Gluing End Grain

[strider]

Hi All

Just a quick post to find out if anyone has any tips for Gluing End grain. I know that this is not and ideal situation, but i feel that this would make the gears a little stronger for my All wood skeleton project.

I fgire that if i make the gears out of 4 pieces each with the grain pattern running in alternal directions this would make it stronger.

Do you think that I am possible over complicating this process :?:

 

[9fingers]

I think you are going to have to give us more detail about what you propose

I can't see that running grain in alternate direction is going to help anything
Do you mean the grain is is at right angles in alternate pieces??

Some pictures might help?

Bob

 

[woodbloke]

Sounds to me like you're going to make a thin ply laminate for the gears :duno: - Rob

 

[strider]

OK, I dont think i explained myself very clearly in my first post, so i have put together a couple of images depicting what I am trying to explain.

Bascially, what I am trying to avoid is a cross grain situation on the very small teeth.

In the following image you can see that I make 1 gear from 4 pieces of material.

The lines indicate the grain direction. So basically the top teeth would be half cross grain, and hopefully preventing the little blighter from snapping off.

In my second picture, i make the gear from 6 wedges, thus removing any cross grain from the teeth on the gear.

does this make it any clearer?

 

[miles_hot]

I think that strider's project is his clock.

Miles

 

[bugbear]

OK, I dont think i explained myself very clearly in my first post, so i have put together a couple of images depicting what I am trying to explain.

Bascially, what I am trying to avoid is a cross grain situation on the very small teeth.

I suggest doing some research on the techniques of John Harrison.

He's around 250 years ahead of you ;-)

BugBear

 

[frugal]

Would you not be better making your own plywood out of laminations or your chosen wood, each with the grain at 90 degrees to the previous.

 

[9fingers]

Ok that helps a lot.

How about your hexagonal scheme but with the grain of each segment parallel to each face of the hexagon and then maybe made into plywood with each layer rotated 30 degrees to hold it all together?

this is wrong - sorry - see further down the thread for a correction

Had you considered using something like boxwood as a single piece. I think its grain structure will give you the strength you need.


I did wonder where gears fitted into a skeleton.....


Bob

 

[strider]

The only consideration that I have to think about on this is that the gears are only going to be between 6mm and 10mm thick.

 

[miles_hot]

Ok that helps a lot.

How about your hexagonal scheme but with the grain of each segment parallel to each face of the hexagon and then maybe made into plywood with each layer rotated 30 degrees to hold it all together?

Had you considered using something like boxwood as a single piece. I think its grain structure will give you the strength you need.


I did wonder where gears fitted into a skeleton.....


Bob

Bob

Would having the grain parallel to the face to mean that when Strider cuts gears into the face each will have short grain? Or do you expect that the rotation will sort this out?

Would making a ply out of alternating grain - with the outer ones being perpendicular to the face - not give the same strength?

Thinking aloud though if he makes a ply with 90 degree differences why go to the hassle of making the hexagon...? I sense something adrift in my thinking

Miles

 

[miles_hot]

how much force is going to come into play on these teeth? Is short grain on some of the teeth actually an issue?

Miles

 

[9fingers]

Ok that helps a lot.

How about your hexagonal scheme but with the grain of each segment parallel to each face of the hexagon and then maybe made into plywood with each layer rotated 30 degrees to hold it all together?

Had you considered using something like boxwood as a single piece. I think its grain structure will give you the strength you need.


I did wonder where gears fitted into a skeleton.....


Bob

Bob

Would having the grain parallel to the face to mean that when Strider cuts gears into the face each will have short grain? Or do you expect that the rotation will sort this out?

Would making a ply out of alternating grain - with the outer ones being perpendicular to the face - not give the same strength?

Thinking aloud though if he makes a ply with 90 degree differences why go to the hassle of making the hexagon...? I sense something adrift in my thinking

Miles

My thinking was a bit adrift there!! -brain re-engaged now

The 'perfect' piece of wood for strong teeth would have the grain lines coming radially from the the centre.

SO something like a hexagon with the grain perpendicular to the edges with layers rotated by 30 degrees to strengthen the joints.

unless anyone has a better idea??

Bob

 

[strider]

Hi,

to be honest I have no idea how much force there will be going through the teeth. Probably not that much, I was just trying to avoid disaster.

I think that may be what I will do is cust a sample gear and see if i can test its strength som how.

 

[woodbloke]

I'd make a standard 3 or 5 ply lamination using single veneers of choice so you wouldn't see (unless you looked hard) the glue lines. The wooden gear teeth could then be cut with little chance of breaking teeth owing to short grain - Rob

 

[xy mosian]

I did wonder where gears fitted into a skeleton.....

Bob

You've got a point Bob.

"The toe bone's connected to the foot bone,
The foot bones connected to the ankle bone,
The ankle bone's ...... etc,."

I can't remember where the gear fits either

xy

 

[Harbo]

There's lots of stuff on the web about wooden clocks - have you done a search?

I would think you are going to need a close grained wood and as already suggested, Boxwood comes to mind?

Rod

 

[Russell]

I would have thought that the problem is not so much teeth breaking but kogs becoming oval with even with wedges the wood would move a small amount. surely laminating your own plywood is the way to go. Oval kogs will really effect the clock and cause no end of problems.

I have the plan also being a fan of skeleton clocks but haven't got round to making it yet.

 

[strider]

All very good valid. points. I guess i will just have to have a go and see what comes out.

 

[Chris Knight]

I'd be inclined to make my own version of ply with veneer. You would get much increased strength and the angle of rotation between each ply could be set optimally. Then just cut the entire gear from that.

To your original question, - by far the best end grain adhesive I have found is a "hide" glue (in inverted commas because I suspect it's more bones than hide!) It's called Sheppy Tug glue and it comes in a pail of ca 5kg - when I bought mine it cost little but is now quite a bit more expensive. It's in a gel form and needs to be heated like most scotch glues.

To test its strength (amongst other candidates like epoxy) I glued 1 inch square by 6 inch long pieces of oak together end to end and when cured put them in a vice and hit the free end of each with a club hammer.

I could not break the ones glued with Sheppy Tug - I think if I used a sledge hammer, I might have succeeded (or destroyed my vice!)

 

[Sportique]

Err - 6mm MDF either ready veneered or veneer it yourself - maybe this is no good for the pursists - I dunno.....

OK I'm going .....

Sorry about that - I'm outta here ....