Turning 2" OD Delrin on an X3- power issues?

[iamscottym]

I am looking to purchase a small mill, because my college's machine shops are only open 9-5 and I find myself needing more time to work. Anyhow, I'm planning on getting an X3, because it's about the biggest machine I'll be able to move around. I would also like to get a lathe, but getting an X3 cnc'ed with cnc fusion's ground ball screw kit, plus geckos, Mach 3 and a cam package will pretty much tap me out for the time being.

Most of my work revolves around a guided rocket I'm building, and so I need to be able to turn nozzles. I'll be using 2" OD delrin in a step collet. Would anyone anticipate power issues with an X3? If so, how powerful of a motor would you suggest? I'm planning on adding a belt drive to get a little more rpm range anyhow, so I'm considering a BLDC motor. I've been seeing some really powerful outrunners lately that I'd love to play with.
Thanks,

iamscottym

[thackman]

I'm sorry but I'm abit confused. If I understand your post you are asking if an X3 has enough power to turn 2" OD delrin but the X3 is a mill not a lathe and this is the benchtop mill forum. Since you have been around a machine shop I'm guessing that my confusion is simply because of how the sentences and thoughts run into each other.


You indicated that your first purchase would be a mill and a lathe later when you could afford it. So are you asking if it's possible to somehow chuck the 2" Delrin stock in the mill spindle and use it like a lathe or are you asking which lathe should you should consider purchasing?

You can perform many lathe ops on a mill if your stock is very short, can be securely held in a collet somehow, and is of a reasonably small diameter. I've seen some pretty amazing videos of a cnc mill performing successive lathe operations on a bushing just like a cnc lathe would but 2" stock is a bit larger than I would feel comfortable starting with. I think it is possible but I would start with a 3/4 or 1" dia. piece and work up from there. If you can clarify how you intended to hold the stock it might clarify some things.

I'm not a rocket builder but I'm surprised to hear of delrin being used as a nozzle. Usually those are either metal, carbon or ceramic. I'm assuming that the Delrin was for the nozzle and not the body from the preceding sentence.

[iamscottym]

Yes, I am aware the X3 is a mill, not a lathe. Most of the work I need to do requires a mill, but I also need to be able to turn a few nozzles and won't be able to afford a lathe at the same time. Given the X3's specs, it has enough travel to be able to turn the nozzles, but I'm not sure it has enough power.

Assuming I upgraded the motor, would an X3 otherwise handle the extra power (say 2HP)?

The nozzles are short enough that I just use a collet on a Hardinge lathe, so work holding is not an issue.

(These are not pyro rockets, they use compressed gas and water- the FAA wouldn't like me putting a guidance system on a pyro rocket)

[Andre' B]

You can always mill the nozzels as a 3D surface.

Or you can put a rotary table on the mill to turn the part for working on really large diameter stuff.
I finished the OD on some 24 inch diameter wooden wheels using an 8" rotary on an RF30.

[Oldmanandhistoy]

Originally Posted by iamscottym I am looking to purchase a small mill, because my college's machine shops are only open 9-5 and I find myself needing more time to work. Anyhow, I'm planning on getting an X3, because it's about the biggest machine I'll be able to move around. I would also like to get a lathe, but getting an X3 cnc'ed with cnc fusion's ground ball screw kit, plus geckos, Mach 3 and a cam package will pretty much tap me out for the time being. Most of my work revolves around a guided rocket I'm building, and so I need to be able to turn nozzles. I'll be using 2" OD delrin in a step collet. Would anyone anticipate power issues with an X3? If so, how powerful of a motor would you suggest? I'm planning on adding a belt drive to get a little more rpm range anyhow, so I'm considering a BLDC motor. I've been seeing some really powerful outrunners lately that I'd love to play with. Thanks, iamscottym

The simple answer to your question is imho yes there will be enough power in a 600+ Watts spindle. I have turned 2” Delrin on a mini lathe with a 350W motor without problems. As I am sure you are aware depths of cut will need taking into account.

John

[gmfoster]

Originally Posted by Andre' B You can always mill the nozzels as a 3D surface. Or you can put a rotary table on the mill to turn the part for working on really large diameter stuff. I finished the OD on some 24 inch diameter wooden wheels using an 8" rotary on an RF30.

Actually turning on a mill isn't all that hard. Just mount your lathe tool in a holder on the the table and have a go..

Works quite well for short stubby parts.
Garry