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General Forestry => Sawmills and Milling => Topic started by: quadracutter222 on January 28, 2019, 09:45:18 AM

Title: Still not cutting SQUARE!?!?!
Post by: quadracutter222 on January 28, 2019, 09:45:18 AM
Morning, well here anyways.

Thought I would outline my methodology to see if there are any gaps that shine through.  A bit reference, the mill is a WoodCraft, four post, 8 jacks, cutting with brand new blades in 2g douglas fir.  I have adjusted and taken the slack out of the idle side wheel and have the blade tracking well.  The blade guides are pads that apply down pressure only and have been adjusted to 1/8" deflection.  Both the clamp and offside supports have been squared 90 to the bed.

I have re-leveled and realigned twice, and am still cutting out of square.  Here is my leveling/aligning sequence:
- drop front and back jacks, level mill front to back
- drop 4 middle jacks, level entire mill side to side at each jack interval
- run a string from end to end on the frame rails that are perpendicular to the long rails.  Put a 3/4" block under the string at both ends, and make sure all the gaps between the short rails and the string are 3/4"
- back blade guides off
- tension blade to 2500 psi
- set mill scale to 6 inches
- measure up from the left and right side of each bunk to blade, adjust to 6" if needed
- tension blade with 1/8th" deflection, movable guide in the middle of the blade
- re-check each bunk is 6" on either side inside the tensioned portion
- load and start cutting

The finish and flatness have been awesome, but it cuts a parallelogram, with a consistent 1/8th out on all faces.

I am thinking either something is happening during the cut, or indeed the bunks are still not square to the supports.  I have been working on a cant going round and round, but would a fresh log be better?  Make face cut, flip 180, cut again?

Cheers and happy Monday :-[ 
Title: Re: Still not cutting SQUARE!?!?!
Post by: Tin Horse on January 28, 2019, 10:46:52 AM
Sounds like your putting lots of effort to the problem which is good. I also tried the string line. To slow and can't re-check periodically. I find it fast to have a laser level or transit set up. Guaranteed accurate. Even a cant or heavy log can move the base support. Best of all you can double check during the work. Also could there be any movement in your back supports when clamping? If everything is square and supported it should good. 
Title: Re: Still not cutting SQUARE!?!?!
Post by: charles mann on January 28, 2019, 12:04:43 PM
Sounds like your putting lots of effort to the problem which is good. I also tried the string line. To slow and can't re-check periodically. I find it fast to have a laser level or transit set up. Guaranteed accurate. Even a cant or heavy log can move the base support. Best of all you can double check during the work. Also could there be any movement in your back supports when clamping? If everything is square and supported it should good.
@Tin Horse (http://forestryforum.com/board/index.php?action=profile;u=32199) 
what laser level are you using? i found out a string is way more accurate than my bosch grl300hvck level, which is within 1/4" per 100'. i thought it was to within 1/6", but after some research online and hands on measurements, i found out otherwise, by checking it against a string on my frame rebuild. i was shooting about 30' away from the closest end to the laser head and 50'. 
i dont want to buy another laser, but if it there is a tighter tolerance laser for around the same $$ as my bosch, ill sell and buy the other brand. 
Title: Re: Still not cutting SQUARE!?!?!
Post by: Tin Horse on January 28, 2019, 01:35:38 PM
Sounds like your putting lots of effort to the problem which is good. I also tried the string line. To slow and can't re-check periodically. I find it fast to have a laser level or transit set up. Guaranteed accurate. Even a cant or heavy log can move the base support. Best of all you can double check during the work. Also could there be any movement in your back supports when clamping? If everything is square and supported it should good.
@Tin Horse (http://forestryforum.com/board/index.php?action=profile;u=32199)
what laser level are you using? i found out a string is way more accurate than my bosch grl300hvck level, which is within 1/4" per 100'. i thought it was to within 1/6", but after some research online and hands on measurements, i found out otherwise, by checking it against a string on my frame rebuild. i was shooting about 30' away from the closest end to the laser head and 50'.
i dont want to buy another laser, but if it there is a tighter tolerance laser for around the same $$ as my bosch, ill sell and buy the other brand.
Hi Charles. I can understand your need for accuracy on a build. My Enercraft is older but heavily built; however as stated by others there is some twist/flex in the frame. On my mill this showed up in a bad way. On the 4 post system mines gotta be right on. my engine is a Kubota 30 HP. The lift system is 3 chains, 2 front and 1 at the back. Would raise up OK but not down. It would jitter then 1 chain would skip a cog on its sprocket. Not good. Then it would re-set again when raised.
I thought I could set up with level and string line but it often just didn't work. I started using an older Dewalt laser (DW073KD) that worked but not well in outside daylight. Then bought a Bosch GOL 26x automatic. Its worked very well since and no problems. Not sure about your level but mine gives instructions on calibration and verifying its accuracy. Mine is also rated at 1/16" at 100'. Distance shooting about 20' to 50'. Hope this helps
Title: Re: Still not cutting SQUARE!?!?!
Post by: redbeard on January 28, 2019, 02:03:21 PM
Check face for level on second cut using a good torpedo level, it will determine if squaring arms are culprit.
Once you get the 90į right on first too cuts of log your golden on the rest.
Title: Re: Still not cutting SQUARE!?!?!
Post by: charles mann on January 28, 2019, 02:37:07 PM
Sounds like your putting lots of effort to the problem which is good. I also tried the string line. To slow and can't re-check periodically. I find it fast to have a laser level or transit set up. Guaranteed accurate. Even a cant or heavy log can move the base support. Best of all you can double check during the work. Also could there be any movement in your back supports when clamping? If everything is square and supported it should good.
@Tin Horse (http://forestryforum.com/board/index.php?action=profile;u=32199)
what laser level are you using? i found out a string is way more accurate than my bosch grl300hvck level, which is within 1/4" per 100'. i thought it was to within 1/6", but after some research online and hands on measurements, i found out otherwise, by checking it against a string on my frame rebuild. i was shooting about 30' away from the closest end to the laser head and 50'.
i dont want to buy another laser, but if it there is a tighter tolerance laser for around the same $$ as my bosch, ill sell and buy the other brand.
Hi Charles. I can understand your need for accuracy on a build. My Enercraft is older but heavily built; however as stated by others there is some twist/flex in the frame. On my mill this showed up in a bad way. On the 4 post system mines gotta be right on. my engine is a Kubota 30 HP. The lift system is 3 chains, 2 front and 1 at the back. Would raise up OK but not down. It would jitter then 1 chain would skip a cog on its sprocket. Not good. Then it would re-set again when raised.
I thought I could set up with level and string line but it often just didn't work. I started using an older Dewalt laser (DW073KD) that worked but not well in outside daylight. Then bought a Bosch GOL 26x automatic. Its worked very well since and no problems. Not sure about your level but mine gives instructions on calibration and verifying its accuracy. Mine is also rated at 1/16" at 100'. Distance shooting about 20' to 50'. Hope this helps
yes sir it does. i bought my sec hand, and there were no instructions for it, but i will download them when i locate them. IF its out of cal, i will cal it and check it again. i just finished watching a vid with a couple that moved to idaho to start an offgrid life, and they had the same level as i do and actually said the same thing about calibration and evidently, is good for 1/16" at 1000' ft. i will check cal when i get finished with my work hitch. thank you for your insight. 
 
Title: Re: Still not cutting SQUARE!?!?!
Post by: ladylake on January 28, 2019, 03:54:36 PM
 Really no need for anything except a square

Take a slab and 1 board off the opening face

Turn 180 and do the same
Turn 180 again and make sure the blade is level with the top of the cant, if not you need to adjust so it is,  Make sure the cant is laying on the bunk good from 1 end to the other with no chips or debris under it.  Then turn 90 and clamp tight against the log stops, check with the square, if not square adjust the log stops so it is.  Steve
Title: Re: Still not cutting SQUARE!?!?!
Post by: YellowHammer on January 28, 2019, 06:59:17 PM
I would add a couple steps when you take off the one board off as Ladylake describes, measure it for thickness accuracy.

Then when you rotate 180 put a big straight edge across the top of the cant from one end to the other, perpendicular to the cant, but parrallel to the bed rails and sight or measure down from each end of the straight edge down to the to the bed, moving the straight edge down several positions along the cant.  Just like using a blade alignment tool.

Then flip 90 and continue as LL says.  Also make note that the backstops sometimes flex under pressure so watch for that when you tighten the clamp.  

If you are sawing rotating 90 when milling a cant will really show if there is any out of square.  
Title: Re: Still not cutting SQUARE!?!?!
Post by: OffGrid973 on January 28, 2019, 07:41:18 PM
 
(http://forestryforum.com/gallery/albums/userpics/33352/A062C4B2-7CB6-4256-9745-5815C0BE722F.jpeg?easyrotate_cache=1548546565)
 
(http://forestryforum.com/gallery/albums/userpics/33352/0F236D11-E3AC-45E6-9EF3-04E9E3726FB8.jpeg?easyrotate_cache=1548546562)
 As mentioned do a cut ensuring the ends are supported and make a nice slow cut.  Flip 180 degrees ensuring the rails are clean where the fresh cut will sit. Put a level on after your second cut and use a fresh blade to start, at this point you will know of anything is off.

If successful get a simple square, i use 6Ē all metal and place on your horizontal rail (short ones) and flip the cant 90 up on its side.   Make sure you have a pretty decent size piece so wood stress and deflection donít cause it to dance but rather sit straight regardless of what horizontal you test for square.

If this passed flip 180 and cut the other side.  Make sure to NOT overclamp, I used to do that a lot and it would lift the log out of square.  Send some pics of each step and the Guys and Gals will find whatever else may havenít been mentioned in the thread.


Title: Re: Still not cutting SQUARE!?!?!
Post by: esteadle on January 28, 2019, 07:49:33 PM
I agree with Flipping 180 and checking. 
Flipping 180 is the way to get square lumber ( |_| )
Flipping 90, 90, 90 with slanted bunks or clamps nets a Rhomboid (\_\ or /_/). 
If blade height changes over the length of the cut, a trapezoid results ( /_\ ) 
If you are sure the bunks are level over the length, and do NOT change, then it must be something else. 

The next thing to check is whether the blade height is changing over the length of the cut. How is the blade supported? Chains? Posts? Hydraulics? Think about how they could change over the length of the cut. For example, if the head is hydraulic supported, perhaps, it is leaky hydraulics letting the head drop over the length of the cut? 










Title: Re: Still not cutting SQUARE!?!?!
Post by: esteadle on January 28, 2019, 07:51:20 PM
Another question is what kind of wood are you cutting, and is it moving during your cutting? Thats a whole new can of worms.... 
Title: Re: Still not cutting SQUARE!?!?!
Post by: quadracutter222 on January 29, 2019, 01:07:26 AM
Thanks ladylake. So if after the 180 flip and second cut and the blade is not square to the second face, what gets adjusted? The guides for the blade or all the bunks?

The wood is 2g Douglas fir.

I will take pics for sure. Tonight was checking level and re squaring bunks to blade. Next is setting deflection and checking support square. Iím getting some western hemlock and balsam fir this week as to not use my Doug fir for practice.

Checking the vertical face for square to bunk makes so much sense.  Thanks all for that suggestion.

I appreciate your help and time! The old timer we bought the mill from passed a month after we bought it and he was meant to be the mentour so you guys are filling in some!!!

Keep you posted :)
Title: Re: Still not cutting SQUARE!?!?!
Post by: ladylake on January 29, 2019, 04:42:16 AM
 
 You could adjust the blade with a little more down pressure on one side or the other but I would only do that with roller guides and not a real big adjustment.  Most mills are adjustable to raise the head up or down on each side , that would be the best way even if you might have too add a washer to the head mounting bolts.. Mine uses acme threads so I just unhook the chain between them and turn one side to get the blade level with the bunks. If your adjust the blade to the bunks do it with no down pressure on the blade, add that later.   

 (So if after the 180 flip and second cut and the blade is not square to the second face, what gets adjusted? The guides for the blade or all the bunks?)  Steve
Title: Re: Still not cutting SQUARE!?!?!
Post by: quadracutter222 on January 29, 2019, 10:24:54 AM
I canít understand how though the blade would not cut parallel to the bunks if all 8 have been adjusted to parrel to the blade. Testing will tell
Title: Re: Still not cutting SQUARE!?!?!
Post by: ladylake on January 29, 2019, 11:21:21 AM
 
 The reason to turn over 180 is to make sure the cant is the same thickness on both side, if it is the  stops need adjusting to make square lumber.   Steve
Title: Re: Still not cutting SQUARE!?!?!
Post by: quadracutter222 on January 31, 2019, 07:26:06 PM
I have a feeling that this may be part of the problem...
(http://forestryforum.com/gallery/albums/userpics/51095/unnamed~0.jpg)

These will be dressed square and Cooks rollers will be upgraded to in the next few weeks when they arrive.




Title: Re: Still not cutting SQUARE!?!?!
Post by: dgdrls on January 31, 2019, 08:47:10 PM
What am I looking at?

D
Title: Re: Still not cutting SQUARE!?!?!
Post by: quadracutter222 on January 31, 2019, 08:51:33 PM
What am I looking at?

D
That is the underside of the drive side guide block.  Showing how much out of square it is.
Title: Re: Still not cutting SQUARE!?!?!
Post by: dgdrls on January 31, 2019, 09:08:35 PM
Ah!

I think some rollers will be a big help as well

D
Title: Re: Still not cutting SQUARE!?!?!
Post by: redbeard on January 31, 2019, 09:15:22 PM
 
(http://forestryforum.com/gallery/albums/userpics/22539/rps20190131_180139_696.jpg?easyrotate_cache=1548986945)
  Do your guides look similar too this style ? These are the shoe types with a bearing,  too stop the back of blade.  Using this type there is no deflection the shoes just help stabilize the blade futtering. Adjust them when blade is tensioned with a 1/8" clearance between shoe and blade. 
Title: Re: Still not cutting SQUARE!?!?!
Post by: quadracutter222 on January 31, 2019, 10:40:27 PM
These are the guides, to pad only.

(http://forestryforum.com/gallery/albums/userpics/51095/unnamed_28129.jpg?easyrotate_cache=1548979426)