# Crankshaft Turning Fixture



## Draw-Tech (Mar 26, 2014)

Hope this helps anyone.


View attachment Crankshaft Turning Fixture.pdf


Read attached pdf

Jack
Draw-Tech


----------



## Mknorr (Apr 3, 2014)

Hi Jack. Not sure if its an ipad thing, but there is nothing attached. Just an image of a disk with 3 points.



Sent from my iPad using Model Engines


----------



## cfellows (Apr 3, 2014)

Mknorr said:


> Hi Jack. Not sure if its an ipad thing, but there is nothing attached. Just an image of a disk with 3 points.
> 
> 
> 
> Sent from my iPad using Model Engines



 There is a PDF file attachment which does show up on a PC.

 Chuck


----------



## BaronJ (Apr 3, 2014)

If you can see "crankshaft-turning-fixture.pdf" under the picture, click or tap that.

Or try http://www.homemodelenginemachinist...urning-fixture-crankshaft-turning-fixture.pdf

HTH.


----------



## Draw-Tech (Apr 3, 2014)

Hi all

If you can't read the pdf drop me a PM I'll send it to you.

jack
Draw-Tech


----------



## BaronJ (Apr 3, 2014)

Hello Jack,
I've no problem reading or downloading your PDF.  Thank you for posting it.


----------



## Swifty (Apr 3, 2014)

Works fine on my Ipad.

Paul.


----------



## MachineTom (Apr 4, 2014)

If turning between centers is the plan What is there to support the tailstock end of the crankshaft and keep the crank in phase at all times. 

I assume that your idea is the plate you have drawn is held in the headstock chuck, I don't see how the idea will work without a rigid connection at the headstock chuck ??


----------



## Mechanicboy (Apr 4, 2014)

How can crankshaft be supported by tailstock?? How can the tool give rotation of the crankshaft??


----------



## Draw-Tech (Apr 4, 2014)

Hi all 

look at top of post, hope this helps.
Jack
Draw-Tech


----------



## ICEpeter (Apr 4, 2014)

You would need to hold an identical offset fixture in a rotating chuck that fits into tailstock. I have such a rotating chuck, dia. 3 inch, with a 2MT for use in the tailstock.

 Peter


----------



## Woodster (Apr 4, 2014)

ICEpeter said:


> You would need to hold an identical offset fixture in a rotating chuck that fits into tailstock. I have such a rotating chuck, dia. 3 inch, with a 2MT for use in the tailstock.
> 
> Peter



No you wouldn't. This fixture is for turning crankshaft offsets using a standard 3 jaw chuck. Hold the fixture in the chuck, slide the offset adjust slide plate and use the 3 centres to drive the shaft. The centres are drilled in the crankshaft ends using a mill so you don't need to offset the tailstock. The tailstock centre will line up with either the 1st or 3rd drive pin.


----------



## ICEpeter (Apr 4, 2014)

Woodster,
 I understand that but it does not appear to be a significant improvement over the traditional method of machining a crankshaft. What it boils down to is the shown fixture is used just as a driver for the crankshaft with an adjustable offset to enable the fixture to turn the crankshaft during machining the offset. The idea though is good and helpful in the machining process, no doubt about that.

 Peter


----------



## Draw-Tech (Apr 4, 2014)

Woodster said:


> No you wouldn't. This fixture is for turning crankshaft offsets using a standard 3 jaw chuck. Hold the fixture in the chuck, slide the offset adjust slide plate and use the 3 centres to drive the shaft. The centres are drilled in the crankshaft ends using a mill so you don't need to offset the tailstock. The tailstock centre will line up with either the 1st or 3rd drive pin.



YOU GOT IT Woodster

Jack


----------



## TimTaylor (Apr 4, 2014)

I like the general idea - eliminates the need to drive the work piece with a lathe dog or some other similar means. It's a much cleaner setup.

The only tricky part I see is making sure the offset of the slide in the fixture is set exactly the same as the offset in the drilled center holes on the tail stock end of the work piece.


----------



## Swifty (Apr 5, 2014)

Good idea, you could roughly set the offset in the chuck, indicate the tailstock end and then move to the chuck end and adjust until you have the same readings.

Alternatively, you could zero the indicator at the tailstock and run the saddle along towards the chuck and adjust the fixture until it reads zero on the indicator.

Paul.


----------



## TimTaylor (Apr 5, 2014)

Swifty said:


> Good idea, you could roughly set the offset in the chuck, indicate the tailstock end and then move to the chuck end and adjust until you have the same readings.
> 
> Alternatively, you could zero the indicator at the tailstock and run the saddle along towards the chuck and adjust the fixture until it reads zero on the indicator.
> 
> Paul.



That was my thought as well. Adjustable fixtures are great as long as you can set them up accurately with a minimum of fuss......


----------



## Mknorr (Apr 6, 2014)

Swifty said:


> Works fine on my Ipad.
> 
> Paul.




Yep, looks like it was the app that isn't working right. In Safari it show up fine. 


Sent from my iPad using Model Engines


----------

