Thursday, February 8, 2018

Building a new track for the sawmill

Refresher on the need for a sawmill...

In the LHBA class, they recommend building a 25x25 cabin before attempting anything bigger. Actually, they recommend building a garage first, and then the house. But I didn't want to wait, so we started with a 40x40- the biggest cabin LHBA makes plans for.  There are multiple reasons they don't recommend starting with the 40x40:
  • Permit headaches: For a 40x40 home, you'll need a minimum of 44' logs (2' of overhang on each end). Transporting of logs commercially that are 44' can be a headache when 53' is the max length (including the truck) most highways allow. It's problematic for the driver- and they'll pass that cost on to you.
  • Ridge pole needs to be at least 5' longer on each end (50' minimum), and 17" average diameter, with little to no taper. This means this log will probably weigh around 7,000 lbs- 1 ton more than my heaviest log.
  • More materials equals more headaches, more work, more cost, more time, more skill, etc.
  • The reason for this post: rafters. 

Rafters for a 40x40:
  • Rafters span half the house, or 20' horizontal "run".
  • 6/12 pitch for roof means they "rise" half of the "run" (20'), so that's 10' 
  • Put on your math hat (sorry, can't help it, former math teacher): Pythagorean theorem shows: 10² + 20² = 100+400=500. Square root of 500 is the hypotenuse, or the length of the rafter, or 22.4', plus some overhang. 
  • The plans say use 4x10's, 26 feet long.
  • Home Depot and other places- it's a special order for a 4x12 beam over 16', and they want around $300 per beam. I need 32 - $9,600! Wow! 
  • I have tons of trees and access to more- I could cut my own rafters and save about $7,000....

I bought a sawmill from a fellow LHBA member for very cheap- let's say less than half of a new one- yes it was a great deal- "Thanks, Allen". It's a Hudson Oscar 121, with a 21" capacity. But it had two problems:
  • It only came with 12' of track
  • Came with no log dogs.

Collecting information and materials

I checked with Hudson- they wanted about $100 each for their log dogs. I felt sure I could make my own. I looked online- and there are thousands of styles- using all thread, chains, even hydraulic set ups. I just wanted something simple. And I needed steel track- 2"x2"x1/4" angle steel and cross beams for stability. Total length of track to add to the 12' I already had would be 18'. I designed two tracks that were 10' and 8' each, and will bolt them together for use.

Getting started

With my plans in place, I called my friends at C&J Welding- Mr. Williams loves what I'm doing, and he also lives in the town I'm building in, so I always show him pictures of my progress. The guys at the shop are really knowledgeable on steel, and I take their recommendations. I bought a bunch of steel and some round bar and square tubing for the log dogs and delivered it to the neighbor's garage.

A little snag that I thought was a big snag

 I cut out all the pieces and got the track all welded. I was about to start on the log dogs when the neighbor came out. This is the guy that taught me to weld, and lets me use his welder and shop. I take him seriously because he has great ideas.

Side story: he bought some land on top of a mountain with no road going to it. His son told me he built his own road grader out of an old combine that he turned around backwards and put a plow on it. Cool stuff.


Anyway, he comes over and looks at the log dogs I built for the existing track- now, I've already used the log dogs and track to cut a 7"x7"x 10' beam, and it worked out pretty well- just a little rounded on the edges, but I thought that was due to my blade not being tight enough.

My log dog, almost complete
He says, "Those dogs ain't gonna work."

Me: "Ummm....They should- I already cut this beam with them and they work fine."
Him: "No, let me show you a better way."

He tries to explain how I can use all-thread and a pipe and a nut, but he can't talk very well due to a stroke; and listening to him I'm getting frustrated because I've already used my idea and it works, and felt like he's slowing me down. And it's pouring rain.

I finally agree to try his idea. I weld it up like he tells me, then turn the track over, and I'm still not sure how it works.He also says we should cut my log dogs off, but I said, "No, I think I want to test out your idea before I change anything. I still can't see how it'll work."

At this point, he's not happy, and I'm not happy. I decide to go get a log to test the set up I have, and so I go out in the pouring rain over to my property and pick up a 10' log tip I cut off one of my logs a few weeks ago. I'm so frustrated, I don't even care about carrying it back over to his place in the rain and mud. I bring it back to his garage and put it on the track, but it's got a big knot sticking out. I get even more frustrated because it takes both of us to set the log with his threaded rod - this should be a one man operation. He had me take the sharpened bolts out of my logs (because I don't need them, he says), so now my dogs are flopping around while trying to hold the log in place.  Anyway, we couldn't cut the log because of the knot and I didn't have a chainsaw to cut it off, so I leave that night.

I was so frustrated I'm thinking about things like buying my own welder.  I call my mechanic and tell him what's going on, and ask, "What should I do?"

He says, "Can you do both ideas? Meaning, weld up like he says, but then just not use it if it doesn't work?"

I hadn't thought of that. "That's a great idea, but I wonder how he'll react."

Next morning is Friday. After work, I drive out there, dreading what's coming. I get the saw, cut off the knot, and fire up the sawmill. As I predicted, without any screws in the log from my dogs, the mill throws the log off the track.

I put the screws back in the log dogs, and it works a lot better. But I also notice that his threaded arm helps set the log at a right angle on the second cut - not what he had in mind, but I like it.

The whole time, I'm waiting for him to come out and supervise, but he doesn't. I finally have a sample cut - it's a 2x2. I don't think it's working like he wants, but it is helping keep the log square. I go to his door- he comes out and says he's not feeling well today (he's in his 80's). He gives his approval on the log, and I feel a lot better about everything. I think I overreacted the other night- none of the bad feelings are there. I weld up the rest of my dogs that night. Big snag turns out to be nothing.

Saturday, I get there around 6:00 AM. I finish welding up everything, then I had to go take my daughter to an activity.


Finishing up

Monday, I laid the whole thing out on the ground, and clamped the pieces together to drill holes to connect all the tracks together and set the whole thing up. I cut 4 out of 8 holes, and on #5, the drill bit broke.  Meanwhile, the neighbor comes over to supervise. He spends a long time looking at my log dogs, not saying anything. I'm nervous- I'm sure he notices I made 3 more of my style of log dogs.  Finally he says, "I don't think your set up is going to work, but I'll keep my mouth shut, and we'll see what happens." Without a drill bit, I can't finish, and it's getting dark, so I gave up and put everything away.

Test run

set up
Wednesday I finally got a new drill bit- a 1/2" cobalt steel bit, things went smoother. Then I was able to get the track oriented, leveled, and put the mill on it. There's one little misalignment in the track- the manufacturer's track isn't exactly 24" wide, so my track sticks out about 1/16".  I need to grind that area down. Other than that, the mill rolls along like a choo-choo train. I drove around on the tractor in the dark, looking for a log that I could put on the track, but all of the ones I could see on racks were spoken for. Finally it was too dark, and I couldn't see them, so I put the mill and tools away.

Thursday- I found a log I'm not going to use for the house, but it was crooked about 20 feet into it, so I cut it at 20 feet, and made a 7"x7" by 20' beam:
too crooked That's better (but shorter- darn)

Super excited now. I need to cut 32 of them. But I talked to my engineer and I'm waiting for a response. The plans call for 4x10 beams, but is a 7x7 equivalent? None of the engineering span tables I can find include tables for 26' rafters. I could probably dig out my calculus and figure out the moment of inertia, blah, blah, blah, but I think he'll have the right info for me.

Friday, February 2, 2018

Sometimes you work alone

 The set up...

My wife had to run some errands yesterday. I had already lifted log #40 to the top of the wall the day before, but I hadn't done any final positioning. Today, I went in the afternoon by myself. I knew the log needed to be rotated about 180 degrees, so I set to work. The main issue when rotating a log is that you are trying to rotate it with the strap that is also preventing it from falling to the ground- which is now about 16 feet below. I also found out early on that you can only rotate the log by the strap on the butt end- you can't turn it at the tip. If you have two vehicles- a tractor and your wife's Landcruiser, you can use the tractor to lift the log, while the Landcruiser pulls on a chain connected to the log to keep it balanced. She can pull forward or back, depending on where the log wants to balance, while I lift it up and down or let it be loose so I can rotate the strap.

The trap....

Working alone, with just one tractor, meant I had no way to hold the log in position while I rotated the strap. The log kept wanting to roll off the wall. I tried to chain bind it to the logs below, but the chain binder can only hold the log down, and when the log wants to go down anyway (meaning, way down- like- to the ground), it's just not effective.

I tried three times to use the chain binder, but finally gave up and went and got gas. When I got back, I tried something new.  I chain binded the log loosely- tight enough to keep it from falling down to the ground below, but loose enough that I could move it a few inches with the tractor.  I used another couple of chains around the log, and attached to the tractor, to replace what would normally be my wife's Landcruiser. I backed the tractor until the log was held tight and couldn't roll off. Then I moved the chain binder to the new position afforded by backing up the tractor.

 

The solution...

With the log now held tight by the chain binder, I pulled forward with the tractor to release tension on the chain attached to the tractor and disconnected the chain.  Then I loosened the rope, letting the log settle again into a new position that let it roll back a little, but not all the way off the wall. I then loosened the rope a bit more to give the rope about 3 feet of slack, but kept it tied to the tractor as an anchor just in case.  I could now remove the chain binder completely.

With the rope now slack, and the log balanced somewhat on the wall, I climbed up to rotate the strap so the lift point was now at the bottom of the log. With the pinch point of the strap now at the bottom of the log, lifting the log would lift at the pinch point, causing the log to rotate until the bottom of the log was now on top. The other strap on the tip end of the log was tied off to the house, but the strap was kept open to allow the tip to rotate within the strap, but not fall.

 

Surprise!

It was now a few minutes past sunset. I had about 45 minutes of daylight left to get this thing positioned. From the top of this log, I'm now high enough that I can almost reach the top pulley, which is about 6 feet from the top of the lifting pole- about 26 feet to the top.  Standing safely (ok, as safely as possible, but still able to build my house) near the log, I pulled on the rope to tighten things up, and the log started to roll! In fact, it rolled right off the wall! I had enough sense to hang onto the rope to slow things down at least (with gloves on, of course) as it slipped through my fingers, pulled by over 800 pounds of log (using pulleys reduces the log from 5,000 lbs down to a "still not manageable" 800 pounds- now you know what they mean when they say "an 800 pound gorilla"). The #8 heavy-duty triple blocks clanged as the full weight of the log hit them, and I heard the gears inside the tractor go "clunk" and it jumped forward an inch when the rope went taught. Dust sprang from the rope, and the lifting poles swayed gently, along with the safety lines.

Luckily (not really- I kept it tied to the tractor for this very reason), the rope was still tied to the tractor, and the log settled about a foot down from where it was, rotated nicely  at the pinch point, and 180 degrees from where it was before I started defying Nature.

When the adrenaline subsided, I climbed down until I felt wonderfully soft earth under my boots and fired up the tractor. I called my wife who was on her way and let her know it was rotated, and all she needed to do was give the final ok. I backed up the tractor, lifting the log back up on top of the wall, eye-balling it for the correct position. It was now starting to get dark.

 

 Ah....all is well....

Keeping it in the air above the log below, I got the ladder and my chainsaw and started cutting knots just as my wife pulled in the driveway. She nodded her approval, and set to work identifying log #'s 41, 42, 43, 44. I finished cutting knots, and trimming up the log, and then lowered it into its final resting place. I eyeballed it- it was as perfectly centered as it could be over the log below. She checked it from the inside of the house, and also the outside, and said, "pin it".
And that is what a one-man operation looks like.