Colchester CHIPMASTER taper attachment-Finished!

All discussion about lathes including but not limited to: South Bend, Hardinge, Logan, Monarch, Clausing and other HSM lathes, including imports

Moderators: Harold_V, GlennW

Post Reply
wally318
Posts: 171
Joined: Sun Jun 05, 2011 1:06 am
Location: Kelowna, British Columbia

Colchester CHIPMASTER taper attachment-Finished!

Post by wally318 » Thu Jan 28, 2021 12:07 am

For now I'll just post a couple pics that I had to take now or the opportunity
would have been lost.
I'll expound and or answer questions later on.
Attachments
P1040316.JPG
P1040318.JPG
P1040317.JPG

wally318
Posts: 171
Joined: Sun Jun 05, 2011 1:06 am
Location: Kelowna, British Columbia

Re: Colchester CHIPMASTER taper attachment-THE making of

Post by wally318 » Sun Jan 31, 2021 3:55 pm

Here's a bit of background for the 1st 3 pics.
To start I used 1 x 3" CRS
squared up the ends to 4 inches and
milled the top to 15 degrees to mate with the underside of the
saddle and help to hold the part in good alignment when drilling
and tapping holes into the pad on the bed.

The parts were then put into the 4 jaw and leaned the same 15 degrees
and bored to accept 1.5" CRS-length was determined by full swivel of
the slide bar and enough room for cross slide movement/staging.

Next the blocks were drilled 5/16" and then mounted on the bed of the
Chipmaster, under the carriage with a 1/8" parallel as a spacer, to help keep both sides
even and clearance. The blocks fit under the carriage like a glove.
They were held in place with a large C clamp while drilling.
After all holes drilled the block holes were opened to 25/64"
and remounted on the lathe. The bed was now tapped with the blocks in
place as a guide, for 3/8-16 bolts.

wally318
Posts: 171
Joined: Sun Jun 05, 2011 1:06 am
Location: Kelowna, British Columbia

Re: Colchester CHIPMASTER taper attachment-THE making of

Post by wally318 » Sun Jan 31, 2021 4:06 pm

Next I mitered the back ends of the 1.5" CRS bars
for more material insertion into the blocks and to get
an even length from lathe bed to the ends.
The bores were just a tad on the loose fit so I
did a bunch of center punches and then pressed them
into the blocks. Measuring them they were about .001"
difference between the 2.
Next they went for welding. I ring around the front
and an inch in the pocket at the rear.

With the blocks welded on I was able to line up the 15 degree pads
in the mill and milled the ends of the 1.5" rods to form a key, for
positive alignment with the slidebar assembly.

During this week at work I hope to mill the underside of the slidebar to fit the keys
and drill/tap the rods/slidebar for bolts.
Attachments
P1040319.JPG
P1040320.JPG

Russ Hanscom
Posts: 1883
Joined: Wed Mar 15, 2006 11:10 pm
Location: Farmington, NM

Re: Colchester CHIPMASTER taper attachment-THE making of

Post by Russ Hanscom » Mon Feb 01, 2021 12:25 pm

Please, the ultimate destination first. I have trouble following making parts and only revealing the full project at the end.

wally318
Posts: 171
Joined: Sun Jun 05, 2011 1:06 am
Location: Kelowna, British Columbia

Re: Colchester CHIPMASTER taper attachment-THE making of

Post by wally318 » Mon Feb 01, 2021 7:59 pm

I'm sorry, am I missing something?
I was under the assumption that the title referred
to the making of a taper attachment for a Colchester Chipmaster lathe.
I only put Chipmaster first to attract attention of Chipmaster owers.

wally318
Posts: 171
Joined: Sun Jun 05, 2011 1:06 am
Location: Kelowna, British Columbia

Re: Colchester CHIPMASTER taper attachment-THE making of

Post by wally318 » Sun Feb 07, 2021 2:41 am

So we're getting close to complete now.
Pic 1 is the underside of the slider bar-base milled to mate with the support brackets,
and holes drilled and tapped.The swiveling slide bar assembly is from a Sheldon lathe
from the 40's or 50's.
Pic 2 is the slide bar shimmed and bolted down. The assembly is extremely rigid.
The base bar is parallel to the lathe ways within .002 both horizontally and vertically.
Also the swivel/slide bar has been added. The swivel bar has had the curved slots
extended and a couple extra tapped holes added to each end of the base bar to
increase the taper range to 17-1/2 degrees either way.
Pic 3 is the cross slide adapter made from 1/2 x 10" 6061 and drlled to mate with
existing holes in the cross slide-the Chipmaster has lots of holes.
The 1 bolt sticking up a bit is on account of a slight miscalculation in hole
layout. So is filed out to allow the bolt to fit. Will add some epoxy and re-countersink
later.
Pic 4 is the underside of the slide block.
The tapered gib was missing, so made a new one in bronze.
Quite simple really. ~It's only tapered in 1 direction.
It slides beautifully.
The hole has been opened with a step bore to accept
the adapter stud. Thats the pc. sitting beside it, which
I'll fit tomorrow and then give it a test run.
Attachments
P1040321.JPG
P1040323.JPG
P1040322.JPG
P1040324.JPG

wally318
Posts: 171
Joined: Sun Jun 05, 2011 1:06 am
Location: Kelowna, British Columbia

Re: Colchester CHIPMASTER taper attachment-THE making of

Post by wally318 » Sun Feb 07, 2021 8:08 pm

The taper attachment is NOW FINISHED.
Pic 1 is if the completed and installed drive stud for the slider block
Pic 2 is of everything assembled and in place the slide block connects to
the cross slide bracket with a 1/2-13 button head bolt.

I did full mock up tests with hand feed and power feed
with slide bar set at tapers of 1 and 4 and 8 and 17 degrees.
Couldn't discern significant increase in drag towards the limits.

Pic 3 is a 20 thou cut with fairly high feed rate on 1-1/2 6061 aluminum.
The taper is at 16 or 17 degrees.
Attachments
P1040329.JPG
P1040300.JPG
P1040331.JPG

wally318
Posts: 171
Joined: Sun Jun 05, 2011 1:06 am
Location: Kelowna, British Columbia

Re: Colchester CHIPMASTER taper attachment-THE making of

Post by wally318 » Sun Feb 07, 2021 8:11 pm

Got wrong pic in #2 place.
Attachments
P1040330.JPG

Russ Hanscom
Posts: 1883
Joined: Wed Mar 15, 2006 11:10 pm
Location: Farmington, NM

Re: Colchester CHIPMASTER taper attachment-Finished!

Post by Russ Hanscom » Sat Feb 13, 2021 7:06 pm

Interesting, If I understand the pictures correctly, the rail assembly is mounted to the side of the lathe and not to the actual carriage. No reason why that should not be perfectly functional.

I also used a non-dovetail rail on the one I made, with an adjustable gib, and it worked quite well.

Enjoy.

wally318
Posts: 171
Joined: Sun Jun 05, 2011 1:06 am
Location: Kelowna, British Columbia

Re: Colchester CHIPMASTER taper attachment-Finished!

Post by wally318 » Sat Feb 13, 2021 8:46 pm

It works VERY WELL, thank you.
as I posted it was cutting under power a 17 degree taper, or 34 degree included angle w/o any binding.
After that I decided to cut a morse taper 2 just for kicks. It would have been a #3 but didn't have any
1" lying around so 3/4" gave a #2. I found a chart that said 1.49 degrees.
So I set the slide bar to 1.5 degrees by eye, knowing that the slidebar was within .002" of parallel
I knew it would be quite close.
I took several 10 thou passes to see the advancement of taper length.
When I got to full length- 2.5 inches, I measured the major/minor diameters and I was 2.25 thou
off per side so taking a measurement of the slidebar it was 6 and something inches from the pivot
to the end. Which translated to a .0061" movement of the slidebar using an indicator.
1 rough cut did it and 1 fine pass and a minute or 2 with some 320 grit paper and I had a MT2 that fit
as good as the dead center that I took the measurements from.

User avatar
liveaboard
Posts: 1594
Joined: Sun Dec 08, 2013 1:40 pm
Location: southern Portugal
Contact:

Re: Colchester CHIPMASTER taper attachment-Finished!

Post by liveaboard » Sun Feb 14, 2021 2:42 pm

Nice work.

Post Reply