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Questions about square rule layout.

Started by trouts2, August 16, 2018, 09:27:27 AM

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trouts2

   I've been wrestling with the square rule for quite some time and have a foggy understanding of it.  Since my understanding is incomplete I'd like to make some comments about it from my own understanding and from write-ups I've read from Sobon's book, the Timber Framing section of TF and the TF Guild.  I would appreciate any help or comments on my understanding, thoughts and questions.  
 Some background.  I'm a computer engineer that does wood working so have tools but never worked with TF beams.  I bought some chainsaws and a Timber Tuff Beam Cutter and over the last two summers squared trunks into beams I cut from clearing my lot.  The squared beams are 5 3/8's square 6 to 18 feet long.  There is great variation in how square the beams are for a number of reasons.  Over time the cutting got better.  I've got about 80 beams of varying length and squareness.  
 Because of the crop of beams I have I think I need to work with the layout described by Sobon in his section, "Layout on Hand-Hewn Timbers" (p77) of "Build a Classsic Timber Frame House".   So I'll start my questions here.

[Question 1]  In the layout for good beams (Sobon p74) with minor variation he says 8 x 8's will be off so "frame" them to 7 ½ x 7 ½.  What exactly does that mean (assuming start is from an edge)?  If you layout joints someplace on 7 ½ there is extra on the side.  What happens to fits with that extra?  If you mate a mortise in a corner beam to a top plate or tie beam mid way up the post there will be extra that has to be dealt with.  I assume you would put the edges you are measuring the 7 ½ from on the two outside edges of a corner post.   Is this were housings come in?  That the top plate or tie beam would be fitted to a 7 ½ ideal beam and to get to that surface you have to cut into it making a housing.  Is that what happens?  I get the impression that some layout methods have housings and some do not due to the layout method.  Is that correct?

[Q 2] Just for clarity (hopefully) I'll separate Square Rule (SR) in general and Square Rule for Hand – Hewn beams (SRHH).  With SRHH you level and plumb, snap lines on the best face and use a framing square to layout mortises and tenons.  Those are offset from center which seems weird to me but done I gather for convenience as the line is easy to snap and layout on that line quick as the framing square is there and the mortise layout quick.  For SR it seems you can layout anywhere on the 7 ½ surface so you could layout offset or off a line in the center of 7 ½.  How are things generally done with SR?  Do you center mortises and tenons or offset them?

[Q3] The bigger question is what differences are there in SR versus SSHH?  I have not been able to sort that out.  Can both layout methods be mixed or are they really the same things so does not matter?  With SS lines to not get snapped but both having ideal internal logs and both working off a best edge seem to make them the same thing. ??

[Q 4]  When you have a lot of beams that could be done with SR I think you would select one size ideal beam size for the batch.  So just say your batch has worse case 7 ¼ for the ideal you would layout all logs to the 7 ¼ ideal beam.  Is that right?  

[Q 5]  For SRHH.  You get a level line then do a plumb line off that with the framing square.  The square tongue against the beam side should be at the shallowest spot on the beam.   You snap your layout line but the side opposite your first plumb will vary in length from beam to beam.  Do you just save those with great variation for places were the extra will not matter?  If you had to cut a second joint on that face you would select a better beam?

[Q 6]  There is a "Tools for Timber Framing List" by Jim Roger that has a lot about SR (which is excellent).  Again the post talks about the ideal beam inside a beam so other than the SSHH layout with level and plums measurements could apply to both SR and SRHH.  
 He lays out a tenon 1 ½ inches from the best edge.  That ballparks to about were you end up with SSHH giving an offset tenon i.e. not centered.  Why choose 1 ½ versus centered?   Again this ends up like SSHH except you start with a square beam so don't have to do the level and pumb.  But aside from the rest seems like SSHH.  Is that correct?

[ Are these comments right?]  The biggest thing in all my reading about the square rule was in this series of posts about Tools at post Reply #3.   For me at least there is great confusion on using the ideal edge versus the actual outer edge for both SR and SRHH.  Quoting the post, "Once we have our timber faces selected and out inner timber is slid over to create a reference face and reference edge we label our face and edge so we can see here it is at any time".  In other discussions the reference edge just happens so a "how do you get there from here" type thing.  They just start talking about taking measurements from the outside reference edge and you don't know how they got from the ideal edge to the outside edge.  For me that was a huge confusion.  In actuality for this to happen, you have to have a great outside edge to begin with.  If you have that the rest not so important as you have two sides at 90 and an edge that is a straight line (hopefully), otherwise you would have to go to SRHH layout.  

 Again concerning housings.  With SRHH tenons cheeks will end up flush to mortise edges but the amount of housing could be anything from a quarter inch to inch or even be lopsided from edge to edge with one side of a housing be ¼ and the other ¾.  

[Q 7]  In that same thread at Reply #8 a tenon is being laid out at 4 ½ inches from 5 "to comply with out frame rule."  That frame rule is that all timbers a sized down to the next one half inch in size, at the joint location."   It is not stated what dimension size beams are being used.  Is the assumption that whatever is being built is done with 5 x 5 beams, they are not perfect so they are being framed to ½ inch less?   If this is correct then the tenon length is cut shorter to match the beam it is going into which is an ideal beam of 4 ½ inches.  Is that correct?  If so then I think there will be housing of ½ inch.

A bunch of other stuff is not clear but this is long enough.  Any help would be appreciated.

Ljohnsaw

 :P
Wow, a lot of questions.  I'm curious about a few as well.  Jim and others will be along shortly to answer. 

But, to help them, can you modify your post? (hit the Modify button upper right on  your post).  Put a number by each question, maybe like this: [1] so it stands out and respondents can just reference them without having to quote them.
John Sawicky

Just North-East of Sacramento...

SkyTrak 9038, Ford 545D FEL, Davis Little Monster backhoe, Case 16+4 Trencher, Home Built 42" capacity/36" cut Bandmill up to 54' long - using it all to build a timber frame cabin.

tburch

For the SR method, you visualize the "perfect timber within" your actual timber.  You elude to this in your questions.  If you have 80 beams, there will be variation in the actual dimensions.  However, each one of them is a perfect timber, of some size, within the actual imperfect timber.  That might be a 7.5" x 7.5" inside an ~8" X ~8" timber.  Or a 4.5" x 4.5" inside a 5+ x 5+ timber.   

You have to choose 2 adjacent reference faces using the SR method.  They should be square to each other and the arris should be straight.  It is from these two reference faces that all measurements are taken and layout is made.    You "pretend" all your timbers are 7.5 x 7.5.   

Let's say you need to cut a mortise on a post and a tenon on a beam.  One reference face of the post will be an exterior face of the building.  This is because you want your siding to all start from the same plane.  If this is a corner post, the two reference faces will be the outside corner faces of the post.   If this is an interior post, one reference face will face north and one will be east (or whatever directions you choose for the whole project).   

One reference face for a beam will be the top face.  If this is an exterior wall beam, the other reference face will face the exterior.  Otherwise, it will face north.  

When you cut the tenon for the beam, you cut it 1.5" in from the outside face.  Similarly, for the mortise, you cut it 1.5" in from the reference face of the post.  Mortises are always cut parallel with the grain.   You cut both the mortise and the tenon 1.5" wide.  So far, we're at 3".  The other 4.5" or 5" or 5.25" worth of material left doesn't matter.  It faces down, if a beam, or it faces towards the inside of the building, or it's parallel with a wall - it doesn't matter.  

When laying our your timbers, you measure post and beam lengths from the shoulders of tenons (or dovetails, or whatever joint you are using).   

If your perfect timber for the post is 7.5 x 7.5, then you consider that your timber is only 7.5" wide, and since you have a post on either side of your building, then that's 15" of your building width.   If your building width is 12', then your beam length, shoulder-to-shoulder is  12' minus 15", or 10' 9", plus the length of your tenons.  If your tenons will be 4" long, that 10'9" + 8" for your beam. 

When cutting a mortise for your perfect 7.5 x 7.5 post, typically you would house the mortise, and cut out that extra .5" of the face of the timber leading into the mortise.  Sometimes you cut a housing for load bearing purposes.  If you needed a 1" housing for a tenon/beam, in this same scenario, you could cut a housing 1.5" deep.   1" for the structural load bearing part, and the 1/2" to create your perfect timber at that joint.   

Taking a TFing class cleared all this up for me.     I've no experience with the SRHH method.    
Peterson 10" WPF with slabber. Cooks AC36 Diesel.
'94 Ford 4830 Diesel 2WD & FEL.  Norse 450 skid winch.  Logrite fetching arch.  Fransgard Forestry Grapple.

tburch

To answer Q1 specifically... 

[Question 1]  In the layout for good beams (Sobon p74) with minor variation he says 8 x 8's will be off so "frame" them to 7 ½ x 7 ½.  What exactly does that mean (assuming start is from an edge)?  

You pick two adjacent faces to measure from.  These are your "reference faces".   All measurements are taken from these faces.   It means you visualize a 7.5 x 7.5 "perfect timber" that exists inside your imperfect 8X8.    You pretend your beams is 7.5 x 7.5 when doing the layout at the joint.  At a joint, you "get rid of" the extra material beyond 7.5".    

Q1B: If you layout joints someplace on 7 ½ there is extra on the side.  What happens to fits with that extra?  

You get rid of it if it is not on a reference face.   There is no extra material on a reference face.  

Q1C: If you mate a mortise in a corner beam [you said "beam", you meant "post"] to a top plate or tie beam mid way up the post there will be extra that has to be dealt with.  

Probably. 

Q1D: I assume you would put the edges you are measuring the 7 ½ from on the two outside edges of a corner post.   

Yes, you put the reference arris in the actual corner, and a reference face will be on each wall.  

Q1E: Is this were housings come in?  That the top plate or tie beam would be fitted to a 7 ½ ideal beam and to get to that surface you have to cut into it making a housing.  Is that what happens?  

Yes.  You cut away the material to make your joint area a perfect timber. 

Q1F: I get the impression that some layout methods have housings and some do not due to the layout method.  Is that correct?

The SR method will probably have housings.  Some joinery, due to loads, etc., will require housings, regardless of the method.   The scribe method (I don't think) has housings. Sometimes you will have a housing for load bearing purposes AND to accommodate the SR method.  
Peterson 10" WPF with slabber. Cooks AC36 Diesel.
'94 Ford 4830 Diesel 2WD & FEL.  Norse 450 skid winch.  Logrite fetching arch.  Fransgard Forestry Grapple.

trouts2

TBurch,
 On the last part of your first post about the drawing calling for a 1 inch housing.   Just thinking, maybe the 1 inch could be looked at in a couple of ways.  The builder could say he has .5 extra and counts that in the housing calc.  He then goes in .5 extra and considers he satisfies the drawing.   The arcitech does not know about the extra half inch and called 1 inch.  I guess it could be said that to fulfill the spec the builder goes into the timber 1 inch and for a 7.5 beam that lands the tenon cheek at 6.5 so 1.5 physical inches in.  I had to sketch it to think about it.  In doing so I realized that going in 1.5 puts the tenon past the 4 inch mortise in the post.  The tenon has to be cut or the mortise lengthened.  I guess since there is a substantial bearing area that the tenon would be shortened rather than lengthen the mortise.  I guess that is another common thing when housings are called out.  You probably get a housing in SR just because you are working with a reduced size ideal log but the tenon and mortise length and depth match.  When a housing is spec'ed you have shorten the mortise.   I guess they are laid out together so a mismatch is less likely.

 The post is very clear, informative and excellent feedback.    It was great to read, "the other 4.5" or 5" or 5.25" worth of material left doesn't matter."  I was never quite sure so nice to read that.  

 This part is nice also, "If your perfect timber for the post is 7.5 x 7.5, then you consider that your timber is only 7.5" wide, and since you have a post on either side of your building, then that's 15" of your building width.   If your building width is 12', then your beam length, shoulder-to-shoulder is  12' minus 15", or 10' 9", plus the length of your tenons.  If your tenons will be 4" long, that 10'9" + 8" for your beam. "  It makes SR more sensible to see the fingers and toes matchup.  

 I've read the post a number of times and will read it again many times so it will hopefully sink in permanently.  Thank you for taking the time to give clear answers.   Still digesting your second response.

trouts2


Arris caused some confusion for me also.  The first time I came across arris was in a drawing that showed SSHH being laid out.  The level and plumb lines met and that corner was labeled arris.  I thought that the word was specific to a corner that was internal to a second outer log so a special name.  When I later saw it on a reference face I was surprised and confused.  I later found out that arris was not so specific a term as I thought.  It's just and edge formed by two flat surfaces so could be a label for a reference edge or internal edge from level and plumb lines.
"Yes, you put the reference arris in the actual corner, and a reference face will be on each wall."  It seems like a simple thing but for me the above clears up a lot, the moving of the "reference arris" to the "actual corner".    Lots of explanations skip over this so confusing. 
  I'm feeling more comfortable with "extra", "housings" and SR in general.   Thank you for the Part Two point by point clarifications.  They are very much appreciated.

tburch

One point about your comment relating to this: 

"The builder could say he has .5 extra and counts that in the housing calc.  He then goes in .5 extra and considers he satisfies the drawing. "

Yes, the builder could do this.  Problems could arise with this, however, when builder's helper or the builder's crew comes in behind the builder and doesn't know the builder deviated from the method for that joint.  When the guy who drills the holes for the pegs, measuring from the reference face, drills them .5" off.  When the beams are placed in the wrong positions during raising, and when you hang the last rafter, you realize you have a twisted wall face, and your roof is wonkered now too.   

When he deviates from the SR (emphasis on the "Rule"), method, the builder just morphed from the SR method to frankenscribe.  That particular beam length now does not match the other 3 beams that are being cut, and the builder has more unique math to do to ensure everything ends up plumb and level.   

Now...  there might be a valid reason for the builder to alter that particular joint to be different from all the rest.   Maybe there is a wood defect, or he accidentally cut his last beam .5" too short.  But these could be justified as valid reasons.  Laziness isn't a valid reason. (IMHO!)   

I'm glad you found my explanations beneficial.   

I can read books all day long, but until I see it being done, it doesn't sink in as far as it needs to with me.   
Peterson 10" WPF with slabber. Cooks AC36 Diesel.
'94 Ford 4830 Diesel 2WD & FEL.  Norse 450 skid winch.  Logrite fetching arch.  Fransgard Forestry Grapple.

tburch

Also, your comment here causes me some anxiety:

"In doing so I realized that going in 1.5 puts the tenon past the 4 inch mortise in the post.  The tenon has to but cut or the mortise lengthened."

When you decide on your mortise depths and tenon lengths, you should stick with them.  

On your 8" post, you have a 7.5 perfect timber.  So for your mortise, you measure, from the reference face towards the opposite face 7.5".  You see that your have .5" of extra wood to remove.  Before you cut your housing to create the housing face, you have to drill your mortise.   You are drilling from a non-reference face that is ~8" from the reference face.  You don't drill 4" deep for the 4" deep mortise.   You drill 4.5" deep because of the extra .5" of meat you will remove from the post to create the perfect mortise housing.  

For the mortise of a joint where you have a 1" housing necessary, on a ~8" post, using a 7.5 perfect timber, you drill 5.5" deep for your 4" mortise, because you have to drill through the 1.5" of meat you will be removing after you drill.  
Peterson 10" WPF with slabber. Cooks AC36 Diesel.
'94 Ford 4830 Diesel 2WD & FEL.  Norse 450 skid winch.  Logrite fetching arch.  Fransgard Forestry Grapple.

trouts2

  The .5 and 1.5 inch was more me working through it for my own clarity versus saying which way was valid, better, best, short cut or other reasons.   I'm new to most phases of all of this from boning up on using chainsaws, felling trees, clearing a lot, efficient ways to move logs and beams around & etc.  An orderly process in laying out a crew would follow seems essential.  

 I've done all this alone so unaware of lots things other than what I have picked up so far mostly on the net.   The lot clearing and beam making ended about 10 days ago so I'm now focusing the building part.  
   Last week I cut my first joints making a horse from an old Jim Rogers post.   The pieces used were odd balls so every face was off and the two legs I used had live edge round corners on all 8 edges.   I laid it out off center lines and used a level  to line up the cuts.  It was an interesting exercise.   I'm not ready to head up a crew yet.

  I've been wanting to post some questions for a long time but I could not organize what confused me enough to write anything that made sense until now.   Your responses have given me more confidence that I'm on the right track and better able to go through various forums posts with more understanding.

 Thank you for taking the time to help out.

Jim_Rogers

First of all we need to clear up this 1 1/2" stuff.

Mortises and tenons should be 1/4 the thickness of the timber. Not actual thickness but nominal. So if your 8x8 timber is being laid out and cut then the tenon and mortise is 2" and usually laid out 2" off the reference face. Pegs for this joint are 1".

If the timber is 6x6 then 1/4 of it is 1 1/2"  and the offset is usually 1 1/2" and the peg is 3/4 of an inch.

These are standards. That's why a true framing square has a 2" body and a 1 1/2" tongue.

If your roughed out timber by chain saw mill or hand hewn are 7 1/2" or so I would call them an 8x8 and use the 2x2 sizing.

If your timbers are 5 1/2 x 5 1/2" I'd use the 1 1/2" size and offset rule.

So, now that this is clear, you hopefully will understand it.

Next most joints are cut into the timber on the opposite of the reference face or opposite the adjacent face.

If you haven't watched any of my videos on YouTube you should watch some about laying out reference faces and adjacent faces on your plans first which will help you to understand which faces the joints are cut into, which ones have housings and where the timbers are reduced to the "general frame rule" that the timber is 1/2" under size.

Establishing general rules for a frame helps to understand how each joint is laid out and cut.

Jim Rogers

Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

trouts2

  What you wrote is clear except for when I got to offset rule".  I had to google that.   I think that is referring to offsets for peg placement.   I'm familiar with that but not to the point that I have internalized all that I have come across.  If you had written "peg placement offset rules I would have immediately known and thought nothing about it. 

  Yes, I'm going with 5 3/8ths square beams and planned to use 1 ½ mortises and ¾ inch pegs.  Just picked up some dry rounds today of ash and maple which I cut and split into peg blanks this afternoon to shape on the shaving horse. 

    Lots to learn.  Thanks for the help.

Jim_Rogers

Offset mean the distance from the reference face or adjacent face that the tenon is offset. 2x2 means that the tenon and mortise are 2" thick and they are offset by 2".
In your case the tenon and mortise are offset by 1 1/2" and are 1 1/2" wide.

Why? so you can use your steel tools to verify the offset:



 
In the above picture the framing square is laying on the cheek of the tenon at the shoulder of the timber. The offset is 1 1/2". If it is correct the try-square will slide right over the framing square tongue. If the offset is not enough the try-square will hit the framing square. If it is too low the there will be a gap between the try-square and the framing square.

You establish the offset first when cutting a tenon. Then you make the tenon the correct width/thickness.

To check your tenon's thickness you use a caliper tool. Like this:



 

But before you do that you set your caliper tool with the correct distance between points with your framing square like this:



 

Why? Because you're going to use your framing square to check your mortise width. Like this:



 

You're using one tool to verify that both the tenon and the mortise are the same size so that hopefully the tenon will fit into the mortise.

In some of the above pictures the tenon and mortise were 2" but it is the same procedure if doing 1 1/2" tenons and mortises.

Jim Rogers
PS. this is why tenon and mortises are not centered on timbers.
If I have an 8x8 tie beam and I center the tenon, then 8" - 2" = 6", 6" / 2 = 3" on each side. I don't have a framing square with a 3" tongue or blade.
Keep it simple and follow the standards that have been used for hundreds of years and your frames will go together and everything will line up, if the joints are cut right.
Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

Jim_Rogers

In question one you asked: "What happens to fits with that extra?"

When a timber joins with another timber the mortise timber is cut to the inner timber mentioned before. This inner timber is 1/2" under the nominal size of the timber. For example in his book he's using 8x8s so the inner timber is a 7 1/2".
This means the mortise for the timber joining it is cut back to the inner timber. This creates the housing:


 
In the above picture the post has been reduced in width to 7 1/2" and the mortise is set 2x2. That is 2" off the reference face and then 2" thick.
The tenon has be reduced to 7 1/2" tall, on the bottom side of the timber. This "reduction" is carried back away from the tenon shoulder 1 1/2 or 2" and then it is finished off with a short 45° cut.
Here is a view of one in real life turned up so you can see the reduction:


 

The tenon timber is reduced on the opposite of a reference face or adjacent face. Not usually reduced on a reference face or adjacent face.
In review, the area where the timber is smaller at the mortise is called a housing. And the area where the timber is smaller at the end where the tenon is called a reduction.

Jim Rogers
Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

trouts2

   OK on "offset" being tenon offset.  The experienced people on the forum would probably have read that, understood it and moved on but for me references which require a some background are show stoppers when I go through posts. 

   With the help from tburch and yourself on my post a lot has straightened out for me.  I've gone through a few forum posts I've read a number of times in the past I was not able to understand but now can. 

    Last night and this morning I went back over a post from 2010 by mmhailey, "Question on Square Rule" I had struggled with.  He had a brace miscalculated by not fixing the leg of the hypotenuse at the right location on the corner post.  I now get what all the post drawings were showing and why, well 90-95% versus 10%.  You put in a number of very helpful drawings in his post. 

   I think I can now go back to Hodgson's, "Light and Heavy Timber Framing" and get more from his layout which I think is SSHH.  By the way, do you consider what I call SS (Square Rule) and SSHH (Square Rule for Hand-Hewing) (related to Sobon) to be any different if other than how the ideal beam is found once the arris and two working faces are established?  Do you or others have terms or names to separate out the two different layout methods?   To me they seem the same once the arris and faces are gotten by what ever method. 
   Hodgson sights "wind" with bats and framing squares.  Uses a brad awl to stick them in the beam end to line up one on the other end & etc. But all in all Hodgson seems to be SSHH except he gets the arris edge by a level and plumb line off that with a framing square tongue on the log side with blade on the level line.  There are other methods of establishing a level line to eventually come up with an arris edge and faces but it seems like they all arrive at the same place.  I have read people refer to I think SS level line or plumb line but once that is done I think they are laying out with SS.
 
    I've got curved calipers at home (Marlboro, MA) which I'll bring up here (Oquossoc, Me) on the next trip home.   I've got a few regular framing squares and a couple of shorties with 1 ½ inch blades and 1 inch tongues which will be good for my small beams (5 3/8.

   OK on the reasons for layout not being off a center line.  It's just a bit tough to used to.  One point I was unsure about was twist loading by having unbalanced beam weight on the tenon.  But I've never read about any restore work of a few hundred year old building having issues with twist from offset tenons. 

  Thank you for the help.

Jim_Rogers

You asked: "do you consider what I call SS (Square Rule) and SSHH (Square Rule for Hand-Hewing) (related to Sobon) to be any different if other than how the ideal beam is found once the arris and two working faces are established?"
and: No.

You asked: "Do you or others have terms or names to separate out the two different layout methods?"
and: Square rule layout is called square rule. There is snap line square rule for laying out timbers on non perfect timbers such as hand hewn. And then there is scribe rule which is where each timber is laid up and the locations of each joint is transferred from one timber to the other. Very time consuming but can be used to put curved timbers into any frame.

I have not read "Hodgson" so I can't comment on anything about his writings.

Jim Rogers
Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

Jim_Rogers

You wrote: "I was unsure about was twist loading by having unbalanced beam weight on the tenon."

In today's design work we usually understand the intended use of the frame/structure and the loads that will be placed on that frame. The timbers are calculated to be the correct size to support that load. And the joinery is reviewed by an experienced timber frame structural engineer to verify that the joint chosen by the designer can withstand the load, and not twist.

Historical designs were based on the framer's experience with that type of structure. And we have seen, sometimes, some beams that have twisted due to overloading by the farmer after his barn was build. Or caused by modifications of his frame years after it was erected. I personally have never seen a tenon fail from being twisted off the end of a timber.

Jim Rogers
Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

Ljohnsaw

And I think the twisting moment (if any) is accounted for with the housing you generally see supporting the bottom edge of the beam, full width.
John Sawicky

Just North-East of Sacramento...

SkyTrak 9038, Ford 545D FEL, Davis Little Monster backhoe, Case 16+4 Trencher, Home Built 42" capacity/36" cut Bandmill up to 54' long - using it all to build a timber frame cabin.

trouts2


   Got a notice of your last post just after I sent mine.  OK on all of it.  

   I now get it and the reasons for the various dimensions.  "What happens to the extra" was a problem for several months.   Like how can siding be fit when there is a bulge??   It is not an issue anymore and I'm happy as heck to be done with that problem.   I'll mention again one of the biggest light bulb moments was when I read your post where you mentioned sliding an ideal log over in a post to become references faces and arris edge.   That got me where I could even write up my post with the questions.

   Got it on the term "reduction".  I've come across that in the past and not known what it was referring to or why.  A bunch is different now.  I actually, at least think, I know a lot isolated parts from the past year of reading quite a bit but little of it was understood in context.  A great deal has changed in two days.

   Wrote the above and your next post came in which I'll comment on.

  The "No" on SS and SSHH being different is very good to hear as that is what it seems to me.  There seems to be several front ends to teasing out working edges with slight variation that all work.  One might be more efficient or cumbersome than another but work. They are not a big deal for me now.  
    In the past I was not sure when reading people mentioning aspects of laying out if they were part of one or another method I read, the same, different or whatever.   If someone now describes layout scribing lines with a compass and a stick of pepperoni I'll probably get it.

  The snap line square rule I've seen a number of  times in the past and foggy but that's not a problem anymore.  I'm ok with scribe rule.

   My crop of beams has a lot of issues and just how to deal with them was a problem because I did not understand enough about the total layout picture.  I now think I can deal with them fairly easily.  I think I have enough decent beams to use in places requiring them and work the scruff onto locations where crummy beams will work.  Complicated layouts would be difficult but for the simple structures I'm doing there won't be any complex layouts. 

   Ijohnsaw, I was thinking of something like a tie beam between posts with no housings or braces.    I was wondering after a few hundred years if some sag might happen as the structure loosens up.   There are usually braces and etc so all in all twist probably not a factor.  Jim has seen a lot of beams and never encountered an issue.  I've never read anything about beam weight alone causing twist.  Since all major schools and architects teach and call out offset beams it must not be an issue. 

Jim_Rogers

So, now what's your next question?

Sometimes, writing these things out help others later on when they read these threads and have the same or similar questions.

Terms and word meanings are a big part of it.
If you haven't read the glossary of timber framing terms you should.

Jim Rogers
Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

trouts2

>>”So, now what's your next question?”

   I’m sorry.  If you are looking for work you’ll have to go to unemployment.  I’m good.  You and tburch gave me some key information that unlocked a boatload of things for me.  The other issues were really variations or reformulations of the same things I asked about.  They have all evaporated and I’m tickled pink about that.  SS, SSHH and all the variations are no long fearsome opponents to wrestle with.  They’ll throw me to the mat now and then but they’ll never win a match from me again like they had been doing.  

  The hangup was guys like Sobon and others generally saying well if you don’t have good faces when you go over the beam then toss it and get another.   For me it seemed the purpose of the dealing with an ideal log was there were no good faces.  Then somehow he ends up with two ideal faces and a perfect arris he using a framing square on the crummy beam.  If you have two good faces to start with then you have something you can work with up front.  For me it was a “you can’t get there from here” thing.  

  Just thinking off the top, a better overall write-up might be something like this.  

  “Ok, there is a crummy beam here but if you have two good faces with a straight arris then there are no big issues.  You can work off those faces.  There is a bit of difficulty in working with them to locate joints but here is the way you do that”.    

   For me the difficulty of being focused by descriptions on the ideal log but getting descriptions of work from the actual log was a problem.   Along with that is the difficulty of believing that you can get “perfect” faces and arris from even a high end bandsaw mill.  I figured that “perfect” really meant perfect so must be referring to the ideal log but the descriptions talked about doing measurements on the crummy beam.  I could not see the connection.    That is why your mention of “slide the log over” was such a big deal for me.   I was able to ask some question which I thought might be understandable.  They were and you guys did a great job.  I’m off and running.

>>”Sometimes, writing these things out help others later on when they read these threads and have the same or similar questions.”
   Very helpful.   I’ve been through lots of old posts here, the guild and other forums along with endless hours of youtube videos.  (There’s no TV or radio here, only the net.)  This forum is loaded with great posts.  I wish I could go through all of them.

  Yes, I down loaded the glossary of terms months ago but it will take a while to absorb them.

  Today I built your 32 inch leg gusseted horse and cut parts for another to screw together tomorrow.
 
Thank you.

Ljohnsaw

Quote from: trouts2 on August 18, 2018, 07:40:16 PMToday I built your 32 inch leg gusseted horse and cut parts for another to screw together tomorrow.

GASP! :o NO, you must use pegs! (kidding) :D
John Sawicky

Just North-East of Sacramento...

SkyTrak 9038, Ford 545D FEL, Davis Little Monster backhoe, Case 16+4 Trencher, Home Built 42" capacity/36" cut Bandmill up to 54' long - using it all to build a timber frame cabin.

wodbutchr

Great discussion on this thread.

For me, timbers are often imperfect, not straight and out of square. I am really careful about sawmill calibration, but somehow at good times I end up with 1/8" out of square on an 8x8. It can go up to 3/8 on adjacent faces and then what do you do? It just takes a small piece of bark on the bed of the mill to be out of square. Also the log releases stress as it gets milled and starts to bow. You end up with uneven thickness.
Turning the timber over, I select the best plane as reference plane. Straight with a good edge meaning as little wane as possible, bow up. But the adjacent better face is not square to the reference face, say out of square by 3/8.

Would one snap a chalk line on the reference face to use as an arris, away from a curvy edge and reduce the adjacent face at a joint location?

What are you guys doing with severe imperfection?
LT40 manual, L190 NewHolland, Homemade Log Cart "LogMob"
Andre
Timber Frarmer

Jim_Rogers

When you crown a timber with a bow in it you have to consider the way it bows and its placement in the frame.

Of course we all know that horizontal timbers go in with the crown up. As the weight of the floor (and other things on the floor) will push it down. You wouldn't want to put it in crown down.

And the same goes with rafters, crown up, and roof load will/may push them down.

Now it comes to posts. What do we do with posts?

If your plan calls for a tie beam between two posts and the posts crown out the shoulder to shoulder distance is a given dimension on the plans. If you cut to that dimension you're may have gaps where the shoulders of the tie beam meet the housings in the posts.

Also, the siding is not going to be plumb. It's going to have a belly in it.

So, having said all that, the position we put a post with a bow in it is with the crown in. First of all the siding will span the gap and can be "shimmed" out in the middle where it is secured to the post.

The tie beam shoulder to shoulder dimension now "maybe" too long, but you can always trim off a little when you do your bent fit up test and find that the tie is truly too long.

Hopefully, you post doesn't bow in two directions but if it does then they both get turned to go towards the center of the building, if a corner post.

Any more that 3/8" should be considered extreme and you may want to think hard about using it some place else in the frame other than a post.

I hope that helps you some.

Jim Rogers
Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

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