Thursday, September 23, 2010

Ball Bearings Steady Rest - Finally!!!

Finally... I did it!!!  The ball bearings steady rest is done and its working good!

I am on medical leave today and spent most of the time with my dentist for the last of the 2 implants.  The final session with him was set on early November to have the crown installed.  But the major part was over.  After almost a year, I'm really glad.

I had 3 hours in between the 2 sessions at the dental clinic.  Took a cab down to my favorite Kelantan Lane area to pick up a small hand press (arbor press?) from Hup Hong at Jalan Besar Plaza.  While I was there, I went over to get 4 pieces of 25mm square aluminium stock of 1' long.  I'm going to use that as the base for my mill and lathe, following the fashion of David Clark.

Ok, enough said, pics time:

I'm going to reuse the piece that I screwed up previously.  It should still work...

The made in China hand press I bought from Hup Hong today. Slightly over SGD200 including tax.  Its a 50kg press with a 10mm hole for the pin.  I've nothing to insert in there yet.  Will be using the edge to press instead.

Turning another piece of aluminium to 3.05mm. This time, I kept the length shorter to reduce the chance of bending it during press fitting.

After drilling the 3mm hole 3mm away from the edge, I set it up on the tilting angle plate at 45 degree and milled off both side.

This is just to try out the new toy I bought a few weeks back.

The result.  Some filing will be done next.

After filing.  Ok, not the best looking radius but this was my best effort...

Ball bearings fitted.  Couldn't take a pic while press fitting as I was leaning my weight on the little press to push the aluminium pin in.

Ugly looking but they work!!!

All 3 installed on the steady rest. Actually, they're part of the steady rest... what am I talking about....

Testing done using a short piece of steel stock. Didn't bother to dig out the longer one to test.  All bearings rotates as they should.

Ok.  One project down for the machine.  Some time left before my dear wife reaches home.  I quickly setup the mill to try out 3D milling of a human face.  The attempt failed badly.  I'm reviewing the toolpath generated and the parameters I input.  Will do up a post on that next time.

Here is what it should look like:

Simulated using Bobcad included package - Virtual CNC for Mill.

I screwed up big time on this job.  Lots of chatter and the 6mm ballnose I was using cut into the face!!!

That's all for tonight.  Time to hit the bed.  Its 1.31am and I've a long day tomorrow.


Adam Collins said...


You should do a search on You Tube for that face-I've seen a few vids posted there of similar faces being machined. I doubt any of the ones I saw were milled on a Sherline, but you'll find some pretty nice finished examples if nothing else.

Where did the end mill cut into the face? One thing I would check would be the clearance setting and/or the retract plane lengths in the program; setting each to "full retract/clearance" or larger than the maximum cut depth in the program should keep you pretty much safe if the end mill dug in because of a 2.5mm (0.100") clearance/retract setting during a rapid move to another contour or the start of another pass.


Wongster said...


I believe its more of missed steps than thre rapid plane. It was at the start of another pass it decided that it should move towards that spot to begin its cut.

This was destined to fail from the beginning as the step-over was set a little too wide.

I was inspired to do my own 3D face after watch those Youtube vids. It looks so simple...

Thanks for your comment, Adam. I'll be posting up my job for someone I met last week for only less than 15 mins later today.