External Spline Machining

[tcmmark]

Please could somebody suggest the best latest technology to machine an external spline. The material is steel, I have no further information to spec as yet. dia. 45 mm / length 30 mm / 10 mm clear runout at end of spline before next larger dia. The spline detail has not yet been supplied to me, however it has a vee form and is straight.

Would we use an external ring type broach, hob, or CNC mill on a lathe or machining centre.

I would have to machine approx. 30 parts per hour, and the machine needs to have good operator interface and cover all health and safety / ergonomic req's.

 

[metman]

I have only seen hobbing of splines done on a horizontal milling machine.

What is the material being splined? If it is steel, this will be a slow process. Therefore you likely will want to build a special machine tool which will accommodate multiple shafts to be splined simultaneously.

Jesus is THE life,
Leonard

 

[funnelguy]

Have you considered rolling the splines?

 

[wmdn]

30 pieces per hour for the sizes you indicated would be a walk in the park for spline rolling. Superior finish, increased surface hardness and increased productivity are all reasons my first choice would be spline rolling.

 

[tcmmark]

I agree, folowing further investigation spline rolling seems to be the best option.

 

[bvasa]

There's also a cold extrusion option you might want to consider. Spline rolling is pretty much an industry standard, but there are a couple "rules of thumb" that might impact its applicability to your part:

Module = 1.5 or less
Must be an involute spline
pressure angle = 30 degrees or greater

There's also a slight difference in flank geometry between the flank that was leading during forming and the one that was trailing.

If you can't live with these (not a problem in most applications), cold extrusion may be a better option. No limit to pressure angle, no process-induced requirement for involute form, and the module limits are somewhere beyond 4.0 (at 130mm pitch dia - probably still in the 2.0 range for parts such as your shaft).

Here are a couple links:

builder of specialized axial forming machines:

http://www.felss.de/felssEnglish/siteMaschinenAxialform.html?topID=30&navID=3&navID2=8&allID=3

Cold forging production house working with external splines on shorter parts:

http://www.mfccorp.com

Good luck!