Roll-off shed rails suggestions

[SteveBz]

Hi People,

I have a shed with a very light lift-off Perspex roof and I'd like to automate this with rails.  The shed is actually two sheds joined together, one with bikes and garden tools and one with a scope.  I'm planning to rebuild the tool-sehd only and put a single roll-off roof spanning both sheds.  The whole structure is 4m wide, although during the rebuild, I might expand the shed part by another metre making it 5m wide.  The observing shed is about 1.5m wide.  So the plan is that the whole roof will be motorised to slide by 1.5 m to expose the telescope etc.

Can you please recommend a cost-effective rail for this?  In particular the rails should slide sideways, but also hold the roof down in case of a storm, so I'm thinking a C-profile rail with rollers fitting inside the 'C' so that the roof wont lift off either.

Thanks for your help.

Kind regards,

Steve.

[Peter Drew]

Your suggested C section plan should be fine as long as the gauge is adequate, I use aluminium of suitable composition to be weather resistant.  Make sure to have some lateral rollers as well to make sure the support rollers can't foul the sides.      🙂 

[SteveBz]

6 minutes ago, Peter Drew said:

Make sure to have some lateral rollers

Hi Peter,

Thanks for your comment.  What do you mean by lateral rollers?

Kind regards

Steve

[Peter Drew]

These are horizontal rollers that act on the vertical edge of the rail.  Without them, if the moving component moves from side to side, the support rollers can rub against the sides and spoil the movement.  They dont have to be a tight fit, just enough to touch the sides before the support rollers do.    🙂

[SteveBz]

1 minute ago, Peter Drew said:

These are horizontal rollers that act on the vertical edge of the rail.  Without them, if the moving component moves from side to side, the support rollers can rub against the sides and spoil the movement.  They dont have to be a tight fit, just enough to touch the sides before the support rollers do.

OK, so you're saying when the end rollers come out of the c-section, the lateral rollers guide them back again.  Great point.  I hadn't thought of that.

Tx

Steve.

[Peter Drew]

Not quite what I meant but it would have that benefit, my suggestion was mainly to prevent any binding whilst the roof was sliding.   End stops would prevent the support rollers coming off the ends.       🙂

[Swoop1]

You might be better off with a v profile rail and locking clamps to keep the roof on. less chance of binding.

Like this (go to the 8th post down).

Edited May 23, 2021 by Swoop1

[DaveS]

A lot of us have ended up going to F H Brundle for track and wheels.

[SteveBz]

8 hours ago, Swoop1 said:

locking clamps to keep the roof on.

Hi Swoop,

What do you mean by locking clamps. Would I have to unlock to roof when I wanted to use it?

Regards

Steve.

[JamesF]

I used FH Brundle for my roof rails, as already linked.  My roof is quite heavy -- I welded a steel frame and then fixed OSB to the frame before cladding the sides and covering the roof with EPDM (and it's about 2.5m wide by 4m long).  With a smaller, lighter roof I'd certainly be concerned about the wind lifting it off.  A shallow pitch roof acts like a wing in the wind and generates lift which can be sufficient to allow the entire weight of the roof to be overcome, at which point it flies off.  This has happened to SGL members in the past, even with a fairly substantial roof.

Using a C-section runner with the wheels inside, such as is often used for sliding doors, would keep the roof fixed down (one would hope), but may be a little more awkward to make, especially given the additional complexity of horizontal wheels as suggested by Peter (which I agree would be a good idea).  One of my greenhouses actually has a slightly more complex "C" section runner which has a "gulley" down the middle that the wheels sit in, effectively preventing them from wandering from side to side.  Something similar might remove the need for horizontal wheels.

Some of the benefits of using an open inverted V or semi-circular track such as quite a few of us have used are that there's no side-to-side movement to worry about, and the track is easy to fit and keep clear of debris (and potentially ice, which can build up if rain gets into exposed sections, or even form just as a result of condensation on cold metal subsequently freezing).  The negative side is that there's nothing to stop the roof lifting off other than its own weight.  Some people use turnbuckles or latches to hold the roof down when it isn't in use, and unlock them manually before opening up.  I used something similar to these: https://www.amazon.co.uk/Toggle-Action-Release-Holding-Capacity/dp/B075GZRK4K (the actual ones I bought don't appear to be listed any more).

Another option is to have some horizontal pins that slide into holes as the roof closes, thus preventing it lifting.  This allows remote opening of the roof, but ultimately you may still need something like the above catch to lock the roof firmly in place when bad weather is expected because you don't want it blowing open during a torrential rainstorm.  I don't know what other people have used, but I was toying with using some pins like the ones I have on my tractor implements to fit on a 3-point linkage when I get as far as automating my roof.  Quite possibly that's overkill

One thing to consider regarding freezing conditions: imagine water got into some part of the roller system on a winter day thanks to some blown-in sleet, and as darkness fell and the temperature dropped, producing a night of outstanding best-in-several-years clarity, you then found the roof wouldn't open because that water had frozen.  How easy would it be to clear the ice from your chosen design?

Ultimately I think I prefer the open rail approach because it's simpler to install and to use, but I see no reason the C-section runner couldn't be made to work if that's the way you prefer to go.

James

[SteveBz]

6 hours ago, JamesF said:

I used FH Brundle for my roof rails, as already linked.  My roof is quite heavy -- I welded a steel frame and then fixed OSB to the frame before cladding the sides and covering the roof with EPDM (and it's about 2.5m wide by 4m long).  With a smaller, lighter roof I'd certainly be concerned about the wind lifting it off.  A shallow pitch roof acts like a wing in the wind and generates lift which can be sufficient to allow the entire weight of the roof to be overcome, at which point it flies off.  This has happened to SGL members in the past, even with a fairly substantial roof.

Using a C-section runner with the wheels inside, such as is often used for sliding doors, would keep the roof fixed down (one would hope), but may be a little more awkward to make, especially given the additional complexity of horizontal wheels as suggested by Peter (which I agree would be a good idea).  One of my greenhouses actually has a slightly more complex "C" section runner which has a "gulley" down the middle that the wheels sit in, effectively preventing them from wandering from side to side.  Something similar might remove the need for horizontal wheels.

Some of the benefits of using an open inverted V or semi-circular track such as quite a few of us have used are that there's no side-to-side movement to worry about, and the track is easy to fit and keep clear of debris (and potentially ice, which can build up if rain gets into exposed sections, or even form just as a result of condensation on cold metal subsequently freezing).  The negative side is that there's nothing to stop the roof lifting off other than its own weight.  Some people use turnbuckles or latches to hold the roof down when it isn't in use, and unlock them manually before opening up.  I used something similar to these: https://www.amazon.co.uk/Toggle-Action-Release-Holding-Capacity/dp/B075GZRK4K (the actual ones I bought don't appear to be listed any more).

Another option is to have some horizontal pins that slide into holes as the roof closes, thus preventing it lifting.  This allows remote opening of the roof, but ultimately you may still need something like the above catch to lock the roof firmly in place when bad weather is expected because you don't want it blowing open during a torrential rainstorm.  I don't know what other people have used, but I was toying with using some pins like the ones I have on my tractor implements to fit on a 3-point linkage when I get as far as automating my roof.  Quite possibly that's overkill

One thing to consider regarding freezing conditions: imagine water got into some part of the roller system on a winter day thanks to some blown-in sleet, and as darkness fell and the temperature dropped, producing a night of outstanding best-in-several-years clarity, you then found the roof wouldn't open because that water had frozen.  How easy would it be to clear the ice from your chosen design?

Ultimately I think I prefer the open rail approach because it's simpler to install and to use, but I see no reason the C-section runner couldn't be made to work if that's the way you prefer to go.

James

Great answer James. My existing roof is a light lift off and blows off when I forget to tie it down, once into a neighbour's garden! Last time it happened rain blew my power supply and my qhy guidecam and it took weeks to diagnose and fix, so I'm a little sensitive on this subject.😏

The inverted v rail is clearly designed to prevent lateral movement and sounds easy to install, whereas the c-channel would be harder to install first time with all the lateral and vertical complexities. I think the c-channel could also be quieter because you could use rubber or polyester runners.

[JamesF]

I have to admit that I'd not thought of my V rails as noisy, but I have nothing to compare them with and I'm in the middle of nowhere anyhow.  It doesn't squeal or anything like that, at least.  Quite possibly the roof moving is quieter than a NEQ6 slewing at full speed :)  I appreciate the need to keep noise to a minimum when you have near neighbours though.

James

[SteveBz]

I wish I had an NEQ6 to compare it with! It's on my bucket list.

Really the blowing off is the scary thing. The v rails look nice and easy to install. You said your roll-off roof was quite wide 4m I think you said, mine is as well, 5m probably, but the rails are 3m. How did you handle that?

Did you just use 2 rails?

Tx

Steve.

[JamesF]

The roof is about 2.5m wide and getting on for 4m long.  I needed two rails (or nearer one and three quarters) end-to-end for each side.  This photo taking during construction probably gives you a better idea:

My entire build thread is here, if it's helpful.  There are a fair few photos.

James

[Swoop1]

17 hours ago, SteveBz said:

Hi Swoop,

What do you mean by locking clamps. Would I have to unlock to roof when I wanted to use it?

Regards

Steve.

Something like These.

yes, they would allow you to unlock the roof and slide it when you need to.

[SteveBz]

On 23/05/2021 at 18:13, DaveS said:

A lot of us have ended up going to F H Brundle for track and wheels.

Hi Dave,

I've just phoned FH Brundle (Southampton) and the guy was not very knowledgeable.  Could you by any chance let me know what products you purchased for the slide-off roof.  I'm coming round to the v-shaped idea, as the c-profile idea is just too hard!!

Thanks very much,

Kind regards.

Steve.

[DaveS]

I used  This V-Track, and These Wheels. I also added an End Stop just in case, to stop the roof coming off the end of the track.

HTH

[SteveBz]

1 hour ago, DaveS said:

I used  This V-Track, and These Wheels. I also added an End Stop just in case, to stop the roof coming off the end of the track.

HTH

Great.  I was hoping to find some side-mounted wheels, but I haven't been able to, so you used these top-mounted wheels.  I was also, slowly, coming round to this.  So the roof is like a trolley with exposed wheels underneath and a large gap between the wheels.  Did you put a sort of 'skirting board' round it to cover the side from birds and weather etc?

Kind regards

Steve. 

[DaveS]

Have a look at my obsy build thread from Here on, but remembering that I was making it up as I went along. I ended up putting timber beams on the inside to provide some water proofing and to give an anchor for hold-down toggles.

[SteveBz]

2 hours ago, DaveS said:

I used  This V-Track, and These Wheels. I also added an End Stop just in case, to stop the roof coming off the end of the track.

HTH

Ah, maybe a bit of fascia from Travis Perkins/Jewsons or something?

[DaveS]

Possibly. Don't take what I did as gospel, as there are lots of things I would do differently with hindsight. A lot can be filed under "how *NOT* to build an obsy.

[JamesF]

A few pics of mine during construction that might help (possibly some of the photos from the weeks prior to this might help to show more about how I did it all):

I used this track: https://www.fhbrundle.co.uk/products/0587604000__3_metre_Track_for_V_Grooved_Wheels_in_galvanised_steel

and these wheels: https://www.fhbrundle.co.uk/products/0586604000__80mm_Dia_V_Groove_Wheel_One_Ball_Bearing_Internal_Support

James

[SteveBz]

16 hours ago, JamesF said:

and these wheels: https://www.fhbrundle.co.uk/products/0586604000__80mm_Dia_V_Groove_Wheel_One_Ball_Bearing_Internal_Support

Nice wheels.  Did you have to router a groove on your roof structure to mount each of them?

Steve

[SteveBz]

2 minutes ago, SteveBz said:

Nice wheels.  Did you have to router a groove on your roof structure to mount each of them?

Steve

Ah, no I can see how you did it.

[JamesF]

28 minutes ago, SteveBz said:

Ah, no I can see how you did it.

Ah, jolly good.  I couldn't find any close-ups of the wheel fixings, but I can certainly take some if it would be helpful.  Just let me know.

James