Turning Cone Shaped

[shenion]

Thought about that but...I noticed the existing motor is 6000rpm and the treadmills are 4600rpm,thats a bit unusual for a 1hp(750w thereabout) considering the lathe motor is only 350w

DC motors are usually high RPM.

My drill press has a treadmill motor. It originally had a 1750RPM 1/3HP induction motor. It turned too fast for steel and was wimpy.

The treadmill motor is something like 4500RPM and 2.25HP (1700w). It can now crawl at a slow speed and still snap a drill bit easily if it grabs.

The thing about DC motors is they still have the same torque at low speeds when used with a decent controller.

 

[GeorgiePorgie]

Bit of a dillema here....if you were to do this mod in the link,would you do it with the gibs removed? I was tempted to do this mod and was going to do it but on putting Engineers Blue on the bedways and sliding the saddle up and down found that the saddle didn't make any markings whatsover,so I assumed that the saddles gib faces are fine.

But then I thought is it done without the gibs in place as it doesn't state it in the link?
http://www.toolsandmods.com/saddle.html

 

[GeorgiePorgie]

Ooh! thats not good,the engineers blue has shown discrepencies in the saddles bedway.
Dang I don't think this has been machined more like cast and not machined on the mill.

Ho hum some some elbow grinding to be done,funnily enough the saddle and crosslide have a very minute slight movement.

 

[Pete.]

I just fitted variable speed drive to my milling machine. Made a whole world of difference to it's usability.

 

[Pete.]

And here is one made using variator pulles off a scooter:

http://wktodd.webspace.virginmedia.com/drillmill/page3.html

 

[GeorgiePorgie]

Why've you still got the 3 tier change pully on it,Pete? good one can I see a whole pic of yer MM

 

[Pete.]

I kept the 3-step pulleys because the cone pulleys don't give a wide enough range of speed variation. They are supposed to be 3:1 - 1:3 but in reality it's more like 2.5 - possibly due to the high parasitic losses of the big belt I dunno.

Anyway - here is the complete drive system without the guarding:

 

[GeorgiePorgie]

Its working but I seem to think its defeating the object and that is its supposed to be a direct drive to the tool spindle.

I suppose if you were to hvae a smaller width belt it would give you that extra speed?

 

[Pete.]

Not sure what you're getting at there Georgie.

 

[GeorgiePorgie]

No need for CNC, set the angle on the compound. I advance the cross slide, do a pass with the compound, then advance the cross slide and repeat.

You know Shenion,I've thought of an easier idea.

We grind a tool to a required V shape then cut in to the desired depth then widen one side via cutting in again until we have the desired width summat like this,,,,,,we then part off the two sides