The Forestry Forum

General Forestry => Sawmills and Milling => Topic started by: Southside on January 13, 2018, 09:26:02 PM

Title: Bi-Directional sawing
Post by: Southside on January 13, 2018, 09:26:02 PM
Just wondering what it is about our style of mill - color really does not matter as the heads are basically the same - that nobody has figure out how to run a bi-directional band.  I mean can you imagine the output of a 70 with two way sawing?  Has anyone successfully modified one of these mills to cut both ways?
Title: Re: Bi-Directional sawing
Post by: longtime lurker on January 13, 2018, 09:47:50 PM
Plenty of bi-directional bands out there, its just they're mostly at the big end of town. McDonough, LBL Brenta, Cleereman etc etc.

The smallest double siders I know of are the Select out of Canada and the Pilous ex - europe somewhere, I think they're Czech - they both do mills based on a 4"double sider but in both cases its the poor mans option to the 6"double sider.

If you want to cut both ways you got to have enough band for two lots of teeth and gullets.
And you got to have enough steel to carry the required strain, around 12000lb for a 6"band, up to 30000lb for a 12". You need that level of pressure to keep them cutting straight.
And you got to have access to a filing room that can keep the things dialed in.
And they arent cheap.
Those arent thin band type attributes, and best suit fixed equipment. So does the volume of lumber they can produce on a shift.

Title: Re: Bi-Directional sawing
Post by: 4x4American on January 13, 2018, 10:26:46 PM

A friend of mine had looked into the Select for his operation but he said that the blades were the killer.  Too expensive to buy and maintain them.  IMO, I don't like the way the lumber flow works on them. 


This here would be the double cut mill I'd be interested in if I was in the market:  (2:52 is when it starts double cutting)

https://www.youtube.com/watch?v=2qVIX7J4-R8



Title: Re: Bi-Directional sawing
Post by: etroup10 on January 13, 2018, 11:03:46 PM
When i saw the mebor in person at the virginia show i wasnt all that impressed. It may have been the operater though, looks better in that video. Double cut bands can cut a lot of wood quick! Look up cleerman lumber pro on youtube, thats a slant mill though. I personally wouldnt think itd be worth it to run a horizontal double cut. Main reason is that you cannot see the face for the return cut so when cutting for grade you cannot tell if you should actually be cutting that board or flipping to a better face. And if your cutting low grade where the grade doesnt matter, a circle mill would probably be faster and more affordable(initial costs+blade maintanence). Ive wondered if it would be possible to run two 2" bands on a vertical or slant setup to get away from the expensive blade maintence while still getting more production.
Title: Re: Bi-Directional sawing
Post by: longtime lurker on January 13, 2018, 11:18:58 PM
I think that realistically the double siders are going to go the way of the dinosaur. Could be wrong in that - but I think they're right at that production point where business gets squeezed. If you want straight up production today you go buy a quad, pay the higher setup costs and reap a lower cost per unit of production. But they're also too big and too expensive to maintain for the second tier operations. There will be exceptions to that of course, but unless you got a large supply of big logs then I dont see a lot of demand for them, and world wide large supplies of big logs are becoming scarce.
Title: Re: Bi-Directional sawing
Post by: 4x4American on January 13, 2018, 11:27:31 PM
Good point, Etroup.  Having two 2" bands is a good idea, but, I think that you'd have to stop the blade that's going backwards, or be able to pick it up out of the way or something cause if it was in the cut spinning going backwords I would think it'd be liable to pop off
Title: Re: Bi-Directional sawing
Post by: Kbeitz on January 14, 2018, 07:33:53 AM
You just need to make it so your carriage flips when it get to the
other end. If they do it with blades it can be done with bands.
Title: Re: Bi-Directional sawing
Post by: longtime lurker on January 14, 2018, 07:40:45 AM
you'd need to be able to get sawdust away from the top... when you flip the rig the sawdust ejection will reverse.
Title: Re: Bi-Directional sawing
Post by: Southside on January 14, 2018, 08:57:33 AM
I can see the flip over idea working, would need hydraulic driven wheels and hydraulic dust extraction doors. I suspect that would increase the motor HP needs quite a bit, perhaps a heavy flywheel style like a buncher or baler, but would not be reinventing the wheel.
Title: Re: Bi-Directional sawing
Post by: moodnacreek on January 14, 2018, 09:36:21 AM
For many who use traveling band saws. attached edging blades would seem like the next development.
Title: Re: Bi-Directional sawing
Post by: 4x4American on January 14, 2018, 01:43:47 PM
I'm pretty sure there is a band mill that the head turns around so you can cut both ways
Title: Re: Bi-Directional sawing
Post by: Southside on January 14, 2018, 03:39:55 PM
4 x 4 - your machine makes heads turn for sure!!   :D
Title: Re: Bi-Directional sawing
Post by: 4x4American on January 14, 2018, 04:33:20 PM
lol lol yea WM did a good job with it
Title: Re: Bi-Directional sawing
Post by: 4x4American on January 14, 2018, 04:34:51 PM
Quote from: moodnacreek on January 14, 2018, 09:36:21 AM
For many who use traveling band saws. attached edging blades would seem like the next development.


But then they wouldn't sell as many portable board edgers!
Title: Re: Bi-Directional sawing
Post by: Dave Shepard on January 14, 2018, 04:57:18 PM
There is a small bandsaw that has a head that flips around. I don't remember the name.  I think the best easy to maximize the potential of small portable type bandmills is to improve handling.
Title: Re: Bi-Directional sawing
Post by: Brian_Rhoad on January 14, 2018, 08:00:17 PM
MSG makes a mill that the head can cut both directions.

http://madtyson.com/msg/
Title: Re: Bi-Directional sawing
Post by: Greyhound on January 14, 2018, 08:05:30 PM
This family does a really nice job with a bandmill.  http://www.finewoodworking.com/2008/03/10/horizon-sawmill-tour-sawing-logs  I've been lucky enough to purchase some wood from them and go pick it up in person.  Very good people doing very awesome work.
Title: Re: Bi-Directional sawing
Post by: moodnacreek on January 14, 2018, 08:25:28 PM
4x4: When you get your gang saw to saw cants some board still need to be edged.  Actually,I should have a vertical edger on my mill but I can't run it by myself. Missed You x mass but it was titcher than a colders wit.
Title: Re: Bi-Directional sawing
Post by: etroup10 on January 14, 2018, 10:39:42 PM
Quote from: 4x4American on January 13, 2018, 11:27:31 PM
Good point, Etroup.  Having two 2" bands is a good idea, but, I think that you'd have to stop the blade that's going backwards, or be able to pick it up out of the way or something cause if it was in the cut spinning going backwords I would think it'd be liable to pop off
Ive wondered about that as well. I dont know if putting a splitter between the two blades to push the board out would help. That with running extra set on the blades may do it. I imagine if you got waves bands would be flying off left and right. If im ever rich ill try it and let you know haha
Title: Re: Bi-Directional sawing
Post by: longtime lurker on January 15, 2018, 06:21:01 AM
Quote from: moodnacreek on January 14, 2018, 09:36:21 AM
For many who use traveling band saws. attached edging blades would seem like the next development.

Mebor do an edger option to their mills.Not the best of their mills to me but this clip shows the edger working.

https://www.youtube.com/watch?v=uQlxIVETV5A


Resch also have an edger option... only one saw but it doubles as a chopsaw which is cool in a different way. IMO Resch make the most functional bandmill in the world in that class... so many things just done right... if I ever ditch my circles it will be for a Resch mill.

https://www.youtube.com/watch?v=8BQmC_96wLo

I touched on this in another thread recently but these things here are the future. Thats an edgerman out of a job right there, or for people working alone thats time spent edging that can now be spent sawing. BF a day its a winner.