Bridgeport Series 1 CNC impulse buy

[Lothos]

I've been looking for a mill for CNC conversion for the last month or so.
I was actually looking for a bench mill, but then...

I came across this on ebay with 20 minutes left on the clock and impulse bid on it sight unseen:

Bridgeport Series 1 CNC Milling Machine w Control Box | eBay

I'm now the proud owner of.... a lot of metal in questionable condition. At least it was cheap. $175
It will cost me twice that to ship it.

Looks like everything I need is there..

My goal is to run this with Machinekit, a linuxcnc branch which you can run on ARM processors like this one:

That is a Beaglebone Black. It is basically a cell phone processor with 2 programmable co-processors dedicated to running real-time code independent of the OS.
For another project I have one of these controlling 8 axis, 5 pwm channels, serving up the interface over the network, and a myriad of other stuff and it never gets above 30% cpu.
That part I got covered, provided I can feed in step/dir signals to this beast somewhere.

It looks like it has already been retrofit? The servos don't match a lot of the pictures I've found.
Centronics?


Also curious about:
The collet size. Found a couple conflicting accounts online.

How does the drawbar on this thing work? Specifically, if I build a tool changer, can I tighten the drawbar in some automated way?

VFD conversion (as I don't have 3 phase power and don't want a rotary converter.)
I'll need to check out the existing motor first. If it's crap I may replace it with a servo instead of going VFD.

Scrapping the variable drive for a set of pulleys. Perhaps a toothed belt so I could sync to spindle rotation?

This looks like a lot of work, but I have more time than money currently.

What do you all think?
I still have not laid eyes on it.

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[awerby]

It's certainly a lot of metal for the price. Even if the ballscrews are useless and the ways are worn out, starting with a massive cast-iron frame like that puts you ahead of the game.

If you've got 220v single phase power, you should be able to run the existing 3-phase motor with a VFD; just get one that's rated for a few horsepower more than the nameplate on the motor calls for, since there's a loss factor when converting from 1 phase to 3. I don't think you really need a toothed belt to keep track of the spindle rotation; most people do that with a single-point encoder, which isn't hard to implement. I doubt there's anything wrong with your existing spindle motor - those things live a long time.

Centroid CENTROID CNC controls,CNC Controller, CNC Retrofits,CNC Milling Machines,CNC Lathes,CNC Routers,5 Axis CNC Cylinder Head Porting Machines,CNC Rotary Tables,Fanuc Retrofits,Digitizing Probes,Conversational Programming is still making CNC controllers; it's considered a top brand, although yours is probably pretty obsolete (They have nothing to do with Centronics, though.) You might be able to get some tech support on your unit from them, or at least a manual for it. I'd try to get that working before launching into controlling it with my cell phone or whatever...

[Karl_T]

WHAT A HUNK OF IRON! I ran this exact machine for several years (with the now antique BOSS control)

Yep, that controller is obsolete. You might see if you can get credit toward a newer Centroid.

It won't be any more work to put a control on this real machine than it is to install on an Asian toy (mill drill)

First find out if you got steppers or servos.

[Lothos]

Know what the collet type is?

[Karl_T]

Mine was NMTB30. Bet they came with NMTB40 also.

[vmax549]

It looks like it has a QC30 spindle My series 1 CNC did. QC30 is similar to nmtb30 but not quite. All QC30 tooling will fit a nmtb30 spindle BUT not all nmtb30 tool will fit a QC30 spindle (;-). The guage height and flange diameter are different.

It is also possible it could be a QC40 or either of teh KwikSwitch series spindle( 200/300)

BUT more that likely it is a QC30 . NOW teh spindle MAY or may not have a center hole for a drawbar. Mine DOES and I have seen some that did NOT. IF it does have the center hole then you can run either teh QC30 tooling WITH teh QCnut installed OR change over to nmtb30 or bt30 or cat30 tool holders and use teh appropriate draw bar.

IF it does NOT have teh center hole you are limited to teh QC30 type tooling and must use teh QC nut to retain teh tooling.

Hope that helps, (;-) TP

[seanano]

Congratulations! I was watching that one too for spare parts. Mine has the Erickson QC 30 spindle with a draw bar hole and didn't come with the QC nut. Out of curiosity, how far are you having it shipped for $350?

[Lothos]

Thanks for the info on the collet. I'll have to wait and see.

Freight was to Northern WI with freight terminal pickup. Probably about 1300 miles.
Initial quote for 42x58x80 @ 2400lbs was $270 but after re-packaging the width went to 48" and the price to $350.
Pretty good deal for the size/weight I thought.

[forhire]

The control looks like a Centroid CNC4 from the early 90's. I have one on a Lagun FT-1. My control is 25 years old and still ticking. It lacks helical interpolation and only has 25k of program space but for job shop operations it works fine. A few years ago I thought about changing it out for something like linuxcnc but decided it works fine for what I use the mill for as is. At the time I needed to do some thread milling and was being constrained by the lack of helical interpolation and the limited space to run segmented helical paths. I now have a VMC that doesn't have those limits and the Lagun has been relegated for simpler work.

Here's an old post about using gtkterm in Ubuntu with my cnc4.
http://www.cnczone.com/forums/genera...ng-random.html

Here's a long thread on linuxcnc about it.
https://forum.linuxcnc.org/forum/38-...-centroid-cnc4

[seanano]

Freight was to Northern WI with freight terminal pickup. Probably about 1300 miles.
Initial quote for 42x58x80 @ 2400lbs was $270 but after re-packaging the width went to 48" and the price to $350.
Pretty good deal for the size/weight I thought.

Seems like a great deal to me. I just got quotes yesterday for shipping one (minus the head and electronics cabinet) about 700 miles with freight terminal pickup on my end starting just shy of $600. Do you know who is doing the shipping? Maybe I'm not talking to the right people...

[Lothos]

I went to a freight calculator site, then went to each company on it directly. On the calculator site, the lowest quote was $600.
Directly on the target company site the rate was half that: YRC Freight - The Original LTL Carrier Since 1924

[seanano]

Thanks! I had tried that with some companies, but not YRC yet. Their quote is much more reasonable - $320.