I Need a Yoke (and/or dims) for a Bridgeport
I am looking for a heavy XY nut bracket (yoke, dog bone) for a Bridgeport. I would also like to get a dimensioned print for same.
Any ideas? I have checked E-bay - they always seem to be available until I need one.
Do any of you have one you'd like to unload? How about a print?
Scott
Long read - sorry. Could use a hand here....
Thanks for the reply, JD. I recall you installed rolled Rockford screws, right? Do they offer ground screws - just for price comparison - or only rolled? I am not stuck on ground - depends on the cost difference.
If you have gone through the ball screw thing for a BP - please read this and help me choose a direction, would ya? Many, many thanks.
I realized last night that a stock yoke would not work for what I was planning so now I am in a serious debate here.
I have a perfect NSK ball screw assembly to fit the table but I would have to shorten it a few inches and machine and grind one end, then modify the table mount and yoke. I have the capacity but it would tax my equipment and set-up would be a challenge. I also have a very stout THK ball screw assembly for the saddle but the same holds true - lots to modify and machine. These screws were not made for the BP mill - they are out of industrial equipment that was recently scrapped where I work but both are .200" pitch and appropriately sized for BP use - I lucked out, but they are not drop in replacements. I have three screws total - all are complete with thrust bearing mounts on one end (very similar in size to the standard Bridgeport mounting arrangement but with 4 bearings in a self-contained housing - nice) and appear to be in very good to excellent condition - they were in a clean room environment.
After reviewing all that's involved, I think it's going to be too much time and too much trouble to make these screws fit the BP correctly. I would have to fabricate a yoke from scratch and while this would be possible, it's a lot of high tolerance work and requires tearing down the mill and getting measurements then re-assembling the mill to do the machining with some outsourcing likely. The cost of getting the screws I have to work would likely be more than just buying a set or a kit ready to go.
So - I am searching for a ball screw retro kit.
The players for a complete kit are:
Rockford
Hiwin
Elrod
Nook
Roton (I don't think they make a kit, though??)
McMaster (looks like Mcmaster sells Rockford screws)
Wedin
Rockford is the only one that has replied to me so far. Currently waiting for a quote from my local supplier - Motion Industries.
Hiwin stuff sounds good but you have to jump through hoops to get info - why cant these people make their products easy to understand and purchase? Should I bother with the tricks to get info? (you have to fax them on a form that has absolutely nothing to do with Bridgeport retro-fit kits - why can't they handle a simple E-mail? Is that really all that difficult?)
I saw the Elrod yoke but I think their website stinks for info and I can't gather enough info to feel warm and fuzzy. They have not replied to my direct questions, either. I think I would really like to have the Elrod yoke - it appears MUCH stronger - and they offer ground screws with an attractive accuracy claim - but their sluggish response and cruddy web site has me a bit concerned. I do think they are the front runner right now, but I want to see their quote. I am leaning towards going with them. Maybe I should place a call....
I have requested info from Nook - no response at all yet.
It looks like McMaster carries Rockford - is that correct? $650 for a set of rolled screws and a yoke - ready to bolt in.
Wedin - claim to have a kit, but no info on their site. I e-mailed them but no reply yet.
Are there others I should investigate?
Rolled for me would likely be fine - as long as I can get rid of backlash so that I can profile and pocket without all the issues from backlash. I intend to use the machine to cut injection molds in the very near future (if possible) so accuracy is a requirement.
If I am going to spend close to $1000 for screws, I would be tempted to throw a bit more in and get the best stuff I can at the moment.
Thanks for the shoulder, guys. I needed to get all of this off my chest! I feel better now.....
:wave:
Scott