Pre Model 40, Index Mill

CalebG

Registered
Registered
Joined
Sep 5, 2019
Messages
16
Hi all, I've been interested in machining ever since i started watching Abom79, This Old Tony and AvE years ago. A few weeks ago I saw an Index Mill on eBay for the right price and I brought it home last weekend. Haven't been able to find out what model of Index this is. Numbers on the upper left way on the column read "38 19" Could this be a Index mill from 1938 (the year Index started) and the 19th mill they ever produced? Hopefully i learned a thing or two from all the videos I've watched on machining, but this is the first time I've ever had my hands on the knobs. The machine was in decent condition (I think) but it could definitely use some maintenance, mostly a good cleaning. The table, saddle and knee were loose and the grooves in the ways packed with grease. Screws for oil ports all over the machine had been painted over as well. I'm not planning to do a full rebuild at this point, just clean all the ways, make sure there's no rough spots them, and get all the oil ports clear. Then I'm hoping I can reassemble and see how the machine feels with clean ways and fresh oil. I'm hoping some fine folks on here will be kind enough to point out any mistakes I'm making in this process. This is all new to me so you won't hurt my feelings telling me I'm doing it all wrong. Thanks in advance to anyone reading, and especially anyone lending their advice!

s-l1600.jpgs-l1600 (1).jpgs-l1600 (2).jpgs-l1600 (6).jpgs-l1600 (8).jpgIMG_20190904_181031-2.jpg
 
Hi Caleb
Nice old mill you picked up. Index is still in business and can tell you when it was made. Probably has a Brown and Sharpe #9 taper. My old Index was a good machine and had a table power feed.
Cheers
Martin
 
Thanks! I've contacted Index, they're looking into it. It is a B&S 9 taper. Spindle bore looks a bit rough, but I measured just over a thou of run-out on the side of an endmill holder. I've taken off the table, saddle and knee. Ways look alright. Decent gouge in the left way on top of the knee and another on the left way on the column. The way on the back of the knee also has what looks to be a casting defect in it. I'm guessing this contributed to the gouge in the column, there was allot of gunk in it. The hand wheels had about 90 thou of play on the dials. The lead screws have some wear in them, and the acme thread on the lead nuts is worn so far that it's sharp. I'd like to remake those brass nuts but they're a 7/8-5 acme thread and one is left hand thread. I can't find a tap that size and I don't have a lathe to cut that thread. So I guess I'm just stuck with 90 thou of backlash for now.
 
Here's some photos of the progress so far
IMG_20190904_181155.jpgIMG_20190904_185456.jpgIMG_20190904_185613.jpgIMG_20190904_221918.jpgIMG_20190905_134815.jpgIMG_20190905_134825.jpgIMG_20190905_134859.jpg
 

Attachments

  • IMG_20190905_134908.jpg
    IMG_20190905_134908.jpg
    62.3 KB · Views: 11
  • IMG_20190905_134937.jpg
    IMG_20190905_134937.jpg
    56.2 KB · Views: 9
  • IMG_20190905_134944.jpg
    IMG_20190905_134944.jpg
    54.3 KB · Views: 10
  • IMG_20190905_135030.jpg
    IMG_20190905_135030.jpg
    61.7 KB · Views: 9
1. You're staying organized.
2. You've bought a big thing of the correct cleaning supplies, right? :)
3. If you intend to make any new parts(replacing your acme thread nuts, etc.) take accurate measurements now! So, when/if you ever make them you won't have to disassemble the machine again just to take some measurements.
4. Switching to the proper way oil and removing the pounds of dried grease will make a world of difference. I'm sure there is a good bit of runout when compared to brand new. However, over time you will get to know the machine and could still make some decent parts.

Keep up the good work.
 
I'm sure there is a good bit of runout when compared to brand new. However, over time you will get to know the machine and could still make some decent parts.

Keep up the good work.
[/QUOTE]
I agree. Some of my favorite machines had a lot of wear. They still made good parts. Index made a good mill.
 
I definitely need to pick up some more Scotch-Brite and brake cleaner (I believe those are the correct cleaning supplies). As this mill is around 80 years old I'm planning to do all the cleaning by hand. Making replacement parts is probably a ways out. I have no lathe to cut threads and they don't seem to make 7/8-5 ACME taps, especially not left hand ones. But measurements are a great idea, thanks! I took this opportunity to continue learning Fusion360. Each nut took probably 3 hours to model. These were the second and third parts I've ever modeled in CAD.
Saddle Lead Nut Drawing.jpg
Table Lead Nut Drawing.jpg
 
I definitely need to pick up some more Scotch-Brite and brake cleaner (I believe those are the correct cleaning supplies). As this mill is around 80 years old I'm planning to do all the cleaning by hand. Making replacement parts is probably a ways out. I have no lathe to cut threads and they don't seem to make 7/8-5 ACME taps, especially not left hand ones. But measurements are a great idea, thanks! I took this opportunity to continue learning Fusion360. Each nut took probably 3 hours to model. These were the second and third parts I've ever modeled in CAD.
View attachment 301587
View attachment 301588
Nice!! I love Fusion360. How's that saying go, "A man with a plan...".
 
Google search Evanut basically you thermoform delrin around your lead screws to make new nuts . Worked awesome for me and I was able to get the backlash on my 40h down to around .005 on the x and y axis .
 
Google search Evanut basically you thermoform delrin around your lead screws to make new nuts . Worked awesome for me and I was able to get the backlash on my 40h down to around .005 on the x and y axis .
That is a very clever way to make a custom nut! Did you make an entirely delrin nut, or put the delrin thread into a piece of metal that bolted to the table and knee?
 
Back
Top