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And another sawmill build thread...

Started by Ljohnsaw, July 11, 2015, 12:58:54 AM

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Ljohnsaw

I'll get more pictures when I go back up next week of the engine mount, the pillow block mounts, tracking adjustment and blade tension setups. 

Look at the last picture above and the back rail.  The cross rails are from pallet shelving and has a step on the inside.  I made a secondary frame out of some 1x1.5 tube that fits in between the front and back rails with a 1/4" engine plate welded to the top hanging over the back rail for the engine.  The entire frame/engine mount can slide and clamps from underneath.  No hole in the cross frame.  Same sort of thing going on for the pillow block mounts.  The gray rectangular pieces with all the lightening holes are brackets from Dish Network setups.  They make nice areas to mount stuff and they are powder coated so I didn't repaint them.
John Sawicky

Just North-East of Sacramento...

SkyTrak 9038, Ford 545D FEL, Davis Little Monster backhoe, Case 16+4 Trencher, Home Built 42" capacity/36" cut Bandmill up to 54' long - using it all to build a timber frame cabin.

Ljohnsaw

More pictures of the mods:
The light tan is the original upright.  I added the silver 2x4 tube with the angled top on both sides to increase the "throat" width by 8" and increase the height by 3".



This is the tension side of the head.  The big nut and bolt is just a keeper to keep the tension.  The little space behind the bolt is where a little hydraulic puck drops in that I pump up to set the tension and then hand tighten the bolt and remove the puck.  What the bolt is up against if held in place with four bolts clamping it to the pallet rack rail.  You can see two of them up front and two more way in the back.

 
From underneath, you can see two bolts clamping pillow blocks.  The sub-frame has short sections of 2.5x2.5x¼" tube, two on the right on one on the left, that a C-shaped frame made from 2x2x¼" can slide in.  That frame has the pillow blocks supporting the idle wheel.

 
This is looking at the drive side.  You can see two of the four vertical clamping bolts.  Originally, I was going to mount a bracket to push the near pillow block to adjust tracking.  I had added the two horizontal all-thread you see on the left side to supplement the clamping bolts to keep the assembly from slipping.  I did the same on the idle side.  As it turns out, I loosen the four clamp bolts just a bit and use the all-thread to adjust the tracking - works great!


Here is a better view of the clamping set up, the all-thread for tracking adjustments and the shape of the pallet rack bars.  I didn't want to weld to the bars since the metal is a little thin.  I bolted the 3/16" end plates that fit snugly in the angled ends.  Very rigid.  I used the all-thread to hold the pillow block assembles in place as I worked out where they should be in relation to the engine and the uprights.  Then I cut the all-thread to length.

 
The engine plate is ¼" and welded to the 1x1.5 tube sub-frame that is clamped to the pallet rails.  You can only see one of the angle iron clamp pieces that is also supporting the alternator.  The small uni-strut you see behind the alternator are the clamp bars for that box thing with all the lightening holes.  There are two of those - they were under-eave mounts for Dish Network dishes.  Very stout but light with a powder coat finish.

 
Back on the idle side, looking towards the drive side.  This is the outer rollers.  All four rollers are mounted on the same ¼" plate.  The top and bottom blocks are directly mounted to the plate and have a ¼" screw threaded through to adjust the v-roller.  It contacts the lever at the near end.  It pivots on the far end and the v-roller is attached in the middle - so very fine adjustments can be done.  The ½" bar is threaded for the 3/8" v-roller bolt and the pivot bolt.  Once adjusted, both are tightened down.  All four adjustable, I can angle the bar up or down so it tracks exactly with the blade as you extend the rollers toward the drive side.

Poor picture but the wheelchair motor attach at the far side has a large sprocket on its shaft (~2") and smaller sprockets (~1") are attached to the tops of all four ACME threaded rods.  My old set up I would have to drop the head below my target and creep up to take out any backlash.  I think I have eliminated that with these rods.

 
The campground had a number of trees come down over the winter.  The maintenance guy told me I could have whatever I want.  Most is firs that I don't want but there was this cedar - 17' x 16/18.5.  Nice and straight.

 

John Sawicky

Just North-East of Sacramento...

SkyTrak 9038, Ford 545D FEL, Davis Little Monster backhoe, Case 16+4 Trencher, Home Built 42" capacity/36" cut Bandmill up to 54' long - using it all to build a timber frame cabin.

Ljohnsaw

Update 6/2/2021:

Planned on milling up 3 cedar and 1 Ponderosa logs over the holiday weekend on the new head.  Had a few issues that all but one were resolved.

Mill ran great but the lift seemed a little slow.  Test cutting the worst of the logs (most knots) into 2x4s went great.  I was pushing to lug the engine while going through knots and it didn't dive or rise one bit.  Very happy with that.  After a few passes, the drive belt popped off.  Got it back on for another cut then popped off.  Looking at the idle/tension wheel, the belt kept wanting to walk off the front.  I had welded the mount (note to self, ALWAYS make it adjustable) in such a way that I could not move the wheel forward away from the engine (the way the belt was tracking off).  

So attempted to shim it at different angles but still would not stay on.  I did have long holes in the engine mount plate so decided to pull the wheel off and just slide the engine to tension the belt.  That worked great.  Except for one small problem.  In my haste to get cutting again, left the tension wheel sitting on the frame in front of the engine (out of sight) and started cutting.  It vibrated off and dropped onto the blade with a bang.  The blade dug into the wheel and left marks all the way around while the wheel took out about 9 teeth off the blade.  Straightened out a couple of teeth and continued to cut with this blade for a while.

Finished up the second log making 1x4s.  Some of them crooked a bit but should be able to straighten them when we put up the fence.  Started in on the final cedar log Sunday morning and the lift was running really slow.  Then the engine wouldn't start (starter wouldn't turn over the engine).  So we jumped it and keep the engine running at high idle to charge the battery.  Still the lift was slow - hmm, must not be charging.  Look at the alternator and see that I never wired it in at the end of the rebuild - Dooh! ::)  Made up a jumper and all is good now.

Finishing up the log, the 1x4 thickness was not being consistent using the gauge.  As I was dropping to make the very last cut, the head was hitting the front of the vertical frame.  The front ACME screws had come out of sync with the rear screws, so it seemed.  Turns out, the little pops I would hear every now and then was the set screws on the front, right sprocket slipping.  Adjusted that up and then noticed that the left front ACME nut was stripped out.  Got the head to the level we needed, made the last cut and shut down for the day.  I will be going up tomorrow to retrieve the head and make some repairs.  Thinking of doubling up the nuts.  Perhaps I didn't have all the nuts sharing the load equally.  The left rear seems solid and it is holding most of the weight.  The other thing I could do is add a counter balance to that side but don't really want to get into that.
John Sawicky

Just North-East of Sacramento...

SkyTrak 9038, Ford 545D FEL, Davis Little Monster backhoe, Case 16+4 Trencher, Home Built 42" capacity/36" cut Bandmill up to 54' long - using it all to build a timber frame cabin.

Crusarius

I can't believe you stripped a nut. are they brass? steel? I have 2 threaded rods and nuts mine is 1" 5 pitch. If you add more nuts you will have more friction, that will not help your raise and lower speeds. 

what size sprockets do you have on the threaded rod? I have 12 tooth and have found in order to be confident they are not going to jump you need 180 degree wrap with the chain. 90 degrees is not enough to keep it from jumping.

I would bet once you get all 4 timed and get the chain jumping issue taken care of you will not need anymore nuts. I do wonder if the one that stripped was side loaded from being out of time. That is the tricky part with that many items is timing.

mike_belben

keep chipping away at it, youll get the bugs shook out.  smiley_thumbsup
Praise The Lord

JRWoodchuck

Would love to see a video of the blade guide arm in action. Build looks great!
Home built bandsaw mill still trying find the owners manual!

Ljohnsaw

I'm using 1/2" 10 pitch.  The nut are steel.  I'll be tearing into it tomorrow morning.  I'll see what's what then.  I have 8 new nuts on hand.  Maybe I should have gone with the 1". :-\

The blade guide movement is not that impressive.  With the cables, it kind of moves in spurts.  But it does hold the guide in place and works.
John Sawicky

Just North-East of Sacramento...

SkyTrak 9038, Ford 545D FEL, Davis Little Monster backhoe, Case 16+4 Trencher, Home Built 42" capacity/36" cut Bandmill up to 54' long - using it all to build a timber frame cabin.

Ljohnsaw

As I was raising the head to work on the lift, I could hear/see a chain jump every once in a while.  I have small sprockets all the way around (12 tooth?).  On the far side from the motor, 90° bends.  On the motor end, more like 135° bends because of the drive motor placement.  I think I will move the tension sprocket from the long side to the far end to give me better wrap around those sprockets.  I think I will also need some UHMW guides/supports for the chain along the long sides just before the sprockets and mid span to keep the chain from sagging.

Yep, the steel 1/2" ACME threaded nut was completely stripped out.  After cleaning up the end of the rod thread, I ran up a new nut until I got to the wear area.  I think the thread got a little mushroomed during the striping of the nut threads so the new nut won't go on that area anymore.  So, time for a redo.

I got my stuff from Surplus Center.  They state the rod is 1010/1018 rolled threads.  Is that good enough?  Is there somewhere else I should look for something better? 

Price and weight wise, I'm looking at either 3/4" or 7/8".  Well, I guess its 3/4".  They don't have nuts for 7/8".  The 1/2" was 10 pitch, these others are 6 pitch.  Jumping up to 1.25" 5 pitch or 1.5" 4 pitch, the price and weight go way up and I don't see where I need that much size.  The head is probably 200 pounds - 150 at the engine end, 50 at the other end.
John Sawicky

Just North-East of Sacramento...

SkyTrak 9038, Ford 545D FEL, Davis Little Monster backhoe, Case 16+4 Trencher, Home Built 42" capacity/36" cut Bandmill up to 54' long - using it all to build a timber frame cabin.

Ljohnsaw

OK, I decided to spend the money - pay once, cry once, right?

I would need to replace the 1/2" rod I got from Surplus Center to get this working again but for how long?  SC couldn't give me what the rods were made out of and based on how easy they are to file, must be just plain carbon steel. 

So I went to McMaster Carr.  They have various grades of steel and I went with the alloy steel (153,000 tensile strength) over the carbon (54,000) or stainless steel options and got the long bronze "nuts" over the conventional looking short nuts.  So, went from the SC price on 1/2" rod on the original order o $134 to 3/4" rods/bronze nut of $499! :o  On MC site, they don't give you shipping options or estimates.  Just that tax and shipping will be added.  To my surprise, the shipping was only $37 (pretty cheap for 6' goods, IMO) and will be delivered TOMORROW!  That kind of shipping from SC was $150-200.  Anyhow, I'll work on my blade cooling/water system today and maybe the laser line for the cut guide.
John Sawicky

Just North-East of Sacramento...

SkyTrak 9038, Ford 545D FEL, Davis Little Monster backhoe, Case 16+4 Trencher, Home Built 42" capacity/36" cut Bandmill up to 54' long - using it all to build a timber frame cabin.

Crusarius

hopefully the 3/4 will be good. I don't see why not. still surprised the 1/2" stripped. There is a good deal of load on those threads.

Ljohnsaw

I decided to tackle the laser line first.  Was an interesting journey.  Well, @burlybee did an install back in August of 2020 Mod eliminates parallax error and I wanted to do the same.  Bought all the parts and they just sat there.  

So today was the day.  Just looking back at his thread, I forgot about building a good mount that acts as a heat sink.  Maybe I'll get to that.  Anyhow, here's how it went:  I have a little power supply from a printer that puts out 22vdc unloaded and 17vdc in use.  I hooked up the regulator and laser to make sure it worked - yes!  I added some 16g wire to the super thin wires coming out of the laser and added layers of heat shrink tubing to reinforce those wires.  The last tubing fit over the end of the laser to provide strain relief.

I contemplated wiring into my lift motor switch but decided I wanted to be able to turn on the laser whenever.  So I found a nice momentary switch in my stockpile.  Added spade connectors were necessary and soldered/heat shrink the rest of the connections, including on the voltage regulator.  Hooked it all into the mill and turned on the power (battery isolation switch) and the laser lit right up... ???  Press the button and it turns off.  Dooh, that button switch was a NC - didn't even check.

Back into the shop I have a couple old red Radio Shack buttons.  You know the ones - Red is NO, Black is NC.  Swapped in one of those red ones, back out to the mill and hooked it all up.  Same think - push to turn off.  Back down to the shop and do a continuity check.  Sure enough, NC.  Check the other one - NO - so swap the switch again.  I vaguely recall having an oddball red switch.  Factory reject, I guess.

OK, back to the mill and laser is working great.  I used a 3/8" conduit strap to mount the laser to the side of the control box, directly in front of my scale.  On my laser, you screw the lens in/out to get a crisp line.  But, the line will only be crisp in one orientation - go 90° off and it is a thick blur.  OK, so figure out which way the laser needs to be snugged up and tighten it in place.  When I test again - super dim line. What?  Jiggle the wires, no change.  Try and adjust the focus and it flickers bright/dim.  What?

Messing around for a while, I discover that the "lens" portion will touch the mill frame when left alone and the laser goes dim.  Pull it away and it is bright.  So I shim it out away from the frame (to be finally fixed when I make a good mount/heat sink).  The other thing I notice is the "lens" is rather loose/floppy and will surely fall off from vibration when running the mill.  So I ran a piece of electrical tape around it to the body of the laser.

I'm not too worried about the laser getting hot as it will only be used momentarily to check the scale.  It is pretty bright, and as Burlybee mentions, very narrow spread so somewhat safe for bystanders.  But they shouldn't be standing in front of the mill anyhow.
John Sawicky

Just North-East of Sacramento...

SkyTrak 9038, Ford 545D FEL, Davis Little Monster backhoe, Case 16+4 Trencher, Home Built 42" capacity/36" cut Bandmill up to 54' long - using it all to build a timber frame cabin.

Ljohnsaw

Update 6/17/2021:

Put the mill back on the track.  I put the butt end of one of the cedars I milled the other week on the bed.  Went to remove the transport chains and couldn't find my sawmill keys...  Then a moment of dread - I think I left them in the door lock and lost them on the trip up there.  Bummer.  I happen to have two extra ignition keys but not a lock box key.  Thought about prying it open but didn't really want to bend it all up.  So I thought I'd do a TV lock pick trick.  I stuck a small screwdriver in the lock to twist it and only had a mini zip tie that could fit in the lock.  Poked that in a few times and the lock turned.  So secure!

There was a screw protruding that I removed and ran my metal detector (Garrett) all over with no other hits.  The Garrett is so sensitive, it will pick up my bed through a 20" log.  I slabbed of two 4"+/- chunks and flipped it.  Took off a waste slab and went to cut the remaining into a 3" and 4" when I hit a screw.  I saw it and couldn't stop in time.  Should have looked over the log or run the Garrett over it again.  Oh well.  I powered through the rest of the cut and didn't get any diving with a now really dull blade.  Pretty happy with how it is performing.

These are both sides of 4 slabs.  The 2nd and 3rd pics are book matched from near the center of the tree.  You can make out a 90° bend in the little sapling (probably from snow) that didn't spring back and the tree continued to grow and right itself.  I'm going to try and sell them on CraigsList.  If they don't, I'll make some coffee tables or mantles out of them.



 

 

 

 

 

 

 

 
John Sawicky

Just North-East of Sacramento...

SkyTrak 9038, Ford 545D FEL, Davis Little Monster backhoe, Case 16+4 Trencher, Home Built 42" capacity/36" cut Bandmill up to 54' long - using it all to build a timber frame cabin.

aigheadish

It's been quite the adventure reading along here! I went, at the beginning of the thread, from "oh this is another homemade mill that I think I'm capable of building" to "welp, doing it right makes it pretty dang complex!" 

Your mill looks great and it seems like you are very good at figuring stuff out to make it work better with each iteration, nice work!

I'll add this thread to my growing list of home builds for something I'll likely never get to. Thanks!
New Holland LB75b, Husqvarna 455 Rancher, Husqvarna GTH52XLS, Hammerhead 250, Honda VTX1300 for now and probably for sale (let me know if you are interested!)

Ljohnsaw

6/19/2021:

Soooo, a little update.  

I thought I posted these additions.  More of the Dish Network scrap metal put to use adding the tank for the lube system:


 
Actually works really well.  And the laser cut guide:


 
So even though it eliminates the parallax error, this picture angle makes it look funny.  Works really, really well! The red line is much finer then this picture makes it look.

Anyhow, put a big butt log on the mill and was running the head up.  In the last iteration of putting the bigger lead screws on, I moved the motor to the engine end hanging out the left side.  Well, that's the space for the gas tank to rise past the frame.  That reduced the head height by about 20".  Not good.  Had a couple sheets of thin aluminum so made a bracket to push the gas tank further out and allowed it to pass the lift motor.  I snapped a pic but not sure where it went.

However, the lift is sloooooooow.  I need to change the gearing.  Back to the cutting table.
John Sawicky

Just North-East of Sacramento...

SkyTrak 9038, Ford 545D FEL, Davis Little Monster backhoe, Case 16+4 Trencher, Home Built 42" capacity/36" cut Bandmill up to 54' long - using it all to build a timber frame cabin.

Crusarius

I had the same issue with the fuel can I use. I ended up making my fuel plate that the jerry can sits on angled to help clear the frame and to get the last drops of fuel out. ended up working pretty well. For a future build that will be in a different location.

I still suffer with very slow up. I have thought about a momentary and on switch with a limit switch. use the momentary for lowering and the on for raising till it hits the magnetic limit switch I can move to set head height for log diameter. That way I can set the stop location for the next log hit up and go get the log while the head is moving. gets old holding the switch staring at the log not loading itself :)

Ljohnsaw

Here's the quick solution to my gas can issue.  It has the added benefit that it wobbles and you can shake the tank to see how much fuel is in it ;):





 
I also added a belt guard to keep my fingers safe from the alternator!

 
John Sawicky

Just North-East of Sacramento...

SkyTrak 9038, Ford 545D FEL, Davis Little Monster backhoe, Case 16+4 Trencher, Home Built 42" capacity/36" cut Bandmill up to 54' long - using it all to build a timber frame cabin.

Ljohnsaw

Back on reply #126 I showed my blade guide electric adjustment kludge.  Cables and pulleys from a linear actuator to double the throw:


 

 
It worked and got me through the season.  A guy posted 5 free 30" throw linear actuators (more sealed up than my old one).  I pulled the old set up off and mounted one in parallel with my blade guide.  



 Added a link to allow for any miss-alignment and it works pretty well.  Slow but more travel than the old one.  This actuator has 150 pounds of force so it shouldn't get stuck.  The length of throw is still less than the guide can travel but better than it was.  It gets down to about 10" now, was about 14 or 15" before.  Full travel gets down to about a 6" gap.

 

HOT weather next week will have me chomping at the bit to get back up the hill to mill.  But there is still a chance of a big snow storm before summer arrives.
John Sawicky

Just North-East of Sacramento...

SkyTrak 9038, Ford 545D FEL, Davis Little Monster backhoe, Case 16+4 Trencher, Home Built 42" capacity/36" cut Bandmill up to 54' long - using it all to build a timber frame cabin.

Ljohnsaw

I bought a wired tachometer as well as a reflected unit to double check it.  I mounted the wired one in my control box and for the reflected one, I put a reflector a strip on the fan cover that spins as well as the pulley on my drive-side band wheel.

I thought the wired one was reading high but the reflected unit verified it was ok.  I was surprised the idle was actually 1,080 rpm.  The wired unit gives readings to the nearest 10 rpm.  So it would toggle between 2,000 & 2,010 when I tried to set it at 2,000.  At that speed, I clocked the drive side pulley at 880 rpm.  Now I have the ratio of engine rpm to band drive rpm 2,000:880, or 1,000:440, or 100:44.  With the band wheels being 18.75" diameter, that gives 4.908 feet/revolution.  The blade speed is then 216 fpm (44 x 4.91) for every 100 rpm.  About 2.2 times the engine rpm for blade speed.

At 2,000 engine rpm, the blade is moving at 4,320 fpm.  Looking at the Cook's (IIRC) info, at 18hp, I should target 4,500 fpm.  My engine tops out at 3,400 rpm or 7,344 fpm (WAY to fast).  I didn't think I was going that fast.  Probably explains why my sawdust is so fine.  I was thinking I wasn't pushing fast enough, but when I pushed harder/faster, the engine would bog way down.

With the engine speed now available, I'll try some experiments when cutting.  I can't find an actual torque curve for my engine but the general curves show max torque around 2,800 rpm.  That would give me a blade speed of just over 6,000 fpm.  Still a bit fast.  I don't want to go too low of an rpm and loose the torque, so I think 2,200 should be my bottom end and that gives me 4,750 fpm.  And maybe my top end should be 2,500 rpm (5,400 fpm).  It just sounds so slow!  But, it should cut my fuel consumption if I can maintain the cut speed through the log.  Maybe set the speed up but push to bog down to the right speed/sound?
John Sawicky

Just North-East of Sacramento...

SkyTrak 9038, Ford 545D FEL, Davis Little Monster backhoe, Case 16+4 Trencher, Home Built 42" capacity/36" cut Bandmill up to 54' long - using it all to build a timber frame cabin.

fluidpowerpro

If your running the engine at 2200, I suspect your on the wrong side of the peak of the torque curve. Once you get on the left side, the engine will bog as load increases. If you operate on the right side of the peak, torque will increase as the load increases and rpm decreases.
Change is hard....
Especially when a jar full of it falls off the top shelf and hits your head!

Ljohnsaw

Yes, I get that.  So I probably won't run it flat out at 3,400 but more like 3,000 and bog it down to 2,800-2,600 (peak torque area), hopefully maximizing the cut rate and quality.  I've always ran it flat out and maintained a feed rate that just barely bogged it down.  It will be a matter of learning the sound of the target speed.
John Sawicky

Just North-East of Sacramento...

SkyTrak 9038, Ford 545D FEL, Davis Little Monster backhoe, Case 16+4 Trencher, Home Built 42" capacity/36" cut Bandmill up to 54' long - using it all to build a timber frame cabin.

rusticretreater

I did a bit of research for you as I love engines.  Your Craftsman 18hp engine is a Briggs and Stratton Model 422400 series.  Alas, I was unable to find a specific dyno chart for your engine, but I did find one critical measurement.  

According to the engine spec sheet, max torque is 28.5 ftlbs at 2600 rpm.  Max rpm is listed at 3600rpm.  https://www.surpluscenter.com/Brands/Briggs-Stratton/18-HP-Briggs-Stratton-I-C-Engine-ES-28-1454.axd

These numbers relate well to the hp/torque curves for the current B&S Vanguard 18HP engine(chart below).  So the proper RPM to run at is 2700-2800 rpm.  When the engine starts to bog, the torque will increase with rpm decrease.  You should now be able to rework your FPM calcs to get a more accurate number for optimal performance.


Woodland Mills HM130 Max w/ Lap siding upgrade
Kubota BX25
Wicked Grapple, Wicked Toothbar
Homemade Log Arch
Big Tex 17' trailer with Log Arch
Warn Winches 8000lb and 4000lb
Husqvarna 562xp
2,000,000th Forestry Forum Post

Ljohnsaw

Quote from: rusticretreater on March 27, 2022, 10:14:42 PMBriggs and Stratton Model 422400 series

Thanks for the input.  That curve makes sense that my rpms drop so much at max rpm with min torque.  Yep, Model 422437.  It has a code of 88111412.  Does that mean it was built in 1988?  I guess if I need to rework my pulley size to keep the blade speed down?  I'll see how it cuts at the lower starting rpm and then decide where I want to go.
John Sawicky

Just North-East of Sacramento...

SkyTrak 9038, Ford 545D FEL, Davis Little Monster backhoe, Case 16+4 Trencher, Home Built 42" capacity/36" cut Bandmill up to 54' long - using it all to build a timber frame cabin.

rusticretreater

I don't think the engine is that old.  Yes, you should rework the pulleys to get the desired FPM.  Everything should be in the comfort zone.  You might think about a slightly smaller crank pulley and a larger driven pulley.  This will increase torque further plus slow the blade down.   

Maybe check out the pulleys on some other sawmills and see how they are sized.  I'm not a mechanical engineer so I don't know where the point of diminishing returns would be.

Now I want to check my sawmill and find out those numbers!

Woodland Mills HM130 Max w/ Lap siding upgrade
Kubota BX25
Wicked Grapple, Wicked Toothbar
Homemade Log Arch
Big Tex 17' trailer with Log Arch
Warn Winches 8000lb and 4000lb
Husqvarna 562xp
2,000,000th Forestry Forum Post

Ljohnsaw

Quote from: rusticretreater on March 28, 2022, 11:48:41 AMYou might think about a slightly smaller crank pulley and a larger driven pulley.
I have an electric clutch so not resizing my engine pulley.  It will have to be the driven pulley going bigger - but might not fit!
John Sawicky

Just North-East of Sacramento...

SkyTrak 9038, Ford 545D FEL, Davis Little Monster backhoe, Case 16+4 Trencher, Home Built 42" capacity/36" cut Bandmill up to 54' long - using it all to build a timber frame cabin.

Ljohnsaw

My driven pulley is 12".  I found a 14" on eBay for reasonable money.  Looking at my mill, I think I can get it to fit with minimal modifications (a little cut here and there) and slide the engine over so I might be able to use the same drive belt.  That would give me about a 13.5% reduction in speed and an increase in torque.  Just waiting to see if my 1.5" bushing will fit their hub.  They ship with bushings from 5/8" up to 1-3/8" included with the price.  Worst case, I pull the shaft and turn down the end to 1-3/8".

If, as noted above, peak torque is at 2,600 rpm: My current rpm to fpm ratio is 216/100rpm.  So with the current 12" driven pulley: 216/100*2600 = 5,616 FPM.  Using the 14" pulley: 5616*12/14=4,800 FPM.  A much better number and as the engine bogs down a little (say to 2,400?) then down to 4,443 FPM - pretty much ideal for my 18hp engine.
John Sawicky

Just North-East of Sacramento...

SkyTrak 9038, Ford 545D FEL, Davis Little Monster backhoe, Case 16+4 Trencher, Home Built 42" capacity/36" cut Bandmill up to 54' long - using it all to build a timber frame cabin.

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