Nature Playground Milling

[BobL]

A few days ago I started milling some logs to be used in a Nature Playground that included a couple of pieces of park furniture. As usual progress is slow.

I haven't been at the tree loppers yard for a few months and when you're away things get lost, blunt, broken and moved around.

First step was sharpen a BSM band.

The milling is pretty basic as it just involves bucking the logs to lengh, and then flat topping and bottoming the logs using the BSM.

This one just squeezed by on the BSM in terms of height and width


The BSM was cutting quite nicely with a freshly sharpened band - wood is a Western Australian Eucalypt called Marri - relatively soft.



Two of the logs were too big and too cumbersome for the BSM so I had to break out the Chainsaw mill.
By cumbersome I mean the logs had branch unions that made it awkward to mill on the BSM
It's been over a year since I did any serious chainsawing and boy am i tired after doing this.

Heres the trusty BIL mill flat bottoming this log.

The cut was 38" wide at the widest part.
The BSM only does 35" and the 42" bar on the BIL mill does 39.5"

Normally I just sit my rails on top of the log and screw dogs (pointed bolts) into the ends of the logs.
On uneven logs and logs with sloping ends the amount of "grab" with this method can be quite limited
This time I decided to try a mounting method I saw on this forum, basically cut a notch into the ends of the log and use 5" hex socket screws through a piece of 6 x 1.5" wood into the notched out log. The weight of the rails and any twist is taken by the log rather than dogs so there is much better crossways stability of the log rails .



Wood is a rare Western Australian Eucalpt called Tuart - bloody hard stuff and it fair gums up the chain so have to run double aux oiler flow.

More pics as the work proceeds

 

[Quietfly]

NICE!!!!!

 

[BobL]

After prepping a bunch of longs I finally got to do something new and that was to cut up the first of the park furniture from a solid log.

The 2 long cuts were made with my monorail mill
Clamp at one end

Custom adjustable position clamp at opposite end


Mount saw in mill. Clamped Saw is free to rotate at the clamp point to be able to start the cut mid log - you will see why at the end
20" bar - cut depth was 8"


Another view of mill.


Check geometry against drawing at end of log - cut has to be along the sloped line pointed to by arrow.
The tilt of the bar can be adjusted at the mill by about -5 to +10º as shown by the curved double ended arrow at the top.


Start of cut 1


Mid log cut 1 finished.

Now the horizontal cut


This one was a bit harder to cut.
The cut depth was 15" and so I had to swap to my 25" bar which runs lopro chain.


About 2/3 of the way down the cut I felt the rail move so I stopped and sure enough the sliver clamp had slipped by 1/4" - you see the effect later.

 

[BobL]

A couple of angled and plunge cuts connecting the 2 longitudinal cut and here it is


Here you can see where the rail slipped !!!


It took me about 3 hours to do this although some of this was chewing the fat with the truckies that go in and out of the depot and continually stop to tell me what I'm doing wrong!
With such shallow cuts I could probably have saved time by free handing the whole thing and might still do that for the others although I think I could cut much more accurately using the monorail, provided it doesn't slip.

BTW this is not my design - it was provided to us by the Landscape Architect and I have followed it as closely as I could.

At the park itself a couple of old timers are going to finish these by rounding over all sharp edges and sanding and oiling the back and the seat.
Apparently they are going to be set on stirrups in concrete although I can't see anyone moving these logs as they have flat bottoms.

 

[abbott295]

Has anyone ever said how much we admire your design and fabrication skills? Awesome, as always.

 

[BobL]

Has anyone ever said how much we admire your design and fabrication skills? Awesome, as always.

Thanks AB295. My designs are usually a cut above actual execution although I'm slowly getting better at making stuff. That Monorail mill was made in 2008 when all I had in my home shop was an angle grinder and an old stick welder and I turned the brass V wheels up on a MW lathe at work. I could probably do a much better job with my new TIG welder and I would put bearings in those brass wheels but I doubt it would work that much better. It does have a bit of play that manifests itself when used away from the vertical position but I'm not using it to make precision cuts anyway.

I don't like using the monorail mill that much as it fires lots of sawdust up into the air when the bottom of the bar is used. Unlike basic minimills it will not jump out of the cut so it works equally well when cutting with the top of the bar BUT this only works if the sawdust can clear/exit at the nose. The cuts on this project were blind cuts so using the top of the bar was not happening as it rapidly filled the kerf with sawdust.
When I finished the near vertical cut I was covered in sawdust. Dontcha just hate it when sawdust fills the earbud socket on you cell phone!

 

[Mike Van]

Bob - Will they shed water from the seat or will it be a little pond ? Rot faster if it can't get out. Plus, people get grumpy walking around with wet asses. Nice work, shouldn't have to worry about someone walking off with it -

 

[BobL]

Bob - Will they shed water from the seat or will it be a little pond ? Rot faster if it can't get out. Plus, people get grumpy walking around with wet asses. Nice work, shouldn't have to worry about someone walking off with it -

Good point, The plan shows a coarse hatching on the surfaces and also a groove around the edges of the seat so it drains. I'm not sure who is doing that. Meet with the Architect in the next day to so to discuss this.

 

[Quietfly]

Thanks AB295. My designs are usually a cut above actual execution although I'm slowly getting better at making stuff. That Monorail mill was made in 2008 when all I had in my home shop was an angle grinder and an old stick welder and I turned the brass V wheels up on a MW lathe at work. I could probably do a much better job with my new TIG welder and I would put bearings in those brass wheels but I doubt it would work that much better. It does have a bit of play that manifests itself when used away from the vertical position but I'm not using it to make precision cuts anyway.

I don't like using the monorail mill that much as it fires lots of sawdust up into the air when the bottom of the bar is used. Unlike basic minimills it will not jump out of the cut so it works equally well when cutting with the top of the bar BUT this only works if the sawdust can clear/exit at the nose. The cuts on this project were blind cuts so using the top of the bar was not happening as it rapidly filled the kerf with sawdust.
When I finished the near vertical cut I was covered in sawdust. Dontcha just hate it when sawdust fills the earbud socket on you cell phone!

Would you be willing to share the design of the monorail mill? id love to have something like it to add to the functionality of the grandberg. while I can't weld to save my life i have many fabricator friends who owe me favors.......

 

[BobL]

Would you be willing to share the design of the monorail mill? .

I see you found the thread.

 

[Quietfly]

Good morning Bob!! yes i did. great piece of work there too!!

 

[amberg]

BobL, If there is any credit due It will belong to you. That is very nice!

 

[BigOakAdot]

Really interesting read. Thanks Bob.

 

[Calisdad]

Thanks for sharing. I've never seen one like it. I bet it would come in handy cutting door and window openings in log homes. Very ingenious thinking Bob.

 

[BobL]

Thanks for the feedback.

Thanks for sharing. I've never seen one like it. I bet it would come in handy cutting door and window openings in log homes. Very ingenious thinking Bob.

I hadn't thought of that but yes anywhere the rail can be attached (even upside down) the saw/mill will work although it would not be nice to be showered in saw dust.

 

[BobL]

Two more seats done today in the same fashion as described above. I've done my bit now for this playground/park. The rest of the work is being done by the Tree Lopper dudes on the BSM.

This is a flooded gum log - relatively soft.
The cut looks uneven/not level but its just the change in the cross section of the logs that's doing it


This is a Tuart log - quite hard - really tough doing all the cutting with the bar nose like that
This one is the most comfortable of the 3 as it provides the most back support

 

[Quietfly]

nice work, i'm jealous of all those logs!!!

 

[KiwiBro]

Reminds me of this:

 

[BobL]

Reminds me of this:

If only it had been all end to end vertical cutting like the video.
Getting what are effectively 2 plunge cuts 110º apart to kiss in the middle of the log - not so easy ?

 

[Czech_Made]

Great job.