I think I set a record today for the most hours spent for a part so small.  It is the same diameter as a quarter.  I must have spent a total of 5 hours.  Most of that time was spent configuring my lathe tool table again, and again.  But I found the problem that has been causing me so much grief.  I was using a .004" feeler gauge for setting my tool positions.  Today I noticed something funny about it and looked closer and found a .005" feeler gauge stuck to the back of the .004".  So all this time my setting have been off by .01" (twice the .005").  With all my prior pieces I was having a heck of a time getting the dimensions to come out correct.  I kept adjusting my tool table.  Now, after making the tool table adjustments again with the proper value, my part came out +.001" on the first try. 

Another problem I had was I broke my parting tool with a rapid.  I have been having trouble fining a parting tool that works with my 3/8" tooling the CHNC requires.  I decided to ground down a 1/2" blade that was .0625" too tall.  That took about another hour to get it right.  In the end it worked well.

The part in the picture is the Crank Disk.  It has a 0-80 thread tapped in the small hole.  It required a .020" slot across the flange to allow a press fit.  I did not have anything that small that I could machine so I cut it by hand with a .015" wide jewelers saw.   I made it through without breaking the blade.   The time spent on the part included programming.  For the first time I used a G96 (constant surface speed) with a G95 (feed per revolution).  It worked out very well and cut the time machining the part in half.  I won't go into the first attempt I made that I had to scrap because I read the dimensions wrong.

Yesterday I made another connecting rod end that looks very much like the one shown previously. 

Vince

Hey Vince,
Looks good. As far as time goes, for every part i just allow 2 hours. Even what seems simple
turns into two hours. But you got to admit, if you screw it up it's only a penny in material, 
and wiith CNC you can make another bad one just like the first one.
Additionaly it keeps ya out of the bar! 
RICH

wiith CNC you can make another bad one just like the first one.

RICH

That is something I like about CNC.  When I am all done, I could make another one in about 1/5 the time.  All the bugs are worked out and it is almost just loading stock. 

I attached a couple more pictures to show where I am at.  The flywheel will be the next big challenge.  It will take a couple of hours just to program it.  I think I only have enough stock for one so I have to make it right the first time.

Vince

I got 6 hours work on Thursday and another 6 hours today.  It will help with the mortgage, but it cuts into my projects time ;-)  I have been told that if the company I work for does not sell by Wednesday, I will be laid off permanently.  At least now I know where I stand.   

I made a part in under 2 hours!!! Just barely.  It is made from Delrin.  Drilling on my lathe takes a little more time because I have to zero the center drill, then zero the drill.  After the lathe work I had to transfer it to the mill in a collet to machine the flats and cross drill.  I dream about building a small milling head I can mount to my lathe turret so I can do all of this in one go. 

Vince

I wish you good fortune with the job prospects.

Engine looking good.

Tweakie.

The project is looking very good Vince. You should be proud. 

Good luck with your job. I really hope things will level out for you in that department soon.

Brett

I got a little time today to make another part.  This one was one of the hardest so far and more than two hours.  I was able to use my cheap indexer to rotate the part to turn the .110" shaft with an end mill.  I did some finish work on it with my watch lathe.  The fork actually has a .311" radius so it can fit into the cross head guide. 

Vince

Hi, Vince

Nice work, Won't be long now.

Chip

I made two parts today, spent over 6 hours machining.  The big part was the flywheel.  The little part was a piston insert.  The flywheel took almost 3 hours of machining due to the number of times I had to turn it over and machine the other side, plus I don't have my flood coolant working right now and was limited to about 3 IPM on the feed.  There was a lot of inches to machine.  I had to write seven programs to cut the part, more if you count the bolt pattern for the hold down screws.  It came out perfect.  My 3/16" ball end mill finished so close to the spoke recess you can't even see a machining line.  I did find out that my crank pin is not true enough and there is a slight wobble in the flywheel.  I will have to make the crank pin again.  This time I will make most of it on the lathe.

Vince

I made a couple of crank pins today, .080" diameter with a .053" hole through the center and a .187" flange at the end.  I wrote the program and ran it on faith.  The cutter looked so big (a 1/4" insert), the part so small and the coolant running made it impossible to see exactly what was happening.  It all worked out.  I did have some trouble finding the part after I cut it off, then I dropped one of them twice.  I finally put them on a piece of 18 gauge wire so I would not loose them.  The third part on the wire is the piston insert I made yesterday.  That's a penny in the picture.

Vince