Traversers and moving parallel

[Coombe Barton]

I've seen plenty of comments round here on both the necessty and difficulty of getting traversers to run parallel and the benefits of sector plates. I have enough trouble cutting wood straight so getting a perfect arc of a circle is something I don't want to contemplate. The difficulty with traversers seems, from others posts, to be that of getting them to stay stable in both the horizontal and vertical planes.

 

Going back to a very old drawing board I once had to use, I'm considering the use of a pullley and wire system as in the diagram.

 

 

Blue is track and traverser bed and red is the wire system.

 

There are four grooved wheels round which a continuous (steel) wire system is threaded. The wire is fixed underneath the centre of the traverser and tensioners (nuts and bolts) make the wire sufficiently tight (and adjustable for temperature changes.)

 

When you move the table it stays parallel.

 

Support for the table only needs to be flat and parallel with the top surface - the traverser plate slides on this.

 

Has anyone ever used this type of constraint system on traversers?

[Butler Henderson]

Think the sliding drawer method is simpler, provided the edges are reasonably straight the runners should be able to be screwed in straight enough. On that subject does anyone know of an article covering the construction, the recent RM article was not really much use in terms of actually making one and ModelRail seem only to have covered a sector plate.

[Kenton]

It might work, as long as all he posts are the same height from a perfectly level surface .... but it seems like a lot more trouble (I'd be worried that the wire might snap as the tension would have to be high)

 

Using the ball bearing race type of drawer runners is so simple

 

As used on Quintland and available at small cost from BBQ and other DIY outlets.

[Fen End Pit]

My local hardware shop (Mackey's in Cambridge) sell a range of metal draw runners from about 8" up to about 16" which are ideal for this and make getting parallel movement easy. Alternatively find a friend in the IT industry who orders rack mount servers. Most will order sliding racking rails with each new server and have the old ones spare. I've used two from a Dell rack mount server on my P4 line. (though just to complicate things my fiddle yard runs vertically).

 

David

[shortliner]

It doesn't answer your question completely (use a small spring to tension the string/wire like the sliding pointers on old radio dials did!) but I have just posted this on another forum, and it may help.

There is also another suggestion by me earlier in that thread

http://www.the-gauge...&p=46633#p46633

[Butler Henderson]

There was a layout in Model Rail recently whereby keyboard drawer sliders had been used - these seem to be thinner than the ball bearing type photoed above - any one have experience of them. I assume that they have to be side mounted or has anyone successfully bottom mounted any (which would make the general construction simpler).

[jamie92208]

I used keyboard drawer sliders with bearing in on the narrow gauge (16.5) fiddle yard on my layout. It's worked well for several years and has survived storage in the shed. The key is making sure that the runners are mounted vertically. I I get chance I post some photos.

 

Jamie

[Kenton]

There was a layout in Model Rail recently whereby keyboard drawer sliders had been used - these seem to be thinner than the ball bearing type photoed above - any one have experience of them. I assume that they have to be side mounted or has anyone successfully bottom mounted any (which would make the general construction simpler).

Hmm, I think that is what BBQ packaged them as. You would be hard pushed to find anything thinner at 8mm surface to surface.

and yes they were bottom mounted - as in the link - and I wouldn't do it any other way because lifes too short and my woodwork can't be trusted to have such fine tolerances.

[Donw]

Use the type that give a full extention i.e a 16" runner will allow 16" of movement. I got some from B&Q. used them laid flat worked fine.

Donw

[Tel2010]

Hmm, I think that is what BBQ packaged them as. You would be hard pushed to find anything thinner at 8mm surface to surface.

and yes they were bottom mounted - as in the link - and I wouldn't do it any other way because likes too short and my woodwork can't be trusted to have such fine tolerances.

 

I came across this site www.stationroadbaseboards.co.uk

which provides various fittings for baseboards including drawrunners ,hope its of use to someone

Terry