How To Cut These Angled Slots?

[Machinehead]

I'm faced with the task of cutting 4 angled slots in a cylinder for fan blades that need to be indexed 90 degrees to one another for proper balance. Right now I have the part centered in a chuck on a rotary table straight up, and thought of tilting the head back 35 degrees to saw the slot with my slitting saw. This will not work because since my saw will be at an angle, I cannot feed across the part in the Y direction. Will I have to fixture the workpiece at a 35 degree angle and somehow find a way to accurate index my cuts? How would you do this?

 

[T Bredehoft]

Can you feed in X? That would leave a curved bottom of the slot, but so what!

 

[mmcmdl]

How about you use a 5c square collett block with a .020 slitting saw ? Machine a soft jaw out of alum. that creates your 35 degrees .

 

[Wreck™Wreck]

You haven't answered the most important questions.
How many parts.
What machines do you have at your disposal.

Without this knowledge there is no easy answer, if you have typical home tools and endless time to do it you may easily create such a part, you will spend more time making the tooling then then making one part, also the first parts may not be right and this will require making several until corrected.

 

[Machinehead]

How about you use a 5c square collett block with a .020 slitting saw ? Machine a soft jaw out of alum. that creates your 35 degrees .

Good idea, I'm going to think about this and give it a shot.

You haven't answered the most important questions.
How many parts.
What machines do you have at your disposal.

Nobody asked me that yet but I'm running a Bridgeport Mill with rotary table. It's only one part I need to make for the project.

 

[TOOLMASTER]

indexer at an angle

 

[chips&more]

Easy enough to do with a 0.020” slitting saw and have the part tilted at 30° and so it can index 90° increments.

 

[JimDawson]

Tilting rotary table


You need one of these little guys.

 

[Wreck™Wreck]

Good idea, I'm going to think about this and give it a shot.



Nobody asked me that yet but I'm running a Bridgeport Mill with rotary table. It's only one part I need to make for the project.

Cake with a Bridgeport.
Finish the OD in the lathe and leave it long so you have something to hold, place in a suitable holding device on the rotary table and nod the head and cut the slots with a saw.
Return to the lathe and do the front work then part to length leaving .050" or so for finishing, place the part in the chuck again and do the back work, use soft jaws in the lathe chuck in order to limit jaw marks on the part.

If you don't have a lathe then you will have to do the OD and ID work on the mill which is cumbersome at best.
Good Luck

 

[chips&more]

If you tilt the head you can not get a flat bottom cut.