[fast89]

I'm kicking around the idea of putting some ballscrews on my 9x42 Bridgeport, possibly for a future cnc conversion but for now, just to fix some worn nuts with no more adjustment. Mcmaster sells a kit for $700 for both screws with nuts and the yolk. Mcmaster's part number is 29995A74. Pretty cheap for a bolt in deal. Accuracy is stated as +/- .003" per foot. Anyone use this or have any input on it?

[machintek]

Must be rolled and not ground ball screws. I hope you have a DRO. In theory you can be off up to .009 inches over 36 inches. But if you have ever felt a S1STD with ball screws, they glide! Just do not climb mill unless you are very careful.

George

[fast89]

Affirmative on the DRO, can't live without it. I was kind of wondering what ballscrews would do to the tables ability to hold a position.

[Mel White]

I have precision Ground Ball Screw kits for your mill accuracy .0005 per foot.
$825.00 complete.

Mel White

[NC Cams]

spend the money - get the ground ones. You'll NEVER use an acme or rolled screw after using a precision ground one. BTDT.

Want deadly accuracy? Replace the ball screw bearings with H prelaod AC's. BTDT as well.

Hint 7204A5TYDUH plus custom spacer for outer rings - available from MC as outer ring preload washers. No need for ABEC 5 or 7, Generic 7204A5's 's can be preloaded by KAF Mfg in Stamford CT.

You'll never have to chase backlash again if you do it all right, right now.

[DareBee]

Uh - guys.
This thread is almost 2a old.

Good info though

[bearracecars]

hey mel white
do you have more info or a place to find info on your kits?
bear

[79TigerPilot]

Mel,
Can you give me more information, I am currently searching to buy a ball screw conversion for my Bridgeport J-Head I am converting to CNC.
Do you have a web site etc?

Craig

I have precision Ground Ball Screw kits for your mill accuracy .0005 per foot.
$825.00 complete.

Mel White

[Mel White]

Mel,
Can you give me more information, I am currently searching to buy a ball screw conversion for my Bridgeport J-Head I am converting to CNC.
Do you have a web site etc?

Craig

I have spent the last fifty years in the importing and manufacturing of Machine Tools. A large portion of this time has been the manufacturing of CNC machines. I recently sold my company (AMERITECH CNC) and have a few items that I kept to give me something to do mostly Ball Screws. I have 30MM diameter X and Y ball screws that are industrial grade machined and ground on both ends of X and one end on Y. Same dimensions on the ground surfaces as your existing screws. These are precision products with the accuracy of 0.0005 per foot non accumlative. A set consists of the X and Y ball screws with ball nuts plus the Yoke. These are made in Taiwan by an old friend of mine and are excelent quality I have used hundreds of his products in our machines.The price for the compete set is $825.00.

I also still have a few sets of X and Y castings all machined ready to bolt on the end of x and the front of y. These fit directly to the existing mounting holes on your machine and come complete with pulleys,belts and precision angular contact bearings. These castings are built for Nema 34 motors.
$ 450.00 for the complete package. If you are interested I can forward photos to you. I can give you advice as needed if it would be helpful to you.
Mel White [email protected] 702-443 4447

[nate]

Well, I just bought a set with mounts from Mel.

My money is on its way, I hope to get the kit soon.

Anyone else purchase a set?

[nate]

Well, I just bought a set with mounts from Mel.

My money is on its way, I hope to get the kit soon.

Anyone else purchase a set?

[polaraligned]

Mel, any motor mounts for the knee?

[nate]

Well...my ballscrew kit arrived yesterday!

I will admit that I was a bit nervous sending money orders to a stranger in Vegas, but Mel is a straight shooter. He shipped fast, gave me tracking info and even mailed me a paper invoice a few days later!

I am still waiting on my mounts. they needed to ship from storage at another location.

The ballscrews are very nice. They appear to be very well made. As a Grinderhand, I can tell you that the bearing journals were ground to very precise fits, with good finishes. Both screws came with inspection reports in plastic folders.

I am quite pleased with the ballscrews, and just as pleased with Mel's service. He always answered his phone, and emailed me pictures and tracking info in a timely manner.

I would order products from him again!

Nate.

[79TigerPilot]

Nate,
I picked up my set of screws from Mell in Vegas two weeks ago, they are very nice screws. Mell is a real nice guy who has been in the machine tool business for many years. So far the only thing I have had to do is widen the 3mm key slot to 1/8". As far as I could tell the Y nut flange bolts to the rear side of the yoke. For the life of me I couldn't figure out how I was going have access to tighten the bolts. But if one removes the front bearing mount and slides the saddle and chip shields all the way forward you can reach the back of the yoke from above. Would have had them installed by now but been waiting on some lubrication tubing.

Craig

[nate]

yeah, the rear mounting did not make sense to me either. I ended up continueing the threading through to the front of the yoke. I checked parallelisim of the front and back surfaces of the yoke and they were within a few tenths.

My screws are mounted with the original bearing mounts till tuesday when the cnc mounts arrive from Mel.

I am also waiting on some lubrication tubing before I can do the final mounting of everything.

This was a great reason to pull the table and saddle off my machine and get everything cleaned up really well, blow out the lube passages etc... I was amazed how much **** accumulated under the saddle in the knee casting. I had a quarter bucket of oily chips in mine.

I also took the opertunity yesterday to build marine vinyl way covers. I am not getting chips and swarf into my brand new ballscrews!

How were you planning on running your lube lines to the ballscrews? I did not see any lube ports on them... I was thinking about using copper line for the ballscrews (which i ordered just in case) and just positioning the line over the screw right next to the nut, dripping on the screw essentially...

[79TigerPilot]

nate,
There are three small holes in the outside edge of the ball nut flange, the smaller hole is the oiling hole and a piece or 4mm poly tubing fits in there nice and snug. I think the other holes are set screws to secure the flange to the base nut. I am running oil to both nuts using two #1 metering unit, I hope is not going to be too much oil.

Nice to know the yoke is ture. I installed a couple of roll pins and mounted the yoke in the saddle (saddle is off the mill and on the bench) and test installed the Y ball screw. There is a lot of slop (adjustment room) in the ball screw flange screw holes. Not exactly sure how I am going to make sure it's aligned true with the front AC bearings.

This was a good test because I discovered that you can't install the yoke in the saddle and then put in the X-screw on, as I had planned. The screw will need to be in the yoke first then the yoke bolted down. The flange screws can be tightened later.

I need to do some way covers as well. I was looking at some Hypalon, which should work very well and is oil resistant. Its what they build river rafts from and is available from: http://www.nrsweb.com/shop/product_list.asp?deptid=1034

Would really like some three surface pleted covers but after buying the ball screws the funds are gone. I may try to sew some up from the Hypalon. Pictures of my mill project: http://picasaweb.google.com/cschaffter/CNCMillProject#

Craig

[nate]

interesting...too much oil to the ballscrew? are you thinking that it might cause heating from the churning of the oil?

I was going to run FJB2's for my screws...

[79TigerPilot]

Nate, I don't think there is any harm just the mess of all the dripping oil.
The only other issues with too much oil would be if the screw wipers or the oil line were forced out by hdyraulic pressure, but this is unlikely.

Craig

[broussard]

Always get the Precision Ground to an accuracy grade of C4 class .0005/ft .The ballscrews has a hardening hardness of HRC 58-62 The Ballscrews

[broussard]

I have precision Ground Ball Screw kits for your mill accuracy .0005 per foot.
$825.00 complete.

Jeff