Model Engineer Magazine - old issues?

[crueby]

You're making swift progress with that. I've just about finished another engine with similar two guide rods for the crosshead and it's quite a good yet simple way to do it.

Good to hear!  I've got a woodcarvers bench with a wide vise that works pretty much the same way (not steam powered though!) and it works nice and smoothly, as long as the holes for the rails are all at the same distances in the end/middle parts it should be good.

[john mills]

will be an interesting model  and to see it working   the full size machine is interesting watching it cutting

John

[crueby]

More progress on the CAD version, added the sliding base that Ransome shows in their catalog as one of the options. It was typically used at a sawmill for trimming longer logs, has a handwheel to move the saw back and forth along the log. Most of the parts are on, except for the valve assembly and steam passages...

[Dan Rowe]

Just what I always wanted a steam powered sawzall. I have to add this one to my build list.

Cheers Dan

[crueby]

Just what I always wanted a steam powered sawzall. I have to add this one to my build list.

Cheers Dan

Careful, the extension cord is HOT!   

[Jasonb]

Could always wire the boiler up to an element and 18V power tool battery then you would have a cordless one

[crueby]

Got the valve and passages done. Not totally happy with the arrangement of the blocks around the cylinder, the valve passages are complex, but it matches the original machine. Going to give them some more thought, may change them a bit. The article was written before he made and tested the parts, and there are missing things in the plans that he was going to go back and add but never did, which makes it tricky. But, enough is there to puzzle it out.
Here is another screen shot from Fusion:

[crueby]

As I mentioned in the last post, I'm not real happy with the valve and passages the way that the article drew them, very complex and lots of internal passages interweaving in a small space. Just brought up the original Ransome patent, US206404 in 1878, and it has it all much simpler.  It has the exhaust coming out close to the valve body, where the article puts it through the trunnion opposite the inlet, also through a trunnion. In the patent, both inlet/exhaust are out the top.


So, I think I am going to change the CAD version to be more like the patent, which will simplify construction for the model version in several ways. Now, on the existing machines shown in the photos in the article, taken at steam shows, the inlet and exhaust DID go through the trunnions, and the catalogs I've found also show it that way, but only on the vertically-mounted machines, not on the tree feller horizontal ones. If I change it to be like the tree feller, then the model could be mounted both ways depending on how the builder wanted to display it. The early catalogs mention this was a possibility - I think that Ransome may have changed the layout for the vertical one along the way, they did make these saws for decades.

More in coming days...

[Jasonb]

Always a bit of a toss up between what is shown on a patent and what the company actually ended up making plus the fact they would have been using cored in passages and we have to make adjustments for fabricated parts or non cored castings. Even when Haining was writing there were not that many home workshops with milling machines so designs would have been suited to use of a vertical slide on the mill.

I could not get the Patent to show on Google, maybe when you post the drawings some links to ref material you found on line would be useful to potential builders.

I suppose having the trunnions used for the steam on the feller put them close to the ground risking damage and raising the machine would have wasted wood and made it top heavy, not an issue with the crosscut version.

[crueby]

Hi Jason,
Attached is a copy of the Ransome patent for the tree feller.  Also, here is a picture of the crosscut-mounted version - it has the trunnion-mounted inlet/exhaust that I think is a later change from their production. All the earlier versions of the Feller style have a different valve and steam connection arrangement, shown in the second picture.


They made these types of saws for several decades, and comparing pictures in the catalogs from different years shows that they were evolving the designs over time. At first the same unit was used for crosscut with a different stand, but later crosscut versions were different. So, I'm going to try and draw up that earlier valve style, should be easier to build as a model.

[Jasonb]

Ah that's more like it and what I said back in post #6 when Jo first showed the cover photo, its a rocking valve much the same as the Filer and Stowell that I made a while ago. Maybe another case of Haining's simplification?

Thanks for the patent and other images

[crueby]

Yup - very similar to that!

[Jasonb]

One from a book

[crueby]

Great reference! 


EDIT: Found that book on Google Books, can read it online, great book. Just go to Google Books and search for the title, "valves and valve gear mechanisms"

[crueby]

Got started on figuring out the new valve arrangement late afternoon, and now all of a sudden its almost 8pm - time warp!

But, did get the valve arrangement changed to be like the patent and early catalogs have it, and it will be MUCH easier to build from bar stock (or even from castings if someone makes them). I like this a lot better, and it will allow it to work as a tree feller (horizontal blade) too.
Here is a new screen capture:


Next I'll draw up the horizontal base for tree felling, using the same saw otherwise.