Just finished the 3D CAD work on the Heywood Point Lever for Mike Decker. Mike supplied a 2D drawing and dimensions from which I created the 3D version. First rendering shows front and back views of the lever assembly.
(https://www.finescalerr.com/smf/proxy.php?request=http%3A%2F%2Froughboy.net%2Fimgs%2FHeywoodPointLever%2FHeywoodLeverAssy.jpg&hash=4e83a88afad86fc7b83882073821caab58803880)
The lever function was very simple. It mounted through the lower pivot point, the throw rod to the turnout attached to the middle pivot point. The lever was simply moved forward to backward to open or close the turnout. The counterweight pivoted, via the protruding handle, from side to side to hold the lever in position by gravitational force. The photo below (detail from a shot taken at Balderton) shows a pair of levers in use.
(https://www.finescalerr.com/smf/proxy.php?request=http%3A%2F%2Froughboy.net%2Fimgs%2FHeywoodPointLever%2Fpointleverdetail2.jpg&hash=97d8fd652a2c18dc6047f533126030511fcedb99)
There was a rule that the counterweight had to be moved "gently" into position, probably because of a weakness in the casting at the counterweight's pivot hole. Renderings below show more detailed views of the lower end of the lever assembly. The lever and counterweight were each cast as single pieces. There is some speculation that the protruding handle may also have served as a plug, allowing a hollow casting to be filled with lead for increased weight. Sir Arthur didn't believe in a lot of extra machining on his castings, so most were left rough as they came out of the sand with only minimal, essential machine work.
(https://www.finescalerr.com/smf/proxy.php?request=http%3A%2F%2Froughboy.net%2Fimgs%2FHeywoodPointLever%2FHeywoodLeverAssy3.jpg&hash=921071f5e6f60ce13a8036122cff76e75e17aa03)
(https://www.finescalerr.com/smf/proxy.php?request=http%3A%2F%2Froughboy.net%2Fimgs%2FHeywoodPointLever%2FHeywoodLeverDetail.jpg&hash=b28e28a92d7d3619e27f56be19f98911ef0351ad)
Paul
Paul, Interesting ;) was this used in the US or overseas.
Craig:
They were just used in the UK on the Heywood 15" gauge lines: Duffield Bank Railway and Eaton Hall Railway, late 19th and early 20th century.
Paul
My layout is based on the teachings and prinicples of Sir Arthur Heywood - will these be available in Gn15 scale (1:24)?
Possibly Ian if there's enough interest. I'll make a note that you may be interested. Mike is producing a modified version for 1.5" scale and is using these CAD drawings for his pattern maker to prep for casting replicas in 1:2 for his railway. I have a client building in 1:6 in Europe who has indicated interest and I will probably do a couple for my diorama in 1:12, though that's going to be a ways off yet.
Paul
Hi Paul
Great renderings as usual. What software are you using?
Dave
Thanks Dave. I use Ashlar-Vellum's Cobalt (http://www.ashlar.com/). Started using it a little over five years ago and it's been able to handle everything I've needed to do.
Paul
Paul,
Maybe you 2 guys should introduce yourself?
http://www.chaski.org/homemachinist/viewtopic.php?f=8&t=88836
Paul
Wow, a 14" diameter printed part. $$$$$ if it can be done at all.
Quote from: SandiaPaul on January 25, 2011, 09:14:28 AM
Paul,
Maybe you 2 guys should introduce yourself?
Paul
We have been in touch... it would appear I've started a trend in the Heywood camp. It will be interesting to see if he goes with rapid prototyping or more traditional pattern making for the wheel.
Paul