Someone Ask how to finish body tubes

[Micromeister]

It took awhile but I dug out the ol'e tube finishing gizmo last night. When the Wife bought a new sewing machine some time back I just couldn't see trashing the motor and other good parts.
Heres what I did with the motor, and Foot peddle.
Back when "Blackshaft" phenolic tubing was all the rage, this little gizmo made short work of sanding down these tubes for competition models, Lately I've used it to sanddown the rough spots on layed up fibreglass tubes and bodies and finsih sand pre-Primed and Pre-Painted body tubes.
on parts or whole 36" lengths of estes type tubing I stick one of my tube cutting mandrels floating loose between the motor casing mounts. works like a dream with the variable speed foot control both hands are free to wrap and hold sandpaper and sandpaper blocks on the tube surface.
Fun with junk

 

[rstaff3]

Nice little contraption! What's the biggest tube you can mount (dia)

 

[Micromeister]

Dick:
The largest thing I've actually primed and sanded on this thingy was a BT-80 19+ inches long. Mounting the to be finised tube required making 2 coupler/light ply capped plugs with a 13mm tube sticking out of each end. Like making a BT-101 to 13mm motor mount. Tape the 13mm tubeto the drive casing and away we go. I'm fairly sure I could do the same with any tube size up to BT-101 as there is plenty of swing over center, I just haven't had a need If you're worried about having enough power to turn the larger tubes, this little motor is very strong! it actually burst the first piece of BT-80 I mounted.. had to slow the motor down while sanding the unsupported portions of the tube.
These mounting plugs are sort of like tube cutting mandrels, Once you have them made they are pretty much a permanent additions to the tool

 

[wwattles]

Wow!

That thing looks like quite a rocketeer's friend! I'm guessing you could probably turn light balsa NC's on it as well?

It looks simple enough to build, even without having a sewing machine to cannibalize for parts. With that in mind, what are the speed/amp/hp ratings of that motor? Also, does anyone know of a good place to find a decent rheostatic foot control? Finally, what did you use for the center on the other end? Does it turn as well, or is it just fixed in place?

Thanks,

WW

 

[Micromeister]

Originally posted by wwattles
Wow!

That thing looks like quite a rocketeer's friend! I'm guessing you could probably turn light balsa NC's on it as well?

It looks simple enough to build, even without having a sewing machine to cannibalize for parts. With that in mind, what are the speed/amp/hp ratings of that motor? Also, does anyone know of a good place to find a decent rheostatic foot control? Finally, what did you use for the center on the other end? Does it turn as well, or is it just fixed in place?

Thanks,

WW

Will:
The tailstock is scrap 3/4" & 1/2" plywood put together like a book end with a triangluar reinforcement. it rides on a 1/4-20 x 1-1/4" truss head bolt, upside down in a 3/16 deep x 1" wide "track" routed in the underside of the base board. the bolt slides in a 1/4+" slot about 40" long. there is also a 1/4" dowel in the forward bottom edge of the tailstock to keep it aligned when the 1/4" wing nut is tighten to lock the piece in place. The tailstock center is just a fixed 1/2" hardwood dowel, carpenters yellow glued in place. A 13mm spent motor casing friction rotates on this dowel.

Nope this Giz will not turn nose cones, at least not without a bunch of modifications. remember the only thing actually holding the spinning body tube on this thing is a couple rounds of masking tape.

This little motor is a BEAST! 1100 rpm as i recall at full speed..which I have only used once lower speeds are the best, the motor is a 1/16HP I don't remember what the amp load is... NOT much. The Foot contol is another matter.. I have no idea.
This tool was specifically thrown together to finish BlackShaft phenolic tubing, since then I've found other finishing uses for it so it stays in the shop, but if your looking to make a nose/transition turning lathe, theres another thread at TRF detailing several ways to turn a hand drill in to a 4.5" x 32" lathe similar to the one pictured below
Hope this helps.

 

[Stymye]

sewing machines are handy.. I use one to turn small cones

pics here

https://www.rocketryforum.com/showthread.php?s=&threadid=4862&highlight=sewing+machine+lathe

 

[Leo]

Could you please post another picture including a mosquito.
I want to see if we are talking about a "mirco" lathe here

 

[Hospital_Rocket]

Power = Current*Potential
Horsepower = Power/746

....About 1A at nominal load and 120VAC

Unless you want to get into power factor, which would be kinda silly in this case.

 

[wwattles]

Originally posted by Hospital_Rocket
Unless you want to get into power factor, which would be kinda silly in this case.

I suddenly had a flashback to my college EE course lovingly referred to as "Motors and Rotors!" I can still recall twisting my brain inside out to understand the attraction/repulsion forces in rotary systems... let's not go there again... EVER!

WW