Need recommendation on "precision" spec for mill lead screw

C

Chrisw

Aluminum

Joined

Mar 29, 2010

Location

Utah USA

• Sep 12, 2015

• #1

I am thinking of replacing the table lead screw on my ExCellO 602 mill. Parts are unavailable, as far as I can determine, using internet searches. My only option, as far as I know, would be to buy some acme rod and machine the ends for my application.

What would be the recommended precision to spec out when looking for material? Is .003"/ft precise enough for most mills or is something more precise recommended?

I need a 5 foot piece of 1''- 5 RH. Does anyone have a favorite supplier for something like this?

Also, what material would be recommended? I have seen stainless steel (don't know which grade), 1018 steel (wouldn't wear well in my opinion) and 4140 (I think would be my choice)

Thanks
Chris

 

Peter from Holland

Diamond

Joined

Jan 15, 2005

Location

The Netherlands

• Sep 12, 2015

• #2

If you have a DRO accurracy is not that important
I have a supplier nearby that can whirl those leadspindles
You ship the old one and they ship you a new one
Price is not that bad Perhaps there is one in your area too

Peter from Holland

 

gbent

Diamond

Joined

Mar 14, 2005

Location

Kansas

• Sep 12, 2015

• #3

For Acme threaded rod I have had good luck with Green Bay Manufacturing.

As peterve posted, put a dro on it if it doesn't have one already. It makes the mill more usable as well as negates the lead screw accuracy issue.

 

W

wesg

Titanium

Joined

Nov 4, 2004

Location

Cedar Park, TX - Boulder Creek/Redwood City, CA

• Sep 12, 2015

• #4

I've heard of them being reground, and undersize nuts made. Probably a lot more practical for a Bridgeport, where the cost of a custom tap would be recovered in time. But this seems reasonable to single point anyway.

 

JHOLLAND1

Titanium

Joined

Oct 8, 2005

Location

western washington state

• Sep 12, 2015

• #5

I have very precise ground lead screw in stock

check this ebay ad

Metric Lead Screws 1 5 Meter Length | eBay

 

S

shamanj

Hot Rolled

Joined

Apr 18, 2013

Location

Australia

• Sep 13, 2015

• #6

+10 on DRO. Best investment ever. Could, but wouldn't want to live without it now.

 

Forrest Addy

Diamond

Joined

Dec 20, 2000

Location

Bremerton WA USA

• Sep 13, 2015

• #7

This do you?

1 - 5 Right Hand Acme Lead Screws & Nuts for Power Transmission - Roton Products, Inc.

Hows about this?PowerAC 1"-5 RA | Nook Industries

Lots of sources. MSC, Enco, McMaster, Google "lead screw? or "Acme threaded rod." You have to winnow out some choices and resist high precision grades and cheap home center rack material. Somewhere in the middle of cheap and precision is about right. Few people dial off long distances on a lead screw shooting for a precise movement. 0.003" per ft is plenty accurate for 99% of your work.

 

Spinit

Titanium

Joined

May 13, 2007

Location

Central Texas

• Sep 13, 2015

• #8

I think you are doing good shopping around for one as they are something people most anyway do not cut everyday. I remember some old timers I learned from in my young times a lot of stuff and helped and watched while they made another table screw for the Bridgeport. They heated and poured Babbit in for the nut connection if memory serves me well. Anyway it was damn amazing. They did not have any stinkin DRO's and if they had I am sure would gladly have put them on and used them for sure. Good Luck with the replacement.

 

JRIowa

Diamond

Joined

May 27, 2003

Location

Marshalltown, Iowa, USA

• Sep 13, 2015

• #9

Spend your money on a DRO and don't worry about the screw. The nut is probably worn way more than the screw anyway.
JR

 

C

Chrisw

Aluminum

Joined

Mar 29, 2010

Location

Utah USA

• Sep 14, 2015

• #10

Thanks to all those who commented, but THANKS to Forrest Addy who actually answered the question.

Forrest..I did come up with those vendors also, but was wondering if anyone knew of others. You confirmed my thoughts of .003"/ft as being adequate. Thanks.


DROs are nice, but so is a tight screw.

 

michiganbuck

Diamond

Joined

Jun 28, 2012

Location

Mt Clemens, Michigan 48035

• Sep 14, 2015

• #11

Thread Craft Has been a best source for years. Tell them the machine you have and they likely have the print on hand. Quote likely over the phone in five minuets
43643 Utica Rd, Sterling Heights, MI 48314
(586) 323-1116

Making from threaded rod you still have to cut a thread or two,turn a step diameter or two add a key ways.With making you might redesign the nut to have a bit of take up

You can post the price quote so we all know the current rate.

“[.003"/ft precise enough]” You can measure and find like we did on all the wore out mills but better dial in to close. Yes DRO is good also.

 

JRIowa

Diamond

Joined

May 27, 2003

Location

Marshalltown, Iowa, USA

• Sep 14, 2015

• #12

Chrisw said:

DROs are nice, but so is a tight screw.

Click to expand...

How about the nut? Are you going to have one made. The later Ex-Cell-O mills had a plastic nut. 0.003"/ft for accuracy? You got to be kidding me, that's milled or whirled accuracy. Probably 1/10th that for a new mill.

We used to use these guys for the big stuff: Rolled Threads Unlimited ? LEAD SCREWS
They did a 7" dia acme screw for me in 4140.

If you want the same precision that your mill had new, than go here:Acme Lead Screws - Acme Lead Screw Reconditioning | Barnes Industries, Inc.
They'll do 0.0005" cumlative!

Don't forget to get a matching nut since you want a tight screw!
JR

 

C

Chrisw

Aluminum

Joined

Mar 29, 2010

Location

Utah USA

• Sep 14, 2015

• #13

JR

Thanks for the lead on the screw source. Yes, a new nut is definitely on the agenda. Like you said, it would be worthless to not get a nut with the screw. (Could this thread be considered pornographic?)

Chris