Finally Running!

[marty3d]

A few years ago we had a microburst that center-punched my property - knocked down 30-40 trees.  As I was clearing that, I was thinking about how I would like to use the wood - and a sawmill seemed a good choice.  I ended up buying a sawframe kit from Linn Lumber and started designing and building the rest myself.  I wanted to do both boards and firewood with it, so it became a bit complicated.  The sawmill portion is now mostly done.  Blade guards are being finished right now 'cause I don't want to be eaten by the machine.  The engine is a 32hp Generac - given to me by friends after their shop burned up - including the rest of the generator set.  The little control box runs the show.

  

 

 

 

 

   

[kelLOGg]

Nice work. I'm interested in how you will cut firewood and lumber on the same machine. 

[Wassup8687]

Very ingenious. Good luck with it.

[Brob1969]

I am REALLY interested to learn more about your hydraulic setup. 

What kind of pump are you using?  How many gpm?  What controls?

Looks like you are moving right along with the build.  
Looking forward to seeing more.

[marty3d]

The hydraulic pump is kinda generic - runs on 12v or 24v.  I am using 24.  You can find it using this AISN number: B01D2ESPKM. It puts out about 3gpm.  Raises and lowers the backstop and what I call the pincher.  The pincher pushes the log or cant against the backstops and holds it there.  It takes just 5 seconds or so to raise or lower.  I am using an Arduino to control everything - it operates the hydraulic directional control valves through a MOSFET board (power transistors).  I have a log rotator in the works which will also raise/lower and rotate using the hydraulics.  I have it set up so I can push one button and use the joystick to position the saw head, up or down, fwd or rev.  A different button engages the cut and locks out the vertical.  The cut speed is controlled by a knob that you can leave from one cut to the next.  Just push the button and it goes.  The vertical is operated by two large stepper motors.  Kinda slow, but I can get repeatable cuts within a few thousandths of an inch (each step is 1/4000").

[marty3d]

I did the first cut about 15 minutes ago.  I intended to have 'cruise control' on the motor but that isn't working yet.  Still, cuts fast and no alignment issues.  At this point, I give it some throttle, push the cut button, and I can control engine speed using the cut-speed knob.  Kicks the board off as it backs up.

[Nebraska]

Congratulations on the build!

[trimguy]

Nice job !!

[btulloh]

What kind of steppers are you using?

[marty3d]

What kind of steppers are you using?

NEMA34, 1712 oz-in.  I think they were from StepperOnline...not100% sure.

[sawguy21]

How are you coupling the engine to the drive? I assume being from a generator the crankshaft is tapered.

[Osterman.r]

Also, did you put a carb on the motor? Assuming it was run on propane in a genset?

[Vautour]

Nice solide build... i've got the very same 32 hp generac motor on my ongoing build and am curious how you Mcgivered the shaft.... @sawguy21 if i remember correctly you mentioned to me that those motors were not made to have a side load and would eventually blow the bearing and motor casing apart and was very grateful for that tip,.. so i added a coupler and jackshaft for my pulley.

[marty3d]

How are you coupling the engine to the drive? I assume being from a generator the crankshaft is tapered.

I ended up machining a taper into the centrifugal clutch/drive pulley.   

[marty3d]

Also, did you put a carb on the motor? Assuming it was run on propane in a genset?

I bought a carb and manifold online - the original manifold was plastic and burned up anyway.  The manifold was intended for a vertical shaft motor so I cut the ends off, rotated them, and attached it back together with sections of hose.  I am using two hobby servos to operate the choke and throttle.

[marty3d]

Nice solide build... i've got the very same 32 hp generac motor on my ongoing build and am curious how you Mcgivered the shaft.... @sawguy21 if i remember correctly you mentioned to me that those motors were not made to have a side load and would eventually blow the bearing and motor casing apart and was very grateful for that tip,.. so i added a coupler and jackshaft for my pulley.

I hadn't heard that about the limited side loading.  I did find that the motors had straight shafts in some applications - different crankshaft.  That at least suggests that side loading is possible.  I think Dixie Mowers uses these with a vertical shaft in some of their large ZTR mowers.

[Brob1969]

How are you coupling the engine to the drive? I assume being from a generator the crankshaft is tapered.

I ended up machining a taper into the centrifugal clutch/drive pulley.  

I once had a Chinese diesel generator that the generator side blew up but the little single cylinder diesel was still going strong.  
I "milled" the tapered shaft to accept a pulley.  By milled I mean I started the engine and ran my angle grinder back and forth on the shaft until I got it relatively even and slightly oversized.  Then I used a flat bastard file to get it to size, then sandpaper to finish it off.  I did it all on the back of my pickup, it actually worked out pretty well. 

[marty3d]

My son-in-law and I took the machine out to Montana to cut some wood for friend.  Having only sawed one log as a trial run, we brought a large assortment of tools with us.  The logs were Douglas Fir, blown down in a windstorm a few months ago.  For the most part, the machine worked - decently - but there is much room for improvement.  I programmed a 'cruise control' or governor for the throttle, but the microcontroller lost track of rpms when they got over 1700 or so.  In that event, it went to full throttle and threatened to scatter the motor parts all over the property.  I am installing a faster microcontroller.  

In a similar electronic vein, the main microcontroller refuses to talk to the controller in the control box - so I don't get height, cut, or power readouts.  So, hand measuring, which really slows things down.  

And, a few other things, but the potential remains.  I now have four days to effect improvements - and go back for more.

CANI - constant and never-ending improvement.

[marty3d]

How are you coupling the engine to the drive? I assume being from a generator the crankshaft is tapered.

I ended up machining a taper into the centrifugal clutch/drive pulley.  

I once had a Chinese diesel generator that the generator side blew up but the little single cylinder diesel was still going strong.  
I "milled" the tapered shaft to accept a pulley.  By milled I mean I started the engine and ran my angle grinder back and forth on the shaft until I got it relatively even and slightly oversized.  Then I used a flat bastard file to get it to size, then sandpaper to finish it off.  I did it all on the back of my pickup, it actually worked out pretty well.

I used to be a waterfront guy - and one time a tugboat came in with a wrecked gearbox.  The factory sent a new gearbox, with a technician (probably a $100k box).  Well one of the shafts arrived without a keyway.  This tech borrowed a jig saw and spent a whole day carving a keyway and filing it by hand so things would work.  Machinery hacks are the best - imho.

[nativewolf]

@mike_belben You'll like this one

[marty3d]

How are you coupling the engine to the drive? I assume being from a generator the crankshaft is tapered.

I ended up machining a taper into the centrifugal clutch/drive pulley.  

I am a novice machinist, and this was the first time I tried to do an internal taper - on my 1919 Sydney lathe.  It didn't come out perfect so I used Loctite 660 to fill the gaps and make sure the two parts rotated together.  

[marty3d]

Here are a couple photos of the engine & mods.  As I said, it came out of a fire and then sat for a while - hence the rust.  Since I didn't have a proper manifold and carb for the horizontal shaft engine I couldn't use the built in governor bits.  I also wanted remote and automatic throttle control.  So I used the hobby servos.  They are waterproof and have several pounds of push/pull.  Far more than is required for this installation.  They also work easily with the Arduino microcontroller that manages the engine.  The silver object in the last photo is the Hall Effect sensor that sends an electrical pulse to the
 Arduino whenever the flywheel magnet passes it.  The three holes in the cover were drilled to use an inspection camera to see how close to the flywheel the end of the sensor was. 

 

 

[marty3d]

But, almost all for naught.  This afternoon as I fired up the engine in the mill, it had the sound of death...rod noise.  Drained the oil and sure enough it had metal flakes in it (only about 10 hrs on the oil).  Went to HF and came back with a 22 hp predator engine.  I have never used a Chonda - but at least it has a governor.  While using it, I expect to try to repair the Generac motor to gain back those additional ten horses.  

The biggest complication is that my drive pulley was modified to fit the tapered shaft.  I now have to reverse the mods to fit a smaller Predator shaft (1").  

[Brob1969]

I'm interested in learning how the Predator works out.  I've been considering the Lifan 24HP as an upgrade for my 18HP Briggs.  

[marty3d]

I'm interested in learning how the Predator works out.  I've been considering the Lifan 24HP as an upgrade for my 18HP Briggs.  

While not exactly a scientific comparison, the Predator was heavier than the 32hp Generac that it replaced.  It is up and running.  We will be sawing logs with it on Monday.