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First of all thanks to Travis for posting the pdf of this engine. I wanted a two cylinder model and these plans looked good.
Videos are also provided for most of the construction project.
https://sites.google.com/site/yeoles...o-4-free-plans
So far I have the flywheel, head, cylinders and most of the other parts in this picture.
Work in progress so I will post when I have more of the engine completed.
Cheers, JR
Looks like a nice engine and a fun project, JR.
If you're planning to actually run the engine on steam, as opposed to compressed air, you may want to think about adding some cylinder drain stopcocks. Running on steam, water can condense in the cylinder(s) after shutdown. When the engine is restarted, if that water can't escape, the resulting hydraulic lock can bend connecting rods and do other bad things.
If the engine had floating D-valves, the water would simply lift the valve and escape through the exhaust ports. On engines with piston valves, as this one has, the piston can't float and so lockup is a possibility.
This picture shows one of my engines with a piston valve. You can see the drains on the side of the cylinder.
I hope I'm not preaching to the choir with this post. Have fun with your build.
Aside: Many steam locomotives have piston valves. You may notice them blowing a lot of steam out of ports on the cylinders at startup. The engineer has remotely opened the cylinder drains and the steam escaping through them is carrying any condensate with it. The drains are then closed and the escaping steam stops.
Thanks Marv, I did not know about the condensate problem. At this time I am running on compressed air but in the future I would like to build a boiler and run from steam. After all it is a steam engine!
Excellent info.
Your model engine has a lot of nice detail and shows pride in workmanship.
Cheers, JR
Some progress on the little steamer.
Crank Shaft Parts. Next time I will make a one piece crank but for this one I am building it with parts.
The two cams are shown in the last picture on the right side. They will be adjustable with a set screw for locking.
The counter weights will be aligned, rod journals installed, and then the main shaft cut out between the webs.
In theory it should be "perfectly aligned". We shall see.
Cheers, JR
Completed the Travis Steam #4 today. Gave it a few test runs on the bench and it runs fine. Sounds great.
Here are the Pics and the video will be a follow up later.
I made a few changes to the original which includes the 8mm ball bearing ABEC-7 608z. Why that one? I had them in stock
from another project and they would fit this project. I made one flywheel from aluminum and filled it with lead to add weight.
It is larger in diameter than the lower end is high so I will make a proper walnut base for this engine. Right now it is just sitting
on a piece of baltic birch.
Cheers, JR
Here is a short video of the engine running.
https://youtu.be/aKRMe3_hOWs
Nicely done and it looks to be a good runner. Do you have plans for it to drive anything?
My two cylinder, single-acting...
http://www.homemadetools.net/forum/m...0635#post91833
was put to work driving a PMR open frame generator model.
Thanks Marv, I may add a generator to the engine after I make a proper base.
Right now it is just sitting on a small chunk of Baltic Birch.
Thanks for the link.
Cheers, JR
Beautiful work JR!! Love the sound of it in the vid, with the gentle knocking in the background. Congrats on a great build with your new mini shop tools!! It looks like you pinned the rod journals but also looked like they are soldered...did you have a timing issue? Also, I would be interested how you put the lead into the flywheel...Pour it and then turn it??
Thanks for sharing your great build with us!
PJ
Thanks PJ, This one was a fun build. None of the screws were so small that I needed tweezers to pick them up! 4-40 was the smallest and only 4 of them for the rod bearings. All the rest are 6-32 and 8-32.
The flywheel was machined from a blank of aluminum on the CNC. I made a deep recess for the lead and then used a lead pot (electric) to melt the lead. I warmed the aluminum with a torch first and then just poured the lead into the recess. I did clean it up in the lathe after it cooled. Before cleaning it up I put CA glue in the very slight gap between the lead and the aluminum recess.
While the rod journals look pinned they are not. The holes are just in case the solder gives out. No problems with timing at all and I do like the chug a chuga sound.
Cheers, JR