Mils DIY Sawmill (Will it fly or fizzle...)

milhead · July 24, 2018, 07:56:47 PM

Hi Folks,

I've got a gob of Maple and am too cheap to lay out for a commercial mill (so far)..
On the plus side I love to build stuff and have no real schedule.

I've built a couple CNC Routers and want to scale up to a Sawmill.

Starting at completely the wrong end I bought a 172" blade from Timberwolf, have an old 10HP Chinese clone of a WW2 era Yanmar L100 Diesel Engine.. 4' of 1 1/4 shaft, and a gob of oddball stuff around the shop... oh, and time.. Lots of time.

And lots of problems...

1) Can I use wood band wheels if I laminate them up out of Baltic birch?.. My first try will be 1" web, I may go to 1.5"
2) Can I get the engine running... (No Fuel at injector but I have a new pump coming today)
3) Engine is off a generator (Tapered Shaft.. Adapter or new crank.. Hmmm)

I like the designs that support both sides of the wheels and am starting there.

The CAD drawing is mostly so I can figure some dimensions.. My current build goal is just to get the head assembled and working.

We'll see how it goes...

Not sure I can post video links.. We'll see

Deleted by Admin. All photos must be in Forestry Forum Gallery.

Deleted by Admin. All photos must be in Forestry Forum Gallery.

My last logged build in CNC-Router Space: Deleted by Admin. Link not allowed.

Anyway, I'm reading and learning

sealark37 · July 24, 2018, 08:42:40 PM

Whether you are building from scratch, or rebuilding a sawmill, there is always a series of problems that have to be worked out, replaced, or rebuilt. Just keep at it until it works right. Make sure that your diesel has fuel to the injection pump, and you have compression with no intake air restriction. Bleed the injectors. Good Luck, and keep us advised of the progress. Regards, Clark

Bruno of NH · July 24, 2018, 08:58:49 PM

The band wheels will be to lite
You need the weight for the flywheel effect

bandmiller2 · July 24, 2018, 09:05:15 PM

Welcome Millhead, theirs so much to consider when building a band mill, and theirs reams of reading on this forum. I built my own mill about 15 years ago and its still putting out. Your basic design is good. There are places to cut corners but the band wheels are not one of them, they are one of the most important parts. I would look into Cooks they sell wheels and mill parts, guides est. You might as well engineer a hydraulically assisted mill from the start especially feed and log turning. I'm sure others will be along shortly. Frank C.

Al_Smith · July 24, 2018, 09:08:47 PM

It's none of my business but I wouldn't trust wooden band wheels .I'm not a fan of those old diesels either .That said good luck,be safe .

Percy · July 24, 2018, 09:43:23 PM

This mill has only a 4 hp electric and is seems to cut quite nicely...Wooden band wheels and all. Pretty cool and cheap too. I might add a blade guard to this one...heh

Cutting a pine board using a homemade wood bandsaw mill - YouTube

milhead · July 24, 2018, 09:57:58 PM

Quote from: bandmiller2 on July 24, 2018, 09:05:15 PM
Welcome Millhead, theirs so much to consider when building a band mill, and theirs reams of reading on this forum. I built my own mill about 15 years ago and its still putting out. Your basic design is good. There are places to cut corners but the band wheels are not one of them, they are one of the most important parts. I would look into Cooks they sell wheels and mill parts, guides est. You might as well engineer a hydraulically assisted mill from the start especially feed and log turning. I'm sure others will be along shortly. Frank C.

I'd love to start this way but my Cooks shopping cart says $717! Youza! I'll get the head built and design protect for 19" wheels in case it turns out as my limiting factor, I'll have to make some kick-a@$@ guards in case the birch wheels disintegrate under load. Hopefully if I have a 'safe' spectacular failure I'll catch it on camera...
Thanks for the heads up, I've linked the wheels and now need to increase my budget.

milhead · July 24, 2018, 10:05:56 PM

Quote from: Al_Smith on July 24, 2018, 09:08:47 PM
It's none of my business but I wouldn't trust wooden band wheels .I'm not a fan of those old diesels either .That said good luck,be safe .

It's totally your business or I would not have posted, and all feedback is welcomed!... I've built a lot of machinery out of the voidless Baltic birch, maybe I'll spin one up too watch it come apart... The comments about the missing mass I had not thought about.
I wish I could afford a 10-15 HP engine, the Harbor Freight comes close but makes me as nervous as the old diesel (lordy I hate the smell of diesel), but the 10HP electric I'd prefer, I don't have and my shop only has a 100A single phase feed. (I'm still trolling Craigslist)..

Southside · July 24, 2018, 10:38:58 PM

A lot of old machinery ran on wooden wheels, axles, etc, BUT they turned a lot slower back then. I would be concerned with how your bearings will seat and stay put first. I suspect they will fail and it will be spectacular. Guarding is one thing, a band running at a mile a minute that has come un hinged in a way that is not normally experienced could be a recipe for disaster.

I wish you well and salute you for your bravery!

btulloh · July 24, 2018, 11:01:10 PM

Fwiw - the hf 13 hp engine is pretty good.

milhead · July 25, 2018, 02:05:22 AM

Quote from: Southside logger on July 24, 2018, 10:38:58 PM
A lot of old machinery ran on wooden wheels, axles, etc, BUT they turned a lot slower back then. I would be concerned with how your bearings will seat and stay put first. I suspect they will fail and it will be spectacular. Guarding is one thing, a band running at a mile a minute that has come un hinged in a way that is not normally experienced could be a recipe for disaster.

I wish you well and salute you for your bravery!

I learned on all my CNC stuff not to try to seat bearings in wood.. I'm going to either turn a keyed flange to bolt to the side of the wheels or find some other way to secure them.. For both my drive and idle wheels i'm turning 1-1/4 shaft in a pair of pillow blocks.. Not sure how I'll do it yet.. stay tuned

bandmiller2 · July 25, 2018, 07:22:17 AM

Surplus center sells Vee sheves reasonable. When a fella is building his own he can try whatever he likes. Try the wooden wheels, but I would make them the same dimensions as metal so they could be switched in the future. Frank C.

YellowHammer · July 25, 2018, 08:23:18 AM

Why not use car tires for band wheels? Its commonly done and seems to be quite reliable. Solves much of the tensioning and bearing issues.

The wooden wheel might work, but I can't imagine them being reliable in the long term, seeing blade tracking and strength issues in the long term. It all depends on how long you plan to use the mill, and how hard you plan to tension the band. Safety would also be an issue.

I once built a Jon boat trailer out of wood once, (don't ask me why other than I thought it was a good idea at the time). It worked...for short awhile, just long enough to get me in trouble, ...until it didn't, and it was a bad day. Just my opinion on using wood for parts that should be made of metal.

Crusarius · July 25, 2018, 10:27:38 AM

Linn lumber has decent prices on wheels.

Portable Sawmill Parts,

milhead · July 25, 2018, 12:14:09 PM

Got the Motor Running, A new fuel pump was the key!..

Hi Admin! Can I embed a video from my YouTube channel?

The Engine Runs

milhead · July 25, 2018, 12:36:40 PM

So now my required change for the Engine...

It's was removed from a generator and has a couple inches of smooth 1" shaft followed by a slight taper..

The cost of a new 1" keyed shaft for this motor is about $150 shipped but I would then toss the taper shaft (or try to sell it on eBay)...

My upbringing says modifying crankshafts is a no-no (not sure why) but what's the downside of grinding out a quarter-inch keyway and putting a pulley on this shaft?

I hate to burn $150 and a working crank just to avoid a Faux-Pas...

It

Crusarius · July 25, 2018, 12:40:27 PM

I would be worried about using a grinder and heating one area to much causing a brittle spot. But if you have a mill with carbide cutter I would not feel bad about it at all.

milhead · July 25, 2018, 03:07:00 PM

Yikes, drive pulleys are expensive!

Just some thinking ahead before I start scrounging...

Engine Pulley: 3.15"
Drive Pulley: 12"

This gets near the 3.8:1 that I'm looking for

Ideal------
Engine HP: 7-8
Engine RPM: 3600
Goal Band Wheel RPM 944
Goal Band Speed 5000 fpm

For 7-8 HP I'm thinking a little smaller engine pulley than recommended to keep cost down on the big pulley, it's still expensive. But am planning on running two 'A' belts

These all 1/4 x 1/8 keys

Is it OK to use the belts as a clutch (aka Lawn Tractor Transmission).. If I make or buy a tensioner wheel I could use it to tighten the belts... Centrifugal clutches for 7-10 HP get expensive...

milhead · July 25, 2018, 03:18:25 PM

Hi Again forum!

Sorry to my constant tossing out of questions... I can't stop designing this thing in my head...

Is it reasonable to ask the 10HP engine to carry the load of a pulley or should I run a 1" keyed non-rigid couple to a small 1" shaft supported by it's own pillow block bearings (Similar to the band-wheel setup)...

This would get rid of some of the compactness of the engine assembly but moving some mass away from the band wheels (on the other side of the main frame) will actually help balance the whole head unit.

btulloh · July 25, 2018, 04:12:19 PM

My 9.5 hp carries the load on the shaft. Centrifugal clutch is mounted on the engine shaft. (Woodland Mills HM126). I think most of those engines are designed for belt drive/side load. The drive wheel for the saw is the driven pulley from the engine. The blade runs on top of the drive belt. That also allows a larger diameter pulley on the engine shaft, which is slips less than a smaller dia. pulley.

milhead · July 25, 2018, 05:35:26 PM

Quote from: btulloh on July 25, 2018, 04:12:19 PM
...The blade runs on top of the drive belt. That also allows a larger diameter pulley on the engine shaft, which is slips less than a smaller dia. pulley.

I've seen a lot of designs that do this (using the back of a belt in a big pulley as a band-wheel), Does the resulting narrow drive wheel cause any issues?

Southside · July 25, 2018, 09:50:13 PM

Woodmizer has what, 2 million mills out there that run this way? Seems to be a proven set up.

btulloh · July 25, 2018, 10:44:37 PM

Belts are 5/8. That pretty much makes the crown. Teeth hang over the edge so you don't lose your set. Lots of contact area and there's fewer points to lose power through slippage. Seems to be a proven system.

Al_Smith · July 26, 2018, 05:22:42 AM

Although it can be a bone of contention electric motors actually produce more power than either gasoline or diesel .It doesn't take nearly the HP rating to achieve more power .There's charts on it but if the motor were true HP ,not alleged "develops" such and such I would speculate that around 4 HP electric would equate to 10 gasoline .
This subject has been kicked around nearly as much as the great oil wars so I won't elaborate on it .

Ianab · July 26, 2018, 05:56:32 AM

Quote from: Al_Smith on July 26, 2018, 05:22:42 AMlthough it can be a bone of contention electric motors actually produce more power than either gasoline or diesel

It's the torque curve that gives an electric motor it's advantage. When you load up a gas engine and it loses revs, it's torque also drops off, and you basically "bog down". When you load up an electric motor your torque actually increases, so it's better able to resist the drop in speed, and power through that knot.

It's the same with electric and hybrid cars, they perform better than the specs might suggest, because they have a heap of low down torque, which is great for getting off the line from zero.

Exact numbers are impossible to pin down because different electric and gas engines have different characteristics. But I'd expect a good 4 hp electric to run at least as well as 7-8hp gas engine, and those are common enough on small bandmills.