Best way to mill top and bottom faces

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terry1956
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Best way to mill top and bottom faces

Post by terry1956 »

Hi chaps, I have a small cnc sieg mk2 milling machine. I need to machine some model tank tracks. These need to be machined on both the top and bottom faces. The bed of my mill is too small for any 4th axis set up. The tracks need to be steel are around 3inchs long by an inch wide and 2/8th thick. Can anyone think of away to hold the work piece which will allow the correct alinement of both faces for machining. Thanks, michael
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NP317
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Re: Best way to mill top and bottom faces

Post by NP317 »

A drawing of the part will make it easier to provide advice.
Can you post one here?
~RN
terry1956
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Re: Best way to mill top and bottom faces

Post by terry1956 »

Hi, not made a drawing as yet as I don,t know if it’s possible for me to machine the parts. It’s a panzer tank track
John Hasler
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Re: Best way to mill top and bottom faces

Post by John Hasler »

How about some photos, then?
terry1956
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Re: Best way to mill top and bottom faces

Post by terry1956 »

hi. this is the track front face I need to machine the raised track pin cover as one with the flat part of the track and hollow out the reverse face of the cover. so I am thinking of some sort of jig using the stud holes to a line the track section. anyone have with luck better ideas.

Image
John Hasler
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Re: Best way to mill top and bottom faces

Post by John Hasler »

Good idea.
terry1956
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Re: Best way to mill top and bottom faces

Post by terry1956 »

John, what’s a good idea, using the stud holes. I was thinking of making a sort of jig with bolts that screw into the holes allowing the botton face to be machined as that’s flatter and then turning over and rescrewing to machine the top face. There must be a better way, but I can,t think of one.
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Harold_V
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Re: Best way to mill top and bottom faces

Post by Harold_V »

Give some thought to using aluminum jaws in your vise, whereby you can machine away portions of the jaws where necessary. That's an excellent way to hold difficult to machine parts, assuming they lend themselves to the concept. I machined this antenna latch that way.
Antenna Latches resized.jpg
The spike you see in the picture is a common straight pin.

H
Wise people talk because they have something to say. Fools talk because they have to say something.
terry1956
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Re: Best way to mill top and bottom faces

Post by terry1956 »

My worry is making sure that both faces are set with the correct zero position, and do make sure of this the part must be in the correct position for milling both faces.
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Harold_V
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Re: Best way to mill top and bottom faces

Post by Harold_V »

Then you create a pocket in the jaws, so the part indexes correctly. No big deal, especially considering you have a CNC. That's common practice.

The part shown had incredibly tight tolerances--nothing looser than ±.003", with several dimensions held to ±.001". I indexed off the large hole (.031" diameter). Just get a little creative. You can do it.

H
Wise people talk because they have something to say. Fools talk because they have to say something.
terry1956
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Joined: Thu Aug 30, 2018 5:28 am

Re: Best way to mill top and bottom faces

Post by terry1956 »

thanks for that info. michael
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