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Recommendations on what to do with a 2Axis Prototrak Edge Knee Mill?

adammil1

Titanium
Joined
Mar 12, 2001
Location
New Haven, CT
I am not sure if this belongs under the CNC topic as a Prototrak mill is a lot less of a machine than what is typically discussed over there so if it needs to be moved moderators please do so.

None the less the controller on the 2006 era 2Axis prototrak Edge controlled Bridgeport clone mill at work died and then the machine became mine for the cost of transport. The shop foreman told management that it was irreparable but I think that was really a ploy to replace it with with a modern 3axis Prototrak bed mill, so this machine became mine for the cost of renting a trailer to take it home.

So now the question becomes what is the best course of action? Repair and use as is, repair and sell, or retrofit to something better?

Prototrak sells refurbished control units for $750 which would get the machine up and running as is. Has anyone ever used the Edge control system? Ideally for my needs I would have something with 3 axis and ability to accept G-Code as I would like to be able to do some engraving and have a few other complex parts in mind that wouldn't be the end of the world to do on a 2axis mill but would likely be difficult if not impossible to program thru the prototrak conversational programming methods. This mill only has a floppy disc slot on it and I am not sure how well it will handle G-Code? Does anyone have experience with uploading G-code to one of these machines? The manual seems to suggest it is possible but I am not sure how good it is in reality (not to mention writing to a 3.5" floppy disc is a little out of fashion).

At the same time in my day job I am a mechanical engineer for a custom machinery builder. I have been starting to think that retrofitting a CNC mill would be a fun learning experience and also give me something to put on my resume to either help me advance in my current company or one day help me get my next job. I have wanted to get into motion control for sometime in my current line of work so I am leaning towards wanting to retrofit a machine just for the learning experience. The only question now is whether or not it makes sense to retrofit this one or if the machine has enough value that it is better to fix/sell and use the money towards something already setup with 3 axis worth of ball screws?

Anyone know the current value on a Prototrak Edge 2 axis mill? The iron is in great shape all the scraping marks are there. I see an older Prototrak AGE advertised for sale locally for $8,900 on Craigslist, I am assuming the seller is dreaming but if that is real, I think I will just fix/sell this one and get something else to retrofit.

Anyone know the current state of the retrofit options? I have been researching between the Centroid vs the Mach4 software and am hoping to reuse the ball screws, 160VDC servo motors and probably junk/sell the rest of the electronics on the mill. Then I would still need to come up with a solution for the Zaxis whether it makes sense to motorize the knee or just go with one of the quill retrofit kits that are out there like this one Floor Model Knee Mill Conversion Kit | MicroKinetics. Anyone have good hardware recommendations or can recommend places to do more research? Here's one article I have found so far. https://www.cnc4pc.com/pub/media/productattachments/files/CNCDirections.pdf. I am pretty much as green as they come to CNC retrofitting so if anyone knows of some good how to guides or reading on how to get started that too would be a lot of help.

Thanks,

Adam
 
Fix controller, sell it for $3500.

If you need a CNC mill buy a real CNC mill.

I really doubt that a knee mill CNC retrofit would impress an automation company, or anyone outside of a hobby forum online.
 
I have one in my garage, it's actually very useful as a enhanced manual , since programming is quick and simple. , The works had several of the 3 axis versions as well

What is actually wrong with the one you have? Inside they are a single borad pc running dos . The main failure seems to be the motors and drivers , I repaired the drivers and replaced motors with alternative types wne necessary. Unfortunately, SWI are not forthcoming with any technical info , even plug pinouts are for some reason secret.
 
Acorn CNC controller, Step and Direction 4 axis CNC Control board with ethernet communication.DIY CNC kit

I used this on a bp boss retrofit it works well.

Do ALOT of research before starting a refit there are a great many details of how to wire and configure this to get a good outcome!

I should have done more research on my refit I'm going to have to go back and rewire a few things to get it the way I want...View attachment 338629

What do you have for motors to drive it steppers or servos? I have 160VDC servos, I have been looking at the Acorn, but then I still need some servo drives. I am not sure if it really is worth buying the Allin1DC board for a knee mill.

I have one in my garage, it's actually very useful as a enhanced manual , since programming is quick and simple. , The works had several of the 3 axis versions as well

What is actually wrong with the one you have? Inside they are a single borad pc running dos . The main failure seems to be the motors and drivers , I repaired the drivers and replaced motors with alternative types wne necessary. Unfortunately, SWI are not forthcoming with any technical info , even plug pinouts are for some reason secret.

The whole PC board has indications of smoke marks on it and I was told it never powered up again. As you mention SWI doesn't provide much for wiring to troubleshoot further. How good is the Edge control especially when it comes to uploading code from CAM software? For what I am looking to do, I don't need anything high end but not having a 3rd axis is going to be an issue.
 
I have SWI knee mill with SM controler, 2 axis. The SM controller takes G code as long as the input is in text format and the file is xxx.GCD. My controller is a Windows 95 OS.
I inquired about adding the 3d axis and the reply was that it would be $5000-$7000. I did not proceed.
As to engraving, a kind individual (Barbter) pointed to StickFont, (NCPlot) that has six fonts available and can output in G code or DXF. In G code the .NC suffix needs to be replaced with .GCD. The other issue is that the G code is written for a three axis machine. I modified the code to have an M00 whenever the spindle had to raised.
----
X0.4821Y0.3214
X0.4107Y0.2857
X0.375Y0.2143
M00 (SET Z AXIS)
G00Z0.0
X0.5536Y0.75
G01Z0.0F0.0
M00
X0.4821Y0.7143
X0.375Y0.6071
X0.3036Y0.5
----

A last note: Unless the lettering is large, the standard BP does not have sufficient spindle speed for fine engraving. Consider a spindle speeder or an auxiliary high speed spindle.

Tom
 
The whole PC board has indications of smoke marks on it and I was told it never powered up again. As you mention SWI doesn't provide much for wiring to troubleshoot further. How good is the Edge control especially when it comes to uploading code from CAM software? For what I am looking to do, I don't need anything high end but not having a 3rd axis is going to be an issue.

Smoke damage means something else went bang 8-) psu maybe ?

As to CAM, if your job requires cadcam you probably need a 3rd axis. The edge excells at simple things like drill patterns, milling holes, profiling and pockets that are a pita manually.

I modified a post proc for SheetCAM to output native format to do a few profiles that could not be easily programmed , it works but is short on memory for most things .

If I were you, I'd find someone competent to judge if the electronics can be repaired , then decide if it's worth modding to use another controller. You will probably end up replacing the motors and drivers, the dc servos that SWI use don't seem to be readily supported by contollers.
 
adding the quill or knee (z-axis), or even both, might run less than the controller they are selling you. Counting your time as free of course. I looked at centriod briefly, was a toss up near the end with flash cut or Planet CNC controller. I met both at separate fabtechs and liked the people/attitude. Went with planet because they are the most wide open about everything, and documentation is complete. Decide to add a rotary and it is just turning on another axis. Mr. Plasma went with Flash Cut and is retired gazillionare.
If the drives/motors are good the hardest part is figuring out how to motorize the quill. If you invent a good way I am ears. The quill is nice to have move for when you make the head all cock-eyed- bp wins this over vmc.
Your quill can be a stepper, you have 6 ish inches of travel, and they pack a punch for their size. gecko for good price point drive and seimens new stepper drives are supposed to be all that and more, but how much do you really need 1000 rpm vs 600 rpm is up to you.

I wouldn't recommend converting a manual machine over- but since you already have all the hard stuff done upgrading a controller is not that hard for the gain (a running mill) you get.
 
Just specifically on the floppy issue, you can replace the drive for like $20 with one that has the same floppy interface to the computer but which instead reads a USB thumb drive that has a bazillion 1.44mb partitions. The computer doesn't know the difference, and you switch which "disk" (partition) it's reading from by up/down buttons on the controller. Much less painful than floppies.
 
Just specifically on the floppy issue, you can replace the drive for like $20 with one that has the same floppy interface to the computer but which instead reads a USB thumb drive that has a bazillion 1.44mb partitions. The computer doesn't know the difference, and you switch which "disk" (partition) it's reading from by up/down buttons on the controller. Much less painful than floppies.

Yes they work well, i have one on my mill.

Also, if the lcd dies or fades out there is a standard VGA connection that can be used with a small monitor mounted in place of the LCD
 
What do you have for motors to drive it steppers or servos? I have 160VDC servos, I have been looking at the Acorn, but then I still need some servo drives. I am not sure if it really is worth buying the Allin1DC board for a knee mill.

Just old steppers on my junk

If you can repair at 750$ that's what I would do
Any retrofit will probably cost sufficiently more
 








 
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