Swing mill blade on 2 stroke cut off saw for an edger?

[slowmiller]

I have a carriage style chainsaw mill that I built and do some custom cut lumber with it. I was looking into setting up to cut some specialty "true" quartersawn pieces from small logs by adding a small circle blade to the carriage. It is probably simpler to describe it as an edger. From some looking around it seems like a 2 stroke cut off saw (also called: concrete saw, chainsaw with circular abrasive blade) like a 3120k would make a very good edger saw if it was adapted for a rip blade.

So far I have figured out that the RPM's are a little high - about 5k on the saw vs 3600 for a Lucas blade, but the HP is about right for a 16-18" blade with 3-4 teeth and the blade attachment seems easy to adapt to. As long as the rotation direction is correct (not climb milling) it seems like it should work, at least on paper. With a slight change of gear ratio or engine speed it seems like it should be an easy bolt on to the existing carriage.

My big question then is has anyone done this or heard of this being done? Any fatal flaws, or things that are going to get me killed? Are there other blade options than the Lucas and if I go with Lucas can I use the center hole to mount (like a table saw) instead of the countersunk holes? Would it be easier and cheaper to make a jack shaft with a hub for the Lucas blade and then gear down from a regular chainsaw drive like the Turbosawmill uses?

Thanks

[Dave Shepard]

I don't have any advise for you on what you are trying to do, but welcome to the Forum. 

[landscraper]

I use cutoff saws all the time at my day job cutting concrete/asphalt,metal etc.  I would think that even a smaller saw like the TS400 (65cc/4.5hp) or a Husq. K750 (75cc/5hp) would rip 2" as a single blade, modest feed rates - obviously not going to get a 5hp 2 stroke to take the place of a 10hp.   Watch some of the demolition blade videos on youtube where they cross-cut railroad ties etc to get an idea of power/speed.  A 3120K is a BIG saw, expensive too.  You can buy a used TS400 for $350-400. You would have to remove the blade shroud  , and the arbor "hub" is fairly fat, so of the 14" blade diameter I bet you would get <4"-5" cut depth max, but if you are just edging ... .  I know most of the mid-size saws have a bolt on push-cart attachment that makes them into a walk behind saw, so I bet the attachment of the saw to the edger carriage could be accomplished similarly.  When using the saw, the rotation of the blade is "downward" to the work- or clockwise when viewed from the clutch side of the saw (like a chainsaw).  I have several various mfrs. cutoff saw (Stihl TS400,TS420,TS700, Partner/Husq. K750, K950) so if you need any pictures or measurements let me know.

Good luck.

[firecord]

Look at the warior sawmill.  it is a chainsaw swingmill made by jake peterson.

[slowmiller]

Down the road I would like to be able to "riftsaw" logs to get true quartersawn lumber from all the boards on small logs, edging is just a good way to break it in and get the glitches out. My first thought was to mount the log between centers on my mill and then strap one of the cut off saws to the carriage and rotate the log as I cut. The 3120k would give me 6" of cut depth and a backup set of engine parts for my 3120 that I use on the mill. I got stumped on the blade issue though. From reading around here it seems like a Lucas blade is the way to go but it does not seem like they will mount on the 3120k and the revs are a little too high. If anyone has done this conversion I would be very interested in how and how well it worked.

From reading around and looking at the Warrior I am now leaning towards putting more time into fabrication and less money into a new saw (I have more time than money right now, might as well take advantage of that). I think I have most of the parts to make a warrior style mill using my 3120 to drive it and the 8" lucas blade. The one thing that I have not been able to figure out so far is the best way to go from the 3120 to the mill shaft. I dont want to change out the sprocket on the 3120 since I would like to be able to change from CS milling to the swing mill without removing the clutch. In short, is there a good way to do a 5:1 reduction using a chainsaw chain as the drive chain and not having a jackshaft? Basically, does anyone know where I can get or make a 40 tooth sprocket for chainsaw chain? Or would it be cheaper to get a 3120k (used) and use the belt drive to a timing belt pulley and save the 3120 the wear?

Thanks

[firecord]

Why not just get a spare clutch and convert it to belt drive.  A good machine shop could remove the teeth and replace any pulley you want. Then you could swap clutches back and forth. 

[trim4u2nv]

Funny you should mention this I was researching the same thing for my LM2000.  I want to circular edge and band cut in one pass so we can throw boards right on the mattison to straightline rip to width.  I have a bunch of 2 stroke snowblower engines laying around and wanted to cut with 12 inch blades.  Boston gear makes a package about a foot long that will do the speed reduction.
Online you could get a gear reducer rated at 5.9 hp and 5.1:1 reduction  new old stock.  Cycloidal reduction 5000 rpm input for around $225.  Input shaft 5/8 and output shaft 1.00 inches. 

[slowmiller]

I was hoping to avoid changing clutches to speed up the change over time from chainsaw milling to swing milling, plus the clutch on the 3120 is pretty hard to get off without impact tools.

The original idea was to go with the cut off saw for edging but then is kind of evolved, if you are just looking on edging you can go with a cut off saw and a 12" blade and probably not have to do anything else - the blade should take the rpm okay and you can adapt the arbor with bushings. Plus from what I have read they have plenty of mount points on the saw to attach to a carriage. If you do make the edger let me know how it works out.

I think I am going to attempt a Turbosaw Warrior clone, I found some angle and AL box beam at the scrap yard and have started trying to figure out the angles. The last big issue is how to make the shaft, I would love to get a hold of a 8" cut Lucas blade for a template if anyone has a broken one hanging around. I might start a new thread as the build progresses and the problems build up.

[firecord]

Just remember pictures. Everybody luvs pictures.

[trim4u2nv]

I have a 2 stroke lawn edger (belt drive) that does about the right rpm and tilts for an angle cut.  If it gets repurposed I don't like edging the lawn anyway.  Hopefully it fits behind the saw carriage and my 9 inch rip blades fit the mandrel, I may try it.