adjusting back lash

[BeeleJuice]

i need some one to help direct me to the manual for adjusting the backlash on the stock acme threads. i know i read it some where but i forgot to save the pdf to my computer. im hoping to try to get it within .005. if someone has time by the end of the week i would appreciate it. thanks

[widgitmaster]

any specific machine, or backlash in general?

[Hood]

I have my Bridgeport manual scanned, you will find it here http://mysite.wanadoo-members.co.uk/...ges/index.html it covers basic operation and maintenance and also has good parts section.
Hood

[greg b]

if it is a conventional mill you will find a flange on the lead screw under the table there are generaly 3 screws that you can tighten to compress the flange against the lead screw bronze nut that takes up the back lash. be careful not to tighten to much because when you wind the table to its extremeties it will go tight because the lead screw wears after time.the other flange is behind the handle and dial on crossfeed,you will also need to remove the small plate that bolts on to the knee use the same ajusting proscedures as x hope this helps greg

[BeeleJuice]

thanks guys, exactly what i needed to know.

[chevdrgtrk]

I just did mine last night......went from .030 to .007 on Y, and .020 to .003 on the X and the X seems to move alot easier, and smoother now.

[chevdrgtrk]

I guess I should have included a little instruction with that. You are going to loosen the 2 smaller screws on each side of the bigger screw, then tighten the big screw till it's just barely snug, then loosen about a degree or 2, then retighten the 2 smaller screws, and you are done, be sure not to over tighten the big screw as it will be hard to move the table, and cause premature wear on the screw, and nut. you might want to do all this in the middle of the screw where the wear is the most, it will make it a little harder to move the table on each end of the screws depending on screw wear, but your tolerances will be closer where the table is used the most.

[BeeleJuice]

yes i was looking at that today and havent got a chance to do anything yet. but i only saw one (1) baby screw next to the big one. but im sure i wasnt looking hard enough. is there 2 baby screws on each side of the big acme thread lead screw? i also have 2 other issues. you guys seem to be knowledgable. my quill tightening/ lock mechenism doesnt lock. its like its too loose and need to be adjusted or something needs to be replaced. like when your milling so the quill qill stay and not feed down. today i was trying to mill a 1/8 chamfer at 45 deg. it was slipping down and it started comming bige and bigger. luckaly i had enough material to redo them. my other problem is, i have a manual feed box. but it seems to only feed at a rate of 2inches per min. way to slow with flood coolent. i think there is a lever missing on it to make it shift left to right. am i right or was there some that only feed to the left? LOL what a POS im working with. i need these answerd pretty badly if anyone can help.

[BeeleJuice]

oh and i guees my third question is. is there a new feed box i can get to replace this one? one with an adjustable feed speed? maybe feed up to 5-10 in. per min. i know i have seen them. this feed box i have is soo big they say it warps the table, and there has to be truth to it because this thing is massive. i dont even know how to replace a feed box. is there any links you guys know of?

[widgitmaster]

Search eBay for x-axis power feed, $175-$375
The kits will just bolt on!

[chevdrgtrk]

some mills might only have 1 smaller screw on them, I have seen exploded views on some, and they are only showing 1.........these smaller screws only lock the bigger screw in place once you get it adjusted the way you like it. I agree with widgitmaster, e-bay is one of the best places to find stuff like that, but there are several other places you can look www.wttool.com www.mscdirect.com www.grainger.com www.travers.com if you don't do anything with these sites, atleast order a catalog from each, they have some really great stuff in them. I will do some checking on my mill on your other questions, and get back to you as soon as I can.

[chevdrgtrk]

ok, I ran out to the garage, and if your mill is anything like mine the quill lock is an easy fix.......mine is a spring loaded lever, tighten your lock as far as you can without overtightening it, pull out on the lever and rotate it backwards and let it drop back into one of the positions, you will want to play with it till you get it where you want as there are many positions it can sit in, hopefully this will help you out.