RoR track...thoughts please

[Freff]

I have been looking at this method the last few days, and seriously been considering it for my obsy.

The system appears simple to construct. Two lengths of flat bar and two lengths of round bar welded together.

Nylon profile wheels mortised into the beams would give almost silent running. It would also give a lower profile reducing the roof height.

Any thoughts would be welcomed.

[Bizibilder]

That looks like a very neat solution - especially the low profile of the set-up which will make weatherproofing/weatherboarding a much more lightweight task.

[Peter Drew]

You could consider aluminium T section, stalk up, it would require no welding and would not rust.

[Carbon Brush]

Looks a very good solution to me.

Agree on ali rather than steel.

Depending on what ali T section or similar you end up getting, you could turn the wheel profile to suit. A simple quick job for someone with a lathe.

My track uses a plastic concave fixed section with wheels on the roof.

Cheap and simple and works well.

That was till the tracks filled with snow & ice that tooks weeks to melt.

Clear nights and I couldn't get the roof off.

[Freff]

I had considered using T section, but then had trouble finding a nylon wheel with a suitable profile. Wouldn't a T section have a tendency to cut into the wheel if not the exact match. This is why I considered a round profile.

I have also considered using equal angle with the point 'up' and v pully wheels. But again getting the profile the same will be problematic.

I have a lathe so a bit of adjusting here and there would not be a problem.

[Gina]

My track uses a plastic concave fixed section with wheels on the roof.

Cheap and simple and works well.

That was till the tracks filled with snow & ice that tooks weeks to melt.

Clear nights and I couldn't get the roof off.

Hmm... yes... I'm planning to use aluminium channel and standard nylon wheels but not happy that the channel might collect water, dirt, leaves, etc. I was wondering whether to have the running rails on a slight slope so that water can run out of one end of the channels (the outside one). Of course it would make the construction a lot more complicated.

I think there's a lot more in all this than first comes to mind. I like the idea of grooved wheels and a rod to run on. Yes, the groove in the wheels would need to match the track closely. Best would be a circular profile IMO. V grooves have an intrinsic weak point at the bottom (top) of the V. Another possibility might be square bottomed U section wheels and square section runners. Or maybe standard wheels (with a slightly curved profile), flat track and extra guide wheels. The guide wheels would only need to be lightweight.

[Freff]

I have all the same concerns Gina.

The more I think about it the more I'm convincing myself this is the way for me.

The round profile will be the most efficient shape and the least problematic with collecting crud, snow etc. Also no need to build in fall for drainage.

[malc-c]

Seems an ideal solution, but have to agree with the others in that steel will rust and that will lead to other problems.

As for the traditional square U shaped track and wheels (mine are rubber) I have a cut down 2" paint brush fitted so it sweeps any crud or laying water out of the track as the roof is rolled back

[Gina]

I have all the same concerns Gina.

The more I think about it the more I'm convincing myself this is the way for me.

The round profile will be the most efficient shape and the least problematic with collecting crud, snow etc. Also no need to build in fall for drainage.

Yes, I like the idea very much and I would probably use it if I had the facilities. There are so many things I could make if I had a lathe but even so I don't think it would be cost effective and I can't really afford it. Maybe some time in the future when I've bought the higher priority things. I'm thinking if I could make wheels with a half circle profile... and maybe ali tube or rod to run on.

Well, on thinking about things, I've gone off the idea of channel - good job I haven't bought it yet! Maybe angle would be a good compromise.

[Bizibilder]

I think you may all be over-complicating things a bit! I used ordinary rubber tyred wheels running directly on wooden runners. The only guiding is by two wooden strips, one on each side, outside the wheels. This has proved to be entirely satisfactory in use.

As for putting a slope on the runners I would advise not to! The roof needs to be able to remain stationary in any position on the runners, from fully closed to fully open. You will find that you often have the roof partly closed in use (in fact rarely is mine ever fully open) mainly to combat any breeze that may be blowing and, in my case, to help block a couple of neighbours upstairs lights that they insist on leaving on all evening. I have had no problems with the ingress of water along the runners. The only time I did get a tiny bit of water in was last winter when the snow started to melt and a little did find its way in.

[Gina]

As for the traditional square U shaped track and wheels (mine are rubber) I have a cut down 2" paint brush fitted so it sweeps any crud or laying water out of the track as the roof is rolled back

Yes, I was thinking of doing something similar.

[JamesF]

Forget wheels. Yards and yards of teflon is what you need. Thousands of dob owners can't be wrong

It is definitely a more tricky problem than it first appears. If I can get rid of the idea of caterpillar tracks that's just popped into my head I shall give it some thought this evening. It strikes me that greenhouse doors usually run in a channel, but the opening is at the side, rather than on top.

James

[Freff]

Seems an ideal solution, but have to agree with the others in that steel will rust and that will lead to other problems.

I totally agree. The pictures shown are just to show the idea. If I do go down this route I'd make it in aluminium rod and flat bar.

Another reason was ease of build and maintenance. A friends obsy is built with castor type wheels and recently one broke a spindle. The trouble he had just getting the old wheel out was a nightmare having to jack up one side of the roof.

I think I have been taken by the low profile and the simplicity of the wheel mount, where it can be slid in and out of the mortise by removing one bolt.

[Gina]

I think I have been taken by the low profile and the simplicity of the wheel mount, where it can be slid in and out of the mortise by removing one bolt.

My design is similar except that I'm using two pieces of 4"x1" with the wheels between them. My carpentry is not up to accurate mortices.

[Freff]

That's a good and well proven design Gina. I noticed it earier on your obsy thread.

If I go the mortise way I'll use a plunge router to do the job. The days of marking gauge, hammer and chisel are well gone.

[Gina]

You seem to have all the gear Tony I agree, hammer and chisel are far too much like hard work!

[Freff]

You seem to have all the gear Tony I agree, hammer and chisel are far too much like hard work!

All the gear, no idea..

[laser_jock99]

I'm using a relatively low profile aluminium angle as a track runner.

Aluminium | Aluminium Warehouse

The wheels will run on the 1" wide flat and the 1/2" section will be enough to keep the roof on course. I want the smallest gap between roof and runners for reasons previously mentioned- aiming for about a 5mm gap. To achieve thish the wheels will be mounted on large hex head coach bolts on the inner edge of the sliding roof.

The wheels are 50mm rubber edged castor wheels obtained from Keystone Castors @ £1.50 each.

Keystone Castors - The UK supplier for Castors and Wheels

The idea of a running brush is good to keep the track clear. I am also considering draught proofing brush to provide an additional weather seal.

NEW 3/4" NYLON BRUSH DRAUGHT EXCLUDER DOOR BOTTOM SEAL | eBay

[Gina]

I had planned to buy aluminium channel :- Aluminium | Aluminium Warehouse

But now I'm going for angle :- Aluminium | Aluminium Warehouse

The upright part of the channel (1/2 inch) will go on the outside of the wheel each side.

[Freff]

The upright part of the channel (1/2 inch) will go on the outside of the wheel each side.

Any particular reason for this Gina. I would have thought that the other way around would encourage water, grud etc to be diverted away from the inside.

[Gina]

Any particular reason for this Gina. I would have thought that the other way around would encourage water, grud etc to be diverted away from the inside.

Main reason was that if there is any lack of rigidity, particularly on the longer uprights, this would stop splaying outwards (inwards would be restrained by the dividing wall). When I get the roll off section built I can check the rigidity and if OK I can put the angle the other way round. Unfortunately I don't know any way to determine this until it's built. I agree that having the angle uprights on the outside would probable be better.

I had thought that having the upright side on the outside would help with weatherproofing, but I don't really think there will be any problem as the weather boarding will take care of it.

[JamesF]

If you're concerned with rigidity Gina then you might be able to put some sort of tie bar in the dividing wall? You could even perhaps use a length of your runner material appropriately cut and bent over to form a 90 degree flange at the end, bolted through the top member of the wall.

I'd have thought that merely having an angled section on the top of the wall would help with rigidity no matter which way it faced. One might, I guess, argue that having the upright on the outer side would actually stress the wall outwards more, because any sideways load imposed by the roof is going to be pushing the wall outwards?

James

[RogerTheDodger]

Put the wheels on the bottom (walls) and the track on the top (roof) - nothing can get stuck in the track that way.

[malc-c]

Put the wheels on the bottom (walls) and the track on the top (roof) - nothing can get stuck in the track that way.

Just means twice the amount of wheels needed, half of which will be exposed to the weather: Result rusty wheels.

[RogerTheDodger]

A good point on the amount of wheels, but would you be opening the roof if there is weather to consider?