CSM: 1 post or 2?

[outofstepper]

Greets all.
Don't know how I managed to stumble across an alaskan mini CSM on
youtube a few weeks back and ever since I've been up at night building
a few in my head.

This weekend I'd like to actually make one (in real life ).

Couple of questions from the experts:
1. If I put just one post in my bar (back toward the head).. will I get straight
enough cuts? any big advantage to putting two fixed posts (head and nose
of bar)?

2. how big of a bar do you think a single post design would let your drive
straight? 24" 30" bigger?

I don't have the best saw for this job.. its an MS290. now I know this isn't
the most popular saw.. and I know its a little small (55cc).. but thats all
I got. with a 20" bar. I plan to knock the chain back to 10 degrees and
not have to buy a ripper.

I consider this my test run. If I kill the saw, so be it I suppose.. but I'm
just testing the waters before I start dropping money on a bigger saw
and a lot of steel.

oh.. and I don't plan on cutting anything longer than 8' or 9'.

PS. I like the idea of drilling the bar.. seems "cleaner".. but really, is there
any advantage in terms of cutting length? I figured if you make a clamp
you're still using up the same 3/4" or 1" or so.


Thanks!

 

[Hillbilly3995]

Careful clamps can slip and break stuff.

I have run a 30" bar with only one end supported, results are relative (to what one thinks is good) and I was not cutting full length of bar.

your mileage may vary

You do have the right idea, get your hands dirty and try, you'll learn more in the first few hours than in a day or two here.

 

[sdo]

I just finished building a small mill for my 032 (similar size) here is the tread on it (see post #19 for pics of the mill I just built)

http://www.arboristsite.com/showthread.php?t=153102

Sounds like you have the same plans I do, test it out before spending the $$

Read my tread and let me know if you have any questions.

 

[BobL]

Greets all.
Don't know how I managed to stumble across an alaskan mini CSM on
youtube a few weeks back and ever since I've been up at night building
a few in my head.

Yep - I know what you mean - have built quite a few in my head - and some in real life too.

Speaking technically an "alaskan" CS mill is by definition held at both ends of the bar.
A mini mill is one that rides vertically in the cut.
So there's no such thing as "alaskan mini CSM" even if that is what it was called on youtube.
Im guessing you want to make a "granberg style small log mill"?

1. If I put just one post in my bar (back toward the head).. will I get straight
enough cuts? any big advantage to putting two fixed posts (head and nose
of bar)?

One upright or two doesn't make a lot of difference on a mini. On a alaskan two uprights at each end add extra rigidity which is useful on longer bars.

2. how big of a bar do you think a single post design would let your drive
straight? 24" 30" bigger?

24" is about the longest you can expect a straight cut. Small mills might give a straight cut when they are first made but wear and tear will see they don't do it for long. But don't expect the 290 to pull a 24" bar for too long.
If you are making one yourself why don't you just make a small alaskan - if you make the outboard post removable you can always use it small mill (one ender) - there's no doubt you will get the bug and want to buy a bigger saw

I don't have the best saw for this job.. its an MS290. now I know this isn't
the most popular saw.. and I know its a little small (55cc).. but thats all
I got. with a 20" bar. I plan to knock the chain back to 10 degrees and
not have to buy a ripper.

I consider this my test run. If I kill the saw, so be it I suppose.. but I'm
just testing the waters before I start dropping money on a bigger saw
and a lot of steel.

oh.. and I don't plan on cutting anything longer than 8' or 9'.

That's still plenty long enough to kill any saw but if you are careful and stick to small logs, keep the chain sharp, tune the saw slightly rich and don't push the saw it should allow you to experiment.

PS. I like the idea of drilling the bar.. seems "cleaner".. but really, is there
any advantage in terms of cutting length? I figured if you make a clamp
you're still using up the same 3/4" or 1" or so. !

There are many other advantages to drilling the bar, compared to using the standard clamps, including,
- the chain can taken on and off the saw without removing the saw from the mill.
- if you forget to tighten the clamps sufficiently the saw can slip in the clamp and the chain can be damaged or ruined.
- if for whatever reason the chain comes off the chances of damaging the chain are reduced
- slightly improved bottom clearance when milling the last slab on a log.

A big advantage of drilling comes when using a double ended alaskan

 

[SPM in King]

I have clamped (initially) and drilled the bar. When cutting a large maple this summer, I would bring my 3 chains to the site each day and take them home at night to sharpen. After spending 30 minutes, 3 times a day to install/change chains, I started to think there must be a better way. Drill it! Now, if you plan to use a file to sharpen on the bar, you might not have as big an issue. Drilling a bar is slow hard work. It eats drill bits if you go too fast.

Steve.

 

[cowboyvet]

I don't have the best saw for this job.. its an MS290. now I know this isn't
the most popular saw.. and I know its a little small (55cc).. but thats all
I got. with a 20" bar. I plan to knock the chain back to 10 degrees and
not have to buy a ripper.

I have a ms290 in my collection and think it is a good farm saw. I've cut lots of firewood with it. If you are planning to mill any harder woods like oak with that 290, it will struggle with a 20" bar. It might pull 20" in softer wood. Don't worry though, you'll catch the bug quick and start looking for a 066 soon.

 

[mikeb1079]

I plan to knock the chain back to 10 degrees and
not have to buy a ripper.

not a bad idea but baileys sells ripping chain for the same price as normal chain (about 15-18 bucks for your saw i think). you can save yourself some trouble.
cheers
mb

 

[outofstepper]

Thanks all! some good tips.
I'll start tomorrow, maybe take some pictures. Planned to start today..
had a timber door on the table.. thought "all I got to do is paint this
and then I can start on the mill" -- well.. that was 9am this morning and
the 2nd coat is still drying.

Is it a bad idea to weld to the bar? I figure once I drill the bar its
no good for anything else, right? I'm pretty good with the tig welder.
I'm wondering if I just drill a hole.. round up the end of a square rail,
push her through and do a nice rosette weld on the other side with
some stainless filler, there won't be ANY bolts to come lose and I think
I could get it nice and square.

Just not sure about welding the bar.. if you folks say they're hard to drill..
I'm wondering maybe they're a tool steel and might heat crack?

 

[mtngun]

Bars are high carbon steel, welding not recommended, though it has been done. In any event, if you weld the mill to the bar, how ya gonna flip the bar ?

 

[mikeb1079]

there won't be ANY bolts to come lose and I think
I could get it nice and square.

don't worry about this. just use nylock nuts and you'll be fine. i've never had any issues milling with these and that includes my 075 which is vibey as hell.
umpkin2:

 

[Hillbilly3995]

Thanks all! some good tips.
I'll start tomorrow, maybe take some pictures. Planned to start today..
had a timber door on the table.. thought "all I got to do is paint this
and then I can start on the mill" -- well.. that was 9am this morning and
the 2nd coat is still drying.

Is it a bad idea to weld to the bar? I figure once I drill the bar its
no good for anything else, right? I'm pretty good with the tig welder.
I'm wondering if I just drill a hole.. round up the end of a square rail,
push her through and do a nice rosette weld on the other side with
some stainless filler, there won't be ANY bolts to come lose and I think
I could get it nice and square.

Just not sure about welding the bar.. if you folks say they're hard to drill..
I'm wondering maybe they're a tool steel and might heat crack?

No, just take the bolts out and use it normally

To properly weld high carbon steel, you really need a tig torch and the proper technique. We weld 4130 tubing often but you can easily muck it up.
Drilling is by far the way to go.

 

[BobL]

I figure once I drill the bar its no good for anything else, right?

Holes don't matter one jot for cross cutting. Many bars come with holes already drilled in them and some of my bars have 2 - holes in them from when I used to drill holes in them for Aux oilers. I now use one of these as a fire wood/ bucking bar.

. . . .i if you weld the mill to the bar, how ya gonna flip the bar ?

. . or replace the bar, or go longer or shorter, or lend the mill to a mate so he can use his saw in it etc.

I see plenty of guys that can weld come onto this site and want to make a CS mill by welding every joint and connection they can weld, and what happens is they end up with an inflexible CS mill. This sort of happened to me as well.

If you haven't read this I suggest you read it and take note of Tip #1.

 

[outofstepper]

AAARrrrr brain fart, It came to me as soon as I shut my computer down.
Thats what stream of consciousness typing does to you in public.


"
Originally Posted by mtngun
. . . .i if you weld the mill to the bar, how ya gonna flip the bar ?
"

well, sheesh, I'd just run the chain backwards and use the other
side.

Thanks.
pictures to come.
play safe everyone.

 

[Brmorgan]

No, just take the bolts out and use it normally

To properly weld high carbon steel, you really need a tig torch and the proper technique. We weld 4130 tubing often but you can easily muck it up.
Drilling is by far the way to go.

I haven't welded on a saw bar specifically, but I've had half decent luck experimenting with different stainless and hardfacing rod on high-carbon steel even with my cheapo buzzbox welder. Not ideal like a TIG, of course, but it does better than plain ol' 7018 or 6011. I have a few Eagle Alloys "chrome" stainless rods (forget the actual name or number) that seem to do pretty well; I've used them to weld planer blades and the like to make drawknives and have been happy with the results. But I'm just a backyard welder, certainly no expert!

Just not sure about welding the bar.. if you folks say they're hard to drill..
I'm wondering maybe they're a tool steel and might heat crack?

Dunno how applicable it would be to welding on a bar, but Will Malloff recommends in his "chainsaw lumbermaking" book when drilling out a bar to place an old or spare bar in between it and the drill press table to basically heatsink the entire bar being drilled. And use liberal amounts of cutting lube and the slowest RPM you can work with for the drill size you use. Some bars are exceptionally hard to begin with and might need a carbide bit to drill through; others are less hard but are made of air-hardening steel which, if overheated, will become just as impenetrable to an average drill. Another trick is to start with a small bit and gradually work your way up to the desired size, so you're taking off smaller amounts each time and not hogging out the whole lot at once.

I see plenty of guys that can weld come onto this site and want to make a CS mill by welding every joint and connection they can weld, and what happens is they end up with an inflexible CS mill. This sort of happened to me as well.

Hey, I resemble that remark! Very true though. Light construction like this can be made just as sturdy being mostly bolted together if designed properly. Some things obviously must be welded though.

Back at the beginning of October, I used a 30" bar with 3/8" LP ripping chain on the 395 on my mini-mill jig for the first time, and even used it horizontally unsupported at the nose, and it did quite well actually. But that bar is an old Cannon that's as hard and inflexible as any I've ever seen, so your results may vary. The problem I ran into is that it was getting difficult to push that length of bar through the cut horizontally from only one end. Vertically isn't bad because I'm not fighting the weight of the powerhead at all and can put my weight into pushing it a bit more.
http://www.arboristsite.com/showthread.php?t=150060

 

[outofstepper]

Well here she is. Haven't tried 'er yet -- first thing tomorrow, weather
permitting.

I'll tell ya though it took longer to drill through the nose/sprocket than
it did to make everything else.

I definitely need a bigger saw. When all is said and done I've got about
15" clearance on a 20" bar.

Tried to keep it light. Had some stainless square tubing from another project.
This stuff is a little on the light side 1/2"x1/2" .. little more than a 1/16" wall..
but, being stainless, its pretty tough. Especially considering my bar ain't
so long. Hope it stays together alright.

Next time (and there'll definitely be a next time!) I'm going to use "C" shaped
guides instead of square tubing. This thing is reasonably straight.. but I've
got some places it wants to bind a little (when adjusting up and down). I
can knuckle it into place but I'm afraid its putting a little bow in my bar.
Not much, but that flexing is going somewhere.

Outward facing "C"s with a bolt through them should give me a little more
breathing room in terms of squareness etc.

can't wait to try her out!

Thanks again for all your help..

oh! and it went together like a song.. tightened everything down and
then chain wouldn't budge! thought I pinched the sprocket or something
bad. turned out it was the chain brake! (long day).

 

[Brmorgan]

Lookin good! Did it stay nice and flat and square as you welded it all together?

I have three 15" Husky large-mount bars coming from Baileys (they were on closeout for $3.95 each, how could I argue with that?) and I plan on building a small mill like this to fit one of those. I'm hoping a 15" bar on the 395 or 288 should be a pretty fast combo for slabbing boards off of cants and a lot more manageable than the 066/24" on the 36" Alaskan for narrower ~6" cuts.

 

[jimdad07]

Very nice work. You even put a handle on it. Nice weld joints as well. Can't wait to hear how you like it. CS milling is one of the most addicting and fastest ways to make some lumber for your woodworking needs. Bet you have a bigger mill and saw within the next month.

 

[outofstepper]

Thanks.
The guide came out reasonably flat. I wonder how important
*FLAT* flat is? I figure if its more or less parallel to the bar.. and its
got to be touching in at least 3 points right? -- if its not flat.. i mean,
it is a chainsaw afterall tearing through there.

Guess we'll find out soon enough.

Makes me wonder through.. and keep in mind this is my first one ever and
still untested.. but what if the "frame" was just a flat sled?

Like a piece of .. i dunno.. 3/16" aluminum.. 20" x 12" with the front and
leading edge bent up 45 degree or so? Kind of like a giant jig saw base
plate? Only thing is you couldn't see through it to your work -- sounds
like a deal breaker?

 

[Brmorgan]

Thanks.
The guide came out reasonably flat. I wonder how important
*FLAT* flat is? I figure if its more or less parallel to the bar.. and its
got to be touching in at least 3 points right? -- if its not flat.. i mean,
it is a chainsaw afterall tearing through there.

Guess we'll find out soon enough.

Makes me wonder through.. and keep in mind this is my first one ever and
still untested.. but what if the "frame" was just a flat sled?

Like a piece of .. i dunno.. 3/16" aluminum.. 20" x 12" with the front and
leading edge bent up 45 degree or so? Kind of like a giant jig saw base
plate? Only thing is you couldn't see through it to your work -- sounds
like a deal breaker?

One problem I can see with having a solid piece rather than a tube frame is that more surface area contacting the wood = more friction, making it harder to push down the guide/log/cant. Whether it would be enough difference to be noticeable or of concern would be another matter; only one way to find out I guess!

A bit of twist or off-square on a mill the size of the one you built probably won't be a big deal. When you start getting into longer mills and bars that are inherently more flexible and inaccurate though, it can be a problem because the twist can cause the mill to climb in the cut and not follow the guide nice and flat like it should, no matter what you do. In reality though, your chain filing/grinding skills will be MUCH more important as far as how the mill cuts and "feels" than the construction of the mill itself; a poorly-sharpened chain can produce exactly the same symptoms. I've spent a good deal of time when I was still learning how to mill trying to figure out why the heck I couldn't cut flat or square because of both of those issues.

 

[BobL]

Doh! you went and welded it up solid

Just kidding, I'd say that's a very good first effort.
As Jimdad says you'll be making another one soon.

A couple of comments;
I like the nose guard and if you want to add an aux oiler you have a useful location that you can use.

I'd consider add some locking nuts to the height adjustment locking bolts, you don't want those coming loose while you are cutting.
If it flexes too much, seeing as your mill is a fixed length you can make the whole thing more rigid by welding a tubular handle between the uprights. If you put your upright handle on top of that tube it will give up a more comfortable upright milling stance..

Thanks.
The guide came out reasonably flat. I wonder how important *FLAT* flat is? I figure if its more or less parallel to the bar.. and its got to be touching in at least 3 points right? -- if its not flat.. i mean, it is a chainsaw afterall tearing through there.

If the mill is not parallel to the bar length is easily adjusted and doesn't affect saw operation. However if it is not parallel across the bar this will unnecessarily continually overload the saw. This can be tested as shown in the picture below and corrected with shims on the bar connections.

Makes me wonder through.. and keep in mind this is my first one ever and
still untested.. but what if the "frame" was just a flat sled?

Like a piece of .. i dunno.. 3/16" aluminum.. 20" x 12" with the front and
leading edge bent up 45 degree or so? Kind of like a giant jig saw base
plate?

Here's an example using wood.

Only thing is you couldn't see through it to your work

I agree but there are operators that use a winch and stand at one end of the log so it doesn't matter.

I prefer to stand right up close to the mill and see and feel what's going. Brads on the money as far as friction is concerned. Ideally you want as little and a slippery a contact as possible. Using log rails for every cut is one method and lining the contact point with a slippery material like Ultrahigh Molecular Weight Polyethylene (UHMWPE) is another.