High feed cutter for making window in tube?

[mkd]

got a batch of tubes to make hydraulic bump stop (edit: holders) for off road trucks.

 

need to cut a large window through .125 wall tubing plus 1/4 gap slots.

 

I've used sanvik screw on endmill "tip" (for lack of a better term).

 

just a little nervous about .250 slots, carbide and water-based coolant killing endmills.

[YoDoug®]

I have found that high feed geometry cutters are not good for breaking through the floor. As soon as the piece gets thin the extra down pressure created by that cutter will deflect the floor and build pressure until it is cutting deeper than the max recommended cut depth. Also after it breaks through you run the risk of pinching the rest of the thin floor between the flute and wall.

 

I would use a flat bottom drill to pop a quick hole and then use an endmill with enough flute length to do the window in one depth pass.

[mkd]

aah, you're right.

i was looking for something low side-force just in case clamping is not super rigid.

so far a corncobb rougher sounds like a winner for your solution...

[workmantm]

What Material? I've had good performance luck with a couple OSG Aero EM. For Aluminum the Blizzard line has shown no issues with any con figuration I've thrown it at. For steels I've run both the Aero-SUS line in 15-5PH and the Aero-UVX line in 4340 at Rc36-44 with great results as well.

[mkd]

Doh! steel tubing, customer supplied.

must be a 1018 (i guess) for Chassis welding purposes.

 

not super satisfied with the mcmaster/ carr lane toggle clamps i've been toying with. planning on positioning tube in semi-circle nest (cut into aluminum subplate) and clamped through ends of tube on the ID. Opening-swing of toggle needs to clear top side of 2.0 ID tube.

hmm, nothing from mitee bite floats my boat either.

[workmantm]

The UVX line has info for all steels. The variable helix may just help with the thin walls. I really only have to worry about drilling thru hollow pins around here. I'm not much more help than that.

 

Can you set it up between centers like a HA5C indexer and tailstock? Just a thought on another way to run it. Rovi ID Arbor and a plug for the tailstock end.

[mkd]

tube has a bit of a slash-cut (think Harley tailpipes here) on one end so between centers is no bueno.

plus i gotta run a bunch in a cycle to make it worthwhile.

[workmantm]

How long? Was just thinking soft jaws with rings milled for the part to set in. As long as you don't need to index during the cut. Of course lack of print or other info makes this a fun game of what if. ;-)

[mkd]

softjaws were my first thought on this 9" part. mill a groove in the face of the jaw to positively locate tube would work, but there would be a couple disadvantages:

1. jaws would need a large height difference and would only clamp on the lower tip of the slash cut on one end.

2. maximum of two parts per vise, so i'd only be able to get 4 part per cycle, with more rapiding between.

 

so i b thinking a nice dense linear array of parts best. could almost clamp the parts with a screw and washer. might need to make simple custom clamps with an elongated hole for unloading....seems like it should be off the shelf

[workmantm]

Have you looked into long distance jaws for subplates? They aren't confined to the normal vise dimensions. Of course you could buy the two Kurt double vises that are large paperweights here and have two more vises to use.

[jeff]

What diameter are the tubes? can you side cut the window?

[mkd]

jeff, the tubes are 2.25 OD. with .125 wall thickness. There is some design flexibility on the window dimensions but not so much for the two .25 wide clamping-separation (for lack of a netter term).

the window dimensions approach the tube OD, so side milling would need a comparativly large wheel cutter

oh, i see, side mill with an endmill ! I will look at some window designs for that idea.

didn't think of that.

thanks

[jeff]

 

oh, i see, side mill with an endmill !

 

Yes, plug each end, clamp in vise, and side mill the window in the area between the 2 vises.... IF the shape of the window will allow it.

 

Or, use 3D contour and go around the perimeter with something like a 1/4" ballnose or bullnose endmill.