Modular CSM Rail Build

[Griff04]

Howdy,

So, after snooping this site for all things CSM over the past few months I broke down and created an account just to run this by y'all. Now, I know there are plenty of threads on similar things to this, but try as I might (and I've spent hours looking) I cannot find a good answer to this question:

I am designing a modular rail system. I'm in school for welding so I'm tapping our supplier and getting (2) lengths of 24' x 1 3/4" x 1 3/4", 1/8th" thick angle steel. I plan to cut them down to six foot lengths for transport. When milling 10' logs (my standard length) I can use 12' to have some extra rail sticking out. Then also rip all the way up to 24', presumably. If this design (and yes, my question; it's still coming) works then I assume I could go even longer.

This is a rough concept I drew up for a simple, yet sturdy, method of connecting rail lengths together.
What do y'all think?



I plan to use 1" x 6" 1/8th" pieces of steel to join them. Maybe as long as 8" for rigidity. At least two bolts on each side, 13mm to fit the chainsaw tool, should provide enough strength for 12' of milling. Additional horizontal supports can be added for longer milling. NOTE: I had the (I think) smart idea of mounting, drilling and indexing the plates before I cut it down to 6' lengths, this way when I put it all back together it should go back together as straight as possible.

As for mounting the long parallel bars to the shorter horizontal supports, I saw a nifty way of utilizing vice-grips. You level and screw the two horiz. supports to the end of the log, then clamp the long runners to them. This seems like a sturdy, vibration-proof, adjustable way of joining a rail system together and I'm impressed enough to try.

Finally, my new rig:



This isn't mine, but it's basically everything I ordered (I got a different brand bar).
- Farmertec 92cc G660
- 36" bar and chain
- 36" ripping chain
- 36" Alaska Mill

$450 shipped. Gotta love Black Friday Deals.
I read around online a lot before buying and have already bought a new (stihl) decompression valve, bar mount/stud assembly, and bar tensioner assembly. Seems these were some good parts to replace to maximize the saw's capability.
I'll be milling mostly softwood on my homestead, red and white pine. I also have some oak and maple. I'm excited to get started milling some building materials for my first, building!

Anyway, happy to be on a site with such helpful folks sharing a common interest.

Thanks for having me!

Griff

 

[BobL]

Welcome to the forum Griff.

I think you may be over thinking it a bit.
Using pieces of plate to join two pieces of angle together is not as strong as using a piece of angle to join two pieces of angle together.
A question worth asking is why bother using any extra pieces as joiners?
Why not just join one length of angle (rail) direct to another as it doesn't matter if the rails are offset horizontal especially if the with between the rails can be adjusted so the mill makes contact mainly on the log.
That way a series of holes can be aligned to join the angles over a range of lengths to better suit log lengths.
Angle would have to be joined back to back to avoid a vertical step but that is not a problem

Perhaps more importantly is how the rails connect to each other in a parallel manner, and how the rails are connected to the log.

My long rails are 4 x 10ft lengths of Unistrut and can be expanded from 10ft to 17 ft

The connections between the rails are all thread rods and slotted angled brackets at each end that connect by T-bolts that slide inside the Unsitrut and pointed 5/16" bolts into the log.


If I was doing it over again I would probably make the Unistrut lengths 8 ft and 12 ft long.

 

[M.R.]

Assuming connections making the 24’ are free supporting
W/ 1.75” sq. Tube .120 wall ... before cutting I would support
each end ...measure mid point 12’ off a string line or Plano wire the belly or
deflection of the material itself...then add the sawmill weight + let’s say
25% as pushing it through the cut may add this additional weight
Is this within your specs? If not Possibly rectangular tube maybe be better?
(Or like Bob/ other’s are using, some of the Unitrut) Off this phone I don’t have my bookmarks to link a site
to you to do these calculations..
Jointing instead of the FS, myself with the ID of 1.5” I’d use sq. Tube 3/16 or 1/4” wall inside & loose 2 bolts of the connection in button welding these holes. The two joining bolts could even be omitted or rather exchanged by using longer shoulders on the bolts & cutting to length then drilling for a small hitch pin
(no wrenches) just some thoughts 6 of one & a half dozen of another.

 

[BobL]

My first setup used rectangular tubing and lots of bolt holes to adjust for the attachment of the "end of the log" angle brackets but its was a right PITA to use compared to using Channel/Unistrut to slide the angle bracket hard up agains the log ends.