Hi Everyone,
This is my first post.
I have been poking around the site trying to gather information, I am interested in building a mill.
Im leaning towards:
4 Post design with a 6 x 2 x 3/16" Main saw beam supporting 19" V belt pulleys with a telescoping tensioning setup.
2" square tube uprights telescoping in 2.5" square tube with ACME rod/bearing hoist.
A blade length within the range of 150-225"
15-20 HP gas engine.
6"x 3" Log Bed or Frame With 1/4" angle upright to accept casters of saw carriage 20' Track
I will be milling for myself on my own property but may put an axle under it to move about.
I have added a few snapshots of where I am with a design drawing.
Thanks , Mike
(https://forestryforum.com/gallery/albums/userpics/72149/drive_side.jpg?easyrotate_cache=1672942151)(https://forestryforum.com/gallery/albums/userpics/72149/Track_Base_drive_side.jpg?easyrotate_cache=1672942181)
(https://forestryforum.com/gallery/albums/userpics/72149/tensioner_idle_side.jpg?easyrotate_cache=1672942165)
Welcome aboard! Looks like you did your research. I think 6x3 for your main frame are a bit overkill unless you have a cheap source for that. Be very careful how you attach your angle to the beams. I weld-distorted mine a bit. If I was doing it over, I would have figured out a way to bolt it with the ability to adjust. (actually, just did...) How big of wood are you cutting? With the stoutness of your proposed frame, I'm guessing big so 20 hp would be way better than 15. I'm running 18 hp and wish I had 25.
If it will be on the ground or a fixed base, 6 x 3 is overkill, but if you can swing it, heavier is better.
If you ever plan to make it mobile, 6 x 3 is good.
Not sure how long of logs you want to cut but with a 20' track you will struggle with a 16' log. I would go about 6' longer than your target length. That way you don't have to have the log positioned perfectly when your pushing the length limits.
Hi Guys
Thanks for the responses,
6 x 2 for the saw beam
6 x 3 for the bed
20' length is the length of the stock for 6 x 3 x 3/16 channel, I do want to cut 16' stock maybe I should consider changing the stock to something I can get in a 24' length.
I have done epoxy pour bar tops for a local bar as well as counter tops and other jobs.
in order to get a live edge on top of a 24" deep base cabinet as a countertop you need to have at least 25" to the shortest point of the contoured live edge measured from a straight edge on the back side of the slab. I have been buying slabs and realized in the process that in order to meet that measurement you need a pretty big log. Ive got the epoxy thing down so I think Id like to be able to accomplish that with this mill as well as make dimensional lumber for my own use.
I will consider the method of attaching the angle on the track.
Is the preferred direction for attaching the angle with one leg up as drawn or I see some people with the V facing up?
-Mike
Quote from: Brackish on January 05, 2023, 02:45:31 PMIs the preferred direction for attaching the angle with one leg up as drawn or I see some people with the V facing up?
I used 2x3x¼" angle with the 3" side up. Running wheels on the narrow edge doesn't give sawdust a place to gather.
My thought on attachment would be to bolt a plate on the side of the angle hanging down to bolt to the side of your 3x6. With it being 3/16" thick you should be able to thread it, probably 2 bolts. The ¼" angle would definitely allow for threading, and again, 2 bolts. Probably do elongated holes in the plate for up/down adjustments. Then, use washers under the 2" side of the angle to shim as needed. This way, you avoid welding altogether and any distortion it would bring. If painting, could have it disassembled to get all sides of the metal.
I agree, narrow edge of the angle up. When I built my bed I used the same logic. 6 x 3 came in 20' lengths so that was how long my bed ended up. I often want to cut 16' dimensional lumber and I quickly realized it was too short. I have since added 4'.
If your careful when welding you should be able to add length without warping. Clamp some heavy steel to each side and tack. Make sure each end is cut straight and when you bevel for welding, leave just a little material so you can butt them up to each other. That way there is no place for it to pull.
(I'm not an expert welder, but that worked for me)
Also, don't weld the angle on until you have the mill on top so you can roll it down the bed. Just tack it lightly and then when you roll the mill on it you will see if the bed isn't quite true. If it isn't, you can shim the angle iron before you weld it permanently.
I just noticed that you referenced 6 x 3 channel. I would use 6 x 3 rectangular tube, especially since you may put an axle under it.
tube not channel my bad.
If you bolted or welded the angle to the side of the 3x6 so one part is sticking up above the 3x6 and one part sticking out the side (horizontal) it could be levelled independently from the 3x6 and give you a place to add a safety on the underside of the horizontal leg of the angle iron to prevent the saw carriage from tipping or jumping the tracks.
Welcome to the forum. A few thoughts on your build. You just need to use the front vertical tubes to guide your saw head. Using the back tubes could be a cause for some binding, it's not needed.
About your carriage wheels, have the wheels on one side of the carriage, probably the left side, so they have some sideways movement (clearance) to be able to slide side to side on the axles to allow for any slight misalignment and avoid any binding as it rolls down the track. You will be using U groove wheels and at least 3" or more in diameter. On 1/4" angle legs, use 3/8" U groove.
For band blade length, use a standard blade length readily available. 158" is one common length. There are other lengths also. This makes buying blades readily available instead of having to custom order an uncommon length.
Quote from: RAYAR on January 06, 2023, 03:56:59 AMYou just need to use the front vertical tubes to guide your saw head. Using the back tubes could be a cause for some binding
I could see that being an issue.
Quote from: RAYAR on January 06, 2023, 03:56:59 AMAbout your carriage wheels, have the wheels on one side of the carriage, probably the left side, so they have some sideways movement (clearance) to be able to slide side to side on the axles to allow for any slight misalignment and avoid any binding as it rolls down the track. You will be using U groove wheels and at least 3" or more in diameter. On 1/4" angle legs, use 3/8" U groove.
Would bolting the angle as suggested allow for proper alignment?
On 1/4" angle legs, use 3/8" U groove; Rodger that.I will use a standard blade length, once the design is satisfactory I will figure what to take out of the middle of everything to arrive at a standard blade length.
In determining the width of the saw head at its minimum adjustment for blade tension how much slack should I allow in order to install and remove a blade?
Am I right in thinking I can estimate blade length by taking the distance center to center of the band wheels plus the circumference of one band wheel?
Thank You all
-Mike
Quote from: Brackish on January 06, 2023, 06:22:30 AMIn determining the width of the saw head at its minimum adjustment for blade tension how much slack should I allow in order to install and remove a blade?
I have about ½" to ¾" adjustment. More than enough.
Quote from: Brackish on January 06, 2023, 06:22:30 AMAm I right in thinking I can estimate blade length by taking the distance center to center of the band wheels plus the circumference of one band wheel?
Yes
Quote from: Brackish on January 06, 2023, 06:22:30 AMAm I right in thinking I can estimate blade length by taking the distance center to center of the band wheels plus the circumference of one band wheel?
centre to centre
x2 plus circumference?
Blade length, speed, and belt length calculator (there are others I just picked one)
https://www.blocklayer.com/band-saw-eng (https://www.blocklayer.com/band-saw-eng)
Quote from: ljohnsaw on January 05, 2023, 03:28:57 PM
My thought on attachment would be to bolt a plate on the side of the angle hanging down to bolt to the side of your 3x6. With it being 3/16" thick you should be able to thread it, probably 2 bolts. The ¼" angle would definitely allow for threading, and again, 2 bolts.
If bolting the angle anyways, why bolt a plate to the side of the angle to them bolt it to the frame? Why not just bolt the angle to the frame? Its 1 less step, a lot less holes to drill and tap and less steel to buy.
Granted my mill bed is 2x6x1/4" wall rec tubing and my 2x2 angle is 3/8", i still bolted it to the bed using 3/8" bolts and drill the holes in the angle with a 7/16" bit to allow for a lil bit of adjustment.
But i also clamp my angle to the bed, flushing the back/vertical leg to the outside of the bed by butting the vert leg up against a 1/2"x2" flat bar off cut. Once flushed and clamped, i tack welded the angle on both sides and once the entire length was tacked up, i laid the holes out and drilled with a 1/8" bit for a pilot hole, through the angle and into the rec tubing.
Then i cut the tacks off and proceeded with the drilling and tapping, then using the flat bar off cuts, flushed the angle again and tightened the bolts holding the angle down.
I believe I have seen some mills that just use a flat stock fastened to the side of the frame it does not give you a safety from tipping the saw head but it does make it easier for you to chose a harder steel for the rails.
My thought was to use gravity to your benefit. The bolts would only be doing light duty for placement but the shims (washers) or direct contact between the bottom of the angle and top of the 3x6 would be supporting the weight of the head. Just a thought. But, I suppose bolting through the top would work. Just not a lot of meat in 3/16" to thread.
I welded the angle to my bed and it worked out good. My bed was pretty straight so I only needed a few shims on one end. Whether you bolt it down or weld, you want lots of support between the angle and the bed. If there is too much distance between any shims, the angle will deflect and you will get bounce. I know you wouldn't think that would happen, but it will.
3/16" thick material is the same on the side (6") as it is on the top (3"). If there is enough to possibly tap the side, there is enough to tap the top. Can always tack a 1/4"x3" flat bar to the top, drill and tap and bolt the angle to that plus the 3/16" of the rec tubing.
I ended welding on some 1/2" thick flat bar to attach my linear rails to the vert posts of my carriage and to the bottom of the sawbeam/head, giving me 3/4" of meat to drill and tap into. It was probably (75% sure) over kill, but id rather have it and not need it than need and not have.
This sketch shows how I captured my
(https://forestryforum.com/gallery/albums/userpics/65416/IMG_20230106_121132382.jpg?easyrotate_cache=1673029113)
mill head to the track to prevent it from falling off.
I welded a second angle iron to the side of the 3" track angle. I then bolted a bracket to the side of the mill structure that hooks around the other angle. If I need to take the mill off of the bed, I can remove the brackets.
the distance center to center of the band wheels X2 plus the circumference of one band wheel
Would bolting the angle as suggested allow for proper alignment? >> It would have to be perfect, otherwise, some binding will occur. Better to allow for slight discrepancies and have a smooth and easy rolling carriage.
In determining the width of the saw head at its minimum adjustment for blade tension how much slack should I allow in order to install and remove a blade? >> I would allow at least 1" either way in adjustment.
Also, allow enough length between carriage wheels to avoid the carriage getting too tippy front to back, especially when the saw head is raised quite high.
Rayar, bolting allows for adjustment a lot easier than welding, which welding needs to be as perfect as can get.
So, unless everything was machined ground, nothing will truly be "PERFECT" with hot rolled/extruded mass produced material.
Since, im betting most material we and mill manufacturers building these hm brew and factory built mills with is not truly perfect, being perfect is not on the table.
Quote from: charles mann on January 06, 2023, 08:17:25 PM
Rayar, bolting allows for adjustment a lot easier than welding, which welding needs to be as perfect as can get.
So, unless everything was machined ground, nothing will truly be "PERFECT" with hot rolled/extruded mass produced material.
Since, im betting most material we and mill manufacturers building these hm brew and factory built mills with is not truly perfect, being perfect is not on the table.
It's actually easy to tack weld the track angles straight and parallel to each other. The tack welds should only be about the size of bolts and spaced about 8" to 10" apart. That would keep the heat to a minimum. No adjustments should be needed.
Then the alignment would have to be perfect as you said.
There isnt a right or wrong way of securing them other than aligned as best as the material will allow.
Questionable language insinuation deleted by Admin.
Hi All
Regarding this talk about the "perfect"-ness of the track, how would that relate to the rest of the log bed. if the track is shimmed wouldn't the cross beams need to be shimmed perfectly too?
Are we more concerned with the tracks being parallel left and right to keep the casters equidistant so the casters don't bind or up and down so the thickness of the board being cut doesn't change?
I like theoretical perfectness but we are "rough sawing" right?
That said maybe bolting the angle to the frame is better simply because you can replace the angle?
How does support of the entire log bed play into this? Jack legs; poured footings below frost line bolted down?
How often do you need to adjust calibrate or tune the trueness of log bed as a whole?
Do some mills rely solely on the strength and stiffness of the main beams to keep the shape?
Could you have a mill only on trailer axles and tongue jack that stays true enough wherever you park it?(not my goal)
Thanks,
Mike
My mill is long - 50' or so - and sits on 12 jacks. Four per section (two at 16+', one at 8½' and two sets of 5' sections of angle connecting them). I do mill a lot of big logs (26"-30") and a few monsters (Mill Reset (https://forestryforum.com/board/index.php?topic=66160.msg1918337#msg1918337)) that are a lot of work on my manual mill. My jacks, with ~4x6 pads, were sitting on scraps of wood perhaps 6x10. The first monster log (20k lbs) sunk those in the ground. I have reset my mill several times when a log slipped when loading or just rolled a little too friskily. ::) I've bent my ¼" angle when dinging it with the forks. Nothing that a little 12 lb sledge couldn't tap out. Through it all, my 2x4x¼ frame has withstood it without any bending that I can detect.
My bunks are "registered" to the mill frame and are moveable. Any bend in the frame will affect them. I use the 12 jacks and sight down the rails to "level" it up. A super stretched/tight string is not good enough. Probably need to set up a laser and a sliding target on the track. Not concerned with earth-level, just straight. I'm actually running down hill to make pushing through the log a little easier. Might seem counter intuitive but the only levelness I really work on is the up/down flatness. If the track veers to the left or right a little (less than an inch), I don't see that affecting my final product. That doesn't affect the thickness I'm cutting because it can't - so why fret it? The left/right straightness only comes into play when the log width is at the max and prevents the head from traveling.
Hi There,
I spent some time this morning playing with my design and made quite a few changes to the saw.
This go round I did not connect the sawhead to the aft carriage posts to eliminate binding.
I reduced the saw beam to 4x2 rectangle tube but added 2x2 square tube to the bottom of both ends so that I could; on the idle side nest tubes on the for tensioning and on the drive side to match the height.
I added 2x2 square tube to the front of the saw beam to mount blade guide arms.
I do not show both band wheels wheels, a jack or porta power for tensioning, motor plate, or guard provisions on it nor have I done anything about a raise/lower system (probably acme rod?)
Thanks for your input.
Mike
r>(https://forestryforum.com/gallery/albums/userpics/72149/saw1.jpg?easyrotate_cache=1677430602)(https://forestryforum.com/gallery/albums/userpics/72149/idle_side_wide.jpg?easyrotate_cache=1677430602)(https://forestryforum.com/gallery/albums/userpics/72149/drive_side~0.jpg?easyrotate_cache=1677430603)
(https://forestryforum.com/gallery/albums/userpics/72149/idle_side.jpg?easyrotate_cache=1677430602)
Looking pretty good! Make sure however you mount your drive and idle wheels that there is a way to adjust the tracking. Can be as simple as having one of the pillow blocks be movable with an adjustment bolt pushing on it. Only need one on each end to be adjustable. Needs to be easy and very fine adjustments.
As far as your blade guide arms. Assuming you will have your backstops on the same side as your drive wheel, you don't need that guide arm to be adjustable. Just make it so you have the max room on the bed. Typically inline with the backstop or very close to it. Being on the outside would be better when you have a big log that sits above and beyond the backstop.
As for the adjustable, we had a long discussion about that on another thread. Here is a link to the start with pictures from my mill (V2.0): Sliding guide, part 1 (https://forestryforum.com/board/index.php?topic=121349.msg1962880#msg1962880)and then continued later in the thread with a bit more description of how it works: Part 2: the rest of the discussion (https://forestryforum.com/board/index.php?topic=121349.msg1964855#msg1964855) I'm not saying this is the only way or the best, but I did the tube-n-tube on my first iteration. Doing it this way was much easier, lighter to build, way easier to adjust and more stout. It also affords the ability to motorize it so you can adjust on the fly! This is also the way WM does it on their mills, so it must be good!
Quote from: ljohnsaw on February 26, 2023, 02:01:38 PM
Looking pretty good! Make sure however you mount your drive and idle wheels that there is a way to adjust the tracking. Can be as simple as having one of the pillow blocks be movable with an adjustment bolt pushing on it. Only need one on each end to be adjustable. Needs to be easy and very fine adjustments.
As far as your blade guide arms. Assuming you will have your backstops on the same side as your drive wheel, you don't need that guide arm to be adjustable. Just make it so you have the max room on the bed. Typically inline with the backstop or very close to it. Being on the outside would be better when you have a big log that sits above and beyond the backstop.
As for the adjustable, we had a long discussion about that on another thread. Here is a link to the start with pictures from my mill (V2.0): Sliding guide, part 1 (https://forestryforum.com/board/index.php?topic=121349.msg1962880#msg1962880)and then continued later in the thread with a bit more description of how it works: Part 2: the rest of the discussion (https://forestryforum.com/board/index.php?topic=121349.msg1964855#msg1964855) I'm not saying this is the only way or the best, but I did the tube-n-tube on my first iteration. Doing it this way was much easier, lighter to build, way easier to adjust and more stout. It also affords the ability to motorize it so you can adjust on the fly! This is also the way WM does it on their mills, so it must be good!
Thanks for your response.
For tracking adjustment. On the idle side the 2 nested square tubes that provide tension adjustment will be tied together with plate and the pillow blocks bolted to the plate. I was thinking I could adjust the tracking with the elongated holes of the pillow blocks and shims.
Is there no benefit to having both blade guides adjustable?
Does anyone clamp the log both sides not right up on the backstop and cut nearer the center of the log bed? In the case where there is wane or live edge both sides of the cut? I have been doing a lot of live edge epoxy slab work for restaurant bar and counters and I will be cutting slabs like that as well as dimensional lumber.
Quote from: RAYAR on January 06, 2023, 05:36:48 PMAlso, allow enough length between carriage wheels to avoid the carriage getting too tippy front to back, especially when the saw head is raised quite high.
I second. I originally made mine too short in front and had it almost tip over while working on it. I added a piece of channel under the full length to extend the wheels out further.
Quote from: Brackish on February 26, 2023, 03:39:18 PMDoes anyone clamp the log both sides not right up on the backstop and cut nearer the center of the log bed?
I read on another build where the builder put his backrest on the side where the blade enters the log. He would make his first cut then when he turned the flat side against the post the blade would enter the cut on the fresh cut side instead of the bark side. I would think you would need a really good clamping system for that to work as the blade would be constantly trying to pull the log away from the post instead of pressing it to it. His idea was the blade would stay sharp longer.
The saw frame size or carriage is kinda arbitrary at the moment.
The width i will determine after i'm satisfied by the design, I will figure for a standard blade size by essentially adding or removing (in design) width of the track the wheel base width the carriage cross bars and the saw head beam while leaving the ends and pillow block design alone.
the height of the carriage frame and length fore and aft I could use some suggestion.
I am a little curious as to where the balance will be and not sure yet how long to make the wheel base fore and aft.
I think the saw bed will be out of 24' stock in order to cut 16' logs that means 4' before and 4' of track available before and after the log. but should the base be 4'?
I have also seen some suggested methods of capturing the carriage on the track that I will consider
Mike
Quote from: Brackish on February 26, 2023, 03:39:18 PMDoes anyone clamp the log both sides not right up on the backstop and cut nearer the center of the log bed?
Posted by: RetiredTech « on: Today at 05:15:24 PM I read on another build where the builder put his backrest on the side where the blade enters the log. He would make his first cut then when he turned the flat side against the post the blade would enter the cut on the fresh cut side instead of the bark side. I would think you would need a really good clamping system for that to work as the blade would be constantly trying to pull the log away from the post instead of pressing it to it. His idea was the blade would stay sharp longer.
The idea is that some on my intended use is to produce slabs with live edge on both sides, not cutting with a cut edge on the backstop.
like these bar room tables I am epoxying this week. (had to buy this >:( from a nice guy tho!)
for
(https://forestryforum.com/gallery/albums/userpics/72149/IMG_1724.JPG?easyrotate_cache=1677451616)
I didn't realize you were after a live edge on both sides, I was picturing something like a bar or mantle piece with one flat edge and one live edge. I'd still go with the backstops on the side the blade exits. There's a lot of people on here smarter than me, and that's the way I see most mills made.
The log doesn't have to be centered on the bunks to get two live edges. It would be overly complicated to have movable backstops. There could be some benefits when sawing gnarly stuff with protrusions, but I don't think it's worth the extra complication.
On the other hand, I would like to see somebody build one that way. :)
Quote from: Brackish on February 26, 2023, 05:38:23 PMI think the saw bed will be out of 24' stock in order to cut 16' logs that means 4' before and 4' of track available before and after the log. but should the base be 4'?
There are a couple ways to do this. You need to be able to position your head (at the start of the cut) such that you can load the log. So, the distance from the rear wheel to the front of the saw frame is what subtracts from your bed length. At the far end the distance from the front wheels to the back of the blade is what you subtract. You can raise the blade and run the head back to the start. Not the most convenient but that determines the max log you can cut. Would be better to subtract the amount from the front wheels to the back of the saw frame - where you can clear the log/board for easy removal. And then, probably better to give yourself at least a foot or two wiggle room to load logs so you don't knock your saw head off the track, so I've been told ::)
The other way is to add a section of light weight track at each end to "park" the saw head. It doesn't need to be as strong as the main track as it is not supporting a log. Just the weight of the head. These sections could also be removable and/or fold up for transport or storage.
Also, think about the geometry. The farther the wheels are apart (with the blade being somewhat centered), the less affect irregularities in the track have on the cut. Not saying you have any, but if you have sections (like me) that have a little bump at the connecting point, that distance will reduce the effect down by at least half - making it unnoticeable.
My legs under my 2 post mast are 39" long. The legs are not centered on the skate.
I used 6x2x.188 for my bed. I can support one corner of the bed and jump on the opposite and there is no visible deflection.
For my main rails its is the 6x2x.188 tube with a piece of 3/8" flat stock welded to the tall side. If you do not full weld everything and you space your welds out you should not have any trouble at all with heat affected distortion.
Here is a picture of my wheel / skate setup. The green piece is a tipover prevention and works very well keeping the head on the tracks. The aluminum plate is my rail scraper. It actually sits against the rail normally, not sure what happened in the picture?
(https://forestryforum.com/gallery/albums/userpics/45059/20220315_102757.jpg?easyrotate_cache=1647355067)
When I first built my mill I made it so the fixed guide was in line with the back stop. That was a HUGE MISTAKE. Every time I was cutting a log (since we all know how straight they look till they hit a sawmill) the log would protrude past the backstops and jam the carriage on the guide wheels. I ended up moving the head over 2.5" to avoid that problem.
Take a look at my build. It covers most of the question you have. See sigline for link.
Here is a picture of my bed in the early construction phase.
(https://forestryforum.com/gallery/albums/userpics/45059/20171104_193526.jpg?easyrotate_cache=1509974651)
And here is the picture I wanted to post for the rails.
(https://forestryforum.com/gallery/albums/userpics/45059/IMG_2204.JPG?easyrotate_cache=1506353496)
Also, check out my gallery for a ton more pics.
https://forestryforum.com/gallery/thumbnails.php?album=7990
Quote from: Brackish on February 26, 2023, 12:17:32 PM
I spent some time this morning playing with my design and made quite a few changes to the saw.
I reduced the saw beam to 4x2 rectangle tube...
...nor have I done anything about a raise/lower system (probably acme rod?)
Thanks for your input.
Mike
I would reconsider that 2X4 rectangle tube to something much more stout, as the is a tremendous amount of force on this piece from the tension of the blade.
My mill was built using a garage door lift system using cable for the head lift system. It works good, but I believe the best system would be chain and sprockets, minimum schedule #40 chain size.
My thoughts on these
Ray
My saw frame uses 2x2x.188 for the frame. The pillow blocks are bolted to that so there is only the offset of the pillowblock height. I do not have any noticeable deflection.
Quote from: Crusarius on February 27, 2023, 09:33:37 AM
My saw frame uses 2x2x.188 for the frame. The pillow blocks are bolted to that so there is only the offset of the pillowblock height. I do not have any noticeable deflection.
Crusarius
I just read thru your build thread. Nice Work.
any final thoughts on the 2 post design?
I saw your comment about it walking.
is there any issue with your saw beam being so far ahead of the posts? is it front heavy or did the engine etc balance it out?
My design is considerably different in that its a four post the motor will be facing the other direction the and the band wheels will be closer to the 2 posts supporting the saw head (at first I drew it as using all 4 posts capturing the saw head with tube in tube or 'nested tubes' but I was advised to only capture it with 2 posts to avoid binding while raising and lowering.
I like your backstop and log clamping and you overall did nice work.
Thanks, Mike
I suppose id probably want the saw to be slightly forward heavy so that the nested tubes normally sit in the position that they would be driven into by the force created by pushing the blade into a log?
2 post design. I like it. Would not be opposed to using it again. The best part about it is the sawframe is in front of the mast so the blade has full access to change. I do not have to snake it around a frame.
The walking was early on, I think I ended up fixing that by shimming the skate wheels so the flanges on the wheels did not rub on the track sides. The entire carriage moves easy enough that a steady breeze will move it or if the mill is not level.
It is definitely front heavy. and because of this it does not go up as fast as I would like (threaded rod binding). I used to have the tube in tube design you are going for and it worked well with no problems. I ended up switching that out for cam followers because the tube in tube just kept shaving the paint off the mast. If I was able to balance it better this would not be a problem.
With my design (Linn Lumber design) the engine drives the saw the opposite direction as most other manufacturers. This really isn't a problem except for the fact that then engine is on top of the sawframe making it very unbalanced. This is not a problem with the leg setup I had. The biggest issue I do not like about it is the fact I have to flip every blade to put on the mill, then flip it back to sharpen. My next mill will not have the engine in that orientation.
The carriage is very well balanced with the way I built the legs. I do however, highly recommend a retainer of some type to keep the carriage on the mill. I have had some issues that without those clips would have meant derailment for sure.
Keep in mind you can do a lot more with geometry than you can with over sizing components. For example my legs are 39" long. But the mast is roughly 12" from the one end. this gives me a solid 24" of support under the sawframe. What you do have to watch for though is the blade hitting the skates. That is why my bunks are 2" higher than the side rails.
The backstops, I would not do that again. they work and are nice to have them all connected but the rotating is a nightmare and a half to try to align. I had them at 90 degrees before the mill got final paint. I have not been able to get them perfect since.
Thanks for all the praise on the build. I learned a lot and really enjoyed doing it. One day if someone wants to buy this one I am planning on building a very different one.
Brackish, that is not necessary. Personally I would prefer the tubes to be floating inside each other. As soon as you contact the log and start sawing it will push against the uprights taking care of the what you want. The other thing is to if it is slightly front heavy then you will get friction causing raising and lowering to take more work.
I think I am still going for the tube in tube design at the moment but I still have some uncertainty on the balance between too tight and its binding and too sloppy.
Would sloppy lead to more band blade marks in the slab?
how much does a constant feed speed help in a smoother cut? i.e. does a power feed create a much cleaner cut?
As far as ACME rods for the lifting
What size rod should I use? is there a more common or preferred size or should I just be looking to satisfy the strength needed.
How are ACME rods terminated into a bushing at the bottom and top?
How are ACME rods adapted to a chain gear at the top?
Mike
Slop is not bad. Binding is bad! I have movement and I don't think it affects the cut.
My second set of ACME rod is ¾" IIRC. One inch would be better. Get the longest nut you can in bronze for better wear. Weld or use a coupler with set screws to attach regular rod to the end. If you had access to a lathe, turn the end down.
A thrust bearing on the bottom would be great. Set screws for the sprockets as well. You MUST wrap the chain as much as you can, like up to 180° so it won't hop a tooth.
Had power drive and didn't like it with my limited 18hp.
I thought about adding power feed but I don't think I ever will. I like being able to feel the cut, that way I can adjust speed accordingly.
I would not go nay less than 1" acme rod. Will smaller work? Yes. but for longevity I would lean tow3ards the 1" with a large brass nut.
the looseness of the tube in tube is not a concern at all. once you start cutting the sawhead is pushed against the mast and keeps the head from moving. if the sawhead is not against the mast you are not feeding fast enough.
I bought my acme rods from Linn Lumber. they were already machined for pillowblock bearings on both ends and key slots on one end. I just used a #40 sprocket with key and I needed to do almost a full 180 degree wrap to prevent chain skipping.
I am still not sold on the acme rods for lift. But they do work. I would love to find a way to make the lift faster but the down is perfect speed.
I think my acme rods 1" and have had no issues in 6 years other than lift speed as well. I had mine machined down to 3/4"on each end for a pillow lock bearing at the top and it seems like a trailer axle bearing at the bottom. The top was also machined down the rod further to make room for sprockets as well. On the tube in tube the longer you make your sliding body the less bind there will be even if the head is unbalanced. I think mine are 14" ish long.
My Woodland Mills saw uses HDPE(cutting board plastic) to control the freeplay of the tube inside of tube design. Flanges are needed to hold the bushings in place. The beauty of the design is that they are adjustable.
It also has a really nifty dual cable lifting system. There is an acme screw inside the cranking mechanism. It doesn't take much effort to raise and lower the mill head.
Hope this gives you a few ideas.
(https://forestryforum.com/gallery/albums/userpics/67554/Post_sleeve_adjustment.JPG?easyrotate_cache=1641951565)
(https://forestryforum.com/gallery/albums/userpics/67554/CableB_Routing.JPG?easyrotate_cache=1642052168)
(https://forestryforum.com/gallery/albums/userpics/67554/CableA_Routing.JPG?easyrotate_cache=1642052167)
(https://forestryforum.com/gallery/albums/userpics/67554/Cable_Ends_Mounting.JPG?easyrotate_cache=1642052166)
What I wouldn't have given to see that routing a long time ago when I was playing with different lift setups. Better late than never :) Thanks rustic.
Ok
I still plan to continue my mill build but...
For less the the cost of my list of materials I purchased a used Hudson mill from a local guy that was nice enough to deliver set up demonstrate and give me several hours of training and questions and answers.
It is much less capable than the mill I want to build but I'm sure this will be beneficial to my design ideas as well as get me milling.
I cut my first boards yesterday.
I am considering ordering the stock and start with the frame for the track for the mill I want to build. I think I could use the frame as a platform for the hudson mill I bought as I don't want to be trying to keep the track level on the ground.
That's a great plan. By using the first mill you will learn what you want on the one you build.
Congrats. I agree.
Happy Bday to you Fluid Power!
And if one breaks you have a spare. Also one to give to an heir.
you have all the parts you need and then some. I would almost be tempted to just keep the hudson and sell off the other parts. the hudson can always be modified.
What model Hudson is it? How big will it cut?
One thing I've recently learned, if you're turning your own main shafts, make sure they're high tensile!
I had a bearing failure 3 years in and spun a sleeve on a shaft which ruined the journal. I decided to make new shafts all around as I'd not owned the tools to get a precision press fit when I did make them. 1018 steel was what I had on hand so it's what I made the new ones out of. First one snapped about 3 hours into work and second about 45 minutes later, which is somewhat impressively consistent hah.
So I've made a third set, out of 4140 again and back in business. Certainly the long way around.
(https://forestryforum.com/gallery/albums/userpics/47173/20230324_113428.jpg?easyrotate_cache=1680387761)
I'm also not a fan of pillow blocks. Mine run hot all the time. Much better off with something like what cooks uses (and many others I'm sure) with a tapered roller bearing.
Congratulations on your mill purchase. Sounds like you got a deal. I hope you don't decide to abandon your custom build. My mill is going to be stationary. But I'm already thinking about building a second lightweight easy to transport mill I can take into the woods much like the smaller Hudsons. I can see where two mills would be beneficial.