(2 questions in one thread) Blades & Deflection HF Sawmill

Kingmt · September 23, 2015, 01:23:37 PM

Using the stock blade I'm getting what I'd call deflection when cutting hard seasoned wood. I start at at 2 3/16" on board thickness & by the end of a 6' cut I'm at 2". I can actually see the blade bowing up in the middle. This is better then my other Blades tho which brings me to my other question.

I bought Marvel 3/4 pitch 1 1/4" x .042" Eagle Beak M42 for it. They are actually about 1 1/2" from the back of the blade to the cutting edge. They cut through just fine but walking as slow as I can go & the blade tightened as hard as I'm brave enough to torque on them the blade is still deflecting up through the log. Is this because the blade is to wide or is it just completely wrong for my saw? If I make wider guides will this stop it from deflecting?

I'm new to this so any termonalgy you could help me with in explaining this is welcome.

drobertson · September 23, 2015, 01:28:35 PM

Not sure what mill you have and nothing about that make of blade, or your set up so If the blades are sharp it seems to me that there is an alignment issue somewhere, and to add, the wider you saw expect a few more issues in regards to speed of cut and wave,

beenthere · September 23, 2015, 02:04:45 PM

Kingmt
Welcome to the Forestry Forum.

Where are you located? You can click on your forum name and will be taken to your profile for updating, then your location will help to answer your questions.

Appears more info is needed such as the history of your mill.. bought new, or used and how long have you been having trouble.

Magicman · September 23, 2015, 02:14:03 PM

First, Welcome to the Forestry Forum, Kingmt.

Quote& the blade tightened as hard as I'm brave enough to torque on them

This is not very descriptive, and I have no idea about the blades that you are using, their sharpness, or if your sawmill/blade guides are properly aligned. Your engine drive belt tension is also very important to prevent the belt from slipping and slowing the blade speed down.

Kingmt · September 23, 2015, 03:54:27 PM

I live in WV. The Harbor Freight saw is new. I made a new track for it a few weeks ago. I've paralleled the track & booked it down on a trailer. The track is straight & level. The saw has been squared to the track & the tension set on the blade. The tracking had already been set by the manufacturer for the stock blade so once tension was reset it was good.

I've been cutting Box Elder with no problems. The boards come out the same thickness every time with the stock blade. Doesn't matter if it was 1/4" thick out 2" think.

I ordered the bimetal blades for the hardwood so I switched it out to start cutting Walnut. Guides were still in the right place so I adjusted tracking for the new blades. I had read to adjust the blade tighter until the flopping of the blade stopped so this is what I did first. The blade was climbing fast so I tightened it more. Sorry for the exact measurement of "as right as I was brace enough" but I don't know the measurement of pressure but I'm sure it was over tightened. I did adjust the tracking to get it to start center of the whole tho. The blade didn't climb as bad but it still climbed. I took those blades back off & put the stock blade back on & it again cut pretty good with just slight deflection as I said above.

The guides set back about 3/16" from the cutting edge of the stock blade but the new blades actual measurement from the back of the blade to the cutting edge is about 1/4 longer so they are seeing out about 1/2" from the guides.

With the new blades I had slowed to about 2" per minute. The slower I go the better it did buy it still doesn't go away.

Chuck White · September 23, 2015, 04:26:16 PM

Welcome to the Forestry Forum, Kingmt!

Den-Den · September 23, 2015, 05:16:57 PM

Welcome to the Forestry Forum.

The band blade deflecting in the cut is usually caused by one or a combination of these issues: (no particular order)
* not enough set in the teeth
* dull blade
* alignment less than perfect
* tension too low

Some logs will allow more tolerance to these issues than other logs. Wide cuts have MUCH less tolerance.

Enough tension to stop the blade from fluttering is not nearly enough to make my saw cut straight.

Cutting Edge · September 23, 2015, 05:42:10 PM

Kingmt,

I'm very familiar with your mill and ones similiar to it. What you are describing is a common issue and it can be overcome. It just depends on how far you are willing to go. Once dialed in and/or a couple modifications, these little mills can/will cut Excellent lumber.

1) Make sure your head is clamped tight. It sounds like the vibration might be letting it slowly drop. DO NOT put any sort of lubrication on the masts of the mill. This only makes it worse.

2) Change your drive belt to a Gates Green Stripe. The original will not last long and will require adjustment often due to it's lesser quality. While you're at it, make sure your engine drive pulley is perfectly aligned with the band wheel. Otherwise the belt will wear out very quickly. May as well change the idle side belt too. Keep the original for spares.

3) Purchase blades that are 0.045 thick. The extra 0.003 in blade thickness adds to the beam strength and makes a world of difference. It would also be beneficial to purchase blades with a 4 deg. hook angle. Those little engines just don't have the torque to saw our Appalachian hardwoods with an aggressive hook angle blade. The Kasco Woodmaxx 4 deg. do VERY well in both hard and softwoods. Out of the box, the set is just about perfect.

4) Weld a 3/4" nut in the middle of your "T" handle that you tension the blade with. Get an inexpensive HF torque wrench and a 6" caliper. Open the calipers to 6", clamp it onto a slack blade and tighten the blade until it reads you have stretched the blade about 0.005". This will give you approx. 20,000 lbs. of strain on the blade. Then find out what that equals in "torque" on your wrench. Now you can tension the blade accurately EVERY time and not be concerned about damaging the blade or the mill. Take a Sharpie and write in on the blade guard so you don't forget.

Edit: A new washer is needed that compresses the rubber bushing below it when tensioning. If a snug fitting washer isn't used, the insert itself will deform. When using the dial indicator, DO NOT keep increasing tension due to the reading on the dial indicator lowering. The reading is lowering because the rubber insert and v-belts on the wheels are "settling". If you keep increasing tension to compensate this will exceed the machine's capabilities. Tension the blade to obtain .005" stretch over 6" and note the "torque" and STOP.

DO NOT USE THE TORQUE WRENCH TO ADJUST TENSION AFTER THE BLADE IS RUNNING UNDER ENGINE POWER !!! If the blade is loosing tension, find the cause, don't treat the symptom and compensate by increasing the tension further. The main cause of the blade heating up/loosing tension is the lack of lube and the block style GUIDES.

Note: The Achilles heel of these little mills and ones like it are the guides themselves. The block/sandwich guide system really does little to nothing to "guide" the blade. In all actuality, this guide system contributes to wavy cuts and reduced blade life through heat and friction transfer. If you're up for it, upgrading to a roller guide system is the single best thing you can do to GREATLY improve your lumber quality and blade life. These guides give you ability to adjust/aligned to be perfectly parallel to the bunks and also, provide deflection/down pressure to ensure a MUCH straighter cut. Cooks Saw sells complete retrofit kits. It's not a hard modification and only requires a couple hours time and little cutting/welding.

Hope this helps you out.

fishfighter · September 23, 2015, 06:22:03 PM

Great info there. I, myself will be doing a up grade to my little mill. I'm ready to cut it in half and be able to handle bigger logs. :D

dustyhat · September 23, 2015, 08:10:38 PM

Cutting edge would be a good teacher, thats why this place is so good. people trying to help each other.

kensfarm · September 23, 2015, 08:38:04 PM

There should be a mark to show how tight you should tension your blade.. if it uses a spring type tension.. anything in the manual?

Kingmt · September 23, 2015, 11:02:45 PM

Thanks everyone. There is nothing in the manual that I remember to cover this. I'm going to look into the mods.

isawlogs · September 24, 2015, 08:06:15 AM

Keep in ind that a blade, as it warms up in a cut, will stretch and with stretching will lose some of the tension you applied to it innitially. Ya might want to check the tention everyn so often until you get a feel for it. I have a Woodmizer and there is a dial gauge that gives me a reading of tention at all times.

4x4American · September 24, 2015, 08:14:53 AM

Also, sawing at 2"/minute is way too slow! First get the saw up to snuff, then go alot much more faster than that! ;D

kameljoe21 · September 24, 2015, 10:40:43 AM

I ran in to this problem a while back with some cottonwood
what i came up with was a couple of things...

one was the log was soft and drawing the blade down
two was it was a bad log

i have cut other logs since then and it seems to be fine
the mill i was using was a norwood with a new blade on it

Kingmt · September 24, 2015, 12:59:45 PM

Quote from: 4x4American on September 24, 2015, 08:14:53 AM
Also, sawing at 2"/minute is way too slow! First get the saw up to snuff, then go alot much more faster than that! ;D

I realize that but I was hurting to keep the blade from deflecting. I think I just spent $125 on blades I can't use since I didn't know what I was getting.

I tried to join the forum a month ago to ask questions but the admin thought I was a bot & didn't let me join. I tried to reply to the email but it isn't a deliverable email address.

beenthere · September 24, 2015, 01:07:49 PM

Filling out your profile helps for others to know a bit about where your questions are coming from.

Just click on your forum name and you will see where you can do that.

Admins have a tough job with sorting out the legit and the non-legit hits on the forum. There are those that would give their left leg to sneak in under the radar and be a nuisance. Sorry to hear you didn't but glad to hear you persevered.

How long have you had the Harbor Freight mill ??

Kingmt · September 24, 2015, 06:16:51 PM

I've received & setup it about 4 weeks ago. I've had it on the new track about 2 weeks. The new track allows me to cut 16' & the track is all one piece instead of having a joint. It also has rounded edges instead of the square edge which allows the saw to glide down the track easier & I don't have as much saw dust building up on the track to clog the rollers. I haven't had it clog yet on the new track which was the first problem I had with the saw on the old track.

Wish I knew someone wanting to buy that pretty green metal track before I decide I need a piece to build something & start cutting it up. Lol

Chuck White · September 24, 2015, 07:50:50 PM

Quote from: Kingmt on September 24, 2015, 06:16:51 PM
I've received & setup it about 4 weeks ago. I've had it on the new track about 2 weeks. The new track allows me to cut 16' & the track is all one piece instead of having a joint. It also has rounded edges instead of the square edge which allows the saw to glide down the track easier & I don't have as much saw dust building up on the track to clog the rollers. I haven't had it clog yet on the new track which was the first problem I had with the saw on the old track.

Wish I knew someone wanting to buy that pretty green metal track before I decide I need a piece to build something & start cutting it up. Lol

Advertise it in the For Sale, section here on the Forestry Forum! ;)

Kingmt · September 24, 2015, 08:56:52 PM

Advertise it in the For Sale, section here on the Forestry Forum! ;)
[/quote]

I could do that but I'd think shipping would be prohibitive. I wonder what it would be worth being painted & predrilled. I know I have $380 in my 2 20' pieces(which I thought was a bargain) & had to do the fabricating myself.

boscojmb · September 24, 2015, 10:08:56 PM

Quote from: Kingmt on September 24, 2015, 12:59:45 PM
Quote from: 4x4American on September 24, 2015, 08:14:53 AM
Also, sawing at 2"/minute is way too slow! First get the saw up to snuff, then go alot much more faster than that! ;D
I realize that but I was hurting to keep the blade from deflecting. I think I just spent $125 on blades I can't use since I didn't know what I was getting.

When I first read this thread I assumed that 2" per minute was a typo, but it sounds like you just confirmed it.

As A new sawyer I did OK, then I got my second box of blades. I could not cut anything with them. I was in rural Alaska without phone and internet. It took me several days to figure out that the teeth on the blade where pointing the wrong way. The blades where shipped to me inverted, (inside out). It turns out that band blades are easily inverted and it can happen at the factory, or while uncoiling.

Kingmt · September 24, 2015, 10:29:25 PM

Quote from: boscojmb on September 24, 2015, 10:08:56 PM
Quote from: Kingmt on September 24, 2015, 12:59:45 PM
Quote from: 4x4American on September 24, 2015, 08:14:53 AM
Also, sawing at 2"/minute is way too slow! First get the saw up to snuff, then go alot much more faster than that! ;D
I realize that but I was hurting to keep the blade from deflecting. I think I just spent $125 on blades I can't use since I didn't know what I was getting.

When I first read this thread I assumed that 2" per minute was a typo, but it sounds like you just confirmed it.

As A new sawyer I did OK, then I got my second box of blades. I could not cut anything with them. I was in rural Alaska without phone and internet. It took me several days to figure out that the teeth on the blade where pointing the wrong way. The blades where shipped to me inverted, (inside out). It turns out that band blades are easily inverted and it can happen at the factory, or while uncoiling.

Well I actually didn't time it but I was moving snail slow. The blades I gut we inverted for my saw but I knew to turn them before mounting them. I'll be ordering the correct blades for it tho.

drobertson · September 24, 2015, 11:16:45 PM

If I were you I would hang on to those 3/4" pitch blades, I know a few folks that resaw and even saw with them, with very fine finishes on the lumber, get the mods done and you will be pleasantly surprised. best of luck to you,,

mattyo5 · September 25, 2015, 03:31:32 AM

Kingmt,

where in the USA are you?

are you sure the blade is "deflecting" and the head isn't moving? On my woodland mills (essentially an upgraded HF unit), the head tends to drop (even if I have it clamped) so I have a bunjee cord that I attach to the height adjuster handle ...this keeps the handle from wandering and the head from dropping. a super cheap and very simple mod

If I get a chance I'll post up a youtube vid of the mods I have done to the mill.

Another good one is the mod on the lube system. I have it dripping on a diy wick. super cheap and works pretty well I think.

Kingmt · September 25, 2015, 02:00:51 PM

Quote from: mattyo5 on September 25, 2015, 03:31:32 AM
Kingmt,

where in the USA are you?

are you sure the blade is "deflecting" and the head isn't moving? On my woodland mills (essentially an upgraded HF unit), the head tends to drop (even if I have it clamped) so I have a bunjee cord that I attach to the height adjuster handle ...this keeps the handle from wandering and the head from dropping. a super cheap and very simple mod If I get a chance I'll post up a youtube vid of the mods I have done to the mill.

Another good one is the mod on the lube system. I have it dripping on a diy wick. super cheap and works pretty well I think.

Well the first cut with the new blades I started the cut at 1" & by the end of the board it was only 1/2" thick. I also have the handle drop if I don't start with it in the down postion.