Chainsaw Mill: Milling a log thats longer than your guide board

[danf26]

Hello,

Im wondering if there are any Chainsaw Mill pros out there that can offer me some good advice . . .

What's the best way to mill a long log (aka - a log longer than your guide board)? Fastest, easiest, best result, etc. I need a 24' timber, and have a 16' guide board. I run a Husqvarna 372XP with a 24" bar, and have both the standard Granberg Alaskan Mill, and the mini-mill.

I'm fine once I get that first cut made, so all Im asking is: does anyone have a good system they want to share about how to make that first cut on a log that's longer than your guide board?

Thanks!
Dan

 

[mtngun]

I need a 24' timber, and have a 16' guide board. I run a Husqvarna 372XP with a 24" bar, and have both the standard Granberg Alaskan Mill, and the mini-mill.

Several ways to do it, but since you have a mini-mill, I'd use the mini for the 1st cut.

You'll need an intermediate support board. Notch the middle of the log like |_____|, prolly at least 3" deep, but not so deep that you cut into the finished product. Screw your support board into the end of the notch, making sure that the top of the support is level.

Now put support boards on both ends of the log, making sure that the tops are level.

Mark where you want the edge of the cut on each end of the log, and run a string from end to end. Now mark the middle board where the string touches it -- that's your middle guide point.

Install the mini-mill guide board, lined up with the edge marks. Cut half the log. Now slide the guide board over to the other half of the log and install it lined up with the edge marks. Finish the cut.

The same process can also work with an Alaskan, except that you'll have to take care to put the intermediate support board at exactly the same height as the end boards. With the mini-mill, you don't care about the height of the support boards as long as they are level side-to-side.

 

[BobL]

I have 16 ft long log rails and have only needed to cut longer than this twice. I did it more or less the same way as mtngn method except I mill on a slope so I don't bother about getting the log level.

I set up my log rails like the top view of this image. Notch the middle of the log so the cross piece of the log rails can sit inside the notch. My method means no screws penetrating below the level of the rails - I have often cut within 1/8" of the ends of the log rails.

I measure the log rail angles (both down and across slope) using a DAF and then mill the first half.
When I moved the rails to the second half I made sure to position the log rails to the same downslope and cross angles.

An invariant reference surface is handy but that is easy to setup using a stump or a piece of wood that is not moved during the operation.

 

[mtngun]

Great picture, BobL.

When I said level the tops of the end board, I mean across the log, not along the length of the log. If all end boards are not level, the cut will twist.

How is your shop project coming along , BobL ?

 

[BobL]

Great picture, BobL.

When I said level the tops of the end board, I mean across the log, not along the length of the log. If all end boards are not level, the cut will twist.

Yep - I understand.

How is your shop project coming along , BobL ?

Slowly.

Here is what it currently looks like.

Left hand side is metal work - RHS is woodwork.
Everything is back inside the shop but I need to make a couple of benches, one for my wood working lathe (yellow machine on central metal work ench) and the other for my 4 grinders also clogging up the same bench.
I'm also making a fume hood for my small welding bay.

1 is the front door (the door on the far right is the same door)
2 is the back door. The big dust extractor is located outside the back door.
3 where the lathe bench will go.
4 is my old lathe bench which has now become my wife's bench for her lapidary work.
The chainsaw steel mesh storage shelves (at the back of the wood working wing) with drip trays underneath are working a treat.

Things are going to slow down even more as I am off to Holland and Belgium next week for about 10 days.

Hopefully milling on friday.

One piece of good news is my retirement date looks like being moved forward by several months with an even better financial payout than I had before. So instead of retiring in mid 2012 it could be as early as Feb 2013.

 

[BlueRider]

I use 1/2" x 8" lag bolts set to a pair of string lines running from end to end on the log. The easiest way to set up for this method is to screw a square of plywood on each end and use a level to make sure the top edge of each square is level. Then set up two string lines and use those to locate your lag bolts. the tops of the lag bolts are what your guide board sits on.

You will need to figure out a way to secure the guide board, I shoot some screws hrrough my guide into the log and it works but you will need to make sure the guide stays on top of the lag bolts.

 

[BobL]

. . . . So instead of retiring in mid 2012 it could be as early as Feb 2013.

Err . . . . . that should be ". . . .instead of retiring in end of 2013 it could be as early as Feb 2013"

 

[psgflier]

I made up a couple of plates from aluminum to attach to the ends of the log. The plates were squared up, and marked with rule marks in 1/8 inch increments. I leveled the plate in a vise, and epoxied a string level on each one near the top. Two flat head screws were put through the plats 9 inches apart. I cut some steel brake line for spacers between the nut and the plates. The plates are screwed into each end of the log equi-distance above the heart. Run a string line between the matching bolts, and set 3/8 or 1/2 lag bolts to the string line about 2 feet apart, then take the string line and end plates off. I had a bracket made up of two lengths of angle aluminum with flat bar welded between them with a distance of 10 inches between the angle legs. screw a good straight board or piece of plywood to the bracket to stiffen it and run the mill on. The first board I used, I melted paraffin into it to protect it from the weather and let the mill slide a little easier. I made my guide board 10 feet, but 6 to 8 is plenty if you put the lags 2 feet apart. The aluminum angle slides along the heads of the lag bolts. After making the first cut, I roll the log 90 degrees, and set up the end plates using a carpenter square.

I've cut timbers 60 feet long and over 1/2 a million feet of lumber using this set up .

Carl

 

[Timberframed]

Sometimes we have to use innovation. Here I could think of no other way. 27.5' long and 55" wide at the center. I used an optical level and a string line to get the rails parallel.

 

[psgflier]

I found some pictures of my son and I cutting a 20' spruce log using the string line and lag bolt guide.
Carl

View attachment 233834View attachment 233833View attachment 233835View attachment 233836View attachment 233837

 

[yukon7]

Good pictures Carl, I would like to give your system a try. How long are the lag bolts, do they pull over when sliding the board ahead with the saw sitting on it? I use an Alaskan for cutting larger logs and have been using a steel frame similar to a ladder made out of angle iron. But it isn't that portable to cut at the stump.
Jon

 

[mtngun]

Looks like psgflier has angle on his guide board. Without the angle, the guide board would be pulled to the side as you are cutting. Also the lag bolt method would not work with the unistrut guides that many of us use.

With the lag bolt method, you have to take care that the lag bolt does not extend into the cut. Unless your log is perfectly straight, that may require having an assortment of different length bolts.

When I tried the lag bolt method, I found it difficult to get the height of the bolts just right. If the bolt touches the string, then the string may be pushed up slightly, and it's difficult to see. All in all I found it to be a slow and awkward method.

 

[psgflier]

Length of the lags depends on the log. I use the shortest bolt that will give me clearance for the angles on the guide. I used two inch angle, and the bolts need to be a couple of inches into good wood for stability. If there is a lot of taper in the log, I'll use longer lags on the small end. The idea is to make the cut as close to parallel of the heart of the log as possible to avoid grain run-out.
I don't like driving lags in any deeper than I have to, so I use various lengths depending on the log. High enough so the sides of the guide clear the log, long enough to hold steady. Not all of the lags have to be solid, as most of the pressure is down, but some pressure is sideways on the sides of the angle to keep the guide straight, so some have to be solid.
I use a battery drill with a 1/4 bit to pilot the holes every 2', then chuck in a socket to drive the lags just below the string. I then come back with a wrench and bring all the heads up to just touch the string.
You have to add the length of the longest lag to the thickness of the guide to set the depth of cut plus whatever you feel comfortable with for clearance. I'll sometimes add an inch or two, then flip the slab over and cut flitches from it.
It takes a little time to set up right, but it only has to be done twice per log. When I take my time and do it right, I can get less than 1/16' variance on a 60' timber, or almost perfect lumber, much better than any of the band or circle mills I've seen.
I've tried a lot of guide methods, from just throwing a board on a log, to elaborate guides, but this method has proven to work the best for me, I get good accurate lumber, length of cut is almost infinite, and its easy to pack into the logs and set up. I've packed as far as 1/2 mile into the woods,and packed out beautiful lumber from trees that would rot away,and even carried this set-up in my plane and used in places the nearest road is 50 miles away.
My wife felt sorry for this crippled old fat man packing all this gear into the woods, so she bought me a band mill. Now I have to pack out logs.
Carl

 

[Kicker_92]

Hi All,

Haven't been on here for a while, but saw this topic and wanted to jump in. So how do you mill a log longer than your rails? Just get longer rails!

http://www.arboristsite.com/attachments/milling-saw-mills/120018d1262238525-long-rails-1-jpg

http://www.arboristsite.com/attachments/milling-saw-mills/120019d1262238537-long-rails-2-jpg

 

[yukon7]

Here is a fellow who uses nails ( towards the bottom of the page) similar to what we are discussing only smaller logs. http://thehappytrappers.blogspot.ca/search/label/Alaskan Mill
If you browse around there are lots of milling pictures.
Jon

 

[BobL]

When I tried the lag bolt method, I found it difficult to get the height of the bolts just right. If the bolt touches the string, then the string may be pushed up slightly, and it's difficult to see. All in all I found it to be a slow and awkward method.

Yeah I agree, the lag bolt method is not as easy as it sounds and after hitting a couple of bolts I stopped using it. I prefer to use rails and spend the time nestling the rails into the log as shown here.

Af

 

[yukon7]

View attachment 234223
Here is what I have been using, have an extension to cut up to 16 ft.

 

[BlueRider]

Color me confused because I don't understand how you could hit a lag bolt using the string and bolt method. You put the bolts in the log and since you put them in the log you know how long they are so you can set the mill to that distance plus the thickness of your guide rails and a bit extra for good measure. So how do you hit a bolt?

The string and bolt method does take more time than the method Bob illustrated earlier in the thread but that method also has its shortcommongs in that if the log is not perfecty straight there is no visual refrence for getting the set up straight from one end to the other.

That all said I have yet to use a long board I have milled. I usually cut my slabs up to make furniture and I once cut a seat for a chair out of the middle of a 36" wide 10' long slab because that is where the best figure was, but It is fun to mill some long stuff just for the experiance of doing it. and it is also nice to explore different ways of doing the same thing because each will have its time and place to be the best approach.

 

[BlueRider]

Sometimes we have to use innovation. Here I could think of no other way. 27.5' long and 55" wide at the center. I used an optical level and a string line to get the rails parallel.

Wheres the money shot? What did that bad boy look like inside? without pictures it never happened, for all we know you built a deck on those rails and are trying to pass it off as a milling set up.:msp_w00t:

 

[Timberframed]

My sincere apologies there Bluerider. I had thought that I had posted images of this operation some time back. However I'm going through the process of re-posting all the shots again which is somewhat time consuming and "cutting" into my happy hour. Therefore and in conclusion you owe me a cold one (Bud 12 oz longneck) if we can hook up some day. Here ya go...