jhon hennems

[old man]

High everyone,
                        I have a question about my John Hennems steam engine . Can anyone tell me why the bloomin thing goes faster backwards than forwards .
with all the settings excactly the same , pressure , throttle position etc.. it goes about half as fast again in reverse wich is quite spectacular on the lake
bow wavea who needs bow waves when it goes so fast backwards it becomes a submarine..
any advice would be greatfully received.  Thanks  Old Man

[derekwarner_decoy]

Hi PD's.......to our member 'old man'  ....sounds like a timing issue, however I would be inclined to post a question to John Hemmens in UK.....with a photo image of your engine & outling the fault issue 

You should also provide some detail of the engines history......did it run properly prior to?    how old is it?   ...has anyone taken it apart 

Please post some images of your engine on PD's.....& let us know the outcome to your issue.......

You will find the John Hemmens WEB site in our links page.........as below

http://www.paddleducks.co.uk/smf/index.php?action=links;sa=visit&id=53

Derek

[old man]

Hi Derek,   Thanks for your advice I did'nt think of that too obvious what a numpty. Message sent to John HemmensI'm now awaiting a reply.
                  Thanks    Old Man

[old man]

High on 3rd march this year I posed a question about a John Hennems steam engine and was advised to contast them direct which I did but guess what I still have not recieved a reply, poor service when you consider the price of these things ( over 1,000.00 pounds) so I am going to pose this question to people who I can rely on to a least reply. Problem.. oscilating twin cylinder 4 yearsold  goes faster in reverse than forwards also needs more pressure now to achieve same rpm as when new. Any solutions??? apart from a sledge hammer.

             Thanking y"all in anticipation   Old Man

p.s. you can geuss I know nothing about steam but I am trying

[kiwimodeller]

Old Man I have no experience of an engine with your problem and if the servo travel etc is all correct can only speculate that it might be a valve timing problem but have you considered that the engine might be built that way and that what you are calling reverse could in fact be forward for the engine. Why not just buy another prop with the blades pitched the other "hand" and use your engine in the direction in which it seems to want to go? Cheers, Ian.

[R.G.Y.]

Old man, could you post a photo of your engine. Also if you have any history of said engine.  I will say it is quite common that an engine will run better one way than the other.  Sorry I am still not sailing the Duke. Geoff

[old man]

High Ian & Geoff'
Thanks for the advice.  Geoff  I cannot post a picture I do not know how ( computer illiterate) but it is a vee twin no valves as such but behind the pistons there is two plates which are bolted together in a vee shape and then connected to a block which holds the forward & reverse block. Poor discription I know but I did say I was a learner in the black arts of steam . Hope this makes sense.As for the Duke Geoff Our open day is coming soon any chance we could see you there??.
                  Thanks Guys    Old Man

[R.G.Y.]

Yes that is a good description of the Hemming's twin oscillator. Something must be tight somewhere or the ports have been damaged. cant thing of any thing else. As for open day have to see. So many irons to little fire. Geoff

[mjt60a]

just a thought, I know nothing about this engine (almost any steam engines in fact...) but wondering if the reverse mechanism is similar to that on the wilesco D48 or mamod locomotive with oscilating cyliders ie. a disc with curved slots in that redirects the boiler steam from one pipe to the other (and the same with the exhaust steam) if so, is it possible that it doesn't fully line up with the holes in one direction?

[old man]

My Thanks to evertone for their input.I think it is time to strip this engine and give it a good clean, something I must admit I have not wanted to do.
if everything goes ok I will let you know if not watch the obituary column in the news papers.
                 cheers guys.    Old Man