LT40 Rescue

[Brob1969]

Well? Where's the sawdust?

!  I'm a little ways away from there, but for now the old Briggs is running strong!  Tomorrow I will rebuild the hydraulic blade tensioner and may spin a blade.

I don't know how to upload videos here yet, but below is a link to a short video I just uploaded of the first test run:

First test run 1990 18HP Briggs

[Bandmill Bandit]

Good job boy! It sounds real good to this old mechanic.

[Southside]

You did the video thing right, can't directly upload to the Forum.  

[Andries]

Great job on the motor! 
Most microphones don't record motor sounds very well, but that B&S farty fart fart sound on YouTube is perfect.
You're moving this ahead really well and mechanical skills are in your wheelhouse too.
Keep up the good work and don't get tempted to rush it. 👍👍

[donbj]

Awesome! That is so rewarding. Your thoughtful methodical approach is paying off big time. You're going to have a fine machine when you're done.

[Southside]

Is there a reason the starter engaged when you shut the engine down? Last few seconds of the video. 

[Brob1969]

Is there a reason the starter engaged when you shut the engine down? Last few seconds of the video.

I believe it is because I had the battery + directly wired to the starter to test it out.  When I hit the kill switch it grounded just enough to engage the starter a bit. 
The ignition switch wasn't sending voltage to the starter so I jumped it out.  It shouldn't do that once everything is wired properly with a new switch.   Good eye!

[Stephen1]

Sounds great. now for some sawdust. 

[Brob1969]

This evening I had the opportunity to remove the hydraulic blade tensioner and rebuild the unit. 

Previously I had turned the tensioner handle all the way in only to hear a bit of a spurting noise instead of the the wheel tightening.  I had ordered a new seal kit from Wood-Mizer when I noticed this, just before diving into the engine overhaul. Now that the engine is running, I turned my attention to other areas that need attention.  

The tensioner was a fairly straightforward process.  I first removed it completely from the saw and disassembled it on the bench.  All the seals were completely crumbling, no way they could have held any pressure whatsoever.  I cleaned everything up really well with brake cleaner and installed all the new seals.  After speaking with a tech a while back at Wood-Mizer about the tensioner, he told me a little trick that made refilling it much easier (aside from the ATF shower I gave myself at first).  I had the main plunger fully retracted and the two 90° blocks reattached to one another.   Before putting the top assembly and rear piston in, I filled the cylinder with ATF before installing the remainder of the block and cylinder.  At first I had the plug out and pressed the piston into the cylinder, fluid shot straight down my pants leg!  Clearly I needed to first install the fill plug.  I refilled it and then bolted everything back together on the saw.  I purged the air once the assembly was mounted in place. 

The only blade I have currently is the rusty one that was on it.  I'm sure it's 20+ years old, and I won't be sending it through a log, but I did put 2200 psi on the tensioner.  I have yet to replace the drive belts, from talking with the tech at Wood-Mizer the two belts have been replaced by a double belt. 

[donbj]

Looking good. I'm sure you know but try to get a matched set of belts. I've heard also that the quality of the good brands has the length very precise and match pretty much off the shelf between two. I may be wrong.

[Southside]

If you don't have one get a drive belt tension gauge. Drive belt tension is often over looked but critical to success when sawing. Too loose and band performance suffers, too tight and you can wreck bearings and even break the engine crank shaft. 

[Bandmill Bandit]

That belt tension gauge is a major money and time saver BESIDE give you a leg up on maintaining good quality in the lumber you produce. 

When you've been around belt drives as long as some of us have you get pretty confident in your own arm and the "push/pull test we have done for years on most belts, BUT trust me, this is not the place to depend on that test no matter how good you may be at it. the gauge removes any guess work and ALL doubt. 

Order the gauge with the new drive belt. 

[Durf700]

Congrats on the great purchase and resurrection of this mill!!!  you will get a ton of enjoyment out of it at a fraction of the cost you could of spent!!!!  be sure to post another video once you are ready to mill a log!!! 

(great thread!!!  I read it all just now.. lol)

[Crossroads]

Enjoying following your progress, Keep up the good work

[Brob1969]

This evening I checked a little further into the drive assembly.  The 470uF 50v capacitor I soldered into the control board did the trick for that, but one of the leads on the mosfet board had become corroded, heated up the board and melted some of the solder.   I re-tinned the area, cleaned the bolt and terminal, and put it all back together.   I had both forward and reverse control and the speed control knob slowed the motor commensurate to the position of the knob; I'll call that one a win for now.  I am going to have to replace the drum switch as the mechanism to hold the handle in place is pretty much corroded beyond repair. 

Once operational, the motor seemed a little rough.  The original belts were a contributing factor,  but ultimately I believe I need to open the drive motor and give it some attention. 

I will be ordering the new double drive belt, tensioner scale, the blade brake belt, and the drive assembly belts from Wood-Mizer tomorrow.  I think it's time for a box of blades as well! 

[donbj]

My 94 came with a brake belt(leather). Don't know if this is what you are looking at. They have an upgrade that I purchased that is a metal band with a brake lining that replaces the belt. Not sure if it fits your mill. Very good upgrade!

[Brob1969]

My 94 came with a brake belt(leather). Don't know if this is what you are looking at. They have an upgrade that I purchased that is a metal band with a brake lining that replaces the belt. Not sure if it fits your mill. Very good upgrade!

Yes, the leather belt is what is (was) on there currently.   It's in 2 pieces so it stops nothing.  I will definitely go for the upgraded material. 

[Brob1969]

I'm almost ready to saw a log!
I did end up pulling the drive motor apart.  It looked almost brand new inside, though the outside looked really weathered.  The housing got a wire wheeling and a coat of spray paint, it suspiciously matches the new paint job on my wife's big flower pot she just fixed up...
The bearings felt a bit rough, I soaked it with penetrating oil and rotated it until it felt pretty smooth.  I plan to pull the motor again tomorrow and take it to a local electric motor shop to get a new bearing.  There is a guy here locally who is the sole proprietor of his shop, he's always got a shop full of electric motors to repair, but I generally come in for parts for my motors and he'll stop for a bit to help me out and chat.  He's impressed that someone younger than himself can actually repair something. 
I did go ahead and reassemble the motor and install it on the mill just to test it out. It seems to be functioning properly, but I know that the bearings won't last long after having been so crusty. 

As I wait for the final parts and a box of new blades, I will continue to wear out wire wheels on the drive rails...they got pretty rusty sitting outside for over a decades. 

I ended up buying my first box of blades from Jerry's Resharp.  A box of 10° 737s.  I intend to purchase a box of blades from Wood-Mizer to compare.  What do you guys recommend?  I was thinking of the double-hard blades.

 

 

[Andries]

The blades that work best for you will be the ones that work with the kind of wood you mill, the power you have to work with and way you operate.
* You're Central Florida, so you could be cutting SYP or Live Oak. For the oak, you 'll want 4 degree blades, probably not the 10's. Onna other hand, if you're cutting cypress, 10 degree might be fine. My oak logs are usually frozen, yours probably won't be. Green wood cuts easier than dried out logs, etc. etc.
* Your motor is on the petite side for an Lt40, so generally, a four degree blade will cut better rather than the more aggressive 10 degree. A big diesel motor will cut much faster, but your mill will be able to cut just as straight as a power-house mill.
* There was a recent discussion between sawyers about WM's Silver Tip, Double Hard, carbide and other blade types. @YellowHammer and someone else (sorry guys, can't remember nothin' after a week of ice fishing) concluded that the least expensive Silvertip blade was just as good as any other because they sharpened in-house, and sharpened as soon as the blade showed signs of being dull. Drive belt tension, alignment, feed rate, and voodoo spells all come into play with blade selection.
* WM used to offer a variety pack of bands - that might be a good option for you, as you get the mill acquainted with the logs.

[Brob1969]

I like the idea of a "variety pack" of blades.  That sounds the most helpful in seeing how they'll work for me. 

I was given a BUNCH of hardwood and cypress logs that are about a year old now.  My former neighbor had a couple hundred acres of timber harvested.  They were staging the hardwoods and cypress separately, COVID and the Canadian tariffs happened and none of the mills here would take anything but pine anymore.   My neighbor had already been partially paid for the timber when the broker called him and said they wouldn't be taking the hardwood and cypress.  He actually called me to ask if I could bring my backhoe to clear an area and burn all the logs!  It's probably 8-10 semi loads!  I told him I would instead come get the logs. He said he didn't care as long as the lot was cleared!

There's a lot of oak and cypress and a fair mix of hickory and cherry.  None of it is frozen for sure; if that ever happens here we've got serious problems!

I realize the 18HP Briggs is on the lighter side when it comes to HP.  I intend to run it for awhile while I get used to milling, and later put on a bigger powerplant when I'm more proficient with the machine and it's hopefully earning its keep.  For now though, I have that little Briggs twin cylinder purring nicely!

[Southside]

I would recommend going with the Silver Tips.  I have switched over to them myself and don't ever plan to go back to Double Hards, they cut just as long and have better flex life.  I am also a big fan of the Turbo profile, but at 18HP they might not be the best choice for pine and hardwood, they should do fine in your Cypress.  My 35 with a 25HP Kohler does just fine with them in all wood.  I would try a regular 7 in the pine and you may find it works better than 4's do in your circumstances.    

[YellowHammer]

Silver Tips cut as long at nearly half the price.  I haven't used Double Hards for awhile, and don't ever see a need to.

@Andries, 
Do people actually go ice fishing?  I thought it was just a myth.... 

[Brob1969]

I have been checking out some 25+HP engines as I'd eventually like to upgrade the 18HP Briggs.  It's running well right now, so my current intention is to run the 18HP for a year and then look at swapping it out for something in the 25HP range. 

Another thought is we have an old wood-chipper that was given to us without an engine.  It's pretty robust and could definitely handle 18HP.  My wife is interested in getting I running as she loves the mulch for our chickens and garden.  I am working on making it her idea to put the Briggs on the wood-chipper and upgrading the LT40.  The key here is making it her idea.  I've planted the seed, now I'm nurturing the thought...

[Southside]

Your chipper would actually come in quite handy as a means of waste disposal. This is what chips look like after 4 years of being in a pile. Nothing added, never turned, just squished into a pile.



 

[Old Greenhorn]

@Andries,
Do people actually go ice fishing?  I thought it was just a myth....

Yes, they actually do, but it takes hearty stock to endure and not a lot of folks want to spend all that time it takes to cut a hole to slide your boat in.