Where to get rack and pinion, cogs etc for home project

salad17

Hi guys,

I'm currently working on a woodwork project with moving parts. It requires a pinion with two racks on either side for the opening mechanism.

I've been all over cork looking for an engineering shop what might sell things like that, cogs etc, but no one seems to know! It would be ideal if I could see them first rather than having to order them. I thought there must be some shop for standalone projects like this that require mechanical parts?

Can anyone help me out?!

DublinDilbert

salad17 wrote: »

Hi guys,

I'm currently working on a woodwork project with moving parts. It requires a pinion with two racks on either side for the opening mechanism.

I've been all over cork looking for an engineering shop what might sell things like that, cogs etc, but no one seems to know! It would be ideal if I could see them first rather than having to order them. I thought there must be some shop for standalone projects like this that require mechanical parts?

Can anyone help me out?!

Radionics would sell them in plastic /steel, do you need them in wood?

An engineering shop would be able to make these up if you had dimensions or just get models from grab cad and print them.

mikeymouse

there's a Maplins in Cork , but this might be a bit small
http://www.maplin.ie/p/mfa-rack-and-pinion-set-wc77j

salad17

Thanks but the Marlins one is too small!

To be more specific, it's for a coffee table, where the table top is in two halves, and they open up to vertical and become the backs of two seats facing each other (with a chess board in the middle!). The rack and pinion is the mechanism I need so that the two parts of the table top/the two seat backs open up simultaneously.

Does that make sense?!

So they'd have to be pretty strong, not sure if plastic would do it, steel would probably be the answer. I've had trouble finding an engineering shop in cork that could help me or knew where to go. Is radionics in dublin? I'll give them a call tomorrow.

DublinDilbert

Look up radionics online they will have a large selection, no point calling them till you have part numbers.

Other option would be to use a toothed belt (car timing belt) cut into sections and bond onto flat peace of timber and use a suitable cog maybe also off a car.

Could you weld down a bike chain to a base and use a bike cog?

Does the rack need to be flat? You could get the ring gear off a car fly wheel and use a pinion off a starter motor, both would be hardened steel. I know a company that made mini electric tractors that used this for their steering rack and pinion.

powerfarmer

Try hpc gears http://www.hpcgears.com

They have an agent in Cork have a google, I cant seem to post a link to the cork agent.

Or http://www.igus.co.uk carry a range of linear slides and guide units.

salad17

DublinDilbert wrote: »

Look up radionics online they will have a large selection, no point calling them till you have part numbers.

Other option would be to use a toothed belt (car timing belt) cut into sections and bond onto flat peace of timber and use a suitable cog maybe also off a car.

Could you weld down a bike chain to a base and use a bike cog?

Does the rack need to be flat? You could get the ring gear off a car fly wheel and use a pinion off a starter motor, both would be hardened steel. I know a company that made mini electric tractors that used this for their steering rack and pinion.

I actually have a Beamer that I'll be breaking myself (haven't done it before!) soon so thanks I'll give the timing belt a go I think, I'll fix the belt to a 2 by 1 I think, and use one of the cogs as the pinion.

Yeah the rack needs to be flat so flywheel wouldn't work, or would be very complicated.

Bike chain sounds good too, just more complicated to stick to a rack. I don't weld.

powerfarmer wrote: »

Try hpc gears hpcgears

They have an agent in Cork have a google, I cant seem to post a link to the cork agent.

Or igus carry a range of linear slides and guide units.

Thanks, that first one looks good, hpc. If the car engine fails me I might have to fork out for them! Just gotta get my head around the sizing etc.

mawk

I think reliance bearings in little island have a selection of linear motion gear.

salad17

Just to update, I went with a timing belt which I cut and epoxied to 2 bars of wood as my 2 racks, and a water pump cog which fit the teeth perfectly and had the right diameter as well as being set with a bearing in a small metal frame that I could bolt onto the project, which all worked perfectly!

Thanks very much for the help!