Micro-machining

[Mosey]

Lilliputian Machining

I hope this isn't trivial to you guys, but here goes.
I have been machining for years and tend to take everything for granted in regard to methods and tooling to make them work, using whatever most people have at hand. I make mostly little engines, Silver Bullet, Upshur single, etc. Recently working on a water pump for my Silver Bullet, the light went on. Why am I trying to make things using these full size (4" vice, 6" rotary table, etc.) tools? So, I started by replacing my dividers with old Starrett 2" dividers, that are little gems and fit the task of laying out tiny things. I then bought a little micro drill press from MicroMark for those #60-80 drills, got a 2" precision vice, etc., and am looking for a 0-1/8" Albrecht chuck for it.
I am looking at the entire shop as a realistic shrine for tiny stuff. It's fun and it really helps to make tiny stuff. The Clausing mill and 10" Southbend are fine, but when the going gets really small, put on your magnifier and go to the tiny.
I am very lucky to have an Aciera F1 mill, that now has a Sherline 4" rotary table. It is just right for milling a water pump that is 1" in diameter, with tabs that are 1/4". So, for me, this is a great bit of fun working small stuff with appropriately small tools.

 

[stevehuckss396]

What ever gets the job done. I have been in a similar mode lately.

 

[Cbowler]

Hi Mosey,

If you're into small check out Sherline.com!

Cheers,

Cole

 

[Mosey]

Can I cut 10 tooth 48 dp gears with a home made hob? Can you hob gears with this small number of teeth? (Silver Bullet water pump)

 

[steamer]

With an F1...sure you can!

Got one too... ;D

Dave

 

[gbritnell]

As Dave said, yes you can. The problem with cutting a very low number of teeth on a gear with a hob is that the involute curve is not very smooth. With using them in a pump, either water or oil, you need a very good fit between the teeth so that the fluid doesn't bleed back when it produces pressure. You could probably get away with them for water but not for oil. If you go to my transmission build somewhere in there is quite a few posts on cutting gears with a hob and there are some very nice layouts of what happens when cutting with a hob. (home made hob)
gbritnell

 

[stevehuckss396]

Can I cut 10 tooth 48 dp gears with a home made hob? Can you hob gears with this small number of teeth? (Silver Bullet water pump)

You really need to use the 9 tooth gears that are called out on the drawing. The water is moved by the gear teeth pushing coolant around the outside of case buy the empty teeth. The smaller the teeth the less water will be displaced. If you are going to cut some gears, cut the 9 tooth.

 

[MachineTom]

I have an involute 48DP no.8 it is marked as a 12-13 teeth cutter. Yielding a .291"D gear at 12T, using a .229"D blank for 9T, would just leave the root deeper than profile design. Since it only pumps water and not trasmitting power should work well for the application.

 

[Troutsqueezer]

I agree, smaller equipment makes sense for smaller parts but the older I get, the harder it is to see those parts. Even so, I've kept my eye out for used Sherline or Taig equipment on Craigslist to go along with my bigger machines but they rarely show up.

It might be a challenge to adapt to smaller equipment when I'm so used to having large equipment. Rof} Oh.....bad joke. Sometimes I kill me.... *beer*