Mini Prony?

Discussion in 'Prony Brake' started by DMahalko, Sep 4, 2008.

  1. DMahalko

    DMahalko Intermediate Poster

    Hmm, with hobbyists making miniature steam engines, I am interested to know if anyone has tried building a miniature Prony brake about 1 foot in diameter?

    It looks like it should be feasible to do this using a common small flat-belt pulley.

    Also, having a small one would also mean it'd be easier to test out some of the other stationary engines in the buildings. I was asking someone by the Otto engines if they've been run on the Prony, and he said most have not, and it's a problem of "getting the big Prony over here or the engine over there".

    With a very small Prony it'd be a lot simpler to move one around in buildings to profile the stationary engines, or to have one of the stationaries running under full load during the show weekend rather than mostly just coasting.

    - Dale
  2. Jerry Christiansen

    Jerry Christiansen Mega Poster WMSTR Lifetime Member

    Hi Dale,

    Two smaller, portable Brakes exist and are present at Rollag.

    Ray W. from Bismarck, ND build a Brake that has a lever arm 1/3 the length of the lever arm on the Red Brake. Ray's Brake is on wheels and is samll enough that two people can lift it. Depending on belt pulley size on the enigne and engine rpm, Ray's Brake can measure up to the 9hp range.

    My wife owns the Blue Brake that I built a couple years ago. It has the same 5.25ft long lever as the Red Brake but has a smaller frame, smaller belt pulley and smaller brake wheel. Depending on the type of engine and pulley size the Blue Brake can measure as low as 3.5Hp and as high as 140Hp. The Blue Brake is portable and has been in different locations at Rollag. This year it spent Friday afternoon on Expo Hill running the 'new' 22Hp return flue Minneapolis. During last year's show it went into the trees and ran a stationary engine in the Gas Engine Go Getters building, a couple other smaller gas engines in the trees and a scale Case steam engine that was near the Montana Boiler.

    I would love to run the Brakes as you have described. Unfortunatley there is only one of me and three Brakes I would like to work with (plus the Pabst Engine)! I am working on getting some people interested in working with the Brakes.

    I think I have a couple people that are interested in working with Ray's Brake. As small as that Brake is, it still takes some muscle to move it around. It also takes a bit of effort and skill to get it set up each time it is moved to another engine.

    The Blue Brake is a bit much to pull around the hill of Rollag by hand, it weighs about 1500 pounds. Any crew that moves it to a staionary engine will need something to move it around. Even after it is in place, getting the belt lined up and tight is interesting.

    I think I over answered you question. Perhap someone will read this post and then be interested enough to become a crew member on one of these Brakes. Contact me if you are.

    Jerry Christiansen
  3. 40avery

    40avery Mega Poster Super Moderator WMSTR Lifetime Member


    Is the blue brake going to make an appearance at New Rockford this year??
  4. Jerry Christiansen

    Jerry Christiansen Mega Poster WMSTR Lifetime Member

    Hi Rick,

    If things go as planned, yes. We should arrive Friday evening.

  5. 40avery

    40avery Mega Poster Super Moderator WMSTR Lifetime Member

    Thanks Jerry we will see you there.:thumb:

Share This Page