[G59]

Hope you don't mind, but here is a FEA of a similar spindle body made of 6061 Al. The bearing load for this test is set at 6000lbs. Note the safety factor. Almost 2x. Displacement set to 0.0001 and in Z, is near nil.



I also did a test with stainless and it near triples the aluminum.

But, being that you already have the 303 SS, I would use it, and as you said find other way to mount it?

Nothing wrong with that strategy if you can be that flexible.
Like I said, you are doing awesome work here for a guy using nothing more than his brains and a lathe.

[RustedOut]

Azalea,

I'm working on my spindle housing now and chose gray cast iron. Part of the why was cost and machinability, plus it's the same material my mill head is made of, so growth due to heat distortion will be similar between the two. Turning it, the chips are just little balls, that's a plus. Or drilling, it actually makes small chips. Knowing there was going to be a lot of chips being made, that makes dealing with them a lot easier.

Mine is just under a foot long and my lathe and boring bar selection negates me doing it all from one end. I've gotten the outside turned slightly oversize and am halfway through the inside. I'm in the process of flipping it around to access the other end. Mine has the bearing retainer/labyrinth seal made as a screw in piece, so today I finish that up so I can use it as a thread gauge for inside the housing. Then get the housing set back up and finish the hole through. I've left the bearing surfaces and outer barrel .030" oversize in diameter so I can get a grind shop to finish grind them.

My housing clamps into the mill head, it's not bolted. So I have a bigger diameter on the lower end for the two bearings, but no bolt flange to contend with. But even minus that, I have a lot of hours invested to this point.


Good luck with yours,
Bob

[G59]

I'm working on my spindle housing now and chose gray cast iron.

It is also the material of choice for us.

[Azalin]

And is good for welding I guess.

[Azalin]

Anyway, to turn 100mm stock I'll need a large capacity fixed rest. I'll try to make one today with my CNC. I've made one before for my old Proxxon lathe:

[RustedOut]

I turned the outside of mine between centers, whittling the 4 1/4" cast iron piece down to 3" in the main barrel area. It just then did fit my steady rest. I drilled the centers on my drill press before hand. That's a pretty small steady rest, I nearly can't hold mine in one hand, it's too heavy.

Bob

[Azalin]

I turned the outside of mine between centers, whittling the 4 1/4" cast iron piece down to 3" in the main barrel area. It just then did fit my steady rest. I drilled the centers on my drill press before hand. That's a pretty small steady rest, I nearly can't hold mine in one hand, it's too heavy.

Bob

Yes Bob. Its small but I don't use it anymore. Sold it with my old lathe. I'll do the same but much bigger from 20mm sheet aluminum.

[RustedOut]

Thanks for that info, I didn't see how it would fit on your lathe, from the pictures I've seen of it anyhow.

Bob

[mactec54]

Come on people. Motivate me!

You could always cut a thread on the Body and screw the flange on, up to a small shoulder, no welding needed

[Azalin]

Better I go and get cast iron. They're cheap.

Sent from my GT-I9300 using Tapatalk

[RustedOut]

It means more time and more chips, but I'd try to find a piece big enough in diameter to include the flange. I'd avoid welding if I could.

Bob

[G59]

It means more time and more chips, but I'd try to find a piece big enough in diameter to include the flange. I'd avoid welding if I could.

Bob

I agree. Better than welding as welding cast is also of bag of fun. Unless you are experienced in welding the stuff and can preheat the parts etc.. etc..

[Azalin]

I too agree but it's impossible to turn 150mm round piece in my lathe. There are too many shops that can easily cut it for me for a little cost but I'm just not the type. I want to try things first.

Thanks.

[mactec54]

Better I go and get cast iron. They're cheap.

Sent from my GT-I9300 using Tapatalk

You would have to make it in one piece,with the flange, if you went with Cast Iron

[Azalin]

:drowning:

[Azalin]

Just finished the model.

[RustedOut]

I too agree but it's impossible to turn 150mm round piece in my lathe. There are too many shops that can easily cut it for me for a little cost but I'm just not the type. I want to try things first.

I had that thought with my lathe, but mine was in the Z direction. But I managed to get the outside turned for finish grinding and just lack one half of the inside of being done. But there was no way I could use my tool post grinder as it takes up an additional 12" of Z. I might have been able to do the grinding, but i wouldn't be able to move out of the hole far enough to measure it. So that's getting farmed out. Getting this far has saved me lots of hours at someone else's shop rate.

Is your swing issue over the carriage? Is there a way to stay to the right side with the carriage and turn it with longer tools? Tools pointing in towards the spindle. Like a boring bar, but for the outside. Just thinking out loud without knowing what you're up against. I know I had quite the time figuring out how to do the whole length of mine on the outside. Took me over 2 hours to figure out the setup. Then over 8 hours to actually turn it. The inside has been simple as there's no way I can reach the total length of the housing, so it had to be flipped.

Bob

[Azalin]

Distance between center and the carriage is just a little longer than 50mm. Say 51 or 52mm. That makes 100mm dia swing max.

[RustedOut]

I guess I'm lucky in the fact I got a friend who's lathe is bigger than mine, and he's a retired machinist. Got any friends with a bigger lathe? It'll be tied up for awhile. And boy, like you, I'd try to avoid taking it to a shop and paying to have it done. Good luck there. But like was suggested, maybe you can figure out how to thread the flange on.

Bob

[mactec54]

Distance between center and the carriage is just a little longer than 50mm. Say 51 or 52mm. That makes 100mm dia swing max.

You can do it if you have enough length between centers,the saddle will be in front of the large dia until you can move it forward, you can use a Boring Bar to rough machine the outside, doing it in steps, turning it down to say 102 Plus until you get up to the flange, then once the saddle can pass under, you can finish machine with normal machining, doing the flange face and OD at the same time