Model Boat Mayhem

Please login or register.

Login with username, password and session length.
Pages: 1 [2]   Go Down

Author Topic: Power test bench for steam engines, with Prony brake.  (Read 1594 times)

1967Brutus

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 369
  • I am in it for the learning!
  • Location: The Netherlands, Friesland to be more exact
Re: Power test bench for steam engines, with Prony brake.
« Reply #25 on: November 28, 2024, 04:59:35 pm »

Absolutely impressive, the effort in testing your engines this specific way.
Logged
If you do without observing, you won't learn a thing.
If you observe without doing, you'll never know if what you learned was true.

KBIO

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 542
  • Location: Dinan (France)
    • http://modelismenavalvapeur.forumactif.com
Re: Power test bench for steam engines, with Prony brake.
« Reply #26 on: November 28, 2024, 05:10:19 pm »

Thanks to you guys !  :-)
It is not perfect and some improvements must be done . But now , I have to pull out a Saïto from a boat to please DS88 ! ok2
It will take some time....  :embarrassed:
Cheers !


1967Brutus

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 369
  • I am in it for the learning!
  • Location: The Netherlands, Friesland to be more exact
Re: Power test bench for steam engines, with Prony brake.
« Reply #27 on: November 28, 2024, 06:40:20 pm »

It is not perfect and some improvements must be done .


Never mind that... I am sure there are more people like us, but so far, I have never seen anyone doing these ACTUAL power measurements. So that in itself is allready worthy of huge compliments.

I did some crude measurements with an improvised set-up on my gasoline powered cabin sloop, using two dynamometers/scalebeams and a friction cord around the flywheel. A lot of calculations later I figured out that it resulted in about 17 Watt before modifying valve timing, and 30 Watt after.

I never really video-documented that. I should have.

I am going to try and find a way to test my Microcosm one day, but it is going to take some time...
Logged
If you do without observing, you won't learn a thing.
If you observe without doing, you'll never know if what you learned was true.

KBIO

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 542
  • Location: Dinan (France)
    • http://modelismenavalvapeur.forumactif.com
Re: Power test bench for steam engines, with Prony brake.
« Reply #28 on: December 01, 2024, 04:50:56 pm »

Hello !
I found some time this afternoon to take the Saïto T3R out of its boat and run a test !


Max 2000 rpm @ 2b only . I get 3600 rpm 3.2 b and .6 HP. Then this old engine gave up and jammed !
Below are the only numbers I could measure but I have reserves about these figures.
I don't know what you think of those numbers but I am still away from the manufacturer's one.
Need to do some tests with steam . The boiler STUART HB4 is ready ! ok2
Anyway ! That's all fun and now I have to open engine and see ....  :-X
Steam is an endless story !
I'll try with the big one later on!
Have a nice one ! :-)

DBS88

  • Full Mayhemer
  • *****
  • Online Online
  • Posts: 582
  • Model Boat Mayhem is Great!
  • Location: Surrey
Re: Power test bench for steam engines, with Prony brake.
« Reply #29 on: December 01, 2024, 08:17:06 pm »


Oh No! hopefully the T2R engine can easily be brought back to life without too much trouble
The Saito published power outputs for their engines are:
Saito T2DR has a published power output of 22 watts or 0.03hp
Saito T3DR is given as 28 watts and 0.038 hp.
Saito T2GR (The Big One) claimed power output of 75 watts or 0.1 HP with a max torque of 3000g/cm or 2.6lbs/inch with a max rpm of 3600


The Engine on test looks like the T2DR? if so Saito claim 22 watts.


Your test achieved 21 watts at 2Bar and Saito rate the T2DR at 2 Bar - it suggests your set up is pretty accurate, well done


Here is the performance data for the T2DR from Saito
Bore: 12 mm
Stroke: 12 mm
Speed: 6000 rpm
Power: 0.03 hp
Pressure: 2 kg / cm2
Cylinder capacity: 5.4 cc
Max. Torque: 1050 g / cm




The results from the Big One will be interesting when compared with the Stuart D10
Logged

KBIO

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 542
  • Location: Dinan (France)
    • http://modelismenavalvapeur.forumactif.com
Re: Power test bench for steam engines, with Prony brake.
« Reply #30 on: December 02, 2024, 08:15:16 am »


Hello!
Here's some encouraging news, despite the machine's setbacks.
Which goes to show that Marcel doesn't just drink pasta water, and that his formula is a good one!
I'm going to have to do a lot more measurements to confirm these good figures.
Thanks for your information!  :-))
Have a nice day!

KBIO

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 542
  • Location: Dinan (France)
    • http://modelismenavalvapeur.forumactif.com
Re: Power test bench for steam engines, with Prony brake.
« Reply #31 on: December 08, 2024, 09:36:39 am »

Hello !
Taking advantage of the fine weather (Darragh) to take shelter in my barn, I tested the big Saïto T2GR (+/- 23 cc).
The table shows that the machine performs much better at 3b than at 2b.
To keep up the pressure, my 25 l compressor couldn't cope. I therefore used the 50-litre compressor, which was more suitable.
The test showed that the measurements corresponded well to the manufacturer's data = 75 w as shown by DS88.
The machine could have given more, but the magnet glued and crimped in the friction disc came loose with the friction heat on the jaws = +/- 80 °C . It was smoking like on the brakes like tires burning ! %%



1967Brutus

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 369
  • I am in it for the learning!
  • Location: The Netherlands, Friesland to be more exact
Re: Power test bench for steam engines, with Prony brake.
« Reply #32 on: December 08, 2024, 12:04:01 pm »

No wonder the brake disc gets hot... You're dissipating 75W of friction there, that's a VERY decent soldering irons' worth of heat... :D
Logged
If you do without observing, you won't learn a thing.
If you observe without doing, you'll never know if what you learned was true.

DBS88

  • Full Mayhemer
  • *****
  • Online Online
  • Posts: 582
  • Model Boat Mayhem is Great!
  • Location: Surrey
Re: Power test bench for steam engines, with Prony brake.
« Reply #33 on: December 08, 2024, 04:55:27 pm »

Well done, thats a great result, having used a known standard to verify your test rig, you now know the numbers produced from your test rig are pretty accurate which is a fabulous achievement. Thank you for taking the time to conduct and share the experiments. Are you going to test other engines? It would be interesting to see what a Cheddar Proteus produces in terms of power! In any event you will soon have a league table of engines and their power ratings
Logged

1967Brutus

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 369
  • I am in it for the learning!
  • Location: The Netherlands, Friesland to be more exact
Re: Power test bench for steam engines, with Prony brake.
« Reply #34 on: December 08, 2024, 05:14:33 pm »

Absolutely agree with that!
Logged
If you do without observing, you won't learn a thing.
If you observe without doing, you'll never know if what you learned was true.
Pages: 1 [2]   Go Up
 

Page created in 0.098 seconds with 25 queries.