New Sawmill WIP & Field Days Competition

[echnidna]

My New sawmill pics - a wip

Partly inspired by this (http://www.woodworkforums.ubeaut.com.au/showthread.php?t=77058) thread in wwf

The post and rail idea is also somewhat similar to my old Portamill Band saw mill that I had years ago.

The problem with suspended rail/beam mills is deflection in the rail. So they are usually practically limited to a maximum of 3 metres long. I have seen truss beams used as one method of minimising deflection.

By designing a laminated rail I was able to achieve a maximum deflection under 1 thou inches with the carriage in mid beam, with a beam length over 4400mm. I expect a 6 metre (20 ft) rail would be practical.

By reducing defection to such a tiny amount it is (theoretically) possible to operate the saw horizontally or vertically. This will enable milling of boards or slabs. I have also made future provision for making angled cuts which may enable cutting things like weatherboards or increasing the volume of quartersawn timber from a log.

The height and horizontal saw adjustments are simplified by drilling indexing holes in appropriate frame member locations. (However drilling hundreds of holes is a tedious exercise.)

As I approach completion I notice the Acme Field Days are running a new invention/innovation competition, so I'm thinking of entering the chainsaw sawmill in it.

"Rule 3 states

"Entrants must select only one category for their entry:

* New Invention - the creation of a new product or concept.
* New Innovation - the use of a product or concept that has been adapted to serve a new purpose"

I'm inclined to think that the mill falls under the new invention category as it certainly is a new concept in a number of ways,

I still need to drill a few hundred more holes and weld some more bits together but you can see what it is.

I ask you blokes opinions as to which category the mill best falls under.

[gidgee 1]

Hi Echnidna
Good to see some-one taking the idea and improving:2tsup: as they see fit,once you get used to milling this way there is no looking back,it takes so much of the`pain`out of it:).
Good luck with it
cheers
gidgee1

[echnidna]

I used to hate my old bandsaw mill.
But there were 2 good things about it just like the rail saw. :)

The log could lay on the ground, you didn't have to bust a poopa valve manhandling a big heavy log. :)
And you walk along while sawing instead of being hunched over. :)

[Sigidi]

Bob, I reckon new innovation as it is a different way of using a product (chainsaw) or concept (slicing logs) in a different/easier/more versatile way???

Just my 2 cents...

[BobL]

Looks good :2tsup:



The problem with suspended rail/beam mills is deflection in the rail. So they are usually practically limited to a maximum of 3 metres long. I have seen truss beams used as one method of minimising deflection.

By designing a laminated rail I was able to achieve a maximum deflection under 1 thou inches with the carriage in mid beam, with a beam length over 4400mm. I expect a 6 metre (20 ft) rail would be practical.


The design is similar to a beam machine by an English guy called Railomatic. Unfortunately his website is not working but the principle is the same, beam, roller carriage, vertical or horizontal bar orientation, he uses more sophisticated threaded height adjustment and hangs the CS from the bottom of the rail

Here is a picture of his machine.
http://www.woodworkforums.ubeaut.com.au/attachment.php?attachmentid=94596&stc=1&d=1232619727
Railo is a serious innovator and makes some very interesting mill including several made from large rollers - hence the name Railomatic.

What cross section size/gauge beams are you using He uses single 2 x 4" by 1/8" beam up to 6m long and he hangs an 880 of his beam.

I assume this deflection is just with the dead weight of the CS on the rail. On a vertical cut the CS will pull downwards, much more than the dead weight of the saw. But then again a vertical deflection in that orientation doesn't matter anyway. All good.

Keep posting the pics, especially when you start cuttin wood.

[Arthur Dyason]

Bob

On our monorail I have found that when you extend you can tension the rail with wirerope and turnbuckle. You will need to play a bit for your particular setup but by attaching at a number of points along the rail instead of just each end you can create a curve to the rail so that when it is in place its own weight will streighten it.

We have managed to get our normal 6m truss style rails upto 18m with a bit of fiddling around.

arthur

[echnidna]

Hi Arthur,
I did think of the cable idea but felt it was easier to design a laminated beam with a preset camber equal to the static and live loads of the beam.