Bridgeport Discovery 300 kit

[MT_Argentina]

Hello Ajax, I'll be brief
I really want to buy a retrofit kit for a Bridgeport Discovery 300, but I'm not sure which kit would be the right one. Who do I need to write to to get a reply? I've sent mails to sales and info at ajaxcnc, even a PM to Scott (still in "outbox"), but had no answers whatsoever.

Here is a pic of the patient: good physical shape, erratic behaviour when in DNC mode


Thanks in advance

Hernán.

[cncsnw]

This looks like a pretty basic mill, of a size suitable for Ajax's standard 29 in-lb DC servo motors.

Therefore you could retrofit it using the All-in-one DC control unit, with either an M39-style control pendant and separate computer; or an M400-style console with integrated computer.

It is possible that the machine already has DC servo motors suitable for use with the All-in-one DC; and if so, it is possible that those motors already have suitable encoders. To answer that, though, you will have to look at the motors and/or the original wiring diagrams.

The retrofit could also be done with an Oak control unit, and new AC servo drives and motors. That would give you higher performance, but at significantly higher cost. That investment is probably not justified on a machine of this style.

If you just purchase the All-in-one DC unit and either PC+pendant or a console, then you would likely want to re-use the existing control cabinet, including much of the existing power distribution components: main switch, fuses, transformer(s), DC rectifier for servo motor power, and variable-frequency drive for spindle control. Any of those components could also be replaced with new, if you prefer, but again at higher cost.

[MT_Argentina]

Thanks for the reply
I'm leaning towards the 'separated computer' option (solid caps motherboard, good PSU), keeping the original servos, and changing the encoders for new ones.


I guess the right kit would be:
-Bridgeport Boss 8-12 / V2XT / V2ES / EZ Trak, Heidenhain TNC 145 Interact I or II Knee Mill CNC Kit $4259

Is that correct?

Not sure about the shaft size for the encoders, I'll check that later.

[MT_Argentina]

Ok, here are some pics of the servo & encoder





Removing the encoder to measure the shaft:





So, 10mm it is. I might be able to adapt one of 1/2" if you don't have one for that size.

[cnckeith]

hello. I agree with Marc. This machine is exactly what the Allin1dc cnc control board was made for.
here is a page with some more info and a video that goes over the allin1dc hardware.
http://www.centroidcnc.com/cnc_technology.html
email Liviu and he will get you a quote asap. liviu@ajaxcnc.com
i circled in red the minimum recommended centroid components that you would need to upgrade this machine in the image below.

[cncsnw]

If for some reason Centroid/Ajax cannot supply 10mm encoders, let me know. I have some in stock.

You may need a ring or other spacer, to get the 10mm encoder hub up above a wider part of the stub shaft. The motor in the attached picture was on a Bridgeport V2XT.

[MT_Argentina]

Thanks Keith, cncsn, and Liviu

After some hurdles, I finally have the Allin1DC in my power. I must say that I really like the Control Panel: feels sturdy, high quality built.

Now I'm studying the schematics and figuring out things.



I have doubts about the connections between the Flux Vector Drive and the Allin1DC, any help would be appreciated! Pictures below:



Am I on the right path?

Here are some references for the VFD from the manufacturer

[diycncscott]

Your connections look correct.

Regarding the "At Speed" signal - though not needed, you could connect it to any unused PLC input and modify your M3 & M4 to wait for the "At Speed" signal before continuing the program.

Add the line highlighted in red below where ?? = the input number you connected the "At Speed" signal to. ie.. 50007 for input 7 or 50013 for input 13 etc..
;-------
;M3 macro
; Displays message to select auto spindle mode if it is not set
;-------

IF #4202 || #4201 THEN GOTO 200
M95 /2
M94 /1
IF #61058 THEN GOTO 200 ;skip the check if AutoSpindle is on
G4 P.1
#140 = 1.5
N100
IF !#61058 THEN M225 #140 "Please Select Auto Spindle To Continue!" ;61058 = JPO2/SpindleAutoManualLED
G4 P.5
IF !#61058 THEN GOTO 100
M101 /#500?? ;Wait for "At Speed" signal before continuing
N200

[MT_Argentina]

Thanks Scott, I'll try your suggestion.

Regarding powering up the servos, I have a transformer that outs 70 and 90 VAC. My servos are SEM 125V max.
so, that would be 70*1.43 = 100.1V or 90*1.43= 128.7V. I'm leaning towards the former (70 VAC) because it's under the servo's Vmax, but my partner would like an 'official confirmation' so to speak

[diycncscott]

The conversion you want to use for a full wave rectifier is VAC * ~1.414

That said, MEASURE the voltage on your secondaries to be sure.

Personally, I wouldn't worry about being 1%-2% over but my advice is, of course, to stay within the rating of the motor.