Brian Rupnow build--Hit and Miss air/steam engine

[vlmarshall]

Great work! It's nice to see it together... so quickly!

 

[zeeprogrammer]

Thank you Brian.
I've enjoyed following this thread. I've learned quite a bit here.

Very nice.

 

[Brian Rupnow]

Zeeprogrammer---I have only been machining for about 2 years. Prior to that, I have never ran a mill, and only ran a lathe during my apprenticeship 44 years ago. However, since I have to know what all the shop machinery is capable of in order to design machinery which is built on lathes, mills, shapers, etcetera, I had a big head start. There is a world of good information on this website, and some very informative members. One of the really big issues that you will come up against in learning to machine is knowing what questions to ask. Do a lot of reading, follow the builds on this forum, and don't be afraid to ask questions. Go ahead and start to build something, and then when you are uncertain about what exact method to use to achieve a required result, then you will know what questions to ask.---And we will help you.--Brian

 

[IronHorse]

Great engine! This definitely is on my list to do this winter.

 

[rudydubya]

Nicely done Brian. :bow: Looking forward to following your next project.

Rudy

 

[Brian Rupnow]

Some folks have been asking me about the springs that I used in this engine. ---I just measured the spring that operates the 1/4" diameter sliding valve inside the cylinder head.---It is 0.19" o.d. x 0.023" dia. wire x 1.4" free length and the pitch is measured at approx. 0.077" . The spring which keeps the valve in contact with the cam is 0.25" o.d. x 0.023" dia. wire x 1.5" free length and the pitch is approximately 0.1" (Note that in the final build of my engine I departed from the blueprints in that area). The spring in the governor is 0.31" o.d. x 0.020" wire x 3/4" free length x ??? pitch (I've lost that spring--when I disassembled the hit and miss valving to put on a conventional valve system, the spring escaped and was last seen flying under my desk at 300 MPH.)

 

[Brian Rupnow]

I was sorting invoices today, when Lo and Behold, I came across the paperwork on the three springs I used on this engine. They are identified as #71xINDUS0645655 ----#74xINDUS0615370 and #18xINDUS0615090. They were purchased at Brafasco (Brampton Fastener Company) which (I believe) is an Ontario based company, but the springs are probably made in USA.

 

[chuck foster]

i think brafasco gets there springs from ajax spring company.

chuck

 

[Brian Rupnow]

aermotor8--Seems you are correct---here is a link to their website
http://shop.springsbyajax.com/category.sc?categoryId=2

 

[Donrecardo]

Hi Brian
Over the last few weeks I have been attempting to build the hit and miss
air engine but at 2X scale. Its going ok ,although getting rather heavy.
I altered a few things like for instance the frame is built out of 1/2" plate rather than
machined from solid stock and has a few cosmetic differences.
I have put ball races on the crank rather than brass bearings . The cylinder is made of bronze,
the piston is aluminium and the cylinder head steel . The non governer side has its flywheel
and I just started on the other side and governer parts but I am confused by the drawings

On the drawing the soldered assembly of the backing plate has a reamed hole through its centre of 0.344".
Now normally holes are reamed so they are an accurate fit but I cant see what has to fit
into this accurate .344" reamed hole , can you tell me what it is that fits it?

Also on the drawing of the sliding cam it shows it has a diameter of 0.563" along its length
yet on the drawing flyweight govenor.pdf the outboard end of the sliding cam is clearly
only about 3/4 the diameter of the other end . Which one is right ?


Regards
Don

 

[Brian Rupnow]

Donrecardo---You made me do a bit of reseaech on this one. The 0.344" hole does not have to be reamed. It is clearance for the compression spring to fit into.---My mistake. the other .pdf you make reference to is a drawing by someone named s. goergen, and it is a drawing I used for reference when making my design. My drawing is correct (it is changed slightly from the reference I used), and the 0.5625" diameter is correct on both inner and outer flanges.----Brian

 

[Donrecardo]

Thanks Brian

 

[JackG]

Brian,

Just finished building one of these. Run's beautifully!!!


Thanks,

Jack

 

[Brian Rupnow]

Congratulations Jack!!!!! Post up a picture.---Brian

 

[JackG]

Hi,

Here are some photos of the engine. As you can see, I made a few very minor changes from Brian’s design such as I didn’t round off the valve assembly (What can I say – I guess I’m lazy) .

Jack

 

[Brian Rupnow]

Very, very nice!!!!

 

[slkride]

Brian
In re guards to your valve, I have good success using a polishing compound such as you would use on Al wheels etc. followed up buy using tooth paste. After which the whole thing should washed in hot soapy water. By the way just down loaded the plans so will put on the must build list. NICE JOB ON THE PLANS. Hope this is of some help.

slkride Tom