Author Topic: Chris's Holly Pumping Engine Build  (Read 154170 times)

Online Don1966

  • Full Member
  • *****
  • Posts: 6817
  • Columbia, MS
Re: Chris's Holly Pumping Engine Build
« Reply #1275 on: September 27, 2021, 11:21:22 PM »
Well there was a flat surface there on the top so the solder should of flowed good…..as fir the brass solder would wick very nicely. What I like about sweat soldering is less solder excursion!



Don
Does silver solder flow better on a brass surface? Or is it because of the curve?
Chris I find it flows very good on brass then other metals. Same with copper.

Don

Offline crueby

  • Full Member
  • *****
  • Posts: 18557
  • Rochester NY
Re: Chris's Holly Pumping Engine Build
« Reply #1276 on: September 28, 2021, 08:46:51 PM »
More done on the crossheads, cut out the gap in the center for the top end of the con rods

Test fit on the con rod ends

Also got the slots for the wedges drilled through, two small holes connected with a dental bur in my air handpiece

That leaves the bearing blocks for the out ends of the cross bar. On the real one they have adjustable wedges either side, have to see how the dimensions are to see if there is room to actually make them adjustable or not - its a lot to pack into a tiny space and still get working screws at this scale, the screws on the real one are pretty small. Good task for tomorrow...

Online Kim

  • Global Moderator
  • Full Member
  • *****
  • Posts: 7860
  • Portland, Oregon, USA
Re: Chris's Holly Pumping Engine Build
« Reply #1277 on: September 28, 2021, 11:42:08 PM »
Very nice, Chris!  :popcorn: :popcorn:
Those are very complex crossheads.  And here I am thinking the crossheads I'm doing for the Pennsy are hard.  And you had THREE of them to do, not just two.

Kim

Offline cnr6400

  • Full Member
  • *****
  • Posts: 2729
Re: Chris's Holly Pumping Engine Build
« Reply #1278 on: September 29, 2021, 02:30:50 AM »
 :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:
"I've cut that stock three times, and it's still too short!"

Offline crueby

  • Full Member
  • *****
  • Posts: 18557
  • Rochester NY
Re: Chris's Holly Pumping Engine Build
« Reply #1279 on: September 29, 2021, 02:35:21 AM »
Very nice, Chris!  :popcorn: :popcorn:
Those are very complex crossheads.  And here I am thinking the crossheads I'm doing for the Pennsy are hard.  And you had THREE of them to do, not just two.

Kim
Both shapes are complex - just different!  When I am done, it will pump water to your locomotive's water tower, ready for you to drop into the boiler!

Offline crueby

  • Full Member
  • *****
  • Posts: 18557
  • Rochester NY
Re: Chris's Holly Pumping Engine Build
« Reply #1280 on: September 29, 2021, 02:36:36 AM »
:ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:
:cheers:

End of next week the guy that got me the plans for the Holly engines is stopping by to see the progress and all the other models, be fun to see his reaction to a mini version of the pumps.

Online Kim

  • Global Moderator
  • Full Member
  • *****
  • Posts: 7860
  • Portland, Oregon, USA
Re: Chris's Holly Pumping Engine Build
« Reply #1281 on: September 29, 2021, 06:00:22 AM »
Very nice, Chris!  :popcorn: :popcorn:
Those are very complex crossheads.  And here I am thinking the crossheads I'm doing for the Pennsy are hard.  And you had THREE of them to do, not just two.

Kim
Both shapes are complex - just different!  When I am done, it will pump water to your locomotive's water tower, ready for you to drop into the boiler!

Glad someone is thinking of the upstream water supply issues I'll have later! Thanks Chris!
Kim

Offline crueby

  • Full Member
  • *****
  • Posts: 18557
  • Rochester NY
Re: Chris's Holly Pumping Engine Build
« Reply #1282 on: September 29, 2021, 08:28:30 PM »
Quite a bit done on the crossheads today. Started out by taking some bearing bronze rod, turning it slightly to an even size for the collet (it comes as a rough oversize rod) and milling the end square in a length long enough to get out two bearing blocks at a time (need 6 overall).

Cut off each block a little overlong, and faced the ends on the lathe to dimension and added the steps. The originals had adjusting wedges down each side, but at this scale the screws would be 00-90 or smaller, and there would be no way to get a wrench and my fingers in to adjust them. So, leaving off that tiny detail.

Here is one set ready to assemble onto the model. All three sets are to this stage. The sides of the blocks are a touch oversize, will file them off to be a nice sliding fit in the guides on the frames.


Here is the first one with the blocks filed to fit the guides, and all the bits all bolted up to the pump rods.

That is where things slowed down. The ends of the pump rods step down to 1/8" diameter to go through the holes in the crosshead legs, and the ends of them are threaded. But, it turns out there was still just enough of a bur at the ends of the threads that kept them from sliding into the holes in the crossheads. So, unscrewed each one from the pump plunger, fettled them smooth at the base of the threads, and ran them back in. That is tedious, not a lot of finger room.
Then, got them all in and the top nuts on, and gave the flywheel a slow spin by hand. All went well till the very bottom of the stroke - the pump rods need to be about 1/16" shorter, since the plunger bottoms out just befor bottom dead center on the crank. I was worried about that, and had tried to leave some adjustment room on the rods, but apparently not enough. I tracked it back to the bottom of the corsshead legs, those brass pieces. I left them a bit tall to give more material around the bottom of the cutout where they were soldered to the round center section, forgetting that it would push the pump rods down that same amount. Elf-puckey!
Couple ways I could adjust that - I think what I will do is to take the rods back out, and turn back the top shoulder that same amount since I would like to leave the extra material on the legs, and its less work than to get that first crosshead back out again! The rods for the other two cylinders have not come out the first time yet, so I can do the thread deburring and turning the shoulders back in one go rather than two.
Good news is that aside from that last bit of the rotation, everything moves smoothly, and the plunger movement does not add any noticeable drag - it will when actually pumping, but at least the mechanism works!

Stopping there for the day, will tackle that next time.
 :cheers:

Offline RReid

  • Full Member
  • ****
  • Posts: 1668
  • Northern California
Re: Chris's Holly Pumping Engine Build
« Reply #1283 on: September 29, 2021, 09:16:11 PM »
Glad you see a fairly easy solution to that little glitch. You'll soon having it all spinning as sweet as it looks.
Regards,
Ron

Online Don1966

  • Full Member
  • *****
  • Posts: 6817
  • Columbia, MS
Re: Chris's Holly Pumping Engine Build
« Reply #1284 on: September 29, 2021, 09:24:26 PM »
Yep! Your definitely the man for the job. Outstanding work Dog……..I……………likeeeeeeee…… :Love:



 :drinking-41:
Don

Online Kim

  • Global Moderator
  • Full Member
  • *****
  • Posts: 7860
  • Portland, Oregon, USA
Re: Chris's Holly Pumping Engine Build
« Reply #1285 on: September 29, 2021, 11:42:57 PM »
Yeah, these are the kinds of things that happen when you insist on creating new ginormous models that haven't been tried out before!  You get to be your own guinea pig! :Jester:

I'm certain you'll get it squared away, Chris.  Taking a break and tackling it tomorrow sounds like the right move for now.  It's all part of the charm of the hobby, right?  :naughty:

Kim

Offline crueby

  • Full Member
  • *****
  • Posts: 18557
  • Rochester NY
Re: Chris's Holly Pumping Engine Build
« Reply #1286 on: September 29, 2021, 11:50:11 PM »
Yeah, these are the kinds of things that happen when you insist on creating new ginormous models that haven't been tried out before!  You get to be your own guinea pig! :Jester:

I'm certain you'll get it squared away, Chris.  Taking a break and tackling it tomorrow sounds like the right move for now.  It's all part of the charm of the hobby, right?  :naughty:

Kim
And by not following my own plans the guinea pig got stepped on!   :o

Easy fix at least! 


Thats one thing I've (mostly) learned over the years, when to stop, walk away, go do something else before mucking it up from getting tired.

Offline cnr6400

  • Full Member
  • *****
  • Posts: 2729
Re: Chris's Holly Pumping Engine Build
« Reply #1287 on: September 30, 2021, 12:25:31 AM »
Is your shop's guinea pig named Murphy by any chance?  :Lol:

The mechanism is looking great!  :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:
"I've cut that stock three times, and it's still too short!"

Offline crueby

  • Full Member
  • *****
  • Posts: 18557
  • Rochester NY
Re: Chris's Holly Pumping Engine Build
« Reply #1288 on: September 30, 2021, 01:12:45 AM »
Is your shop's guinea pig named Murphy by any chance?  :Lol:

The mechanism is looking great!  :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:
His name has to be Murphy, its the law!   :ROFL:

Online Kim

  • Global Moderator
  • Full Member
  • *****
  • Posts: 7860
  • Portland, Oregon, USA
Re: Chris's Holly Pumping Engine Build
« Reply #1289 on: September 30, 2021, 05:44:38 AM »
And by not following my own plans the guinea pig got stepped on!   :o

The best-laid plans of mice and guinea pigs!

Poor Murphy....   :'(

Kim


 

SimplePortal 2.3.5 © 2008-2012, SimplePortal