Ulma Doctor

Infinitely Curious
Registered
Joined
Feb 2, 2013
Messages
3,539
I have a vintage/antique Brown and Sharpe 4-1/2" indexing center that suffered an injury before i got it.
FullSizeRender_7.jpg

the spring loaded indexing pin was broken :oops:
so i decided to construct a replacement from 303 stainless steel, just because i have a lot of scrap stock waiting to be reclaimed and into something useful,
like this :grin:
IMG_2714.JPG
for the record, it was not my 7 yo son's drawing, sorry it was my shop hieroglyphics :grin big:

i took a 20mm x 3.5" long piece of 303 stainless and faced and centerdrilled the stock to be turned between centers.
but that means that i needed{wanted} to make a soft center for my 3 jaw chuck with a dog driver built in.
it was constructed from what i believe to be some 1141- (i have no proof, only conjecture.)
after i completed the soft center, i was able to put the slug between centers and start the reduction process.

here is a live action shot of the shaft reduction.

IMG_2712.JPG

it measured out to .380" rough in the center and .260" for the thinner sections
IMG_2713.JPG
that means that i removed a total of .606" of material for this insanity :rolleyes:
sure i could have chosen a different material to use that was closer to the actual diameter, but that would have not giving me what i was after,
i'm looking to gain some quality time on the machines after spending time upgrading them!


coming soon, ACT 2- the reduction continues!!!
same bat time, same bat channel!
 
Last edited:
latest work:
here is a live action shot of the tool post grinding of the shaft blank

tpg shaft.jpg
this is the maiden voyage for my Dumore tool post grinder, that was graciously given to me by a good friend and forum member BFD
Thanks Bill!!!
the tpg worked well at .001" passes
 
i did some more tool post grinding...
IMG_2741.JPG IMG_2742.JPG

and further ground the shaft, shaping the .125" point

IMG_2743.JPG

now comes the dimension checks! .125" , .250",& .375"
IMG_2744.JPG
IMG_2739.JPG
IMG_2737.JPG

FullSizeRender_1_2.jpg
 
Last edited:
well i finally got the pin done
FullSizeRender_5.jpg

i made a shop made external lap from some scrap 6061 aluminum and reamed a hole to .250" and lapped the pin shaft
FullSizeRender_3_1.jpg

i used wd40 and scrapings from a sanding sponge to do the lapping work.
i held the pin loosely in a handheld drill and lapped with the homemade slurry

FullSizeRender_1_3.jpg


IMG_2749.JPG IMG_2750.JPG

i drilled the OEM handle and tapped it, and the newly made pin to 1/4-20 tpi and assembled with red locktite

FullSizeRender_6.jpg

and the final assembly and testing!

FullSizeRender_1_4.jpg


Operation is Excellent!!! :grin:


As always, thanks for reading!
 
you are welcome ulmadr glad to see it used. although .001 a pass is a bit much but if it worked ok. If you turn your compound to 30 degrees you get .0005 per .001 feed bill
 
Back
Top