questions about swing blade mills

[NCEric]

I'm going to throw out some questions here in case anyone is inclined to share thoughts on any of them.  Thanks in advance!

1. How do the different mills -- the only ones I'm aware of are Lucas, Peterson, and Turbo, but I'd certainly be interested in hearing about any others -- compare in terms of portability.  One of the things that especially appeals to me about swing blade mills is the option of taking the mill to the log and thereby minimizing the money I'd otherwise have to spend on log moving and loading equipment.

2. How do they compare in terms of ease of double cutting.  (I think that's the right term, but what I mean is cutting boards approximately twice as wide as the maximum cutting depth of the saw.)

3. How do swing blade mills work with relatively smaller logs?  From the videos I've seen it appears that larger logs are just wedged in place and kept from moving mainly just by their own weight.  It seems like that might not work so well with relatively smaller logs.  Are there other ways that swing blade mill owners normally secure smaller logs, in particular, and prevent them from moving?

4. Related to #3, what are the options for sawing the last of the log into boards after most of the log has already been removed?  Is it possible to saw right down to the bottom of the log (assuming the log is up off the ground enough to create a minimum amount of clearance)?  Does that require any work besides what's necessary for the rest of the log?  Or is there always a more substantial waste piece left over at the bottom with a swing blade mill than there would be with a bandsaw mill, for example?

5. How much of a problem is soft ground?  It seems like the mill frame could continue to settle or move after beginning to saw leading to cuts that aren't straight or parallel, etc.  How do swing blade owners deal with that potential problem?

[Ianab]

OK, I'll take a "swing" at answering. 

1 - As well as the mills you mention, there is also D&L out of Canada. There are all "portable" to varying degrees. The smaller units tend to be easiest to move, as you would expect. The larger mills are heavier, and the "auto" mills have more parts to assemble. The Lucas and Peterson ATS (and JP) are probably the lightest and most portable. 

2 - As far as I know they can all double cut, although it's more work on the Lucas design as the saw head needs to be swapped direction. 

3 - If you are doing a lot of small logs it's probably worth setting up a decent bunk system, with some form of clamping. You can get Aluminium dogs that simply clamp onto a 4" wide wooden bunk, and will hold small logs steady. 

4 - One thing I often do is remove the bottom slab from the mill and put it aside. As I'm cutting the next log, flip the first piece over, and lay it on the flat of the 1/2 sawed log. Lift the mill up by the increments you want to cut, and resaw that bottom section. It's also a way to make live edge slabs without a slabber, just you only get one per log. This also works on large logs that are sitting on the ground. The mills won't lower to the last few inches as you risk hitting dirt or cross members. 

5 - Never had a problem with soft ground. Even if the mill does settle a bit, you don't reference cuts from the "deck" like a band mill does. Your reference is from the last cut. If the mill rails move slightly as you mill the log, any error is spread across each layer of boards. The error in each board is within tolerances. Other thing you can do is put some scrap boards down under the supports, sometimes it's necessary to do that to cope with uneven ground. Unless you are in an actual swamp, a 6" board is going to spread the weight so it won't sink much. 

Hope that helps.

[EOLogtruckin]

My experience has been with the D&L mill. I have the 816 so it is the smaller model. After I got it, I quickly realized portable sawing wasn't for me unless I could set it on a trailer, square the tracks and everything, and leave it there. Really heavy and awkward to push the mill around on the dolly. Then I would have to lift the logs onto the trailer, requiring equipment anyway. I have seen a few other swing mills operate and agree that the Lucas and Peterson look more portable than mine but I don't know first hand.

I purchased an older single axle truck with a Hiab knuckle boom on it that has proved to be worth every penny. I have a non moving infeed deck to the mill track which is great for logs under about 15 inches. I can just roll them on to the mill bunks, chock, and saw. (Doug Fir and Ponderosa 8 to 20 feet long) Now try to do the same with a 24 inch plus log and, yikes! Might as well start making appointments at the chiropractor. Or schedule back surgery. Or worse if one gets away from you. Forget about centering pith or adjusting the log a little one way or the other (without adjusting the mill).
 My point in all this rambling is while it works for some, to not use equipment with their mills, I don't know how I could do with out it. Now with hydraulics on the mill... Nevermind.  

I use wood bunks to set the logs on. I cut small chocks out of hardwood and screw them into the wood bunk to hold the log in place. No problem with anything moving down to an 8 foot long 10 inch log.

Using the chocks, unless I have a major taper to deal with I can cut down to less than a 1x4 left in the slab pretty much all the time. On a bigger log with a bigger radius I just do like lanab described in #4. 

The double cut feature is really handy on the D&L mill I have. I have been glad for the 180 degree swing feature when I get a bigger log under it. Tension in the log? Go cut off the other side for a while.   
Wanna sink the blade to the arbor and cut both directions? It may be possible but I haven't been able to make it work quite that good. If it is cutting perfect one way the other direction will suffer a little. Within rough cut specs to be sure, but not quite within mine. A lot of the lumber I sell is used where the saw marks are seen, so it matters more than some other applications. Also if your selling lumber a double cut board costs twice as much to saw as the others. And it seems like an awful lot of my customers want a board that is 1 inch wider than I can cut in one pass. 

My two sense.   CG 
 
  

[Ianab]

ANY mill operates better with support machinery, be that a hiab / wheel loader / forklift / larger tractor with FEL etc. That's not always available. 

Because I'm not sawing commercially I can mess with jobs like this. Salvage logs in a local back garden. No access for machinery, so the logs were sawed on the ground, and bottom slabs flipped to resaw, It was all going as firewood otherwise. 
https://forestryforum.com/board/index.php?topic=120380


The bigger mills are much more productive, but you have to be pretty keen to move them log to log, UNLESS the log is HUGE

[scsmith42]

What part of NC are you in?  I'm 30 miles SW of Raleigh and have a Peterson 10" WPF that you're welcome to stop by and look at.

Scott

[blackhawk]

Ianab has answered you very well.  I have a Lucas 7-23 and I will just add some more info to what Ianab has said.

1.  The Lucas is extremely portable.  I have setup inside a backyard that only had a 36" wide opening in the fence for access.
2.  Double cutting video for the Lucas is here:  DoubleCut  The method in the video works, but it is time consuming.  It is tough to get the rails raised back to the exact same height, but you can get very close.  This just creates a shallow line in the board.  It's easy for the cross carriage roller to come off track next to the engine and it is a bear to get back in place.  The best method for me requires two people.  We run the carriage out to the end of the track then we both stand inside the carriage with the engine between us and then spin the carriage 180°.  This method is pretty quick and you are dead on with your height since you don't have to move the rails at all.
3.  It is tough to hold any logs smaller than 16-18" with clamps.  I've had 12" logs move on me, even with clamps and caused my blade to get hot enough to warp.  I don't cut anything less than 16" for this reason.  You could use thick bunk boards with notches that the small logs could set into, but you need to be sure the bunk boards can't move or slide.
4.  I do exactly as Ianab with flipping the bottom slab on top of the next log being cut.  But, I use 8" tall bunk boards with about 2-1/2" tall wedge blocks that I screw into the bunk boards to hold the logs.  With this, I can get down to only leaving a 3" thick slab at the bottom.  Generally there is not enough good wood left to bother saving.
5.  No problems with soft ground.  Lucas is not that heavy.

[M.R.]

If it's permitable here is a link to a thread on FB in the Luca Mill Operator Club ...on FF here the sponsorship of the swingblade mills are also worth checking out.

re: tip on not having to chalk it doesn't take much to keep the log from moving whether it's smaller log or larger on deep vertical cuts.
https://www.facebook.com/share/v/EstWcPuX2N6gbPxR/?mibextid=oFDknk

[NCEric]

Scott, thanks very much for that offer.  I'm very interested in taking you up on that offer, although I'm too busy this time of year to get away, so it would have to be sometime between about November and February/March.  I'm not super close -- I'm west of Winston-Salem, almost to I-77 -- but I'm probably close enough for a day trip.  Could you ever use any extra help off-bearing or anything like that?

Everyone else, thank you very much for all the very helpful information.

[NCEric]

One thing I don't really understand is what a bunk system is.  Could someone help me understand how I would set up a bunk system?

[blackhawk]

One thing I don't really understand is what a bunk system is.  Could someone help me understand how I would set up a bunk system?

My bunks are just two 6"x8" pieces of pine about 4 feet long.  

[NCEric]

They're just laid on the ground, not connected to each other?  Does is matter if they're lying in the same plane?  Do they serve any purpose other than positioning the saw log a little higher and off the ground?

[blackhawk]

They're just laid on the ground, not connected to each other?  Does is matter if they're lying in the same plane?  Do they serve any purpose other than positioning the saw log a little higher and off the ground?

Yep, just laid on the ground.  You want to have them at the ends of the log for the best support, so I move them when I have different length logs. 

They don't have to be in the same exact plane because you can adjust the winches on either end of the mill high or low to get you aligned with the log in the horizontal plane.  If you have a log with a significant difference in diameter from one end to the other, it helps that my bunks are not square.  With them being 6" x 8", I can sit one to be 8" and the other at 6" to get the log more level. 

They serve two purposes for me.  1) Gets the log off the ground so that you can cut to the bottom of the log.  2) Gives me a surface to screw in my wedge blocks that I use to secure (clamp) the log.

I attached a pic of my bunk boards.  They are about 6 or 7 feet long in this pic.  I cut them down to about 4-1/2 feet long just so that I could pick them and carry around by myself.  I made ramps out of the pieces that I cut off to aid in rolling the log up onto the bunks.  I have 2 of the Logrite mega hooks, worth every penny.  For big logs, I use a 12,000 lb winch on my truck to parbuckle the logs up onto the bunks.

[scsmith42]

Scott, thanks very much for that offer.  I'm very interested in taking you up on that offer, although I'm too busy this time of year to get away, so it would have to be sometime between about November and February/March.  I'm not super close -- I'm west of Winston-Salem, almost to I-77 -- but I'm probably close enough for a day trip.  Could you ever use any extra help off-bearing or anything like that?

Everyone else, thank you very much for all the very helpful information.

I'm probably around 2 hours from you.  Take I 40 to GBO, then south on 421 to Siler City, then east on 64.  I'm in-between Pittsboro and Apex around 7 miles south of 64.

I have three mills.  In addition to the Peterson WPF, I have a dedicated chain slabber and Tom the Baker band sawmill.  We do the vast majority of our milling with the Baker.

You're welcome to stop by and I'll let you try out the various mills.  We Primarily use the Peterson on logs over 36" diameter or over 25' length.  

Send me a PM if you'd like to meet up.

Scott

[Ianab]

They're just laid on the ground, not connected to each other?  Does is matter if they're lying in the same plane?  Do they serve any purpose other than positioning the saw log a little higher and off the ground?

Like Blackhawk has said, the bunks are just 2 sturdy lumps of wood that support the log. Generally you have a notch cut in them to stop the log rocking, or some sort of "log dogs", or even screw on wedges. The Bunks don't need to be aligned perfectly, you aren't referencing the sawing from them like you are the bed of band saw. If you know your log has taper, then you can adjust for that by slipping a board under the small end bunk and raise it an inch or 2. Doesn't need to be laser accurate, just get the pith approx level, or with the Lucas design, you can adjust the rails a little and still cut fine.

For BIG logs, ones you basically can't move, you don't have to use bunks are all, just set up around them in the ground. But you will end up with ~6" of log that the saw can't reach. That's what's going on here, the logs were a bit over 36" dia, and no machinery. The bottom slab that's under the mill however can be moved with levers and jacks, and wrangled back onto the top of another part sawed log.


With logs that you can move, sit them on notched cross bunks and you can then basically cut down to the top of the bunks, and there usually isn't enough left in the bottom slab to make a 1" board.