Odd Joint - will it work?

[Fitzroy]

Been looking for a floor lamp for the bedroom for a while and can’t find what we’re looking for, so I’m going to make one that amalgamates the features of two we like. The body of the lamp is a tripod, excuse the sketch, sketching is not my strong point!

I’ve worked out pretty standard solutions for most of the joints, but the point in the base where the three legs come together is stumping me. I planning on a three way ‘mitre’ using splines to provide the required strength.

The mock up is a little rough, but as proof of concept it’s convinced me I can make the joint. And with a little practice and some more accurate/improved jigs I think the quality will be acceptable. However I’m still left with two questions:

1. Is there a more standard joint for this type of application, if so what is it called?
2. Are the any obvious problems/issues with the joint I’ve contrived that I’m not seeing that mean it’s a non starter?

Thanks and any other related thoughts/comments welcomed.

Fitz.

 

[MikeG.]

The only time I've done something similar I joined the 3 legs not to each other, but to a hexagonal vertical block. Then it was a simple case of a (square-on) mortise & tenon joint into every other face. No angles to work out. other than in making the hexagon.

 

[yetloh]

Given that it is a floor lamp, my concern would be that one of the legs will at some point be kicked sideways with unfortunate results, particlaruly if one or both of the other legs was constrained by being against a wall or another piece of furniture. I think it would be quite a bit stronger,but hatder to make if the splines were dovetailed into the the feet. Alternatively, you could perhaps make the joint with lengths of stainless steel threaded rod epoxied through each mating surface. You might need to stagger these in height off the floor but it could make a very strong joint. It would also have the merit of being invisible, leaving people to wonder how it was made, and look very crisp and neat, although depending on your point of view dovetailed or plain splines would add visual interest.

Jim

 

[Sheffield Tony]

How strong is your mock-up ? Take care that you can actually assemble the joint - do the splines slide in from the side ?

 

[Racers]

Looks similar to my occasional tables.

VIV_5439_000032_zps00ff6f35 by pete maddex, on Flickr


VIV_5445_zps3a37c51f by pete maddex, on Flickr

I did this at the bottom.

VIV_5443_00006_zps9982469f by pete maddex, on Flickr

And this at the top.

VIV_5442_00005_zpsbe816cbe by pete maddex, on Flickr

They seem to be strong enough for an occasional table, thry have been knocked over several times and stayed together.


I hope that gives you some ideas.

Pete

 

[Jacob]

Been looking for a floor lamp for the bedroom for a while and can’t find what we’re looking for, so I’m going to make one that amalgamates the features of two we like. The body of the lamp is a tripod, excuse the sketch, sketching is not my strong point!


I’ve worked out pretty standard solutions for most of the joints, but the point in the base where the three legs come together is stumping me. I planning on a three way ‘mitre’ using splines to provide the required strength.
View attachment 9

The mock up is a little rough, but as proof of concept it’s convinced me I can make the joint. And with a little practice and some more accurate/improved jigs I think the quality will be acceptable. However I’m still left with two questions:

1. Is there a more standard joint for this type of application, if so what is it called?
2. Are the any obvious problems/issues with the joint I’ve contrived that I’m not seeing that mean it’s a non starter?

Thanks and any other related thoughts/comments welcomed.

Fitz.

Doesn't look durable to me. I'd perhaps file a bit of brass to make a 3 way bracket screwed on underneath.
3 leg tables, lamp standards etc are pretty common - I'd google a few images and get a better design together.
That pyramid shape would take up a lot of space and could be clumsy - why not a straight vertical shaft on a base - solid, or a little low 3 leg thing. Google up some images. First rule of good design - always copy unless you really have a brilliant design - a rare thing!

 

[ColeyS1]

Just saw this and thought of this thread.

Looks smart as well!

Sent from my SM-G900F using Tapatalk

 

[Myfordman]

The isle of man joint looks interesting but most of the glue surfaces are end grain. I think I'd try a halving joint or perhaps it should be called a thirding joint in this instance.

 

[Fitzroy]

Thank you so much for all these comments, given me lots to think about! I love the isle of man joint but looks a step to far for me. The occasional tables are fab, love the pippy wood in them.

I think I’m going to go with my design as I like the look, but reinforce underneath with a metal plate and screws, recessed into the wood to hide the evidence!

Spent most of my allowable shed time today making a decent shooting board and repurposing an old woody plane into a shooting plane. Just need to work of the donkey’s ear angle so I can shoot the ends.

Fitz.

 

[Fitzroy]

Too many projects not enough time. Ended up combining everyone’s thoughts into a three way mitre, with splines to give long grain gluing surfaces, and a 3mm hidden brass plate on the back for strength.

Lots of bits I had to make/learn to complete it.
- 120 degree mitres were done on a donkey’s ear shooting board.
- Splines are a single saw kerf on the table saw, with sycamore scraps sized to fit.
- Brass plate was cut with a hacksaw, finished with a file, then drilled and countersunk on the drill press.
- Recess for plate was scribed around finished plate and a router plane used to cut out.

Happy with the outcome although glueup went badly and one of the arms grabbed before it was properly aligned and I could resolve. Some judicious planing somewhat resolved but joint is still a bit hopefully will look a bit better after finish is applied.

Brass counter sinks have a rim around them, which I don’t know how it’s happened, and I need some slotted brass screws to finish properly.

Fitz

 

[Deadeye]

Well, to a newbie... that looks proper!

 

[AJB Temple]

Well done, you did a nice job.

 

[OscarG]

How did you do those splines on the table saw?!

With those angles I'm trying to figure it out!

Very nice job by the way.

 

[yetloh]

Unless it looks awful from the other side I would be more than happy with that. You should be very pleased with it. The fact that it was a struggle doesn't detract from the end result.

I 've had the same problem of a raised rim forming around a brass countersink. In effect, it is just the same as a burr forming on any cut edge. I would re-finish the surface using a block of wood covering the the whole surface to press the face onto abrasive paper on a flat surface like a machine table.

Jim