Author Topic: How to mark out domino placement in this angled chair?  (Read 3083 times)

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Offline gearhound

  • Posts: 65
How to mark out domino placement in this angled chair?
« on: January 21, 2019, 11:22 AM »
I came across a YouTube woodworker's channel and really like this design of chair he made in one video:

I'm in the process of making something really similar and I've got all the parts of my plywood prototype made and just need to attach the legs to the seat, but not sure how to accurately cut the dominos in the legs and seat? I asked the guy who made the video and he got back to me, but I'm still struggling with how to accurately layout where to cut the mortises. At the 6:28min mark in his video he starts this process so you can clearly see what I'm talking about.

Does anyone have suggestions or videos I can watch to learn how to mark out the domino placement in joints like this?


Thanks! (btw, if you're into watching youtube woodworkers I've found this fellow to be really inspirational and love his general demeanor)

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Offline ChuckM

  • Posts: 1009
Re: How to mark out domino placement in this angled chair?
« Reply #1 on: January 21, 2019, 11:43 AM »
Like as shown in the image below. For some parts, consider cutting the mortises while the stock is still rectangular, then shaping it.

The joinery angles don't matter as long as your placement lines are straight across the members to be joined. Use double dominoes where needed.
« Last Edit: January 21, 2019, 11:50 AM by ChuckM »

Offline gearhound

  • Posts: 65
Re: How to mark out domino placement in this angled chair?
« Reply #2 on: January 21, 2019, 11:48 AM »
I've already got the splayed leg domino joint completed and glued up @ChuckM. I'm trying to figure out how to accurately mortise into the legs and attach them to the seat portion of the chair.

Do you have a link to where that photo is from though? Looks like it could be a fun read!

Offline ChuckM

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Re: How to mark out domino placement in this angled chair?
« Reply #3 on: January 21, 2019, 11:58 AM »
Ok for the seat (back, too?) portion. Do you know the technique of using the milled flats and scribed line on the baseplate to position the joiner against two intersecting lines? https://www.instagram.com/p/BS3s0jcjHSH/

You can layout your tenon placement lines on the legs and the seat, and mortise them as long as you have two intersecting lines. If the stock was mortised before shaping, the job would have been much easier.

I've PMed you the link to that project.

« Last Edit: January 21, 2019, 12:21 PM by ChuckM »

Offline gearhound

  • Posts: 65
Re: How to mark out domino placement in this angled chair?
« Reply #4 on: January 21, 2019, 12:24 PM »
Thanks for the link to Sedge's video...hadn't seen that one yet.

Here's where I'm currently at and am trying to figure how to scribe the lines necessary on both the legs and seat. Thinking I just need to measure each off the scribe about an inch or so? I'm definitely overthinking this, but glad I've got a plywood mockup and templates to play with before making this out of walnut


Offline ChuckM

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Re: How to mark out domino placement in this angled chair?
« Reply #5 on: January 21, 2019, 12:32 PM »
Heading out...will come back to give my opinion if you haven't got an answer by then.

Offline duburban

  • Posts: 1033
Re: How to mark out domino placement in this angled chair?
« Reply #6 on: January 21, 2019, 12:35 PM »
I'm wandering from your question but I'd consider using a different seat construction, something with some give. I did a version of Jory Brighams Hank chair and will change that in the next version, even with a thick cushion you max out onto the hard wood.

helper: i used a festool "circular saw" to do something simple and it made it really hard

me: exactly, it makes simple cuts complicated and complicated cuts simple

Offline gearhound

  • Posts: 65
Re: How to mark out domino placement in this angled chair?
« Reply #7 on: January 21, 2019, 12:58 PM »
That's a good point @duburban ! The YouTube'r I linked actually used to work for Jory, which I found pretty cool...been learning a lot watching these two guys videos the past year.

This is my 1st ever chair build and 1st time ever making templates for a project so I've got a lot to learn. On my next build I'm planning on making a similar walnut version of this chair my wife bought from Room & Board and incorporate this stretchy seat material they used.

Offline duburban

  • Posts: 1033
Re: How to mark out domino placement in this angled chair?
« Reply #8 on: January 21, 2019, 01:08 PM »
Yes, something just like that. I’ll post mine when I get to my data storage. I’d really push to get that done on this chair though, makes it that much more valuable to have around for the coming years
helper: i used a festool "circular saw" to do something simple and it made it really hard

me: exactly, it makes simple cuts complicated and complicated cuts simple

Offline Gregor

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Re: How to mark out domino placement in this angled chair?
« Reply #9 on: January 21, 2019, 02:18 PM »
Here's where I'm currently at and am trying to figure how to scribe the lines necessary on both the legs and seat. Thinking I just need to measure each off the scribe about an inch or so? I'm definitely overthinking this, but glad I've got a plywood mockup and templates to play with before making this out of walnut
You already have form of the respective other piece marked, so on both you have the identical area (just mirror'd).

I would use a precision compass to construct the positioning, using the diagonals from the corners of the area with their intersection as the center point for the compass. That way you could easily replicate the measurements onto the other pieces or a jig.

Offline gearhound

  • Posts: 65
Re: How to mark out domino placement in this angled chair?
« Reply #10 on: January 21, 2019, 02:46 PM »
Here's where I'm currently at and am trying to figure how to scribe the lines necessary on both the legs and seat. Thinking I just need to measure each off the scribe about an inch or so? I'm definitely overthinking this, but glad I've got a plywood mockup and templates to play with before making this out of walnut
You already have form of the respective other piece marked, so on both you have the identical area (just mirror'd).

I would use a precision compass to construct the positioning, using the diagonals from the corners of the area with their intersection as the center point for the compass. That way you could easily replicate the measurements onto the other pieces or a jig.

That's an interesting way to do it...I haven't used a compass since high school almost 20 years ago. What's the difference between a "precision" compass and one of the cheap metal ones I used in school? I assume accuracy, but would that matter if firmly held since I'm only making two or 3 marks for mortises?

Once I've marked the intersection, then I would set it at say 1 inch and reference off that/make marks and then draw a perpendicular line from there to the angled scribe lines? Have you seen any photos of this being done so I can get a better grasp of how it would work?
« Last Edit: January 21, 2019, 07:07 PM by gearhound »

Offline Gregor

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Re: How to mark out domino placement in this angled chair?
« Reply #11 on: January 21, 2019, 04:06 PM »
That's an interesting way to do it...I haven't used a compass since high school almost 20 years ago. What's the difference between a "precision" compass and one of the cheap metal ones I used in school?
I assume accuracy, but would that matter if firmly held since I'm only making two or 3 marks for mortises?
I guess the threaded bar between the legs that keep it at a setting makes it 'precision'.
No clue how well yours holds his setting, the precision ones arn't that expensive and have the upside that you can set them aside for a moment without having to worry...

Quote
Once I've marked the intersection, then I would set it at say 1 inch and reference off that/make marks and then draw a perpendicular line from their to the angled scribe lines? Have you seen any photos of this being done so I can get a better grasp of how it would work?
Basic concept to construct a geometry for where to put the dominos (numbers are order of drawing):

Should be no problem to reproduce that on both faces as long as you correctly marked the contact surface between the two.

Certainly you could also use the other direction (which in the example would be vertical green lines), just make sure to place the dominos in a manner that they intersect the ones in the joint of the leg as little as possible.
« Last Edit: January 21, 2019, 04:17 PM by Gregor »

Offline gearhound

  • Posts: 65
Re: How to mark out domino placement in this angled chair?
« Reply #12 on: January 21, 2019, 06:10 PM »
Thanks for taking the time to make that sketch @Gregor, really appreciate it! Seeing it drawn out makes a lot more sense. I'm going to pick up a compass tomorrow and see how it goes and will keep you posted!

Offline gearhound

  • Posts: 65
Re: How to mark out domino placement in this angled chair?
« Reply #13 on: January 22, 2019, 01:33 PM »
Picked up a compass and got the dominos in! Great tip @Gregor! I did a dry fit and the joint is incredibly tight....actually too tight and I needed a mallet to get it fully seated. Doing vertical plunges I think I'm getting just a tad of vibration slop, wondering if there's a good way to eliminate that? Maybe it's just user error trying to line up the plunge just right. I used Festool Sedge's tip of referencing off the lines and using that black faceplate connector along with scraps taped along the sides to aid in balancing the tool. 


Offline Gregor

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Re: How to mark out domino placement in this angled chair?
« Reply #14 on: January 22, 2019, 02:13 PM »
Vibration slop can be avoided by clamping the machine to the workpiece after aligning it or (easier to handle) you make yourself a jig (that you can clamp to the workpiece) that gives you a reference corner to push the machine into which keeps it from moving/vibrating.

To make dry fit easier you can either microwave/oven the dominos to dry them (so they get a bit thinner) or sand some down a bit (and reduce the fins on the sides a little) and give them a highly visible paintjob (so you don't accidently use them for a glueup).

Offline gearhound

  • Posts: 65
Re: How to mark out domino placement in this angled chair?
« Reply #15 on: January 22, 2019, 05:23 PM »
Vibration slop can be avoided by clamping the machine to the workpiece after aligning it or (easier to handle) you make yourself a jig (that you can clamp to the workpiece) that gives you a reference corner to push the machine into which keeps it from moving/vibrating.

To make dry fit easier you can either microwave/oven the dominos to dry them (so they get a bit thinner) or sand some down a bit (and reduce the fins on the sides a little) and give them a highly visible paintjob (so you don't accidently use them for a glueup).

Thanks, yeah I need to come up with a good jig to limit that slop. Have you seen any good examples of one of these jigs in action? Definitely going to be sanding the dominos for dry-fit on the next leg.

Marking out these scribe lines has proven to be the most tedious part of this build and has me wondering if people ever incorporate where to place the dominos into their templates? I'm planning on making at least two of these chairs out of hardwood once I get this plywood mockup finished and see if I like the angles and overall form. If I could somehow speed up this step for future builds it would be quite the timesaver! 

Offline Gregor

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Re: How to mark out domino placement in this angled chair?
« Reply #16 on: January 22, 2019, 05:33 PM »
Hm.

Let's say you take a piece of sturdy paper, the form of the contact surface, do the drawing on that once to get the center points of the dominos, put it aligned onto the contact surface, apply a small center punch on the 4 marked centers, remove the paper and use a ruler + pencil to draw lines through the 4 marking holes so you can align the Domino machine on them?
Just flip that marking template over for the mirror side, now that is has the 4 locations you need to punch marked by holes.

Offline ChuckM

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Re: How to mark out domino placement in this angled chair?
« Reply #17 on: January 22, 2019, 08:45 PM »
As I pointed out, it is easier to lay out the mortise placements before the stock is shaped, but I have not studied the chair to see if that is also the case.

If the stock is already shaped as in your case, I would use a sliding bevel gauge (something like this: http://www.leevalley.com/en/wood/page.aspx?p=32594&cat=1,42936,50298,43508) to draw the angled lines (use a pair if the angles are different for the two rows of mortises), and then a flat square http://www.leevalley.com/en/wood/page.aspx?p=66573&cat=1,42936 (even better, if a flat body T-square can be found, looking like this: https://www.homedepot.ca/en/home/p.4-inch--zinc-t-plate.1000773686.html) for the perpendicular lines (90* to the angled lines).

If the plan is to make multiples of the same chairs, a placement template (for laying out only) or, even better, an actual jig* (for mortising with an angled fence to butt against the registration edge of the stock) can be made.

By the way, cradle the work on the width side with spacers (of same thickness) to enlarge the registration surface for the joiner. The cradle will allow you to use the base support that is shop-made or when TSO releases its version: http://festoolownersgroup.com/festool-jigs-tool-enhancements/right-angle-adapter-for-domino-700-xl/   I use cradles (as well as the trim stop) in a lot of my narrow joinery work.

* Your jig may need to have a fence on both the top and bottom sides to cater for the left- and right- chair arms, unless you make two jigs.
« Last Edit: January 22, 2019, 09:11 PM by ChuckM »

Offline gearhound

  • Posts: 65
Re: How to mark out domino placement in this angled chair?
« Reply #18 on: January 23, 2019, 10:51 AM »
As I pointed out, it is easier to lay out the mortise placements before the stock is shaped, but I have not studied the chair to see if that is also the case.

I'm not sure that is possible with the tapers on this chair design and different angles needed. I think it would get really complicated trying to make sure I attached the square stock exactly to my templates to have the pre-cut mortises in the places they need to be. Maybe I'm wrong, but this seems to be the easiest way get the seat attached at the angle and placement it needs to have on the legs. 

Offline duburban

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Re: How to mark out domino placement in this angled chair?
« Reply #19 on: January 23, 2019, 11:44 AM »
Found a photo of my Hank chair knock off. Even with this massive cushion I wish the seat was webbing instead of hardwood.
helper: i used a festool "circular saw" to do something simple and it made it really hard

me: exactly, it makes simple cuts complicated and complicated cuts simple

Offline gearhound

  • Posts: 65
Re: How to mark out domino placement in this angled chair?
« Reply #20 on: January 23, 2019, 03:37 PM »
nice work @duburban! I'm curious where you sourced your cushions from? Also wondering if you came up with the plans for that yourself or if you found them somewhere? I'm slowly trying to learn sketchup, but my skills are sub-par at best with it and have been just drawing out most my designs on paper. I'd love to find a good resource of printable templates for future projects, but most stuff I've found online is too ornate or 'classic' for my tastes.

Offline duburban

  • Posts: 1033
Re: How to mark out domino placement in this angled chair?
« Reply #21 on: January 23, 2019, 04:05 PM »
nice work @duburban! I'm curious where you sourced your cushions from? Also wondering if you came up with the plans for that yourself or if you found them somewhere? I'm slowly trying to learn sketchup, but my skills are sub-par at best with it and have been just drawing out most my designs on paper. I'd love to find a good resource of printable templates for future projects, but most stuff I've found online is too ornate or 'classic' for my tastes.

I worked through this chair in a furniture design class while in architecture school.

I started with 3d model in Rhino3D then went to a framing lumber mock up which I forced as many different types of people to sit in as possible to approach average comfort zone. Because it was a school project I had a deadline and took a short-cut with the back. The next version will have the leg continue through the back and the cushion will be attached to it.

Cushions I made which you can see are lacking in the photos.
helper: i used a festool "circular saw" to do something simple and it made it really hard

me: exactly, it makes simple cuts complicated and complicated cuts simple

Offline gearhound

  • Posts: 65
Re: How to mark out domino placement in this angled chair?
« Reply #22 on: February 25, 2019, 08:58 PM »
It took me awhile to figure it out but the layout process finally clicked for me! I knew I was overthinking it a lot but it turned out to be a lot simpler than I envisioned. If anyone is interested, I'll type out the steps and it even has me thinking about making my 1st woodworking video about it as I think joinery like this can result in some really cool designs.

Cheers,
Matt 


Online RKA

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Re: How to mark out domino placement in this angled chair?
« Reply #23 on: February 25, 2019, 09:32 PM »
Yes please!!  (And well done!).  [smile]
-Raj

Offline Terry Fogarty

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Re: How to mark out domino placement in this angled chair?
« Reply #24 on: February 26, 2019, 09:45 AM »
It took me awhile to figure it out but the layout process finally clicked for me! I knew I was overthinking it a lot but it turned out to be a lot simpler than I envisioned. If anyone is interested, I'll type out the steps and it even has me thinking about making my 1st woodworking video about it as I think joinery like this can result in some really cool designs.

Cheers,
Matt 

(Attachment Link)
  You've done an excellent job. Well done.
.

Offline gearhound

  • Posts: 65
Re: How to mark out domino placement in this angled chair?
« Reply #25 on: March 06, 2019, 11:34 AM »
Finally got finish on it over the weekend and posted photos of it over in the member projects forum.

Just wanted to say thanks again to everyone who helped me out on this forum in case you didn’t end up seeing that post.

It took me a long time and lots of frustration to come up with this mortising method...hope it makes sense! (Still considering making a video on it as I couldn’t find anything about it online):

1st: mark the angle you want the seat on the joint of the back leg/armrest...I've got mine at 98.5 degrees. 2nd: determine mortise placement (I have the bottom mortise at 10mm and the top 2 mortises at 10mm and 30mm from the 98.5 degree angle line). 3rd: use a protractor to draw perpendicular lines from that 98.5 degree angle line through the mortise marks so the machine has something to line up with and cut mortises. 4th: lay the seat piece on the leg/armrest and mark the spacing used in the previous steps on the back. 5th: mortise the seat piece referencing off the lines from step 4 using the fence set at 10mm/30mm. 6th: dryfit the top joint and mark out where the seat hits front legs. 7th: basically repeat steps 2-5 using the angle marked in step 6 to layout the mortises for the lower joint

Using the fence to complete half the mortises really sped up the process and accuracy. My 1st couple attempts I was vertically mortising everything and had to create far too many reference lines to line up the machine.

Hope this helps someone out with how to use the domino for a project with weird angles like this one...and if anyone knows of a simpler process to speed this up even more I’d love to hear it!

Cheers,
Matt



« Last Edit: March 06, 2019, 11:47 AM by gearhound »

Offline Mtpisgah

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Re: How to mark out domino placement in this angled chair?
« Reply #26 on: April 12, 2019, 10:00 PM »
Good job, Matt. My wife saw the same video and wants me to make a chair like that. As soon as I finish two desks and a coffee table, I will get started. I will be referencing your build for sure.