Tailstock Problem

[f350ca]

Why does it need to be hardened?

 

[Dragon]

Ulma Doctor, Tq60 thank you guys for your inputs

Ulma Doctor, thank you for sharing this method !! As I never saw that tool before and it may work!!

I put that roller box in my first priority must to buy! It's sounds like a good way to insert it in my 5/8 AxA tool holder

But the only thing I am thinking about is that how to turn the different OD with that tool
It's looks like it designed to do one single cut only! Then adjust to the next OD and so on!!

Tq60;
This is the best way to turn part and re-adjust the length without thinking about adjusting the 4 jaw chuck every time for every OD

But in my case the G0602 lathe dosn't have accurate spindle so I believe whatever the collet chuck is good the spindle will play the game of the accuracy and will give me about .001 TIR close To the collet !!

But it can be done with bison adjustable collet chuck it just need another $600 to spend and try!

F350, I need to install that shaft inplace of the stock short shaft of my 630kv 12 pole motor that will run about 12000RPM so that can spin the main gear and that main gear spin the main rotor for the Helicopter and also will spin the tail rotor

So it need to be really accurate to prevent any vibration can cause the flying Model from crashing

Any bad vibration can cause the Flybarless system or the controller system and the GPS system to act wired and can cause expensive crash!!!

I wish I can see some videos on how to turn small shafts to different ODs. That will short cut my search!

Thank you guys
Oz

 

[f350ca]

Hardening the shaft won't increase strength or accuracy. Hardening only improves wear

Greg

 

[tq60]

Only area where friction exists it where the yoke slides assuming collective pitch so having proper swivel that has the movement for pitch control be in a ball joint and not on shaft would remove that wear factor somewhat.

Sent from my SAMSUNG-SGH-I337Z using Tapatalk

 

[Ulma Doctor]

Ulma Doctor, Tq60 thank you guys for your inputs
Ulma Doctor, thank you for sharing this method !! As I never saw that tool before and it may work!!
I put that roller box in my first priority must to buy! It's sounds like a good way to insert it in my 5/8 AxA tool holder
But the only thing I am thinking about is that how to turn the different OD with that tool
It's looks like it designed to do one single cut only! Then adjust to the next OD and so on!!
Oz

Hi Oz,
you are correct, you would need to adjust the box for each cut.
if you had or made a few boxes, you could make each box to finish the shaft to the specified dimension, and simply change boxes as the work progresses
i wish the best of luck!

 

[petertha]

You probably should be using a travelling steady on that long, skinny piece of shafting because its bound to be deflecting as you traverse. Mic it at various points along the length & map any bowing. Typically its larger diameter in the mid section & smaller diameter near the chuck & tailstock. I've tweaked a couple thou with careful file work but its tedious.

I'm not exactly sure what RC heli shafts are made from. I dabbled with heli's a bit (Mikado Logo 550). I think shaft was 10mm & it was for sure harder, at least on the outside. I don't know a Rockwell number but I could tell with file it was harder than plain steel & very likely higher tensile stock as they see a lot of bending load. But shaft looked precision ground, that I'm quite sure because the bearing fit was the same sliding down the entire length.

I suspect to replicate you would turn it slightly oversize between centers, harden & anneal (hopefully minimal warpage but that's probably wishful thinking & a whole other topic). Then use tool post grinder for last couple thou using same centers. I think the best you could do on lathe is turn the toughest machinable material you can source & lap it to dimension. Lapping is another 'art' but you can make yourself simple dedicated tools like this. http://www.americanlap.com/External Laps.htm

 

[Dragon]

You probably should be using a travelling steady on that long, skinny piece of shafting because its bound to be deflecting as you traverse. Mic it at various points along the length & map any bowing. Typically its larger diameter in the mid section & smaller diameter near the chuck & tailstock. I've tweaked a couple thou with careful file work but its tedious.

I'm not exactly sure what RC heli shafts are made from. I dabbled with heli's a bit (Mikado Logo 550). I think shaft was 10mm & it was for sure harder, at least on the outside. I don't know a Rockwell number but I could tell with file it was harder than plain steel & very likely higher tensile stock as they see a lot of bending load. But shaft looked precision ground, that I'm quite sure because the bearing fit was the same sliding down the entire length.

I suspect to replicate you would turn it slightly oversize between centers, harden & anneal (hopefully minimal warpage but that's probably wishful thinking & a whole other topic). Then use tool post grinder for last couple thou using same centers. I think the best you could do on lathe is turn the toughest machinable material you can source & lap it to dimension. Lapping is another 'art' but you can make yourself simple dedicated tools like this. http://www.americanlap.com/External Laps.htm

I tried the fallow rest but it didn't work, the reason is because it need same kind of double side cutting tool so that that both side can cut accurate and push each other with no need to steady or fallow rest
Because it's many cut to get into 3 different diameters !!

I see some high end cnc machines like this one here

It's dream !!! But if I have the money I will get it!! I mean reall MONEY ..

Now the Rc heli shaft made from O1 tooling and Hardened to CR~62 and that can eccept some amount of flex and return so that the load that the blades cause can't brake it to two pieces !!

But it's like F350ca said will give it more resistant to wear! Also that hardened willnot give it accuracy but will make it strong enough to handle the load on the head! Without bending !

So hardening it and tempering it to specific degree will give more rigidity and nice smooth bearing ride!!

Petertha; I am looking into that link you provide me with, yes it can be done with that way too,,

I wish I can find straight forward way to machine these shafts without needing into difficult setup, different grinders or making it complicate the job !! That can spend more time hours or maby days and money!!



But if somebody can make that fancy cnc cutting on the manual lathe will be great !

Oz