the cabinet in the same area as the original PC-AT mobo.  The mobo will wind up mounted so that the 'back' will be pointed down (but it will be 8" or so off the cabinet floor).  This will let the 100 wire Galil cable travel neatly up the back corner to the IC-2900 (a terminal board for the Galil) which feeds from the back.  Where the big green board (SAF board) was removed from the center of the cabinet two 16 position Opto-22 racks will be mounted (the hold 16 opto-isolated Solid state relays, either inputs or outputs).  I had the Opto-22 racks, and they fit perfectly.

Happy machining , Jeff Birt
 
Re: Bridgeport Discovery 308 retrofit
« Reply #15 on: July 25, 2007, 10:20:26 AM »
Looking good :)
Fixing problems one post at a time ;)

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Offline Jeff_Birt

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Re: Bridgeport Discovery 308 retrofit
« Reply #16 on: July 26, 2007, 03:43:25 PM »
I got a bit more work done today.  The side panel was removed from the machine and fitted with the new mobo, ICM 2900 (breakout board for Galil board) and places for two 50-pin ribbon cable breakout boards (made by Phoenix Contact).  I made a angled bracket from some 1/16" x 1" aluminum angle that mounts to the rear of the motherboard tray (and cut couple tabs out of the scrap) to mount the motherboard to the side panel.  It worked out pretty good allowing the motherboard to be removed with four thumb screws (the former case screws).  I had to remove the wire duct shown on the right of the side panel as it was way to tight in the corner.  The 64 point I/O extension from Galil uses two 50-pin ribbon cable connectors, so I'm running a ribbon cable from the Galil I/O board to the  Phoenix Contact breakout board.  I can then run separate cables up to the two 16-point Opto-22 racks. I still have a spare 32 I/O points ans the place to mount another breakout board, just no place to mount anything else  :).

Happy machining , Jeff Birt
 

Offline RV

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Re: Bridgeport Discovery 308 retrofit
« Reply #17 on: December 28, 2007, 12:33:57 PM »
Although I am not using MachIII, this looks like the best place to find some help.  I too am doing a Bridgeport Discovery 308 retrofit, I will be using Vital Systems' MOTENC Lite PCI card (8DAC, 8ADC, 4ENC version) with their analog breakout board to control the MSI servo amps for the 3 axis drives; the remaining 4th axis analog control will be for spindle control.  The spindle motor controller is a V400 Flux Vector Drive by Control Techniques and the input requires a serial interface with RS485 protocol. 

The question I have is what has anyone else done for the spindle control or its communication for a retrofit such as this?  I have considered a signal conditioning circuit with the use of an ADC and a comminucation interface such as a Phillips SCN2661 (CI used in the original machine circuitry).  I don't mean to hijack this thread but thought this would be an appropriate place for this information and maybe spark some more updates or input from the existing Bridgeport retrofitters.

Offline Jeff_Birt

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Re: Bridgeport Discovery 308 retrofit
« Reply #18 on: December 31, 2007, 12:41:31 PM »
The spindle drive can bet set to accept 0-10V signals as well. In the original machine while milling the spindle drive runs in RS422 mode, basically just getting the speed command. The drive uses separate encoders for velocity feedback (this encoder goes to the drive) and position (this encoder goes to a little circuit board beside the spindle drive). When doing tool changing, the spindle drive is set to 0-10V mode and another circuit board takes over to control. It supplies the analog reference and reads the secondary spindle encoder signals to properly position the spindle for tool changes. I have retained this original setup, but I think it would work just as well, perhaps, to run the spindle drive the whole time in analog mode. But, by retaining the original setup I have a spare 4th axis to use for a indexer etc.
Happy machining , Jeff Birt
 

Offline RV

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Re: Bridgeport Discovery 308 retrofit
« Reply #19 on: December 31, 2007, 02:32:05 PM »
We acquired this machine in a non-working condition, so I am at the disadvantage of not having seen it in action.  I am at the mercy of the Installation, Parts, and Maintenance Manual to provide the descriptions of what the machine is supposed to do and how it accomplishes those functions.  Unfortunately there are some key misprints in the manual and I believe I may be hung up on one now.  In the description for Parameter 18 (Analog Speed Input Scaling) of the spindle drive it states the default is "6-- rpm/volt" I read this to mean 6 rpm/volt or 60 rpm=10V and assumed it was set at this value to achieve better low speed resolution for 0-10V analog signal from the orient card (tool change positioning circuit board) and would not work for regular milling rpms.  After closer inspection I see that it also states in parentheses that 6000 rpm=10V and must mean that the default setting is 600 rpm/volt.

If it can be confirmed that parameter 18 is left at its default setting of 600 for both normal run and tool change control functions then I will be off and running with it set to use the analog reference for all spindle speed control.

The serial connection was also used to monitor and set a number of the spindle drive's parameters and bit parameters, will I need to retain the ability for the serial connection to monitor and/or set any of those drive parameters in real time?  I see the important ones such as enable, reset, zero speed, drive at speed, external trip, etc. are all hardwired 24V logic I/Os, is that all I will need for full control and functionality?

Thanks.