Author Topic: Small Flash Single  (Read 10497 times)

Offline vtsteam

  • Full Member
  • ****
  • Posts: 753
Re: Small Flash Single
« Reply #15 on: November 28, 2022, 11:27:37 PM »
Very stylish looking compressor, Michael. It would make a good looking steam engine if it worked out as suitable. Compressor to steam engine conversions have been done before successfully.

Well, it was a long boring day today in a cold shop. It took over 60 passes to bring the crankcase space to size. When I mentioned a ten thou cut earlier, that was diameter. Actual DOC was only .005" without getting too much skipping  against the cylinder bore. But I did finish by supper time, so, happy to move foreward now.  :smokin2:
Steve

Offline vtsteam

  • Full Member
  • ****
  • Posts: 753
Re: Small Flash Single
« Reply #16 on: November 28, 2022, 11:50:27 PM »
A bigger hole:

Steve

Offline vtsteam

  • Full Member
  • ****
  • Posts: 753
Re: Small Flash Single
« Reply #17 on: November 29, 2022, 02:05:44 PM »
The crankcase so far. The center of the main bore was located by indicating off of the turned cylinder to keep the two aligned.  Originally, there was a small shrinkage depression on one side of the cylinder, as cast. It was turned off by offsetting the casting slightly in the lathe to reduce the amount that needed to be turned off.

The base block had been roughed in slightly oversize before turning. Final size would depend on how much offset was needed to clean up the cylinder. Now the left side of the lower block needs to be milled down to match the right.

Steve

Offline Roger B

  • Global Moderator
  • Full Member
  • *****
  • Posts: 6133
  • Switzerland
Re: Small Flash Single
« Reply #18 on: November 29, 2022, 05:02:36 PM »
Very nicely done  :praise2: Metal casting tends to scare me like big propellors do ::)
Best regards

Roger

Offline vtsteam

  • Full Member
  • ****
  • Posts: 753
Re: Small Flash Single
« Reply #19 on: November 29, 2022, 07:56:34 PM »
Roger, thanks so much.  :cheers: Molten iron deserves respect, I have to admit the adrenalin is definitely up for me whenever I turn off the fuel and blower, swing open the furnace lid and look into that still grumbling inferno -- even through a filter and with protective gear on. That never changes. But the feeling after pouring isn't just relief. I don't know how others feel, but for me it's a feeling of calm elation, if there is such a thing. Keeps me doing it.

Well, one more pattern made, and one more pour today. This is the front plate and bearing housing pattern:

Steve

Offline vtsteam

  • Full Member
  • ****
  • Posts: 753
Re: Small Flash Single
« Reply #20 on: November 29, 2022, 10:25:49 PM »
Three hours after pouring, the casting looks good and cuts with a file, so it's usable. Total today including making the pattern,  was six hours from cutting wood to cooled metal part. That's a record for me with iron.



Steve

Offline vtsteam

  • Full Member
  • ****
  • Posts: 753
Re: Small Flash Single
« Reply #21 on: December 01, 2022, 08:57:57 PM »
Cold winds outside today, even without heat it felt warmer in the shop out of them! So I chucked my new raw casting in the 4-jaw and turned just enough off of the back face to give me a flat face square to the round part:

« Last Edit: December 01, 2022, 09:11:30 PM by vtsteam »
Steve

Offline vtsteam

  • Full Member
  • ****
  • Posts: 753
Re: Small Flash Single
« Reply #22 on: December 01, 2022, 09:02:14 PM »
That let me grip it flat against the back face of the milling vise, with the round part against the moveable jaw. I cleaned off all of the edges. None to actual size, I just wanted them clean and square to grip again in the 4-jaw:

Steve

Offline vtsteam

  • Full Member
  • ****
  • Posts: 753
Re: Small Flash Single
« Reply #23 on: December 01, 2022, 09:06:06 PM »
Then I put it back in the lathe and went to work cleaning up the front suraces"

Steve

Offline vtsteam

  • Full Member
  • ****
  • Posts: 753
Re: Small Flash Single
« Reply #24 on: December 01, 2022, 09:10:00 PM »
And here is the bearing housing casting cleaned up and squared off. It will need to have a register cut in the back face, and bored to fit the bearing races, which are on order, now. That's all for today. Going in the house to get warm!


Steve

Offline vtsteam

  • Full Member
  • ****
  • Posts: 753
Re: Small Flash Single
« Reply #25 on: December 02, 2022, 11:48:55 PM »
I turned the register today. It seats in the crankcase by wiggling it a little, and when I turn it upside down it doesn't fall out. That's about as close a fit as I can make, so I'm happy!

Steve

Offline vtsteam

  • Full Member
  • ****
  • Posts: 753
Re: Small Flash Single
« Reply #26 on: December 03, 2022, 04:19:05 AM »
I've been thinking about what  specs I'd like to achieve with this little experimental engine. I'm not trying for a racing engine, but I am building it very much like one in terms of materials and part dimensions. Just to get a handle on a plant and pumping requirements, a reasonable goal for this engine might be 3500 RPM, and as a guess a flash boiler producing 400 psi steam pressure.

Using those very off-the-cuff figures, I could gear the water pump 2 to 1 or 3 to 1, and so not need to go to a large spur gear or worm and wheel as required for full-out racing engines.

I'm just thinking about this now to help me plan the ancillary equipment needs.
Steve

Offline Admiral_dk

  • Full Member
  • *****
  • Posts: 3750
  • Søften - Denmark
Re: Small Flash Single
« Reply #27 on: December 03, 2022, 11:17:59 AM »
They work well as Racing Engines - but I can't help wondering if the Bore/Stroke ratio isn't too oversquare for slover running  :thinking:

Interesting journey you are taking  :ThumbsUp:

Per              :cheers:    :popcorn:

Offline vtsteam

  • Full Member
  • ****
  • Posts: 753
Re: Small Flash Single
« Reply #28 on: December 03, 2022, 02:53:39 PM »
Hi Per thanks so much!  :cheers: I have to admit I'd intended a square engine to start with but after I'd spent some time drawing and pattern making, I realized the rod would interfere with the case walls at mid stroke unless the walls could be relieved. but since I'd also tried a unitary cylinder and case, there was no way to access that area with a tool. A rookie design mistake, but well, so I am in this!

Now that I have the parts in hand, I see maybe I could have done the relieving with a Tee-slot cutter. Next time also maybe a removable cylinder. Well, woulda, shoulda, coulda.  I'm still very excited to see what happens with this one. It's becoming fun, when before I had some trepidation about starting because there seemed so many variables to work out before building an engine. Now it's just one solid thing, and I can focus on just working around that one thing.

I'm happy to have a person of your experience along for the ride. Well, all of you.  :cheers:
Steve

Offline vtsteam

  • Full Member
  • ****
  • Posts: 753
Re: Small Flash Single
« Reply #29 on: December 03, 2022, 03:16:37 PM »
The next thing I'm thinking about is the bearings and how to be able to disassemble the crank from the bearing housing. The inner bearing is an R8 open and the outer bearing is an R6 sealed. The overhung crankshaft will have a nut on the end holding everything in place. The outer bearing can be a tight fit in the housing. But the inner one should be removable intact, because the cam lobe will be outboard of it and won't pass through the bearing.

So, I'm now thinking about how to prevent that bearing from spinning? Will tightening the shaft nut trap it adequately? But I don't want to put much side pressure on those simple ball bearings (which arrived by the way). Just enough to keep them in place. Is that enough to prevent spinning? Or should I put a set screw in from the side of the register for the bigger bearing, and just a slight dimple in the outer race to seat. I don't want to put radial pressure enough to distort the bearing either. But is there enough meat for a dimple?

That's the kind of stuff that runs through my head, when I'm trying to sleep!  :headscratch:

--Steve
Steve

 

SimplePortal 2.3.5 © 2008-2012, SimplePortal