Run in stand/dyno build.

[Terry Keeley]

Beautiful work as always Jim, my Engineering Department looked long and hard at your gallery when they were in the design phase.

Just curious about your bearing fits? I'm about to bore my pillow blocks and was thinking to go for a few tenths press. I haven't put bearings on the shaft yet but expect them to be a very light "push" fit. It checks about 0.5905 so about a tenth under the nominal 15mm bearing ID.

Did some reading and found electric motors like to press the shaft on and leave the housing slight loose (H7/K5). Looks like you have a retaining plate in the third photo there? Is that to retain the loose fitting bearing?

Some good fit info on page 19 here: http://www.nachiamerica.com/download/75/Deep-Groove-Ball-Bearings/

 

[Jim Allen]

One important fact to remember when building miniature size dynos is there inability to measure small amounts of torque. Careful consideration of materials used & the elimination of friction loses becomes critical. The material shown in the photo (Rulon) has the lowest "STICK SLIP" of any material available. It is used to support the dyno's housing. Align boring of these bushings after assembly insured perfect alignment. Notice how all parts are doweled pinned together.

JA

 

[Jim Allen]

Beautiful work as always Jim, my Engineering Department looked long and hard at your gallery when they were in the design phase.

Just curious about your bearing fits? I'm about to bore my pillow blocks and was thinking to go for a few tenths press. I haven't put bearings on the shaft yet but expect them to be a very light "push" fit. It checks about 0.5905 so about a tenth under the nominal 15mm bearing ID.

Did some reading and found electric motors like to press the shaft on and leave the housing slight loose (H7/K5). Looks like you have a retaining plate in the third photo there? Is that to retain the loose fitting bearing?

Some good fit info on page 19 here: http://www.nachiamerica.com/download/75/Deep-Groove-Ball-Bearings/

Yes. The black Delron plates are added protection to ensure the Rulon bushings cannot move. They are a "slight press fit" (.0001" to .0002") before align boring. Bearing fits for radial type bearings (C-3 radial clearance) can stand .0002" to .0003" shrink fit. The shaft in the bearings should be a "tight push fit". You don't want anything lose fitting if you plan to rotate the shaft in the 30,000+ RPM range! Also consider a split pillow block which would allow a clamping screw to set the bearings radial play amount. I did this on one of my test stands & it works extremely well.

JA

 

[Terry Keeley]

Great, thanks. Sounds like I'm headed in the right direction...

 

[Terry Keeley]

Got the bearing pockets done, just havta drill the oil passages then it's assembly time.

Was tedious work getting the 2-3 tenths press needed.

 

[Ray Sametz]

OMG Terry, is that some shavings behind your thumb!!!!!!!! Your slipping.

 

[Terry Keeley]

Lol! Yup.

Here's what 0.0001" worth of shavings looks like:

 

[RaceMechaniX]

Terry, did you have to run pretty low chuck speeds to avoid any vibration from the uneven mass distribution?

 

[Terry Keeley]

Terry, did you have to run pretty low chuck speeds to avoid any vibration from the uneven mass distribution?

For sure, partly why this part took so long. Was thinking about adding some counter weight to balance it but under about 300 rpm is was OK.

 

[John Beardslee]

For sure, partly why this part took so long. Was thinking about adding some counter weight to balance it but under about 300 rpm is was OK.

Terry, is your mill not working? That would have been my first choice for boring bearing pockets.
Thanks John

 

[Jim Allen]

Terry,

I use my face plate to hold many different pieces. I took one finish cut on the entire face & marked its mounting position. The D1-4 camlock mounting will repeat well within .0001" if everything is clean.

Jim Allen

 

[Terry Keeley]

Terry, is your mill not working? That would have been my first choice for boring bearing pockets.
Thanks John

Maybe if I had a Wohlhaupter! https://www.mscdirect.com/product/details/66310061

My run of the mill Criterion will never hold tenths unfortunately.

Terry,

I use my face plate to hold many different pieces. I took one finish cut on the entire face & marked its mounting position. The D1-4 camlock mounting will repeat well within .0001" if everything is clean.

Jim Allen

Great mind think alike. My plate was pretty good as is, 0.001" runout and about the same dish. Took a finish cut and it's now dead nuts after I set up my lathe with a test bar and Starrett Master level:

https://www.practicalmachinist.com/...11-324468/?highlight=emco+headstock+alignment
Love this thing. I can literally take a tenth out of a bore (50 millionths cut). I'm going to put a DRO on it next like my mill.

What's that at the top of the photo on your's? Light?

Here's one for you Ray:

 

[BobHorowitz]

Looks like a guard. I have one one my big lathe.

 

[Jim Allen]

Terry,

Your looking at the bottom of a chip shield, splash guard, not a light. I adapted the stainless steel plumbing from a 13" Clausing Glowchester tool room lathe to provide coolant. Be aware that the coolant used was the same "oil based coolant" used in a Hardinge tool room lathe. Also notice the water proof, shock resistant, jeweled movement, indicators, permanently mounted on the carriage & the compound. They tell me if there is any movement of the carriage or compound due to vibrations from cutting operations.

Jim Allen

 

[Terry Keeley]

Very nice! Is that a taper attachment in the second photo?

 

[Jim Allen]

Yes. Notice the custom way wipes made from very high density felt material on the taper attachment. I added this same material to the carriage & compound ways. The taper attachment made the machining of tuned pipe tapered sections "a piece of cake".

 

[Joseph Durnya]

Maybe if I had a Wohlhaupter! https://www.mscdirect.com/product/details/66310061

My run of the mill Criterion will never hold tenths unfortunately.





Great mind think alike. My plate was pretty good as is, 0.001" runout and about the same dish. Took a finish cut and it's now dead nuts after I set up my lathe with a test bar and Starrett Master level:

https://www.practicalmachinist.com/...11-324468/?highlight=emco+headstock+alignment
Love this thing. I can literally take a tenth out of a bore (50 millionths cut). I'm going to put a DRO on it next like my mill.

What's that at the top of the photo on your's? Light?

Here's one for you Ray:

LOVE MY SUPER 11

 

[Terry Keeley]

The ultimate hobby lathe!

I see a Royal collet closer there too. Got mine a year or so ago and love it!

 

[Joseph Durnya]

here is my 56 from back in the manual shop..

 

[Joseph Durnya]

im collecting attachments.. lol