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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Carpentry Questions >> the easel I made wobbles https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1251580856 Message started by mnova on Aug 29^th, 2009, 10:20pm

Title: the easel I made wobbles
Post by mnova on Aug 29^th, 2009, 10:20pm

I make a very simple 2-sided, 5-foot tall easel - a sort of A-frame.

The two sides are identical. It is is made with wood 1-1/4" by 3/4". Each side has two 5-foot pieces connected to each other by a cross-bar along the top and another half-way down. A thin rectangulr panel is attached to the top half. The two sides are hinged at the top, and chains run between them on each side half-way down.

Although I was very precise in cutting and fastening, and the two sides match each other perfectly, when I open up the easel on a flat floor the easel wobbles terribly. When three legs are touching the floor, the fourth is more than one-inch higher than the floor.

1. What causes that?
2. How can one prevent it?
3. What is the best way to correct it?

Title: Re: the easel I made wobbles
Post by big_all on Aug 30^th, 2009, 1:23am

heeelllooo and welcome mnova ;D ;D ;D

need a picture realy ;D ;D

if the structure is made from triangles it will be firm

if there are any oblongs[squares] they will wobble without a diagonal brace or triangulare corner supports

Title: Re: the easel I made wobbles
Post by woodsmith on Aug 30^th, 2009, 8:14am

wrote on Aug 29^th, 2009, 10:20pm:

1. What causes that?
2. How can one prevent it?
3. What is the best way to correct it?

1. For a 5 foot high easel you have used very thin timber and this will not have helped.
2. Make a three legged easel which is inherently more stable.
3. Try altering the length of the chains to compensate for the out of square.

Welcome to the form btw

Title: Re: the easel I made wobbles
Post by Zambezi on Aug 30^th, 2009, 8:39am

...or chop a bit off the one leg so all 4 touch the floor...

Title: Re: the easel I made wobbles
Post by Joiner on Aug 30^th, 2009, 8:59am

I'm just wondering if you were as precise in your ASSEMBLY as you were in the measuring and cutting.

A few years back I used to make a lot of A-frames for a local signwriter, a mixture of both four- and three-legged frames, either of which could have display panels on one or both sides. The choice of three or four legs was usually decided by their intended use: three-legged on rough ground, four on level floors, the inherent stability (as Big All and Woodsmith have said) of the three-legged ones also made them good for use where there was a lot of foot traffic and the board was likely to get knocked. (4-legged ones 'collapse' easily if knocked hard enough for the legs to move closer together, whilst 3-legged ones just move around a bit. Oh God, cafes all over the country are now going to be hit by a spate of collapsed A-boards as people go around trying to prove me wrong! ::))

On the four-legged ones, when assembling the component parts I always "mirrored" them for assembly, checking the diagonals for squareness on both the first half AND the second half, despite fixing the second half together whilst it was lying on top of the first, aligning the two.

I'd then fix the hinges to the top of the one half then stand them on a flat surface leaning against each other AND THEN FIX THE OTHER HALF OF THE HINGES to the top of the other side.

Anything in that assembly procedure needed only to be a fraction out to add a wobble, and you've got one hell of a wobble!

Disassemble and start again.

Title: Re: the easel I made wobbles
Post by CWatters on Aug 31^st, 2009, 3:26pm

My guess is that the two halves are twisted slightly. It's the warped picture frame problem. They may appear flat when folded and laid flat on the bench but twist when open. Might be able to correct this by adjusting the length of the chains as woodsmith suggests.

Also double check the floor is flat!

Title: Re: the easel I made wobbles
Post by londonman on Sep 1^st, 2009, 10:00pm

A three-legged object will always be 100% stable. No matter what the surface is like.

Check that your hinges are parallel to each other (co-planar).