The First day of The InterMechanicoMill

[InterMechanico]

Good morning, everyone. A few days ago, I alluded to the fact that I'm building a Bandsaw Mill "on the sneak". Yesterday i got started on the actual build, after a couple weeks of sourcing steel and parts.

The steel I've used is either 1/4" wall 2" x 2" square tubing or 2" x 4" rectangular tubing. The frame dimensions (outside) are 77.5" wide X 72" tall X 34" Long (front to rear). The brackets on the bottom are removable from the frame, and house the track wheels, which are 3.05" sheaves with a bronze bushing.

The bandsaw wheels are 25" diameter 2 groove sheaves, with split taper bushings and 1 1/2" shafting.

The Bandsaw drive will be hydraulic, incorporating a Char-Lynn 18.7 cu.in Disc Rotor motor and a 5 gpm pump. Pump RPM will be 1800 which produces roughly 70 RPM at the motor, or 5500 inches per minute on the blade.

There will be a second pump (3 gpm) that will operate the power feed and the saw deck hoist (probably using a 24" stroke cylinder and double sheave pulleys.

Here are some pictures for you. Criticism is appreciated. Please give me your input.



  

  

  

  

 

[Joe Hillmann]

It should be interesting to see how the hydraulic drive will work for you?  How big of a reservoir do you plan to have?  Do you plan to use a cooler to get rid of the heat?

I would also recommend mounting your band wheels below the beam going across rather than on top of it that way you can make deeper cuts.

[InterMechanico]

Thank you for the mounting recommendation. I was unsure which way to go, but that settles it. It'll also free up the entire deck to mount the engine, pumps and reservoir.

I have a 22 gallon reservoir I may use. Not sure yet as it will depend on space. It heat is an issue, I will install an air to oil cooler, and drive a small fan off non-driven saw shaft.

[Magicman]

No criticism from me, and I will enjoy watching the build.  Do I see adjusters on the legs?   ;)

[gww]

Thanks for posting the pictures.
gww

[fishpharmer]

Your mill progress looks great!  Welcome to FF!  I am curious if you will you have pump mounted to an engine on the saw head? or independent of the sawhead with long supply/return hoses?  The motor rotation direction should be reversible so it can be mounted on either side as you probably know.  Keep up the good work.

[Joe Hillmann]

Since you are still early on in your build here are some pointers for you.

The carriage is going to flex.  It doesn't really matter unless it flexes so much that one wheel lifts off the tracks.  Putting lots of 45degree braces will reduce the flexing.

For raising and lowering the head use a system that forces both sides to move the same amount at the same time.  I have a cable system on mine and when going down the head "walks" down.  Which can lead to tapered cuts.  Lead screws would be best but some type of chain or rack and pinion set up would work too.

As you are building kind of keep in mind where and how you are going to mount the guards.  Otherwise they can be very hard to build because things are in the way.

The area on your deck is going to fill up real fast. When I built mine I thought all I would have there is the engine but it is full of electronics, the battery, the gas tank the blade lube tank and other items I hadn't planned for.  Yours will have even more since you are going with hydraulics. so try and plan ahead.

[Den-Den]

I love home made tooling; yours will be interesting to follow with the hydraulic motor.  The 25" sheaves should make great wheels.  I did not check the math but 5500 inches/minute seems slow, 3000 - 4000 feet/minute is more common.

[boscojmb]

The bandsaw wheels are 25" diameter 2 groove sheaves, with split taper bushings and 1 1/2" shafting.

The Bandsaw drive will be hydraulic, incorporating a Char-Lynn 18.7 cu.in Disc Rotor motor and a 5 gpm pump. Pump RPM will be 1800 which produces roughly 70 RPM at the motor, or 5500 inches per minute on the blade.

I was looking at the same thing. Your math all works except that your blade will be moving at 458 FPM instead of 4500 FPM.

[Hilltop366]

  , thanks for posting your build!

[InterMechanico]

Hi everyone, and thank you for your valuable input. I have noticed the saw tables' tendency to get jammed up. I'm looking at a way to power the table up and down, maybe using another hydraulic motor.

I'm glad I haven't gotten too far into the hydraulic system design! I was sure I'd read that the ideal blade speed was 4500 inches per minute. Feet per minute is a different story. I will recalculate using 3000 sfpm which will certainly be fast enough for my purposes.

what kind of reduction ratios are you guys using on straight belt drive units?

[InterMechanico]

I think i might go electric then. I have a 15 hp electric motor laying outside at the shop I can use. Once i mount the pillow blocks onto the saw table, I will see about a belt drive to knock the speed down by half. Then I'll build a small 1 gpm electo-hydraulic powerpack to power the table lift and feed motor.

[Joe Hillmann]

I think i might go electric then. I have a 15 hp electric motor laying outside at the shop I can use. Once i mount the pillow blocks onto the saw table, I will see about a belt drive to knock the speed down by half. Then I'll build a small 1 gpm electo-hydraulic powerpack to power the table lift and feed motor.

When you mount the pillow blocks make sure they are adjustable in every direction.  They usually have slots to move them side to side and you can use shims to move them up and down and the locking collars usually allow for in and out adjustment.  Once you try to get a blade to run true you may need a lot of wiggle room.

[InterMechanico]

The pillow blocks I purchased have slotted mounting holes for adjustment. I'm going to tack everything together as square as possible (so far so good), then throw a blade onto the wheels and re-tack if necessary.

Now I worry about three phase power on rainy days.... I do live in Vancouver after all.

One thing at a time; table and wheels.

Thanks for the help, Guys!

[4x4American]

It should be interesting to see how the hydraulic drive will work for you?  How big of a reservoir do you plan to have?  Do you plan to use a cooler to get rid of the heat?

I would also recommend mounting your band wheels below the beam going across rather than on top of it that way you can make deeper cuts.

Yea, but he'll be able to lift the blade up off the bunks higher with them mounted above the beam.  I would think that having the blade go higher is better then deeper cuts!

[boscojmb]

what kind of reduction ratios are you guys using on straight belt drive units?

I'm running a 4.5" drive pulley to an 18.75" Driven pulley. This works out to 4.16:1
Engine speed is 3000 rpm and my band wheels are 30"
Band speed ends up being 5650 FPM.

[bandmiller2]

Inter, to raise and lower my sawhead I used A hydraulic cylinder and wire cables worked to perfection for at least 12 years. Commercial overhead door hardware is what to find. I bought a new good quality hydraulic cylinder with a clevis end and two thin cable wheels. The wire is reeved so one inch cyl. travel gives two inch head travel. One cable to the balance point each side of the head. Distractors will say the head will drop and it won't work, it is whats used on man hoists and arial ladders. Controled with a spool valve you drop the head to the mark. With this system weight on the sawhead is good for stability and it moves fast up so you can make cuts then up and back for the next cut. You may want to keep dry spray lube on your uprights to reduce bind and chatter. Build everything heavy and adjustable, you have the ability just take the time. Frank C.

[DMcCoy]

I use string to align my wheels before a band ever goes on.  Stretch a string tight across both wheels as close to the middle as you can.  Use washers to off set the string at the outside edges of each wheel, so the middle is 'free' as doesn't touch the string.  Use a third washer to check and adjust.
I use a plumb bob to check the vertical, same thing, offset with a washer so the bottom is free.  I have never had a tracking problem.  I would not start a band without checking with string. 
Use the same method for aligning your drive pulleys.

[BCsaw]

This may be premature but, when you go to build your track and frame assembly, ensure that you plan the height of your bunks correctly to be able to saw down to a small enough dimension..i.e. 1"

It is a very easy thing to forget. A lot of builds end up with spacers added to the bunks to bring the height up to be able to saw small enough. A bunk that is installed into a ladder type frame even with the side rails will usually leave you without enough movement down.

Once you have your carriage setup, plan how low the saw head will travel down and see where the blade will be. Plan the bunk height accordingly. My bunks used brackets that allowed the top of the bunks to be above the top of the side rails, allowing me to easily cut down to ¾".

Good luck with the build. ;D

[gww]

To BC's point of cutting small at the end.  I got that pretty close on mine but then messed it up with the doggs being not low enough of a profile.
gww

[InterMechanico]

When you mount the pillow blocks make sure they are adjustable in every direction.  They usually have slots to move them side to side and you can use shims to move them up and down and the locking collars usually allow for in and out adjustment.  Once you try to get a blade to run true you may need a lot of wiggle room.

Pillow blocks have been mounted, and adjustment is possible . Thank you!

[InterMechanico]

It should be interesting to see how the hydraulic drive will work for you?  How big of a reservoir do you plan to have?  Do you plan to use a cooler to get rid of the heat?

I would also recommend mounting your band wheels below the beam going across rather than on top of it that way you can make deeper cuts.

Yea, but he'll be able to lift the blade up off the bunks higher with them mounted above the beam.  I would think that having the blade go higher is better then deeper cuts!

I ended up mounting the blocks underneath the saw frame. Basic estimation of the cut capacity is 48" wide @ 3" thick, and 18" from the blade to the underside of the frame. Maximum height of the blade from the deck/floor is 56 inches or so.

[InterMechanico]

what kind of reduction ratios are you guys using on straight belt drive units?

I'm running a 4.5" drive pulley to an 18.75" Driven pulley. This works out to 4.16:1
Engine speed is 3000 rpm and my band wheels are 30"
Band speed ends up being 5650 FPM.

Thank you. I've limited my driven sheave size to 10 inches or so to get the shaft as close to the edge of the frame as possible. I will probably use 3 belt sheaves to suit the smaller diameter of my sheaves.

[InterMechanico]

Inter, to raise and lower my sawhead I used A hydraulic cylinder and wire cables worked to perfection for at least 12 years. Commercial overhead door hardware is what to find. I bought a new good quality hydraulic cylinder with a clevis end and two thin cable wheels. The wire is reeved so one inch cyl. travel gives two inch head travel. One cable to the balance point each side of the head. Distractors will say the head will drop and it won't work, it is whats used on man hoists and arial ladders. Controled with a spool valve you drop the head to the mark. With this system weight on the sawhead is good for stability and it moves fast up so you can make cuts then up and back for the next cut. You may want to keep dry spray lube on your uprights to reduce bind and chatter. Build everything heavy and adjustable, you have the ability just take the time. Frank C.

Thank you for the input. Using a system of cables, pulleys and a hydraulic cylinder is definitely an option. I may use roller chain and sprockets at all four corners of the frame to facilitate exact adjustment at each corner, with the chain powering the frame up and down. This system would be best in terms of function, but requires at least 14 sprockets, a 72" cross shaft, 23 miles of single roller chain, 8 threaded clevis adjusters, etc....

I'll decide in the near future...

[InterMechanico]

I use string to align my wheels before a band ever goes on.  Stretch a string tight across both wheels as close to the middle as you can.  Use washers to off set the string at the outside edges of each wheel, so the middle is 'free' as doesn't touch the string.  Use a third washer to check and adjust.
I use a plumb bob to check the vertical, same thing, offset with a washer so the bottom is free.  I have never had a tracking problem.  I would not start a band without checking with string. 
Use the same method for aligning your drive pulleys.

Thank you, DMcCoy. I will use a string and plumb bob to align the wheels. Very good idea. I was only going to spin the band by hand once I had the wheels very close. Certainly wasn't considering power up the saw without full and complete alignment  ;D .  I will probably make a few blank bands using steel box strapping to get it close once I'm at that point.