Has anyone ever adapted a C&M pickoff to fit a 1 1/4 52 New Britian? We need a reliable solution to back chamfer and back machine a variety of parts on a Model 52 New Britian.
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C&M pickoff
(4 posts) (4 voices)-
Posted 5 months ago #
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I don’t have any experience with the Model 52, but I had a somewhat similar situation on an ACME machine. I'm not sure if this will help you, but this is what we did:
We needed to cut-off our parts and add a chamfer with a specific size & angle to the cut-off end. We had two machines for this job, but neither of them had any back-working capabilities.
We received quotes for upgrading the machines, but they were very expensive so we had to rule that option out. For the first couple months of production, we did the back-working on a secondary operation (drill press & mill). The results weren’t very good; we had parts missing the operation and too much dimensional variation. We needed to come up with something else.
We had a ramp-type tool slide on hand, so we designed a custom carbide boring tool to mount in it. We then went in from the front, through the bore, and cut the recess in the back of the part (before cut-off). When the cut-off tool came through the part, it would intersect the recess, removing part of it, leaving the needed chamfer behind after cut-off.
This isn’t a perfect solution because there is a small cut-off burr left behind, which varies in size depending on the recess angle, tool wear, etc. We were able to take advantage of an operation further on in the process to remove this minor burr.Posted 5 months ago # -
As my experience on the 62's, the best way to make a nice & constant back chamfer on a variety of parts, is by using a Schlitter recessing attachement mod# 58-1 at the same position of the cut-off. I'm not familiar with the 52's, but if your machine work with 125 deg. of feed. The recessing cam muts not exceed 190 deg. total lengh with approx. 4 5/8" stroke. the tool lengh must not exceed 3 1/8" or you'll get vibration. And to eliminate the cut-off burr, the tool should have a strait edge of .010" at the end of the chamfer aligned with cut-off. With this king you can do any thing, chamfer, groove within ±.005"
Posted 4 months ago # -
letitrun, are you looking to do an internal or external chamfer?
Buelldog, I like your plan 'B'. That's a great fix. It reminds me of an illutration in a tooling catalog ( http://www.slatertools.com/davenport17.htm ). The illustration shows the recess chamfer before cut-off.Posted 4 months ago #
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