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Crusarius’ sawmill build - started with Linn Lumber basic kit

Started by Crusarius, September 18, 2017, 01:02:23 PM

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Kbeitz

I thought making the back stops was easy. Now the front paws or clamps or
what ever you want to call them is a real pain in the neck... I'm still not happy
with mine... I use both screw type and cam type. i'm waiting for someone to
come up with a better idea.
Collector and builder of many things.
Love machine shop work
and Wood work shop work
And now a saw mill work

Crusarius

Mine are spring type. So far the mockups I have done I really like. really seems to hold 2x's nicely :) My big issue is the have enough play they like to lift when I clamp twisting the board. With bigger cants that probably won't be a problem but as they get smaller it will be

Kbeitz

Collector and builder of many things.
Love machine shop work
and Wood work shop work
And now a saw mill work

Crusarius

yea. maybe :) I dunno I may not be able to figure out how to post them :)

I will probably post some from work on monday I can upload 2 million times faster there.

Crusarius

So here we go. "The 3 week backstop story". Sponsored in part by design funk, stopping productivity since 3 weeks ago.

So I have been fighting with how I want to do the backstops on the mill. I thought about vertical stops but was not wanting to have to raise and lower each one individually. I then thought of a way to make them all powered. Unfortunately, that was going to be quite expensive. So the next reasonable option was rotating backstops. This created 2 issues. I needed to have them square to the bed through the full rotation and I want them adjustable for after I drop a big log on them and need to re square them.

I went through many iterations in my head and in AutoCAD, I just couldn't find anything I liked.
So here is version 1: This is how it started. I tried to weld tabs to the bottom of the bunk square to the bed rail. I was not very successful. Welding upside down can be quite challenging, especially with the low ground clearance under the mill. Since I did not get those tabs perfect my backstop would pull away from the rail as it rotated. End version 1.







Version 2: after what I considered epic failure, I did not take any pictures. Instead, I went and tilled the garden.

Version 3: I decided I need to make the backstops adjustable in 2 planes. I needed to be able to rotate it to keep it parallel to the rail and also keep it perpendicular to the bed. I decided trying to use tabs on the frame was far to challenging and not strong enough. I ended up using 2x3 tube welded to the frame for my hinge. The angle will have the pivot point for the vertical once I get to that point.



This picture you can see the adjuster bolt I added to make the fine adjustments after its welded in place. It ended up working out better than I expected. Unfortunately, it requires a good deal of fabricating.


The vertical piece will have a pivot pin on the top of the open tube and an adjuster screw on the bottom. That will take care of keeping it perpendicular to the bed.




This is with the backstop in the vertical position you can see the angle where the vertical pivot will be along with the hinge setup.




This is up inside the hinge block. It is the only way I could make it adjust in both directions and stay put after getting it set. There is a small piece of angle with a hole drilled in it for the bolt to pass through and a nut welded to that angle. The threaded rod then is rotated to slide the bolt in a slotted hole. I only slotted the one side to force it to pivot. The nut is there to lock it in place after it is set. Ignore the extra holes it took me almost all day to come up with this, and a few different attempts at hole placement.



I finally managed to squeeze this design out on Sunday. Man do I hate design funks...




Crusarius

Here is my preliminary design on my log clamps. I chose to make them spring loaded. I still have quite a bit of work to do but I have the concept in my head. If only I had a print button 
The c-clamp is acting as the back stop while I was contemplating the meaning of life (aka banging my head against the wall in design funk frustration). The piece of steel on the bunk is acting as a piece of wood (it was easier to grab). There is an angled plate on the end of the bunk with the spring connected to that. I had to angle the plate so the spring would to clear the carriage as it rolls past. I am really hoping this is not going to be a problem with how tight my clearances ended up.

The vertical tube on the side is setup for a sliding piece that I am hoping to drill holes in and make a spring loaded pin for quick raise and lower.








The tube against the rail is just temporary while I am proving the clamp concept. The other tube is set into the pocket that will be welded to the clamp. There will be a spike welded to the top of the sleeve as well.






The proof of concept worked out very well. The only thing I am not crazy about is when clamping a light piece of wood the sleeve likes to lift up a little bit. Probably won't be a problem on a large cant but is definitely a problem on lighter boards. I will probably just drill and tap the bottom of the sleeve and install a nylon bolt to keep it tight. That should allow it to slide freely and not lift.

After playing with it for a while I realized I built it to be left handed. I am not left handed. I have since cut all the tacks and reversed everything to be on the right side. I may have been able to get used to it but trying to twist the chain to go in the slot was kinda challenging.


Kbeitz

So your hoping that little spring is going to hold your log ?
Sometime it take a lot of force to hold a log up tight to the
backstops. On a log like this it takes a lot of push.



 
Collector and builder of many things.
Love machine shop work
and Wood work shop work
And now a saw mill work

Crusarius

I was pretty impressed with the holding forces when I was playing around with it. We will see how it works.


Kbeitz

E-bay has wheelchair motors much cheaper and they come with a gear box.
That looks like a good motor but the RPM's are way to fast. You need something
with low RPM's.
Collector and builder of many things.
Love machine shop work
and Wood work shop work
And now a saw mill work

Crusarius

I was afraid of getting something to slow and having to take forever for it to move. It would be great if it had 2 speeds. I guess a wheelchair motor is variable.

What Rpm's would you recommend. My threaded rod is 5 turns per inch.

Kbeitz

Only you know how fast you want something to move.
Remember more speed less torque. Put a speed control
on your machine and have the best of both worlds.
You can also get them real cheap off E-bay. Just watch
your amp draw when buying.
Collector and builder of many things.
Love machine shop work
and Wood work shop work
And now a saw mill work

Crusarius

The amp draw is definitely a big concern. hate to kill battery going from bottom to top. Especially without a pull start on the engine.

I tested that linear transducer I scored. it runs great on 24 volts plugged into the wall with the transformer. It is really slow on 12 volt straight from a battery. But I was able to lift the corner of the trailer off the ground very easily. I think I may try it for my toe board and see what happens. I am a little concerned it is not really weather resistant so I may need to make an enclosure for it.

Crusarius

Quote from: Kbeitz on November 13, 2017, 01:42:26 PM
So your hoping that little spring is going to hold your log ?
Sometime it take a lot of force to hold a log up tight to the
backstops. On a log like this it takes a lot of push.



 

I will have 4 spring clamps. The spring is not really holding the load. What is actually happening is its holding the piece that slides. That piece is getting cocked and locking to the bar. It is just like a cam clamp without the cam but the spring keeps it locked to the bar.

Kinda hard to explain but that is how other mills cam clamps work. The ones that slide on the bar then they lock into place with a side load.

Kbeitz

I used rack for that. I have to lift up to get it to slide.



 



 
Collector and builder of many things.
Love machine shop work
and Wood work shop work
And now a saw mill work

qbilder

The spring clamps work just fine and will easily hold any log you're able to handle on that mill. I have a Linn based mill with similar clamps & it's no sweat holding 30"+ diameter maples & oaks.

The electric motor I fear will be too weak. You'd be best using a gear reduction motor. I raise & lower my mill head manually and it's a bear, especially when the threaded rod & brass nuts get gunked up with sawdust. A motor that turns 100rpm would give you 20" of movement in 60 seconds, meaning 3 seconds per inch. While not rocket speed, it's not slow and it will exponentially increase your torque. That reduces the strain of the motor, stretching its life expectancy. Get a 300rpm motor & move an inch/sec.         
God bless our troops

Crusarius

I worked on the clamps and backstops a little more. I started out with this for my backstop left to right adjuster


Then after the concept was proven I moved to this. Believe it or not one of the holes is threaded the other one is just a through hole.


I also added the vertical adjustment point. I used a 3/8" through bolt for the pivot and a ½" for the fine adjustment. The long carriage bolt may be temporary till I get the right length bolt.








All 4 backstops. I did make #1 1" taller than the other 3. Thanks everyone who suggested that.

Crusarius

Here is the sliding clamp. I am using 3/8" plate with a 45 degree angle cut on the end. I am hoping this will be strong enough so when I drop a log on it, it doesn't deform to much. You can also see in the picture I started closing up the ends of the bunks to minimize critters and bees nesting.





Top view showing the spring.

I originally had it so the spring was connected to the plate covering the end of the 2x2 slide piece. When I was showing it off to a friend I found that every time I tried to hook the spring it lifted the board I was trying to clamp. I ended up making a tab to weld to the main rail so the spring cleared whatever I was clamping.






Darrel

Looks like some progress is being made. Glad to see that you overcame your obstacles! 8)
1992 LT40HD

If I don't pick myself up by my own bootstraps, nobody else will.

Crusarius

yea. since I pretty much lost my window to be milling this year I slowed down and am taking my time. Hopefully I can do everything right or at least close on the first attempt.

Georgia088

Crus,
Have you had a chance to try the clamp out? How did it work? Very neat and interesting design.


Crusarius

only testing i have done is playing in the shop. haven't got it cutting anything yet. I am planning to have it ready to go by springtime. today was the coldest i have ever seen in my shop it dropped to 38 degrees f.

Really want to get some painting done so I can reassemble and test everything but can't keep the heat high enough for long enough to do it. I do have some updates on work I have done. Just been to lazy to post them. Maybe I will try to do it tomorrow.

Crusarius

So at 25 degrees in the shop I think it may be a little to cold to be out working. I guess it is finally time for an update.

I left off on the clamps. I now have all four of them tacked together in the configuration I think I am going to like. I still need to figure out the vertical sliding piece. Good thing is I have a crazy idea in my head for that.









Crusarius

Now to revisit the backstops. I have all of them made and welded to the bed.


The vertical piece is 2x2x.188 wall the large square is 2x6x.188 wall and the small square is 2x3x.188 wall. The bolt on the upright is the pivot for adjusting squareness to the bed. Ignore the extra washers I couldn't find the right length bolt. It has been fixed since these pics were taken.

The carriage bolt adjusts right to left rotation to align parallel to the bed. The bolt on the upright is the pivot to allow squaring to the bed. With these 2 adjustments I should be able to dial each of these backstops in to be pretty close. And be able to fix it after I smash them with a big log.


The 2x3 is welded to the bottom of the 2x6 bunks. Each of these stops will rotate together for raising and lowering from one end of the mill. That is the reason I had to make them two way adjustable.


Looking down on the backstop.


Looking up inside the backstop. The 1/2" bolt is to adjust the angle of the upright. I know this is going to be quite challenging squaring all four of them to each other. But once done hopefully I won't have to do it again for a while


Crusarius

Last time I put the trailer in the shop I put it in tail first. Up until then everything was being built and figured from the other direction. I finally decided it was time to reverse the trailer since I was sick of welding stuff together backwards.

Don't forget to ooh and ahh over the awesome set of pallet forks I made just for this project :) they have definitely been more useful than I thought they would be. (this is sarcasm I am not usually this vane just in one of those moods. Thank you please drive through)

The rails on the trailer are 24' long. I do not remember if the axle was connected in this picture or not. I don't think it was because it looks to far back. Could be an optical delusion?









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