Headstock/Spindle Design Suggestions

[glentner]

Here's the situation, I have a home built CNC VMC that I've built and have slowly been upgrading for years.

I've finally gotten to replacing the headstock. I started with (and currently am using) a sherline headstock assembly. This headstock is way too underpowered and not very rigid, but at the time was the best way to go.

So now I'm working on what to replace it with. I've read MANY threads here on spindles which were very helpful but also added many more options then I originally was thinking about. So I'd like to through this out to the wisdom of the zone and see if anybody has any suggestions/tips as which way to go (or not go).

I'd like a headstock that is only as powerful and rigid as needed for my mill. My mill is about 500lb, LM rails and ballscrews on all axis, and a table about the size of a bridgeport table. So that being said, I would also like to have an R8 spindle like a bridgeport.

So I start with two options:
1. Find a headstock from some other machine and fit it to mine.
(anybody know of any good mid-powered heastocks)
2. Design and build one.
I would like this option better, but from what I've read from the other people that made their own spindle, it was not very fun.

So anybody want to kick out any ideas to start with???

Thanks for the help,
-greg

[The Blight]

I guess the X3 R8 spindle from little machineshop would work. You could get the whole assembly from them, but it comes with a collumn, and its pretty heavy. You can also just buy the spindle and build a housing for it.

A couple questions about the machine. I'm curious.
How much travel?
Are the tubes welded togther? And have you filled them with something like EG, Sand, Concrete.. etc?

Looks big! Got any pictures of it?

[glentner]

Yeah, the X3 might work, but the motor is little smaller then what I want (probably looking for 1-1.5HP). Also, the manual Z feed thing would have to be delt with.

I just talked to Tormach, and they won't sell the complete headstock, but they do sell just the spindle cartridge as a replacement part. That would include the R8 spindle and bearings so maybe take that and mount it to a custom cast headstock might be the ticket. From what I've read in the forums, the Tormach mill is pretty good for a benchtop model.

As for the mill specs:
X axis= 13.5"
Y= 8.5"
Z=11.5"

The tubes are welded together, but not filled with anything but a little spray of WD-40 for rust prevention. I uploaded an assembly CAD file of it a long time ago, and it's still in the forums somewhere. I think if you search for tubing frame design or something like that you'll find it.