Best way to indicate part on rotary table?

[KenErickson]

I plan on building Jerry Howell's beamer engine . I have a 6 x 26 Knee mill and a Palmgren 8 inch rotary table.

For example when forming the spokes on the flywheel, which Jerry suggests using a rotary table, what is the best way to indicate the flywheel onto the rotary table?

 

[kvom]

Assuming you have already formed the rim and bore on the lathe, you need to center the rotab under the spindle. Then mount a dti in the spindle and adjust until you can turn the rotab without moving the needle.

For what is reasonable accuracy if you don't have a dti, you could turn a taper on the lathe, chuck it in the spindle, and lower onto the bore of wheel as a centering device. Keep it pressed down while you clamp the wheel. This will almost always get you within .002 as long as the rotab is centered itself.

 

[rdhem2]

I ground a 60 deg taper on a piece of 3/4" shaft for the quill. Took an old, dead, useless drill with a good #2 morse taper to match my rotary table. Cut the drill portion off and turned a 60 deg female to a 5/8" opening. Then by lowering the quill and mateing the two the rotary is pretty much centered. Needing better than this I mount a DI to the quill and circle the female center to get the last bit adjusted. Simple, fairly fast, works for me.

 

[lensman57]

Hi,

First machine the rim of the flywheel on the lathe and bore the crank hole,
Then assuming that your rotary table is trammed on teh mill use a dti with
n entesion arm of some sort to indicate the flywheel aroun its rim or use the crank hole. Make sure that the flywheel is true to the surface of the rotary. since you manchined the rim and the crank hole on teh lathe all parts should be concentric with the mill axis and sitting true to the surface. you can then use the X-Y axis and the rotab to machine the spokes .

Good luck,

Reagrds,

A.G

 

[KenErickson]

Thanks for the quick and thoughtful responses guys! It helps me a ton. Ever since receiving the plans in the mail I have been looking them over, in my mind figuring out the different set-ups for the parts.

 

[AussieJimG]

Russ (rdhem2) uses a male and female centre. I use two male centres and put a steel rule between them - like setting up to cross-drill. I think this is slightly more accurate than the male/female.

Jim

 

[rdhem2]

Russ (rdhem2) uses a male and female centre. I use two male centres and put a steel rule between them - like setting up to cross-drill. I think this is slightly more accurate than the male/female.

Jim

Good idea my man. I never considered balancing a scale between two points. Just on shafting. woohoo1