Manual bridgeport to cnc

[Techbuilder]

Hey. Everyone I was hoping maybe you can help me out. So I was curious if I converted my Bridgeport to Cnc with just stalk lead screws and without re scrapping the ways what accuracy and backlash do you think I can get. The ways are about a 6 or 7 out of 10 and the table allows me to go all the way to the end without binding. I know converting an old Bridgeport Cnc is cheaper but there isnt anything in my price around the area so your advise would be very much appreciated

[nate]

A ballscrew kit can run under 1000.00 and the mounts can be made or bought for ~500.00, I converted a series 1 2J and then built a z axis conversion for it. I could not have been happier with the results.

for about 3K, I bought ball screws, mounts, motors, power supply, gecko G203V's and a smooth stepper. This was all money WELL spent. Add this two a 250.00 BP and I now have a 10K machine for 3250.00

I can get you an itemized list of what I used if you are interested.

I got my screws and mounts from Mel. I can get you his info if you need.

Convert with ballscrews (ground) and you wont be sorry.

[nate]

[nomedia="http://www.youtube.com/watch?v=kLQ3Pn2Gg0E"]YouTube - bridgeport milling with flood coolant enclosure.[/nomedia]

[ichudov]

I would not do it, I would rather get a used CNC mill and upgrade the control.

Too much trouble and too much work with a manual mill, in my opinion.

With a real CNC mill, you get automatic lubrication, coolant, all the servo stuff all mounted on etc.

I bought my Bridgeport Series II Interact 2 CNC mill for $500 and retrofitted.

Bridgeport Series II Interact 2 CNC Mill

I could not be happier.

i

[Techbuilder]

nate did you re scrape the ways and re surface the table? if not what tolerance can you hold on your surface?

ichudov as stated it's hard to find a decent old cnc bridgeport that's not worn down or under 3,000 dollars and if they happen to be under 3000 there in terrible condition with the ways all worn down and not to mention bridgeport cnc have mostly chrome ways not surface grounded which are harder to re-scrape.

I already have a bridgeport and I just got it two weeks ago and I have 1500 dollars to either go to cnc conversion or to re scrape the ways.

I want to be able to hold at least .001 but I'm not sure if I have to re scrape the ways to achieve that.

Will changing to a ball screw allow me to have that? or will it only get rid of backlash and the surface tolerance would be all jacked up from the worn ways?

[ichudov]

As far as I know, the market value of a manual mill "converted" to CNC is less than the value of same mill as it was.

It is like converting a horse to a motorcycle, sure you can add wheels to a horse and a engine too, put fuel tank on the back, it will even run if you try hard enough.

As far as difficulty of finding a disabled Bridgeport CNC mill, it really depends on your scrounging skill level.

i

[Techbuilder]

As far as I know, the market value of a manual mill "converted" to CNC is less than the value of same mill as it was.

It is like converting a horse to a motorcycle, sure you can add wheels to a horse and a engine too, put fuel tank on the back, it will even run if you try hard enough.

As far as difficulty of finding a disabled Bridgeport CNC mill, it really depends on your scrounging skill level.

i

What do you think of this one
Bridgeport Milling Machines
you think it's worth getting and selling my manual?

[ichudov]

What do you think of this one
Bridgeport Milling Machines
you think it's worth getting and selling my manual?

I am not so sure, it seems to be stepper driven and not super cheap, but it is not entirely crazy, especially if it works.

i

[Techbuilder]

I am not so sure, it seems to be stepper driven and not super cheap, but it is not entirely crazy, especially if it works.

i

It works the guy said it has .010 backlash
if the ways are worthless do you still think it would be cheaper to update it then to do a full conversion from my manual?

[RevEdo]

There are many retro-fit kits out there for a std Series 1 or copy.If you stick with the reputable ones: Fagor, Anilam, Accu-Rite, even Proto-Trak, you are looking at $13g for 2 axis plus labor. Includes ballscrews. Do not even think of using any type on non-ground screws in X & Y, and ballscrews are damn near a MUST. A Series II with an Interact control is nothing more than a retrofit. Plain and simple. There are lots of PC based retrofits out there on the cheap, some might be great. Bottom line is, start with a tight machine, add ballscrews and tinker. It is possible to get in under $5g if you are really smart.

[Techbuilder]

There are many retro-fit kits out there for a std Series 1 or copy.If you stick with the reputable ones: Fagor, Anilam, Accu-Rite, even Proto-Trak, you are looking at $13g for 2 axis plus labor. Includes ballscrews. Do not even think of using any type on non-ground screws in X & Y, and ballscrews are damn near a MUST. A Series II with an Interact control is nothing more than a retrofit. Plain and simple. There are lots of PC based retrofits out there on the cheap, some might be great. Bottom line is, start with a tight machine, add ballscrews and tinker. It is possible to get in under $5g if you are really smart.

those kits seem a bit hefty and I have some conversion plans
to do it for 3/4 of the price.

I've seen people convert there machines and be pretty successful but i'm just wondering is it cheaper and is it worth all the hassle of selling my machine and getting a new one.

It would cost 1500 for servos and controllers
it would cost 900 for ball screws
and it would cost 150 for one shot lube system
and another 300 dollars for belts and pulley and such for the plates
so 2850 for total and I paid 2000 for my Bridgeport so it would be a total
of 4,850

that's not even with the ways scraped that would be an additional 2500

[RevEdo]

those kits seem a bit hefty and I have some conversion plans
to do it for 3/4 of the price.

I've seen people convert there machines and be pretty successful but i'm just wondering is it cheaper and is it worth all the hassle of selling my machine and getting a new one.

It would cost 1500 for servos and controllers
it would cost 900 for ball screws
and it would cost 150 for one shot lube system
and another 300 dollars for belts and pulley and such for the plates
so 2850 for total and I paid 2000 for my Bridgeport so it would be a total
of 4,850

that's not even with the ways scraped that would be an additional 2500

Again, tram the head, sweep the table in. Is it tight?? Good thing about Bridgeports is, the castings get better as they age. Ballscrews are a must and if you go CNC, 1 shot lube is not gonna cut it. Auto-lube is a must. And don't tell me " I promise to feed the puppy daddy, one shot lube is fine" Never happens, lol.


And BTW, a new BP is most probably made in Taiwan. They've been getting their heads from Taiwan since the mid 90's and the columns/everything else from China since 2000.
I work for the oldest Bridgeport distributor in the country, we opened our doors in LA in 1938.