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Machining a fork truck carriage ? solved! shipped back to China!

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solo

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#1
I have 130 of these to be reworked, from China. This is a forging. I need to machine the 20deg area removing about .020-.030 thou. The areas marked in red are critical.
The carriage is about 42"-48" wide. It has to be machined from underneath as shown. There are heavy arms protruding past the area needing to be machined.
I can do this on the mill, using a 90 deg head.
tilting the head back 20 deg. But now we only have one mill. (the powers that be, decided we didn't need the Bridgeport Series II)
And I'd have to move, and re-clamp a long and slow process. Plus tram the head every time to run another job.
I'm not sure if I could set up a grinder on 4 rails, capturing it. Then using a lead screw to move it, maybe motorizing it?
Suggestions, thoughts?
 

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extropic

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#2
You circumstances are clear as mud, to me. A picture or two (with dimensions or scale references) could help clarify.

How tall is the surface you need to cut?

How long is the surface you need to cut.

How does the 20º surface terminate (at an intersecting surface, in air, ???

Is the forging steel?

The "heavy arms protruding" in what direction on your sketch?
 

solo

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#3
This is pretty much what I'm dealing with. 42"-48" wide x 28"- 32" high, the angle land is around 3/4" , Steel Forging
 

extropic

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#4
Is the 20º surface next to the "notched" feature (facing up in the photo) or somewhere else?

If I understand your problem correctly, that is so much steel to cut and 90º Bridgeport heads aren't really built for heavy cuts.

Could you make a fixture to hold the part on your mill with the arms toward the table surface (same as in your sketch in the OP) and the 20º surface toward the column of the mill?
The fixture should key to the mill table and reference the part from Datums to simplify and speed setup. Make or buy a custom 20º cutter that uses indexable inserts and leave the spindle normal (no 90º attachment and no 20º tilt). Search "custom indexable milling tools" for lots of sources.
 

solo

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#5
it is next to the notched area. It would be a lot easier if the arms weren't there. I'm thinking have work out source them to a bigger shop.
 
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