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debequem
08-24-2005, 10:00 PM
I am hot. I just bought some ChiCom table feed for my Bridge port and the damn thing does not fit. The instructions are the worse thing I have ever seen. Might as well be Chinese poetry because at least that would be entertaining.

What is a recommended table feed for a real USA made Bridgeport mill. I don't want to even consider anything made in Asia. I don't care if it is Chinese fried rice.

I've wasted $300 on this piece of crap and 2.5 hours of lost shop time. Hell, I wouldn't even consider cutting off and using the electrical cord on this thing.

hoffman
08-24-2005, 10:06 PM
I'd say a Servo although B'port made some feeds.

MikeHenry
08-24-2005, 10:42 PM
Have you thought about Servo power feeds?

You might reconsider after seeing the price of a new one ($700+?) but the pain is a little less if you find one on sale or take advantage of one of the periodic J&L Industrial 25% off everything-in-the-catalog sales.

Mike

debequem
08-25-2005, 09:14 AM
What is a servo power feed?

knutz
08-25-2005, 09:17 AM
Servo is the name of the feed. Very good feeds but also very expensive as compared to some of the imports.

I've installed a lot of feeds on mills over the years. Never had a whole lot of problems with Servo or the Align brand. Align is an import though at roughly half the price of a servo if you pay list.

jeff

debequem
08-25-2005, 11:47 AM
Jeff,

I might want to ask you a few questions about the "Workhorse" brand I tried to install. I originally thought that the manual was worthless, but after I read it again I decided that it was actually comic relief! I am thinking that it might be there to help the owner overcome their despair when they fail to get it to work.

What confuses me about this power feed is the way that the lead screw bearing is supported. On my Bridgeport the lead screw is held longitudinally in place by two nuts on the outside of the hand cranks. When the nuts are tightened it pushes against the lead screw bearings driving them into the end plate castings until they hit a stop. You adjust the tension until the backlash is minimized and you can still rotate the screw smoothly.

However, on the Workhorse there is no stop for the internal lead screw bearing. When you tighten the handle the bearing simply pushes through the casting. There does not seem to be a way to tighten the led screw so that it doesn’t float or move longitudinally when you turn it.

Also, the ring gear did not slide over the lead screw’s end shaft all of the way. The ring gear hits the shoulder lead screw shaft that contacts the bearing, but the shoulder sticks out about .325” past the bearing. I counter bored the ring gear’s through hole to let the gear slide over the shoulder of the shaft. I can now get the ring gear to engage with the pinion gear, but it ether binds into the casting when I turn the lead screw one way or walks out away from the pinion gear if I turn it the other.

I think this is because the lead screw isn’t sandwiched between the bearings like it used to be.

The only solution I can see is somehow locking the bearing in place or adding a thrust washer between the ring gear and the power feed housing with the necessary shims to draw the ring gear into that thrust washer. I could see counter boring the ring gear such that the thrust washer provides a precision shim to keep the ring gear correctly spaced with the pinion gear. The thrust washer would provide the low friction spacer to keep the rotation of the lead screw smooth.

Another thought is to make a circular pillow block for a radial bearing and modify the power feed housing to replace the needle bearing with a large pillow block. That sounds tricky. The bearing Workhorse uses for the lead screw is a needle bearing, which seems wimpy to me. The Bridgeport uses radial bearings.

The last option is to deep six the Workhorse and buy a Servo or something equivalent. How long should I budget to install the Servo?

Marv

SGW
08-25-2005, 12:19 PM
www.candomachinery.com (http://www.candomachinery.com) sells Servo products. I don't know what kind of deal they can give on Servo power feeds, but I got a great deal from them on an Acu-Rite DRO. (Usual disclaimers....)

rockrat
08-25-2005, 03:52 PM
Sorry to hear about your power feed issues.
We bought a Servo brand mill when they first started importing them. Damn heavy. Takes good cuts, large table fan cooled motor etc.

And... The 3 servo drives that were mounted on it are fantastic. They take a beating and keep working. The only thing that has happened to ours was that the on/off switch on the bottom has broken off and I had to find a replacement.

We have some Enco Super Power feed units on a bridgeport and they are ok. But they don't hold a candle to the Servo brand.

mochinist
08-25-2005, 07:59 PM
I noticed in my J&L flier I got in the mail the other day, that servo power feeds were on sale thru Sep 30th, I dont remember the exact price discount, but it was over a hundred dollars.

kenc
08-25-2005, 11:20 PM
Hmmm, I bought a cheap Chinese "servo" clone off Harbor Freight of all things. The (real) servo on the mill I purchased was shot to hell. I had no problems mounting the drive and it has worked flawlessly - even when this idiot had the table locked down and tried to move the table with the power feed!
I *may* have had to make a sleeve or adapter or two (don't recall) but if you own a mill whats teh problem in that?
Ken

Michael Az
08-25-2005, 11:48 PM
Here is a Servo that just closed out at ebay. I wanted to bid bad, but just couldn't afford it now.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7539742885&rd=1&sspagename=STRK%3AMEWA%3AIT&rd=1
You are supposed to have a chinese mill, then you wouldn't notice how junky the feed is.
Michael

wierdscience
08-26-2005, 12:54 AM
Last Servo I bought was $15 at auction in the bottom of a junk box,it worked pefectly,but did take about 3hours to install like most aftermarket feeds Asian or otherwise.I put a new one on for a shop down the road awhile back and it too took at least two hours to get everything shimed and working right.

Have you looked into the Wellsetting brand? Taiwan,but way better than the Chincom units.I had one last 6 years in semi production.

You may have something amiss with the mill table too thou.Seems like left end of the leadscrew actually bears up on a shoulder in the bearing and is captured with the nut.The feed end should have a set of spacers,then the bearing support,then shims,then the gear,then finally the dial and handcrack.Getting the right shim stack is what takes time.

Also no matter what you end up with,remember to coat(and I mean thin enough to read through)the end of the table with a little RTV silicon gasket glue.That way it doesn't let collant leak and run down the side of the new feeder.

Hope this helps.

debequem
08-26-2005, 02:28 PM
Looking at the pictures for the eBay sale it looks like there is a thrust bearing that rides between the brass ring gear and the casting for the needle bearing for the lead screw.

Can anyone verify this?

The Workhorse version I have looks like a clone of the Servo, except my brass ring gear lacks the counterbores on the gear side and I don't have that fat black spacer (which is what I suspect is a thrust bearing).

All the other parts look very much like the clone I bought.

Marv


<font face="Verdana, Arial" size="2">Originally posted by Michael Az:
Here is a Servo that just closed out at ebay. I wanted to bid bad, but just couldn't afford it now.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7539742885&rd=1&sspagena me=STRK%3AMEWA%3AIT&rd=1 (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7539742885&rd=1&sspagename=STRK%3AMEWA%3AIT&rd=1)
You are supposed to have a chinese mill, then you wouldn't notice how junky the feed is.
Michael</font>

Wirecutter
08-26-2005, 08:49 PM
When I got my Bridgeport, the power feed was there, but the board was gone. The story I hear is that the oil in some of the feed gearboxes could leak down onto the driver board, frying the board. That's probably what happened to mine. So for another $80, I got Minarik drive that works fine with the original motor.

Anyway, if you don't mind a little work, you might want to look for a "fried" Bridgeport drive at cut pricing, and replace the driver board.

quasi
08-28-2005, 12:18 AM
I installed these chinese feeds on all 3 axis of my bridgeport, had to make and modify a few parts. The instructions are useless, I figured it all out by going to Servo's website, these feeds are a cheap Serve clone.

The instructions on Servo's site will help a lot, for instance there are 3 different mounting methods for the z axis feed on a bridgeport, depends on year of manufacture.