PMR #1 - Finished

[vederstein]

It took considerably longer than I thought, but my PM Research #1 is complete (Video below the photos):

 

[pirmin kogleck]

heres mine

 

[Steamchick]

Vederstein, I don't like to criticize, but PM research are at fault: The flywheel needs a counterbalance weight to minimise the imbalance of the piston, rod, crosshead, con-rod and big-end masses. I simply hate manufacturers that sell kits that have not been properly engineered with a counterbalance cast-in to the flywheel. They make a lovely, well made model look "amateurish" when finished and running. But it is nothing you have done, following their instructions. Just their poor omission. You can add a balance weight, (lead and clay/plasticine for experimenting?) with a bit of trial and error, and reduce the imbalance oscillation considerably. Then the engine will be able to run much slower as well.
(Old man's rant finished!)
But a smooth runner all the same, which is proof of good machining and assembly.
Well done.
K2

 

[cheepo45]

Very nice!
I like the paint job.
Scott

 

[Steamchick]

My "less than perfect" table engine. I aspire you the quality you achieve Verderstein, but fail by a measure or 3!
K2

 

[pirmin kogleck]

Honestly, my engine can run on very low pressure,and very slow at aprox 50-60rpm. I domt see the need for a counterbalance on such a small model.

 

[vederstein]

I don't like to criticize, but PM research are at fault:

It's been some time since I've completed an engine. I'll freely admit this isn't one of my best machining jobs.

I'm fully aware it doesn't run appreciably smoothly, but that's ok.

If I was perfect, I'd have no reason to keep doing this...

Thanks,

...Ved.

 

[Steamchick]

OK Pirmin. Ved, Your engines are better than mine, but I try and balance them so they run slowly and smoothly. Just one of my little quirks, to improve my own sub-standard machining and assembly skills.
"Balancing" a steam engine (and any multi-cylinder engine) means getting both the valve timing even between the cylinders, and the mechanical balance, though it was just the mechanical imbalance that I could see was a manufacturer's fault with this one. If they had bothered, they would have cast-in a balance weight on the flywheel, and provided instruction about where to set it relative to the big-end. But manufacturers of kits are simply too tight on costs to bother.
As long as you are satisfied with the end result, I have no worries.
I spent 20 years getting my Moto-Guzzi to idle reliably... by NOT setting the carbs to be identical, as the V-twin had different characteristics of engine speed for each cylinder.. (firing 285 degrees and 435 degrees apart) - so maybe I have hang-ups about such things.
Looking forward to seeing the next builds!
Thanks for posting your engines,
K2

 

[packrat]

Steam engines take a long time to build, I have spent 3 years on one, {that was when I was working full time} and just worked
on it when I had time...

 

[Steamchick]

Speedy! I am retired but hardly find more time for modelling than when I was working...
" years have passed since I started machining castings for a water pump - still Work-in-progress!
A new boiler assembly has stalled - for 3 months - due to other boilers needed re-certification.
Too much ambition, too little application!
K2

 

[radial1951]

Vederstein, I don't like to criticize, but PM research are at fault: The flywheel needs a counterbalance weight to minimise the imbalance of the piston, rod, crosshead, con-rod and big-end masses. I simply hate manufacturers that sell kits that have not been properly engineered with a counterbalance cast-in to the flywheel.

Steamchick, with respect, that's a bit unfair. PM Research are not really "at fault". They are just providing a period-correct simple stationary steam engine model. I don't recall seeing such full size engines with a counterbalanced flywheel although there may well be some. Most basic traction engines and portables, for example, have plain spoked flywheels and even bent-from-round-bar crankshafts with no obvious attempt made to balance anything. Hence they gently rock back and forth when at work. Unfortunately, the model in the video is running way over scale speed which accentuates the imbalance. At 1/2-1/3 the rpm this would not be an issue...

 

[Steamchick]

Point taken. Though I shall try and balance my engines as they are not actual models of real engines but representations of type. - and I like them to run a bit smoother than the unbalanced "shake".
That is my preference, and I was simply expressing my opinion.
Hope I didn't offend? Sorry if I did. Not my intent.
K2

 

[Propforward]

It’s a nicely built engine - looks great! Well done Vederstein you should be happy with that - great presentation as well. Nothing wrong with the model supplied by PM Research. The negative criticism is not appropriate and detracts from the thread.

I like the video presentation with some still shots before the action.

 

[vederstein]

negative criticism is not appropriate and detracts from the thread.

In my world, negative criticisms are ok depending on the presentation.

Sometimes a criticism isn't meant to be derision. Other times they are.

I know that Steamchick didn't mean and harm based on earlier correspondence and the content.

Other's (particularly comments on Youtube) are meant to be hurtful.

Also, If I'm going to put my work out there, I have to be ready for the Hellscape that is the Internet....

Thanks,

RJC

 

[Propforward]

Well said, the internet is indeed a hellscape. Life is too short for that. Model engines are all good, and that should be enough.

 

[55fairlane]

I personally think you did a wonderful job and congratulations are in order.....can't wit to see it this fall at the show!

 

[Richard Hed]

In my world, negative criticisms are ok depending on the presentation.

Sometimes a criticism isn't meant to be derision. Other times they are.

I know that Steamchick didn't mean and harm based on earlier correspondence and the content.

Other's (particularly comments on Youtube) are meant to be hurtful.

Also, If I'm going to put my work out there, I have to be ready for the Hellscape that is the Internet....

Thanks,

RJC

LOL, you are so right. ONe time I was critiquing someones story. I warned the fellow that often a critique NOT meant to be harsh, might appear to be ripping one's innards out, but is indeed NOT all that harsh. So this fellow had a GREAT sci-fi idea and wasn't all that bad of a story line. HOwever, he had certain annoying methods, particularly, every time one character would speak to the other character, he would ALWAYS say, " Bill . ...", then "Fred . ....", "BIll ....." "Fred..." Well people simply don't talk like that in real life. If there are a large number of people around, one might say the other fellow's name once in a while, but come on, do you know who you are talkinhg to if there are only two people involved? So I pointed this out and he thot I was being harsh. OH vey. He wouldn't talk to me after that. I thot it was horrifying because I wanted the fellow to succeed--and he DID have a pretty good story. He also had a major error but with one rewrite could fix that--not too difficult.

Just so y'all might know--He was an Australian writing a story about a war on American soil where he separated the factions north and south. I pointed out that in the modern day, it would most likely be east and west or possibly east + west vs mid-west. But this all came from the fact that he didn't really know what America is like at the present day, nor it's history. If you want to write about something, make sure you know it's history and present day politics.

 

[vederstein]

I spent a bit of time today and was able to improve the running somewhat. I can get it to idle reliably at round 15 psi.

It has a bad knock that I cannot get rid of though. It's the crankshaft. I tried three times to make it and it's still not straight. I'm officially at "Screw It" mode. It's done.

I remember at the Engine Show at NATMUS. I was looking at the the vendor's items and was talking to another modeller. I mentioned that everyone in this hobby has their particular place of expertise. I joked that mine is apparently half-assing it.

Otherwise, in the second video, I did find a novel orientation to run it!!