Bridgeport Boss 3 X-axis ballscrew

[meanstreakpulle]

Does anyone know of a place to get a replacement X ballscrew for a reasonable price for my Bridgeport Boss 3? If none are available new or used in great condition then has anyone had any luck with any of the ballscrew repair companies on these ballscrews?

It is currently right at about 0.010" of backlash on the X-axis and would really like to get it back to sub .001", but it is still a very old machine and I don't want to spend more than it is worth on 1 ballscrew..

Similar Threads:

• Bridgeport R2E3 BOSS 8 axis limit.
• Need Help!- Bridgeport Series I Boss Z axis stuck!
• Need Z axis ballscrew drive for Bridgeport
• Bridgeport BOSS 6 X-axis Belt
• How To; troubleshoot an Axis problem on Bridgeport BOSS

[mactec54]

Does anyone know of a place to get a replacement X ballscrew for a reasonable price for my Bridgeport Boss 3? If none are available new or used in great condition then has anyone had any luck with any of the ballscrew repair companies on these ballscrews?

It is currently right at about 0.010" of backlash on the X-axis and would really like to get it back to sub .001", but it is still a very old machine and I don't want to spend more than it is worth on 1 ballscrew..

When new they have zero Backlash, they use a C3 grade Ballscrew, the good remanufacturers can regrind and reball the Ballscrew as to like new again, they used mostly NSK Ballscrews for these machines, so NSK could make you a new one also, this would be expensive from them to do this, so if you don't want to spend a lot of money the a rebuild would be the cheapest way to do it, only use a company that can regrind your screw, there are plenty that will just reball your screw, this does not take care of any wear on the screw and nut

I have a new Y axis Ballscrew for that machine but don't have any intention of selling it at this point, I recently sold a Z axis Ballscrew for this machine but have no spare X axis Ballscrews and they would be hard to find in good condition or new

[meanstreakpulle]

Yes, I was aware that it would have had 0 backlash from the factory, I was just stating that I would be fine with sub 0.001" of backlash. The machine is not a high production/high precision machine (as I use it) and I don't expect it to have absolutely 0 backlash. Shoot, the Hilbilly BOB/Mach 3 combination makes the machine slightly unreliable anyway, sometimes it will just freeze up for no reason and you have to power cycle to get the machine to respond again (The computer will be running fine, but no response from machine to commands).

The part that kills me about these ballscrew repair places is what they charge. I work for a large CNC manufacturer and we sell replacement ballscrew assemblies for our machines cheaper than what they want to just "reball' one and ours are high-end zero backlash ballscrews assemblies as well. I was hoping to avoid having to machine something to make one of the ballscrews I can buy from my employer work, although this would net me a new ballscrew that would then be easily obtainable for less than half the cost of just having the factory screw "reballed".

I am still on the fence, I may just reball the original screw for now. I removed the screw from the machine and there appears to be no damage to the screw it's self. I will get the collar off the end of the screw so I can remove the nut and check the internal condition of it. I have reballed older ballscrews before on machines where the control/drive system is obsolete and the screws are no longer available with good results and for very little money.

[mactec54]

Yes, I was aware that it would have had 0 backlash from the factory, I was just stating that I would be fine with sub 0.001" of backlash. The machine is not a high production/high precision machine (as I use it) and I don't expect it to have absolutely 0 backlash. Shoot, the Hilbilly BOB/Mach 3 combination makes the machine slightly unreliable anyway, sometimes it will just freeze up for no reason and you have to power cycle to get the machine to respond again (The computer will be running fine, but no response from machine to commands).

The part that kills me about these ballscrew repair places is what they charge. I work for a large CNC manufacturer and we sell replacement ballscrew assemblies for our machines cheaper than what they want to just "reball' one and ours are high-end zero backlash ballscrews assemblies as well. I was hoping to avoid having to machine something to make one of the ballscrews I can buy from my employer work, although this would net me a new ballscrew that would then be easily obtainable for less than half the cost of just having the factory screw "reballed".

I am still on the fence, I may just reball the original screw for now. I removed the screw from the machine and there appears to be no damage to the screw it's self. I will get the collar off the end of the screw so I can remove the nut and check the internal condition of it. I have reballed older ballscrews before on machines where the control/drive system is obsolete and the screws are no longer available with good results and for very little money.

It's not as easy as that, the Ballscrew in your X axis has a rotating Nut, so would not be easy to change to a regular Ballscrew, sure you can reball if there is not too much wear on the screw

It's not hard to make the control reliable with what is out there now. Mach3 is still fine for what you need just upgrade the control like using a UC100 with Mach3 it will give it a whole new life

[meanstreakpulle]

I'm aware that it has a rotating nut, I have it completely removed from the machine. We use that same style on all of our X and Y axes on the machine we build here at work. The only thing missing from the ballscrews that I have available to me is a flange to mount the timing pulley on to drive the nut and that should be fairly easy to machine. The ballnuts that we use here have a bolt pattern on the side that our timing pulleys bolt to and I could do the same thing to attach the factory Bridgeport timing pulley.

[meanstreakpulle]

It's not hard to make the control reliable with what is out there now. Mach3 is still fine for what you need just upgrade the control like using a UC100 with Mach3 it will give it a whole new life

I don't have any experience with that UC100, I will have to look into it more but it looks to replicate the LTP port by means of USB and adds a "coprocessor"of sorts? I wonder if this would still work with the Hillbilly BOB that is in my machine. The hillbilly BOB works with the original drives and motors and it is convenient in that way. I had been thinking of switching to a Centroid Acorn but then I would have to buy motor drives and so far, all this machine has done is made some small parts and cost me a lot of money, so it's not really justified all that expense yet.

[joeavaerage]

Hi,

I will have to look into it more but it looks to replicate the LTP port by means of USB and adds a "coprocessor"of sorts?

Yes, that is correct. Mach produces numeric trajectory data, and of course Windows is good at that, and a FPGA in the UC100 produces accurately timed high speed pulse streams for the BoB
from that numeric data. This relieves the PC from having to produce accurately timed pulse streams for which Windows PC's are poor.

There are quite a number of very good external motion controllers that work with Mach3 and Mach4, including the UC100. Just beware there are a ton of Chinese fake UC100's out there on Amazon and Ebay,
they are not a patch on the real deal from CNCDrive. Buy genuine or don't bother.

In addition to the UC100 there is the UC300 and UC400 from the same manufacturer, CNCDrive. They have more IO, up to 85 IO's in the case of the UC300 and are Ethernet connected which has
advantages in an electrically noisy environment.

Other worthy choices are the Ethernet SmoothStepper by Warp9TD, the 57CNC by Pokeys, the CSMIO/P from CSLabs and the HICON from Vital Systems. These later two are great quality but start at 600Euro and $600USD
respectively.

There are a number of cheap Chinese external motion controllers...and they work sometimes or even mostly, they have zero manufacturer support, and often only work with pirate copies of Mach3...hard
to recommend.

Craig

[mactec54]

I don't have any experience with that UC100, I will have to look into it more but it looks to replicate the LTP port by means of USB and adds a "coprocessor"of sorts? I wonder if this would still work with the Hillbilly BOB that is in my machine. The hillbilly BOB works with the original drives and motors and it is convenient in that way. I had been thinking of switching to a Centroid Acorn but then I would have to buy motor drives and so far, all this machine has done is made some small parts and cost me a lot of money, so it's not really justified all that expense yet.

You should have detailed all of this in your first post it would have saved a lot of wasted time posting, the Acorn is a great control but if you don't want to spend much money then the UC100 is a good choice

What machines do your company build that uses C3 Ballscrews

[meanstreakpulle]

We build a few different lines of machines, but our 5 axis machines for the aerospace industry would have the tightest tolerances.

[meanstreakpulle]

You should have detailed all of this in your first post it would have saved a lot of wasted time posting, the Acorn is a great control but if you don't want to spend much money then the UC100 is a good choice

What machines do your company build that uses C3 Ballscrews

I should have also said that I do believe we use C3 ballscrews in all of our machines, I just double checked our spec sheet that we require of our ballscrew vendor and it states "Ground Ball Screw C3 or better" as one of the requirements.There are also requirements on the spec sheet for the rating of the angular contact bearings, also that they are to be pre-packed with kluber grease, and the types of seals that must be installed, etc. The specifics of which I am probably not supposed to share.

[meanstreakpulle]

You should have detailed all of this in your first post it would have saved a lot of wasted time posting, the Acorn is a great control but if you don't want to spend much money then the UC100 is a good choice

I also don't mind spending money on it that I feel is beneficial. I was well prepared to pay $1,000 or so for a replacement x-axis ballscrew, but places want that much just to "reball" them, which I think is ridiculous. I can buy an entire Z axis screw assembly which is more than just a ball screw (There's mounting blocks, bellows, the ballnut housing, etc.) at work for much less than that and it's actually longer than the X axis ballscrew on my Bridgeport. I just can't believe how much these ballscrew places charge, maybe I need to raise our prices on replacement ballscrews.

[mactec54]

I also don't mind spending money on it that I feel is beneficial. I was well prepared to pay $1,000 or so for a replacement x-axis ballscrew, but places want that much just to "reball" them, which I think is ridiculous. I can buy an entire Z axis screw assembly which is more than just a ball screw (There's mounting blocks, bellows, the ballnut housing, etc.) at work for much less than that and it's actually longer than the X axis ballscrew on my Bridgeport. I just can't believe how much these ballscrew places charge, maybe I need to raise our prices on replacement ballscrews.

15 /20 years ago, you may have been able to find a Boss3 X-axis Ballscrew for a $1000 used, even back 20 years those NSK Ballscrews where around $3400, it does not matter what machine a Ballscrew is for a quality Ballscrew is going to cost you

We have been selling Bridgeport Ballscrews new for over 3 thousand a piece for the bigger machines, when Bridgeport sold up, we brought everything we could find, some others did also but we then brought a lot of what they had also, we even had some new machines the last new TC3 milling machine we had up until last year.

Here is a photo of one of the Boss3s I build, the horizontal / vertical is the only one in the world that I built which I still have

So, the Ballscrews your company has, if they are from a major manufacture and top quality then they should sell for what the market price is, Quality Ballscrews are not cheap, so a repaired Ballscrew will be gaged off the price of a new Ballscrew, there are very few Ballscrew rebuilds that you can just reball and call it good, most need regrinding and then reballing, and quite often they can be better than new, so a rebuild is worth it if you can't find an alternative to replace what you have.

If you have .010" backlash, then your machine was not looked after very well, normally this means the rest of the machine won't be in that great a shape also, the ways are so important on these machines, to keep them well lubed, they need the lube system upgraded to a high-pressure lube pump

[meanstreakpulle]

That's a good-looking machine. Mine looks to be in fairly nice shape, it's just the X axis ball screw that shows that much wear (It actually has .008" of backlash, but I rounded up). The Y Ball screw shows barely any backlash at all, definitely less than .001". The ways still show factory scraping and are smooth. With the gibs snugged up, the force required to slide the table by hand is even from far left to far right, so there's not a deeply worn spot in the middle or anything. I'm honestly concerned that the X axis wasn't getting lubrication. I removed the oil line before removing the screw and there was no residual oil in the line. My machine still has the bijur oiler mounted on it, but I don't think the previous owner hooked up the electrical portion of it, so I've just been manually operating it each time I turn the machine on. I bought the machine 5 or 6 years ago but I haven't really spent much time on it. I completely rebuilt the vari-speed and put a new motor shaft in it when I got it because it was noisy and someone had put an incorrect key in the shaft which wore out the keyway. I've only made a few various covers for engines and old tractors and made some adapter plates on it, nothing that required extreme precision and the machine managed to do those fine. I could tell it had some backlash on X but didn't really have time to mess with it due to other projects and how busy that work keeps me. Now that I am trying to wrap up some projects around home and looking to get back to working for myself, I want the machine to be a little more accurate, but it's hard to justify spending thousands more on this old machine with no tool changer, yet I still want to make it better. If I intend to make money with a machine I should probably spend a bit more and get something with an enclosure, tool changer and higher spindle speeds, but I am not sure I want to add that amount of expense for an endeavor that hasn't made me any money yet.

We use Umbra ball screws at work and I know the costs for all the items, so the prices I am referencing are not what customers pay for replacement ball screws. But still, the price that we would charge a customer for a new ball screw are close to what these repair shops charge to reball one for such a short screw. I could see reballing an incredibly long screw to save money, but for the shorter ones, like the X and Y on the bridgeport machines, it doesn't seem worth it. We have had customers get their 30ft long ball screws reballed due to the cost of replacing those screws. When we sell a ball screw the price is calculated based on a flat cost for the nut and then so much per mm of screw length.

I am looking to get back to working for myself, It is getting very tiring fighting the struggle every day of trying to get people to work. So many employees are just pitiful but you can't find anyone else to even come in for an interview and we are offering pay rates that I feel are ludicrously high for such simple jobs. I have a decent little machine shop here at home, mainly manual machines and I was looking into taking on some work from a friend of mine that runs a machine shop and is flooded with work, but I didn't want to get into a place where my machine broke down, right when I started to depend on it.

[meanstreakpulle]

I cleaned, inspected, and reballed the screw on Saturday. The X-axis now has less than .0004" of backlash. I could have probably gotten rid of that but I only ordered one set of balls and was anxious to see how it was afterward. I may take it back down later and put one size bigger balls in the X axis, but for now, this is more than acceptable.

[mactec54]

I cleaned, inspected, and reballed the screw on Saturday. The X-axis now has less than .0004" of backlash. I could have probably gotten rid of that but I only ordered one set of balls and was anxious to see how it was afterward. I may take it back down later and put one size bigger balls in the X axis, but for now, this is more than acceptable.

Good job, did your Ballscrew have (2) different size balls, meaning was it using a spacer ball

[meanstreakpulle]

Yes, 2 different sizes. One size was .002" smaller. Original sized balls were .1242 and .1222". I went back with .1248" and reused the .1222" balls as spacers after cleaning them up really well.

[Johns tool room]

sounds like you can reball for some of us guys.