Model Engine Maker

Engines => From Plans => Topic started by: kvom on April 18, 2016, 04:51:58 PM

Title: 3-day challenge - engine rebuild
Post by: kvom on April 18, 2016, 04:51:58 PM

Now that the paddle engine is working as well as it's going to get before I leave for NAMES, I decied to set myself a challenge to get my Bogstandard Paddleducks engine to run again.  If I succeed I'll cart it to NAMES too.  All the parts have been sitting in a drawer since the last pic, posted on HMEM on Jan. 20, 2010.  I need to remake a couple of the shafts that make up the 5-piece crankshaft, but that's mostly a manner of cutting some 1/4" drill rod to the proper lengths.

The build thread on HMEM is http://www.homemodelenginemachinist.com/showthread.php?t=4264 if anyone's interested.  Here's the last pic I mentioned:

(http://m8.i.pbase.com/g3/00/631400/2/121258618.qfkVFf3s.jpg)

One difference is that I will try to replace most of the socket screws with model scale hex heads.

Yesterday I mounted the bearings to the base and aligned them with a long piece of drill rod, then turned with the mill to wear in the shaft a bit.

Today I'm giving all of the brass pieces a short soak in white vinegar to remove the accumulated tarnish of 6 years.

Title: Re: 3-day challenge - engine rebuild
Post by: kvom on April 19, 2016, 11:07:25 PM

Got it back together to match above pic.  Tomorrow's final day is timing the valves and running in.  The motion is still a bit stiff even after 15 minutes driving it with the lathe.

Title: Re: 3-day challenge - engine rebuild
Post by: crueby on April 20, 2016, 12:28:40 AM

Quick turnaround!

Are you going to run in the shaft with any kind of lapping compound or anything?

Title: Re: 3-day challenge - engine rebuild
Post by: kvom on April 20, 2016, 04:54:41 AM

The crankshaft is built up with 5 pieces of 1/4" drill rod.  I did run a straight piece in the bearings for a while. 

Title: Re: 3-day challenge - engine rebuild
Post by: kvom on April 20, 2016, 11:38:10 PM

I failed my challenge.   :shrug:

Spent a good part of the afternoon making an inlet attachment for the air supply as the copper tube let the plastic blow off.  I timed the valves as per John's notes, but no go with air applied.  I did get a slight kick at one point in the cycle; since it did run in the past after lots of fiddling, I see no reason why it can't be done.  I'm taking it to Detroit and can mess with it during the show.  Car is loaded for early departure tomorrow.

Title: Re: 3-day challenge - engine rebuild
Post by: zeeprogrammer on April 20, 2016, 11:41:06 PM

Bummer. But still good to take along.