How to machine this

[SignalFailure]

How can I machine a nice chamfered slot like the one in this cross-head guide? The only way I can think of is by milling a slighly shorter length with each longitudinal pass but that would be very tedious ;D

http://www.stationroadsteam.com/stock pages/2784/pages/2784-d.htm

 

[lugnut]

Paul, I'm not a machinist,(not even close) but it would appear to me that if you put the tube in your mill vice and then come at it with the side of a larger mill cutter and procede the length of the slot. you would get the effect your looking for.
Mel

 

[te_gui]

A ball end mill would give you that look if you could handle a slight radius on the flat. You can also get 90 degree chamfer end mills.

Brian

 

[Foozer]

How can I machine a nice chamfered slot like the one in this cross-head guide? The only way I can think of is by milling a slighly shorter length with each longitudinal pass but that would be very tedious ;D

http://www.stationroadsteam.com/stock pages/2784/pages/2784-d.htm

I'd like to know myself, left end looks like a round cutter, ball shape travels to the right, but then the pic gets fuzzy. Doesn't have the smooth radius the left does.

If I was to try that I'd probably make the initial slot first then use a ball type cutter to get the chamfer, then stick it on the shelf as another great idea that didn't quit work.

 

[lugnut]

I had to go out to the shop and try it and here are some photos of what I was talking about.

I hope this helps
Mel

 

[GailInNM]

After slotting with an end mill (slot drill) a 90 or 100 degree counter sink does a good job on free machining materials. Use a slow feed as there is not a lot of cutting edge relief on countersinks.

The ends will have a larger chamfer due to the diameter of the part if you use the same length of cut as used for the slotting operation, but this can be compensated for by reducing the length of the cut at each end. You can calculate the amount, but I just do it by inspection.

Countersinks also work for putting a bevel edge on material.

Gail in NM,USA

 

[SignalFailure]

Ah, I've never heard of a ball end cutter - that would do it

Gail, I've been thinking along the same lines but with drills instead of countersinks! Doh!

Lugnut, why didn't I think of that?! I've thought about all the cutting directions using the end of the endmill but stupidly didn't consider using the side! Your results look just right to me so I'll go for the easy/pragmatic option ;D

Thanks all!