EDM cutting splines in hardened gears questions

[80's_delirious]

I am contemplating a project that will need a gear and a shaft to be remachined and an internal spline cut in a gear

Are gears and gear box shafts case hardened?
Can they be machined? Ie in a lathe
Is electric arc erosion the right process for cutting a new spline in a gear?
Who can do this for me in Sydney?
Is it expensive?

Cheers

Edited

[1MadEngineer]

EDM! is what you are thinking of, and yes it does get expensive on one off's

[80's_delirious]

Cheers, EDM is what I am looking for info on

[Nuckingfuts]

gears and shafts will be hard, can be machined to some extent with the right inserts. EDM would be the go for the spline. Even wire cutting would be an option.
I do alot of this sort of stuff for work if you have any questions. Like already mentioned it wouldnt be real cheap, you might be suprised at the wire cutting price though.

[nastytroll]

I would use EDW, not EDM. It would be easier and faster to EDW the spline with better results then EDM. I hope the processed have improved since I last worked with it. I was EDW cutting to 3u back in the day. EDM is a rough nasty process, usually needs a fair amount of polishing for a good finish and sizes can be an issue if going for presicion.

[80's_delirious]

Cheers guys, thanks for the comments.

Still in the thought process at this stage, I need to figure out exactly what I will need.


To keep it simple, I am looking at cutting a fixed gear off an input shaft, machining out the centre and splining it to fit onto another shaft, may also need to machine down a shoulder on the gear to suit a different size bearing race, the shaft may need a groove machined to take a C-clip.

What is EDW?

[80's_delirious]

Wikipedia'd EDW

Any idea on the cost of having an internal spline cut in one gear?

[nastytroll]

cost depends on material and thickness. I have no idea on rates. The rest of the machining sounds straight forward. May need cylindrical gringing if hard turning is not an option but should be do able.

[Nuckingfuts]

providing the job is as simple as it sounds ie. nothing needs to be ground because it is too hard to machine as mentioned, you should budget somewhere around $500+ for the whole lot. its not cheap by any means but its not something that many places will touch either. wire cutting on its own wouldn't be that expensive if the gear has a hole through the centre and you supplied a DXF of the profile that needs to be cut. Both of which would be near impossible without access to the right equipment.