[jonboycnc]

I'm from the London Hackspace, a maker community in the UK. We're looking for a CNC mill to go in our hackspace, and something has come up on ebay that's very tempting.

It's a Bridgeport Series II CNC:
CNC MILLLING MACHINE BRIDGEPORT SERIES II COMPLETE WITH TOOLING SHOWN | eBay

The z-axis is not functioning but that seems to be an electronics issue - I'm hoping not expensive to fix.

How much should we be willing to spend on this thing? Some people seem to say they have only scrap iron value like $1000 or something.

I'm scared how much it might cost to sort this thing out. We don't mind putting time into it, and have lots of electronics experience - but as hobbyists not commercial grade CNC machine specialists.

How much would it cost to substitute new electronics if that was necessary? How much to convert it to be driven by a PC?
We only need hobbyist grade functionality, not production speeds.

The professional CNC retrofit kits for Bridgeports seem to cost more than $10,000 - this kind of money is way way way out of our budget.

We couldn't spend more than $1000 bringing it into good working order.

Any advice much appreciated - auction ends very soon!

[underthetire]

Worth it for the iron, but that control is terrible. figure new motors, drives, Mach 3 with a decent used computer
3Axis NEMA 42 Stepper Motor 4200oz CNC Control 220V 8A | eBay

1K will be close.

[jonboycnc]

Can anyone identify this Bridgeport?

I'm asking the seller for more info but he may not reply in time.

Questions I have include:
1) servers or steppers inside?
2) How many HP spindle
3) IMPORTANTLY: what's the X and Y travel on this? What size pieces can it machine?

thanks
Jonathan

[greggv]

I'm pretty sure you'll not get it going for under 1000.00, especially if you toss all the electronice and motors and start over, but it could be a nice machine when finished. I don't know the travels.

[underthetire]

If i remember correctly, old DC servos. Spindle 7.5HP, X 40", Y16". Series 2 sit quite tall as well.

[gridley51]

It's an old Boss control machine with steppers and the bids at the moment are about what it is worth.
This is the UK where crap is cheap.
Don't touch it with a barge pole.

[BOSS5]

Whoever bought it got a great deal at 800 British pounds. This must be the cleanest running machine with tooling that I have ever seen advertized for sale. Sigma Stepper motors & Boss 6 controls, can be fed via an rs232 cable to PC. Table travel 32" by 15 inches. Z quill travel is 5". Throat 16", knee travel is manual but counterbalanced with air cyclinder. Rapids 90 IPM, cutting speed up to 51 IPM. Step resolution is 0.0005". Good conversational G code machine for its age, lots of canned cycles. Probably just a blown power transistor on the Z axis. Easy to replace, simply check this forum's past posts. Weighs 5000 lbs, lots of iron, super rigid. Date of manufacture most likely 1982.

[BOSS5]

Another thought, Series 2 BP spindles are QC30 (QuickChange 30). The head is identical to Series 1 machines, only the rest of the iron is much larger. NMBT30 holders. The seller does not know what he actually has on hand. It is a 2 HP head variable speed head with back gear, like all bridgeports. What is unique is the rigid (fixed) ram and concentric ballscrew that sits atop the quill and feeds it axially (no bending forces).

[gridley51]

Whoever bought it got a great deal at 800 British pounds.

It may be a great deal for someone based in Canada,I can assure you in the UK it's not.I regularly buy Interacts with Heidenhain controls and servo drives for less than half that price.
Maybe you would like to share with us where your knowledge of UK machinery values comes from.
The iron may be rigid (for a Bridgeport) but control wise it's an out of date lump of crap.
ISTR it isn't even in working order.

[BOSS5]

gridly51:
It is all well you can find this type of iron for very low money in your area. The cost of transport can rival the purchase price in many instances and must be factored, however I believe johnboycnc was looking for an overall idea of value proposition for his hobby group and indicating a smallish budget that would not permit changing out any major components to get the system functional, like servomotors and drivers. Certainly the servo Heidenhan Interact versions are superior machines, but modernizing and or repairing the controls is quite a bit pricier The early stepper motor driven BOSS systems are surely the lowest entry point and easiest to modernize, a $1000 budget will cover transport, Mach3, Geckos, breakoutboard, powersupply, pendent, basic set of endmills and misc items needed for the upgrade route (if even required). A well maintained clean machine with tooling / holders always has intrinsic value, even when you need to probe for a blown power transistor on a stepper drive card and solder in a $15 replacement, then run it off the original control; or feed it G-code over RS232. Doing nothing else can get you started with an operable machine, so its a good begining for people who are learning, and a much sounder approach than converting a manual mill of any sort. The mechanicals are rather bulletproof, and I have yet to see a stepper motor die, and if it does Ebay has them as low as $45. Fast rapid moves, automated spindle speed control and other advanced features like tool changers don't save a casual hobbist any time, rather the learning curve just becomes that much steeper, and crashes happen faster / harder. Perhaps you can offer him a great deal on one of your working Heidenhan's for less total money, rather than calling it all a bunch of crap from the start.

[gridley51]

gridly51:
It is all well you can find this type of iron for very low money in your area. The cost of transport can rival the purchase price in many instances and must be factored,

Load of crap snipped out to save space


Perhaps you can offer him a great deal on one of your working Heidenhan's for less total money, rather than calling it all a bunch of crap from the start.

Once again you prove how little you know about anything never mind the cost of stuff in Britain.
As for your suggestion on selling one of mine,how stupid are you? I buy these machines and put them to work,that's how I earn my living,I have a machine shop amongst other things.
Your arguments MAY stand up in your homeland where,from what I can gather there is not a lot of choice,in an industrialised area like the UK things are totally different.

[BOSS5]

gridley51:
Obviously that is why the ebay posting attracted 30 bids in your country, because it was such a bad deal (and a load of crap). Makes one suspect that you actually wanted the machine for yourself.

[gridley51]

gridley51:
Obviously that is why the ebay posting attracted 30 bids in your country, because it was such a bad deal (and a load of crap). Makes one suspect that you actually wanted the machine for yourself.

Actually it was 25 bids so reading is not one of your strengths either.These 25 bids were done with 13 bidders,four of the bidders dropped out when it got to its market value.This left nine people who thought it was worth more and one who thought it was worth £800.
So out of 13 bidders only one of them and you thought it was worth £800.Your opinion of value is certainly in the minority.
Makes one think there is no beginning to your intelligence and TBH I can't see an end to your stupidity either.

[machintek]

Gentlemen! Some perspective, please. Many revolutions around the sun ago, these open position loop stepping machines were state of the art and many companies used them productively to make a profit. Some still do. If tuned and powered correctly (and fans replaced before it is too late) they run and do not blow transistors. I know, I have been working on them for 32 years. I still have some running. Others have been converted to newer controls and are still running. This saturday I have to work on the head of a BOSS 5. I do not expect anyone to be using a PC that is 30 years old or a phone that is 30 years old but to purchase this machine one gets great iron, and maybe a control with some life in it. If not then the proper decisions must be made. This is a forum to help each other. Please remember that. I wonder if the now retired space shuttles were ever upgraded from the 386 based computers they were using?

George

[awemawson]

George,

This discussion won't go an further now. Poor old Mark (Gridley51) succumbed to the Big C at the end of last year and is no longer with us.

Andrew

[BOSS5]

Gentlemen! Some perspective, please. Many revolutions around the sun ago, these open position loop stepping machines were state of the art and many companies used them productively to make a profit. Some still do. If tuned and powered correctly (and fans replaced before it is too late) they run and do not blow transistors. I know, I have been working on them for 32 years. I still have some running. Others have been converted to newer controls and are still running. This saturday I have to work on the head of a BOSS 5. I do not expect anyone to be using a PC that is 30 years old or a phone that is 30 years old but to purchase this machine one gets great iron, and maybe a control with some life in it. If not then the proper decisions must be made. This is a forum to help each other. Please remember that. I wonder if the now retired space shuttles were ever upgraded from the 386 based computers they were using?

George

Thank for that perspective. My Boss 5 shoowed the 70005 boot error (upon purchase), and I could not get past it, so I ended up ditching the controls altogether and using Mach3. I also now own 2 Boss 6, the controls work on both, except the RS232 communications is dead on one. Probably fixable with a new driver chip(s). One of these machines is in storage, the other has everything running on planet CNC & POKEYS to convert original MDI control pannel inputs for the modern controls. Alongside, the original LSI computer is still running whenever the machine is powered up, except that the drive outputs are not connected to anything anymore. You can "run" the machine form the original MDI and watch the LED display show the axis positions, etc. Basically, we did not have the heart to scrap the original controls. A friend has his all original BOSS 6 in storage too (I loaned him mine), and is actually using the above machine daily.

A few days ago I bought some QC30 tooling from a local (retired) mold maker. Found out he still has his Series 1 Boss 5 rigid ram (identical to mine) operational in his ex-shop, using a tape reader to load some of his programs and a version of Powermill for CAM. I think I'll need to pay a visit to see it all.

I have some ambition to keep one machine all original, get a punch tape maker, teletype, etc. 30 years from now it might be worth something to a museum or collector who wants to see and demonstrate a pristine and running CNC machine... in the way I first learned to program. I still have some paper tape programs stored away in old school stuff boxes (and punch card decks too). I believe I saw some of this hardware at the Henry Ford Museum, will have a closer look next time I go. Hey, even my old 8088 computer(s) collecting dust for that matter!

In fact, my technology school had a pair of bridgeport NC's (NOT CNC) from the 1960's that came out of an aircraft manufacturer's shop. They looked practically unused. I remember these had large rack type control's as tall, wide and deep as the machine itself, and ran large size 56 steppers. One was a jig borer as I seem to remember, the other more like a series 2 mill. Did not get to play with them, rather we used the "modern" stuff. I realized, even at the time, that this technology had put men on the moon. I was awstruck by its sophistication, using vacumm tube components. I'm told it was somehow "hand programmed", unlike the the sophisticated canned circular interpolation and pocket milling, drilling cycles were were using with our new microcomputer.

We were even allowed to use Compact II programming for more sophisticated parts, and had a 300 baud acoustic modem to do "on-line processing" (post-processor) and get back the finished NC code, using this "advanced" programming tool. Code trials either case were always run with a felt pen mounted in the quill, in conjunction with a home made holder that allowed the z axis to move up and down without crushing the pen, and a wood board that held the paper. Having passed the "pen plot" trial, we students were then allowed to cut metal. That was a thrill ! I so remember how my teacher made fun of the "antique" Bridgeport stepper design, as our new mill (excello with alphanumerics servo controls) was just so much faster. It was 1980.

[hdokes]

The Big 'C'? Not familiar with that term but sure hope I don't seccum to it. I prefer to be around for a bit longer.

[1875]

cancer