Horizontal cross head slide information for a Donkey engine

[sedge]

I am making a Steam horizontal capstan Donkey engine working from the Dolbeer patent application drawings and an Armitage drawing of a 1895 period Dolbeer Donkey engine.

The Alexander Scale Models HO 7900 Dolbeer Donkey Engine Kit (Circa 1882) shows a horizontal cross slide/piston rod/connecting rod assembly, but the pictures do not give me enough detail to see how it works.

Can anybody give me more information on this set up?

I live in the U.K. so my chances of seeing a "Real Live Steam Donkey" or the Alexander model are non-existant.

This is a "make it up as you go along" job but I am staying as close a possible to the patent drawing.

The scale is about 1"=1'
Sled 15" x 7"
Boiler 4"Dia. x 8" Tall
Cylinder 1/2" Bore x 1" stroke

Any information would be appreciated
Ken

 

[Jasonb]

Can you post what images you have as we may be able to see from them.

Looking at the Alexander model it seems as though the cylinder cover supports two guide bars the other end of which are carried by a separate bracket.

These could simply be rectangular bars and the cross head slotted to fit over them something like this

http://img.photobucket.com/albums/v156/jasonballamy/Engineering/Minnie7.jpg

Or angle like this http://img.photobucket.com/albums/v156/jasonballamy/Fowler A7/Rearcylcover.jpg

J

 

[sedge]

Hi Jason
Thanks for the reply.

First I enjoyed looking at the traction engine build pictures.

The only pictures I have are the Alexander Scale Models HO 7900 Dolbeer Donkey Engine Kit (Circa1882) ones.

I "cheekily" e-mailed the producers of the model kit and asked if the had a more detailed picture or a drawing they could e-mail me.
They replied to say they will try to find a better picture to send
Fingers crossed!

Ken

 

[sedge]

The maker of the kit sent me a couple different views of the cross slide/piston rod/connecting rod assembly.

I have posted them in the gallery Engines, Kens album along with the Dolbeer patent drawing and three views of Donkey engines for interest.

Was this type of horizontal cross slide assembly in common use?

Any comments, pointers would be appreciated.
Thanks
Ken

 

[Jasonb]

Hard to tell from the Alexander but they look to be round rod guides, not that common as most of the Donkeys seemed to use cast round trunk guildes.

You need to be thinking more along these lines

http://www.eckartkercher.de/galerie/har04.htm

http://www.eckartkercher.de/harkort03.htm

http://dampfundmehr.de/im-bau/harkor/fuerung1.jpg

J

 

[sedge]

Jason

Thanks for the links.

I can see the sort of thing that it needs to be, with the connecting rod pin connection turned through 90 degrees.
Mine will not be that fancy though, still a beginner at this steam engine making.

Ken