# Full Cnc Retrofit... Is It Viable?



## Str8jacket (May 15, 2016)

Its probably a question that has been asked hundreds of times, but here it goes again.

Is it a viable option? I can convert my knee mill, or I can build a daughter table, or I can buy a used cnc mill with outdated or non working controls and retrofit. 

I have zero experience in this area but Im not overly stupid, and I want to and am willing to learn, but is somethung of this scale just way to far into the deep end?

I see others on here tackling retrofits but most have help, i will have none that I can foresee. 

So without even getting into which route to take control wise, is this something a newbie should venture into. I do want to learn more than go into production of a given product.... that said i would actually like to get some use out of the finished project. And i would prefer a machine that is productive and usable rather than a toy, which is why I I am leaning towards a cnc retrofit rather than a scratch built project. 

Cheers Str8


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## Andre (May 15, 2016)

http://neme-s.org/Shaper Books/bridgeport_j1_head_2_0_01 Rebuild.pdf


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## Str8jacket (May 15, 2016)

Thanks for that link I will have a read.

Im actually looking more at a machine that is already cnc but needs a change out of controls. Has ATC carousel etc. A full blown machine centre not so much a manual machine conversion.


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## JimDawson (May 15, 2016)

The short answer is YES, any of the above. Having said that. I vote for the controls retrofit of an existing CNC machine.

Many times I think it is less expensive to buy a CNC machine with bad controls. It already has the ball screws, motors, and a lot of other hardware that you would have to purchase for a retrofit of your existing machine.  Normally what fails is the computer system, but all of the drive hardware and motors are still good.  For me the controls are the easy part, none to very little mechanical work.  But if you are not experienced in control systems, it can be a little daunting.  My machine started out life as a 2 axis machine, it is now a 4 axis, and still using the original motors and drives on the X and Y axis.


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## Str8jacket (May 16, 2016)

Thanks Jim, I see on some of your conversions you use Galil controllers and Mach. 
I have been looking at options on how to go about it from a new person getting into the industry so to speak... I want to build a cnc plasma table first up, and this is a machine I want to build and run not experiment on so much, so i think i will most likely use a cncandc linux plasma kit. As all the tuning etc is done. Being that it is linux I was thinking I might go the linuxcnc route on the conversion if I were to tackle a mill, that way i wouldnt be trying to learn different operating systems as much as going polar opposite directions. There "seems" to be a swing towards linux but it is hard to sort 'fact from forum' if you know what I mean. 

Or for something like this would i be better off with cmsio or going the easier way out and forking over for centroid. Which is getting pretty high on the dollars invested then.?


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## JimDawson (May 16, 2016)

It seems like a good idea to have the same system on all of the machines in your shop.  There is nothing wrong with LinuxCNC system.  You are correct, the Centroid system is getting up there in cost, especially when you start adding a tool changer to the system.


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## chevydyl (May 18, 2016)

I did a 2 axis conversion on my knee mill, I bought screws that didn't fit perfectly and make/modify everything to fit, had no help, this is my first venture into controls and machining. I had my mill converted about 6mo after getting it. The only things that were designed to play together is the servos and drives, Allen Bradley. I had to make extentions for the ball screws, adapters for the small pulleys on the servo shafts, and adapters for the servos to motor mounts, motor mounts also had to be modified to fit. I'm in the same boat, buy a real cnc mill and put a new control into it.


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## Str8jacket (May 18, 2016)

Thanks for the comments guys, I had been looking at integrating the controls of the Z axis head I want to build for my manual machine to a full cnc set up when I found this





And thought why reinvent the wheel if I can have something already capable. If I can work out how to get it here and not blow the bank to bits I feel it would be a much more suitable base to start from.
That way I can leave my big machine semi manual and get it going and slowly build something like this up as I learn.


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## chevydyl (May 18, 2016)

Omg lol wow

So how much can you spend? I'd get an old robodrill or brother drill tap machine, they haul ass and aren't giant, and but cheap. There was a fadal vmc 15 or 20 on ebay for like 3500 or so that got flooded, prolly a decent deal if you wanna clean it up and replace the control


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## Andre (May 18, 2016)

That thing looks heavier than anything in my shop, combined....


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## Str8jacket (May 19, 2016)

Andre said:


> That thing looks heavier than anything in my shop, combined....





chevydyl said:


> Omg lol wow



Oh what? That old thing......

Yeah i think its about 4 ton. But the price is nearly to good to refuse. And it looks to be in really good shape. Not sure what to do? Buy it and put it on the back burner or look for something smaller but not as cheap. I think the size and the fact it needs new controls is why its so cheap.


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