Supporting > Vehicles & Models
Chris's Ransome Tree Feller Build
crueby:
Back from the trip to the northern Maine woods to help run the Lombards, and its time to start the build of the Ransome Tree Feller. I had previously posted the plans for this one over in the Plans sub-forum, you can download them from there if you would like to build one.
A little background on these nifty little saws: Ransome made a whole line of woodworking machines, saws, planers, all sorts of things. I was able to find a couple of their catalogs online and get pictures, found their original patent online with details of the valving, plus found an article from years ago where someone built a model based on a couple of surviving machines seen at a steam show over in England. Here are a couple pictures from the catalogs:
They made two versions of the base, one that held the saw horizontal for felling trees, the other that held the saw vertically for crosscutting the logs into shorter lengths. The saw itself is the same, just mounted differently. The handwheel at the back pivots the cylinder and blade to traverse it across the cut. They would use a portable boiler on skids to power the saw, with a flexible hose running to the end of the trunnion where the valve block is.
A drawing of one in use:
There is no crankshaft, it operates more like a boiler feedwater pump where the movement of the piston trips a valve at each end of the stroke to reverse the direction. The invention that Ransome added with their patent was a square rod that runs above the back of the blade to operate the valve. That square rod is twisted along its length, and a square guide on the blade holder causes the rod to turn as the piston moves. That moves a lever back over the cylinder, which operates a rotary valve to control the steam/exhaust passages on the cylinder. Pretty slick setup!
Using the catalog pages, patent drawings, and pictures of real machines as a guide, I drew it up as a 3D CAD model in fusion, with both bases:
The blue body is the valve block with the rotary valve inside, above the spine of the blade you can see the yellow twisted square rod. It has round ends to let it turn, and there is a square busing in the green blade holder that rotates the rod.
From the CAD model, I 3D printed a plastic version of the saw to help in visualizing the parts while deciding how to fabricate it. This is a lot like the 'casting fondling' that a lot of the modelers here on the forum use to get ready for building from a casting set! I finally decided which of the many possible ways to fabricate the cylinder assembly, with its blocks at the end/middle and the passage blocks running down the length. The method I settled on (and there are a number of ways it could be done) is to turn the cylinder body and end flanges from a piece of round bar, then mill in slots for the other blocks and silver solder them on. Then I'll bore out the cylinder and add the end caps.
So, this morning the shop elves picked a piece of 1.25" stainless roundbar, and measured out the length of the cylinder plus extra to hold it from the end:
That was cut on the bandsaw, and mounted up in the lathe with a steady rest. I'm turning one end down to fit the 3/4" hole in the chuck to let the bar be held by the full length of the chuck jaws. That should give a nice sturdy hold for drilling/boring out the cylinder. I'm going to drill the starter hole for the cylinder from both ends to limit the depth of the drilling and ease chip removal. The cylinder bore will be 5/8" when done, and the cylinder is 3.77" long overall. So far the holding end is turned in, and drilling from that end has started:
Once the hole at that end is taken up big enough for the boring bar, I'll reverse the part into the chuck and drill from the other end, and start taking down the center section to form the flanges on the ends of the cylinder.
cnr6400:
:ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:
It begins! This will be fun to watch! :cheers:
Vixen:
Hello Chris,
You say this post is about a Tree Feller?
I guess that will be you and your two shop elves? Ye, that makes three fellers.
I'll be following along
Mike
crueby:
--- Quote from: Vixen on August 01, 2022, 03:19:07 PM ---Hello Chris,
You say this post is about a Tree Feller?
I guess that will be you and your two shop elves? Ye, that makes three fellers.
I'll be following along
Mike
--- End quote ---
:facepalm2:
:Lol:
Kim:
How exciting! A new Cruby build!
I'm all ready to follow another fantastic build, Chris, so pass the popcorn! :popcorn: :popcorn:
Kim
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