First mill - with progress pics

[MickJ]

Heres a few pics of a mill i started making, at the moment ive got the saw - 090, 42" bar, and have made up the uprights/adjusters.
I opted to go for the screw adjusters as there is no chance of them moving during operation, I intend on using an occy strap to hook the adjustment handles together to stop them from vibrating around.
Ive just gotta now come up with the mounts to bolt/clamp the uprights to the bar and then make up the frame/guide/handle for the top - it will bolt to the tabs on the uprights.
The uprights are made from 316 stainless and the knobs ont he screw adjusters are brass - just a nice touch i thought.
Many many thanks to everyone who has put pics up of their mills - there truly has been some works of art and some great ideas - ive tried to take the best ideas from them to create mine! And am still looking as its not complete yet!!

The stuff sitting on the bench

The slides, i tapped a piece of 10mm s/s plate, which is in effect a floating nut - replaceable if it wears and aligns to the allthread ensuring smooth operation and no binding

Handles with brass knobs - i had plenty of time...

roughly sitting in place - note i would remove the dogs to get an extra inch - prabably end up with about 32-33 inches between the guides, lose a fair bit due to the replaceable sprocket tip.
At this stage for the clamps im planning on making up some aluminium blocks - one each side of the bar at each end with a hardened 8mm pin to locate into a hole in the bar, the clamping bolts would be outboard of the bar and chain - sandwiching the blocks together with the bar between them - probably incorporating some rollers...

Any suggestions welcome!

 

[BobL]

Awesome work Mick!

Before you make the clamps I would seriously consider using a GB style inboard connection to the bar bolts rather to the bar since this further maximizes cutting length and mahes it much easier to adjust the chain tension. If you mount the mill to the saw direct to the bar, the 090 is so heavy so it will bow the bar upwards in the middle - to counteract that you will need much heavier and stronger mill rails and have to put the bar under tension to remove the bow. If you design the bar bolt connection and outboard clamp right you can still make it so you do not have to remove the power head from the mill to change the chain and further maximise cutting length. Have you seen my nose clamp design that clamps direct to the nose?

My other concern is - if you keep using stainless, especially for the mill rails and cross sections this thing will end up weighing a ton. You should consider looking at some of the high strength ally profiles available for the rails to save weight.

 

[flashpuppy]

Any particular reason that you have two seperate screws for the height adjust? What I mean is, wouldn't one handle with a chain connecting to the other make sure it is always parallel?

Edit: I don't know if I have ever seen this or not. Why so?

 

[BobL]

Any particular reason that you have two seperate screws for the height adjust? What I mean is, wouldn't one handle with a chain connecting to the other make sure it is always parallel?

Edit: I don't know if I have ever seen this or not. Why so?

It's been done but . . . . .
- a different length chain is needed for every different length bar
- adds weight
- Verticals act as levers and magnify saw vibration even if chain is tight.

On a rail mill, which generally has a fixed length bar and where minimizing weight is less important, a frame arches across the top of the mill and extra cross braces and a chain tensioner can be added.

 

[MickJ]

Yea bob thats a good point about the GB inboard mount, thats why i'm in no hurry, may as well try and make it right.
I'll do a search and have a look at your nose clamp as when i sat the uprights in place there was quite a bit of the nose on the outside.
I'll definately look into aluminium for the rails - also plan on having it adjustable so it could be used with a longer or shorter bar, would only need to adjust the nose end.
As for the chain i thought exactly the same thing first - we use tapers at work for taping up shippers(on a conveyor) and they have one height adjust handle and a chain linking the other side.
My main reasons for not linking the two sides were as bob says and chain is often dirty to touch (unless covered - more weight and complexity) Shouldn't be that hard to make an even height adjustment if you wind together and check it with a decent ruler before you start off.
I mainly used the gear i did because it was mostly what i found at work in the scrap and i had plenty of time, to cut, weld, machine etc
Thanks for your comments

 

[BobL]

I'll definately look into aluminium for the rails - also plan on having it adjustable so it could be used with a longer or shorter bar, would only need to adjust the nose end.

I'm using the 984019 profile from Capral for my mill rails.

As for the chain i thought exactly the same thing first - we use tapers at work for taping up shippers(on a conveyor) and they have one height adjust handle and a chain linking the other side.
My main reasons for not linking the two sides were as bob says and chain is often dirty to touch (unless covered - more weight and complexity) Shouldn't be that hard to make an even height adjustment if you wind together and check it with a decent ruler before you start off.

Yep!

 

[DRB]

You might want to drill a hole through the center of the bar tip bearing and mount the upright this way see pics. There should be enough room between the rivets to drill a 3/8" hole. The reason for the nut on the top side is so that the upright is clamped on the rivets and not bearings. Hope this helps get you a little extra cutting length.

Nice fab work so far. I like your replaceable floating nuts good idea. Nice to have replaceable parts in your tool box when you are out in the field. Looking forward to seeing the rest.

 

[BlueRider]

There might still be a way to adjust both sides at the same time and reduce the weight. If you used a tapered end bill to mill some slots in the stainless box tubing in such a way that it became a rack and then hang an axle off the brackets such that a pinion gear mounted on the axle would engage in the milled slots you would then have a double rack and pinion height adjuster. the axle would need some cam clamps similar to what Bob used on his mill and then the axle could also double as the handle. If done carfully it would't be more than a pound or two heavier than a granberg mill.

If you choose to keep things as they are you might want to look into finding an adhesive backed tape measure to stick on the uprights rather than having to use a tape measure every time. My granberg has the uprights etched with 1/8th inch graduations and it is very helpfull, I only wish it were a bit easier to see the marks. I used one of these years ago on something and it worked out great:
http://www.leevalley.com/wood/page.aspx?c=2&p=43517&cat=1,43513

 

[BobL]

There might still be a way to adjust both sides at the same time and reduce the weight. If you used a tapered end bill to mill some slots in the stainless box tubing in such a way that it became a rack and then hang an axle off the brackets such that a pinion gear mounted on the axle would engage in the milled slots you would then have a double rack and pinion height adjuster. the axle would need some cam clamps similar to what Bob used on his mill and then the axle could also double as the handle. If done carfully it would't be more than a pound or two heavier than a granberg mill.

Interesting idea - I'll have to file that one away for future reference.

If you choose to keep things as they are you might want to look into finding an adhesive backed tape measure to stick on the uprights rather than having to use a tape measure every time. My granberg has the uprights etched with 1/8th inch graduations and it is very helpfull, I only wish it were a bit easier to see the marks. I used one of these years ago on something and it worked out great:
http://www.leevalley.com/wood/page.aspx?c=2&p=43517&cat=1,43513

I bought something similar for my mill but the uprights are ally tubes that slide inside other tubes so backed measuring tape would probably rub off. Also I mill with several different sets of log rails so the tape would not always be in the correct position. I have two pieces of Ally plate screwed onto the major cross sections. These pieces are level with the top of the mill rails and have 1 mm wide slots cut into them into which I temporarily slide a 1ft long steel ruler that reaches down to touch the bar . I then crank the all thread adjusters until the desired height is obtained, adding the height of the mill and log rails onto the slab thickness (minus the extent the chain cuts above the bar). There is enough play in the mill to alternately crank the adjusters about 3/4" at a time without affecting anything.

 

[striperswaper]

back to the chain for a single crank,
any thought to industrial timing belt? very light, many pitches, widths, lengths available. you could get pulleys and a belt lenght that would have no slop so once you got in level it would always be...

 

[BobL]

back to the chain for a single crank,
any thought to industrial timing belt? very light, many pitches, widths, lengths available. you could get pulleys and a belt lenght that would have no slop so once you got in level it would always be...

It would have to be a toothed belt because if either pulley slipped the pulleys would not be in synch. Belt are still like chains, you'd have to have a different length belt for every size bar you used.