There was a discussion about the difference so I thought I'd add my point of view. I ran an MD about 30 years ago and now own a Lucas. And for a very short time I ran a WM that I didn't know how to sharpen baldes for so didn't have a real good experience with.
Having started sawmilling using a MD I kind of fell in love with cutting big logs. Never met a log I couldn't cut size wise. Where I live, Western Oregon, we still have a number of large logs that either the mills can't cut because of size or don't want to cut because of size/grade. Most commercial mills have equipped themselves to cut logs >30" to maximize production. The cost of big logs is actually less than the smaller ones. Most of the big logs (not all) are Douglas Fir and premium fir commands a price equal to or better than most hardwoods. So the profit margin is there withouit having to compete making 2 X 4's.
Two reasons I opted to buy a Lucas. Cost of the mill and the ability to cut big logs. The cost for the Lucas is about 1/2 of a MD so start up costs are reduced. Start up cost were a big factor to me because of the stringy shoes I wear or is that shoe strings.
What I've learned:
Both the MD and the swing mills will cut any size log because of the nature of the cuttin pattern. Basicly a log is planed down from the top one layer at a time. All boards are or can be edged as they are cut. Boards cut from the top or edges can be left with a live edge (bark on), sawyers choice. All of the mills have the ability to cut very long logs (optional additions). MD can edge or not on each board, Lucas it's either/or not both.
The differences as I see it:
The kerf: Swing mills are billed as having a narrow kerf (3/16") and they do compared to a circle mill (1/4"-3/8") and they don't compared to a band mill(>1/8"). Kind of some were in between.
Sawdust leavings: Lucas gives shaving like the MD when the teeth are sharp unlike a band mill which gives dust. This is an issue for some people trying to get rid of the sawdust but I have yet to have enough production to worry about it. (200 hours on my mill) But I do know that mushroom growers love oak shavings.
Production: Given one helper I'll match anybodys production in wood cut from 20"+. From what I've read I can get more boards per blade sharpening than a band mill. The MD will out cut me without a helper unless we're cutting heavy boards (say 20' 8" x 8") where the MD drag back doesn't work well). The MD drag back is nice.
Log size. If you're using end stands with the MD log size is limited to end stand highth. No limit with the block and board method but you really need a good set of blocking to match size of boards you want to cut.
The Lucas is comfortable at around 50" with out any hassels. Bigger logs take a little more manuvering and blocking up. There an extended frame model available if your really have a need for BIG, like add two feet?
Cut size horizontal: One of the limiting things I had with the MD I used was the 4" limited horizontal cut. Yes there was and still is a larger trim saw available to give wider cuts, but I didn't have it. So if somebody wanted a 6" x 6" I couldn't to it. The Lucas I have will cut 8 1/4" either way with no hassle. And there is a 9" blade option.
Cut size vertical: The MD will cut 12" down and that's nice for 1" siding and 2"+ for construction stringers and rafters. The Lucas will only cut 8"s (or 9" with optional blade). The 12" cut is better, no argument there, but that limit hasn't turned anybody away from my cutting their logs yet.
Wider boards: The Lucas and other swing mill have the ability to "double cut" in the horizontal. Thus my saw will cut 16" wide boards. But there are some limiting factors. Only one wide board per pass or layer. Double cutting on smaller logs gets a little dicey because the saw needs a wide stable base to rest on while your spinning the carriage around. You don't want to have the saw on the ground because it overballanced half way in the spin. There can be a slight mismatch in depth of cut from one side to other leaving a ridge on the underside of the board. The reason being you have lower the rails, spin the saw and then raise the rails back to EXACTLY where you started. Perfection may be possible but I'm not there yet. I did hear about one fellow that lifted his saw with equipment to spin the saw and got away from lowering the rails. Should have been a better match. If you consistantly need wide boards (up to about 30") then a band mill would be better.
Cut timber size: MD says they can cut one timber any size, one per log, so can the swing saws. The kicker is you have to be able to roll the log three or four times. Rolling a 30" log with the top flattened is not what one would call easy without some sort of support equipment or winch set up. If you need support equipment there goes cheap.
Wide slabs: Band mills are limited to the throat width, generally 28" max with a few exceptions. Dimension mills and swing saws can cut one slab per log, any width, if the log can be rolled . The slab is what's left after sawing the rest of the log. Band mills can do the same up to throat width.
Swing saws have an option of a slaber either as a seperate cutting head or as an attachment. What that amounts is a 27hp chain saw mill with a wide bar.
Mobility: They'er all mobile but I ain't into adding a mule on my list of support equipment and I are certainly not going to be one! Even circle mills are mobile or can be made mobile. Foley-Bellsaw is really the one that started the whole thing.
Manuf. support: Good support in this market is the standard, not an exception. I think the products are too personal to tolerate poor support.
:)One big advantage the swingmills have over other types of mills is the ability to change direction of cut without moving the log.
Say I'm cutting 2" X 6" vertically and get near the center of the log and would be getting spike knots. (Not a good thing in construction lumber) I can change to 6" x 2" (horizontal) just for the center and then go back to vertical keeping all wood flat grained and spiked knot free.
Likewise If I want to cut verticle grain. In cutting conifir vertually the whole log can be cut vertical grain and never move the log. Oak is a little different because of tighter grading standards and wood patterns but still can be more quarter saw than other mills and not move the log.
If I had a choice of mills, and hang the money, I'd have a 12" swinger w/slabbing attachment, an optional band mill on the other end (I'm working on that) and an trailer mounted MD. And don't forget the tracked Bobcat for support. And then some idiot would probably still ask for something I couldn't cut. Oh well.
This has gotten long but I hope it helps
Stevem
