Finally Running!

[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.

[Brob1969]

Looking forward to hearing how it works out. 

[Silverfoxfintry]

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.  

I had to replace the drive shaft on a 25hp Kohler last year. The shaft had been cut in order to press out the clutch. It took 35t to get it out.
I mounted the crank in my 1954 Boxford (a Southbend clone) holding the drive end in a Three paw steady.
I have a taper turning attachment on the lathe so it was a relatively simple job to bore out the shaft and taper the bore by 3 degrees.
I then machined a replacement shaft using the same angle. I left it 25 thou oversize. The bottom of the tapered hole in the crank was tapped 10mm x 1.5 mm and a high tensile bolt was used as extra security.
The crank was heated to 100c and the shaft cooled to -30c.
A little Loctite was added and the shaft screwed home.
Once everything was cooled to ambient temperature I mounted the crank with the replacement shaft in the lathe and machined the shaft to the finished size.
The key way was milled using the milling attachment on the lathe.
The engine has been rebuilt and is sitting as a spare for now. I intend to fit it to the mill over this summer.
I will let you know how it gets on.
Take care.
Silverfox.

[marty3d]

A few more details on the drive pulley machining... Because the small end of the taper on the crankshaft is just 0.86" or so, and the bore of the centrifugal clutch/pulley was 1.125" I machined an end cap that had a bolt hole on the outside end and was bored to .75 inside for the rest of its length.  I assembled that into the hub with Loctite and then machined the hub with the plug together.  

Now that I switched engines, I have this hub that is straight bored for the outer 2" but tapered for the inner 1.5"  I had to fit that onto a 1" straight keyed shaft.  I machined an adapter out of aluminum, 1.002" bore with an external taper on one end and 1.123" OD on the other.  Works.  

On my way back to MT with the mill to do some more logs.  Photos when I get back.

[marty3d]

So we spent a couple days in Montana - the first real work for this machine.  We (my son-in-law) and I built an extension for the saw so we can cut 20ft pieces.  Our customer, a family friend, needed a number of 20ft full dimension 2x12's.  That little addition is working well.  And, we are learning a ton.  (this is the first time either of us have run such a thing).  

Unfortunately, the extension doesn't allow the use of the power feed or board eject.  (heavy labor)  But, I am happy to note that the 22hp Predator engine has been working well.  Starts easily, fairly quiet.  Seems to have an appropriate amount of power compared to its specs.

   

[marty3d]

So, it ran well, but the stepper motors that lift the saw frame are much too slow.  It was ok to take 3 seconds to drop an inch down for the next board - but it was taking like forever to raise the saw back up for the next log.  Probably only 2 minutes, but that seems like forever.  So, I have installed a couple DC motors, intended for scooters or something like that.  They take 24v and 22 Amps.  The nice thing about DC motors is that they have very high stall/low speed torque.  Anyway, I installed them and now the saw frame moves at about two inches per second.  I am in the middle of integrating them with the NC controls so I will get accurate pre-set moves, up or down. Instead of counting pulses with the stepper, it now relies on an encoder to send position information back.

 


 

 

Making this switch also freed up a ton of real estate in the controls box (second photo) so I decided to re-organize the components to make diagnosing and servicing it easier.   I also added an encoder to the motor that moves the saw carriage.  Since the motor shaft had a nut on it, I used a socket, a hex drive adapter, and some rubber hose to connect the encoder to the shaft.  With encoders on both axes, X and Z, my system will know where everything is- and be able to move the saw up and down as well as back and forth, without my input.

[marty3d]

Update - Finished building the toe board and log turner.  Both are hydraulically operated - and as yet untested.

 

 

[marty3d]

So, it has been a while.  But no idle time.  My mill was being held hostage by some guy named Murphy who was busily pointing out all the weak spots.  As a result, I have done a few jobs in the mean time but I have rebuilt some aspects of the mill several times.  Anyway, it is working again.

Biggest change is that I have taken the large carriage moving chains and drive motor out of the system.  I have replaced them with a smaller motor that sits on top of the saw carriage and two #35 roller chains.  The advantage to this is that the original drive system used an encoder but was too far from the control processor to send the signal directly.  I tried using a separate Arduino and a communication system, but that was unreliable.  The encoder, and a new control box with the Arduino Mega2560 is now on the carriage and both the carriage position and saw height are read reliably.  A separate bonus is that the end of the roller chain runs over a section of a sprocket and is secured by only a bungee cord.  I am building an extension to the mill and this allows me to extend the power feed as far as I want.

The saw lift is still done by two DC motors, but they are hooked up differently.  They can lift the saw 24 inches in just ten seconds or so.  I have added a small box with what I call AutoCut and AutoReturn buttons - with speed controls.  To cut a 10 ft log, I move the saw to the start point with a joystick.  Hit the AutoCut button and the saw proceeds through the log.  When it reaches the end, I hit the AutoReturn button and the saw proceeds for another 6 inches to allow the eject dogs to drop down and the saw raises 1/2" so the blade clears the log.  I hit the AutoReturn button again and the saw ejects the board and runs back to where the log started - not all the way to the end of the carriage.  When it gets there, it drops down to cut the next board automatically (assuming I have previously entered the board thickness using a button and the encoder knob).

Ok, I will post a vid soon...  in the mean time, here is a photo of the control box and joystick.  The end of the roller chain can be seen on the far side.

 

[marty3d]

Here is the promised video...  I can't demo the lifting mechanism because I stripped the threads out of the nut on one side  

Mill Hydraulics: 

And, I built what I call the Claw - for gripping logs to be loaded by my boom truck.