What to get? I want a CNC

[Rickady]

I want a CNC for my hobby garage. I am looking at Ebay and other used machine sellers. I don't know much about the Bridgeport nomenclature? But I am looking at a R2E3, R2E4, V2XT, a Series 2 CNC, or a BTC1 or 2.

What would I expect to pay for each machine?

Any help with this would be GREATLY appreciated.

Thanks, Rick

[gus]

Do not get a BTC

Early BOSS ready for retro are pretty cheap

Heidenhain TNC 151 and later are usually good to go

[machintek]

Of all the ones you mentioned, I prefer a V2XT 2nd generation with a BMDC board or a EZTRAK (which you did not mention).

The rest I would not bother with. Too much trouble.

George

[Rickady]

Bridgeport XT CNC Control w/CRT & Keyboard on the V2XT

This is the description of the controls on one of the machines I'm looking at. Specifically, what year or generation are you talking about when you say BMDC board or a EZTRAK ?

Thanks for all the help, I also like to know what some examples of what you guys would expect to pay? I know it can vary a lot, but I just don't want to pay a lot for a machine that can't be updated or get parts for.

Rick

[fourperf]

my first cnc was a ez trak. Its a great choice in my opinion if you do not oplan to get cad/cam software. Its really easy to program at the machine (with the conversational interface). If you are going to get cad/cam software I would make sure to get 3 axis controlled not just 2 and also r8 sucks for cnc

Mark

[Rickady]

I do hope to update the software. But till then I need to run a machine that is compatible with the new programs. Or easily converted. I have no problem with a PC linked to the machine. In fact that is better for me because I can do CAD work, then transfer the info for machining.
What is wrong with R8?

[fourperf]

r 8 is a drag in cnc because you cannot set the tool length offsets before you run the program

[swarf_rat]

One thing you may want to factor into your decision is the cost of the CAM solution. I have just gone down the road you are looking at and ended up with a Series 1 Mk1 rigid ram with Heidenhain TNC 151B. Once you decide to go with CAM, the controller, as long as it does the ordinary rudimentary moves, is somewhat irrelevant. Something like the TNC control does allow you edit at the control or do some quick things without the computer involved.

But the CAM software is a quagmire. A bunch of packages do 2D and 2.5D fairly cheaply, but 3D seems to cost money. In many cases much more than the machine itself. And my experience was the more you looked, the more you wanted a real 3rd axis, and the more real the 3rd axis the more the software cost to drive it. $1000 is about minimum, $2K-3K give better choices. The software is not that complicated, if there was a mass market it would be $299, not $2999, but there isn't a market to support a low price.

I figured I would have to spend a few hundred on tooling, but hadn't anticipated a few thou on the most important tooling of all.

Also an advantage of the machines built out of the Bridgeport standard manual mill is that at least the mechanical parts are available. On my Interact, they are usually available from Bridgeport, but BPT/Hardinge hasn't got a clue what the numbers are or how to find them. The P.N.s from the manual are English and they don't speak English in Mid-state New York. So each part search is kind of like a treasure hunt. A clue here and a clue there. Against that is the undeniable fact that the rigid ram seems to be considerably more rigid in all three axis and doesn't look like it will wear out in my lifetime.

[NC Cams]

We got started in CNC with a Bridgeport ExTrak.

THey come with either 2 or 3 axis control. If you go with a 'Ttrak, try to get late 90's model with an encoder and full 3rd axis drive capability, specifically the one WITHOUT the outrigger drive of the Z axis. If you go the Extrak route, you can have both a manual mill as well as a true G code compatible 2D/3D CNC.

If you want true 3D, step up to the V2XT. This has an internal ballscrew drive built into the Z axis by the OEM, hence you'll be able to do true 3D milling. Again, go with late 90's model with the BMDC control as this is a well developed, DOS based system.

In my case, I have BOTH an Extrak and a V2XT.

The G code the BMDC runs is darn close to the G code that runs in a Haas. Hence, once you write a program for the BPT, you can port it to run on a Haas without too much screwing around asside from some minor control code adjustments.

The BMDC controller is a nice piece. Sadly, outside of EMI, nobody services it. Too bad as it would make a DYNAMITE aftermarket DIY servo system if someone took the time to reverse engineer it. As long as the PC that's in the machine boots and runs, the thing seems to be pretty trouble free. It runs canned programs and, although not perfect, it is a great starter/intermediate machine.

Do some "Extrak" searches on the 'Zone and you'll find how we went about tuning up the drives and ball screws to get DEADLY accurate milling capabilities - these same fixes work on the V2XT as they use the same drives/ballscrew hardware

Early V2XT's used a FMDC controller, which at this point in time, is pretty much obsolete. I dunno who services it if anyone does so anymore. Lots of FMDC systems are purchased and used as foundations for Mach or other retrofits.

For simply plug and play, I'd go with the BMDC fitted Extrak or the V2XT - they both have exactly the same footprint and much of the same hardware as the traditional "Bridgeport 2J mill".

Besides, the V2XT with BMDC controller (mid to late 90's vintage) will also run a 4th axis in TRUE plug and play mode simply by installing an appropriate servo drive - the machine should be prewired for 4th axis. Although the Extrak can be upgraded to true 3 axis control, it is NOT well suited to being a VMC due to some mechanical feature limitations - it probably is NOT worth the effort to try to turn it into a VMC, simply go with a V2XT.

Or, you can spend a few bucks more and go as far as a Haas TM-1 but that is another thread altogether.

[Rickady]

I have a line on a 94 V2XT with XT CNC control. Is this one to old? Does the "XT" stand for X Track?
What would I expect to pay for a late 90"s V2XT?
Do all the late 90"s V2XT's have the same control?
Sorry if I sound like a total rookie, but this stuff is not easy to find.

Thanks.

[machintek]

The V2XT has either a SX control with the FMDC which is to be avoided or it has the DX control which is the one to shoot for..

George

[Rickady]

How do I know which one this mill has? Do they look the same or is there a physical characteristic I can look for. I have some pics of it, but no mention of the SX- FMDC or DX control.