14 replies to this topic

[Taylor]

Hi all, I built an 8x10 ROR a couple years ago. Due to architectural requirements, I had to use shingles, which makes it quite the hefty roof to roll. 

Its quite difficult to open. I used V track rails with 2" V groove casters. They're all in-line, square, etc. 

I'm wondering if small diameter casters is the source of my issue? Would I be better served with a larger diameter wheel? 

Like a 3 or 4 inch diameter caster?

[rachnoman]

Using a "V" groove setup does not allow for any lateral play. You may want to consider using an inverted channel for a track with steel rollers (not rubber).

[Couder]

I made my ROR for the spectrohelioscope about 25 years ago. I used 5" hard rubber rollers and cut a v groove in the rubber with my lathe. I used inverted angle iron. When we moved here, I moved the shed too. It has given absolutely no trouble in all those years, opens very easily with the slightest push. I do tie the 4 corners down when not in use, as it is about 10 foot in the air and we get high winds here. I sold the SHS last year, and gave the shed to a neighbor who is still using it.

Attached Thumbnails

• 
• 
• 
• 

[lee14]

I used 2 inch wheels on my 10 x 12, but a good number of them. I also used cedar shakes for roofing, which is maybe half the weight of asphalt/fiberglas shingles. Once the initial inertia is overcome, it rolls pretty easily.

 

If I did it again, I would use 3 or 4 inch wheels, and metal or rubber for the roof covering. Lighter roofs require secure fastenings when not in use, but that's an easily solved consideration.

 

Lee

[greenstars3]

I used metal 4 inch v groove wheels, 3 on each side on a 12x11.5 ft RoR and roll it off pulling on ropes that are on each end of the building.

Tie down is with chains and boomers on each corner when closed, it does not move even in the March winds

I do have 120 volt AC run from the house to power things inside but have not motorized the roof

I have weather strips on the perimeter of the building to keep the bugs out so I designed the roof to have a slight (1.5 degree) angle were the roof comes together upon closing

The track is level 

The wheels have grease fittings for the axles I ordered them from Grainger and they are rated for 1600 to 2400 lbs each, (don't remember exact rating) rather overkill but I wanted them to roll freely    

 

Robert 

[HunterofPhotons]

"Using a "V" groove setup does not allow for any lateral play."

 

It certainly does if one is familiar with the materials used and the principles of construction.  The simplest way to do this is to minimize side-to-side movement of the roof when building it.  When fastening the V-groove tracks fasten one side down tightly and the other track should barely be snugged down and be allowed to move by over-sized mounting holes or some such.  This 'follower' track allows for lateral movement over the seasons.

 

_______

 

"You may want to consider using an inverted channel for a track with steel rollers (not rubber)."

 

An "inverted channel" is just a gutter that channels water into your observatory.  V-groove tracks inherently shed water.

Steel wheels sitting in water;  What could go wrong there?

 

dan k.

[555aaa]

4”. I used V groove on both sides in my last build. The axles are wide enough to accommodate non parallelism (there is about a half inch extra space on each axle for lateral play). But you don’t want to allow much lateral. The V groove approach does have more friction than flat rollers however.

Edited by 555aaa, 05 March 2024 - 01:18 PM.

[rachnoman]

"Using a "V" groove setup does not allow for any lateral play."

 

It certainly does if one is familiar with the materials used and the principles of construction.  The simplest way to do this is to minimize side-to-side movement of the roof when building it.  When fastening the V-groove tracks fasten one side down tightly and the other track should barely be snugged down and be allowed to move by over-sized mounting holes or some such.  This 'follower' track allows for lateral movement over the seasons.

 

_______

 

"You may want to consider using an inverted channel for a track with steel rollers (not rubber)."

 

An "inverted channel" is just a gutter that channels water into your observatory.  V-groove tracks inherently shed water.

Steel wheels sitting in water;  What could go wrong there?

 

dan k.

 

Agree. To have one track "floating" solves the problem. 

[*skyguy*]

I used metal 4 inch v groove wheels ....

 

The wheels have grease fittings for the axles I ordered them from Grainger and they are rated for 1600 to 2400 lbs each, (don't remember exact rating) rather overkill but I wanted them to roll freely    

 

Robert 

I also used 4" grooved wheels (4) with grease fittings ... purchased from Graingers  ... running on 1" inverted track. My garage-top ROR observatory is small (6'x8'), so these are also a bit of an overkill. However, the sides of the observatory also roll-off along with the roof, so it is a lot of weight to move.

 

 

[BlakeMC]

4" V groove on both tracks.  As has been mentioned, there is enough lateral play that tracking has never been an issue.  I prefer the V to flat to handle the occasional ice, snow, twig etc.

 

 

https://www.cloudyni...tory/?p=8032563

Edited by BlakeMC, 06 March 2024 - 12:07 PM.

[astrohamp]

Taylor:  Fwiw if your "architectural requirements" are for shingles on the roof, perhaps you can swap them out for metal ones that look like conventional shingles and save some weight.

 

Can be a DIY project although edge flashing and roof peak may need some head scratching if the supplier options are a poor fit.  Saved me tons of weight on my house roof.  Does go though a morning dew cycle and avalanche season can get a bit exciting sometimes without 'snow dogs' installed.

[Taylor]

4" V groove on both tracks.  As has been mentioned, there is enough lateral play that tracking has never been an issue.  I prefer the V to flat to handle the occasional ice, snow, twig etc.

 

 

https://www.cloudyni...tory/?p=8032563

It sounds like 4" is the way to go, from all the replies so far. I am assuming that a larger diameter wheel offers less resistance than the current 2" wheels that I currently have installed? 

[gordtulloch]

"Using a "V" groove setup does not allow for any lateral play."

 

It certainly does if one is familiar with the materials used and the principles of construction.  The simplest way to do this is to minimize side-to-side movement of the roof when building it.  When fastening the V-groove tracks fasten one side down tightly and the other track should barely be snugged down and be allowed to move by over-sized mounting holes or some such.  This 'follower' track allows for lateral movement over the seasons.

 

_______

 

"You may want to consider using an inverted channel for a track with steel rollers (not rubber)."

 

An "inverted channel" is just a gutter that channels water into your observatory.  V-groove tracks inherently shed water.

Steel wheels sitting in water;  What could go wrong there?

 

dan k.

My v-groove is in fact "floating" in garage door C-track so it can move around with the roof, works like a charm! Here's a pic from before I built my current micro-observatory of the wheel, angle iron and c-track. Water can collect in the c-track but it's open on either end so it just runs out and can never enter the building

 

Edited by gordtulloch, 06 March 2024 - 04:02 PM.

[archer1960]

My v-groove is in fact "floating" in garage door C-track so it can move around with the roof, works like a charm! Here's a pic from before I built my current micro-observatory of the wheel, angle iron and c-track. Water can collect in the c-track but it's open on either end so it just runs out and can never enter the building

 

How do you manage snow/ice buildup in the track channel?

[gordtulloch]

Warming cable used to desnow roofs is run under the angle iron which melts the snow and prevents ice buildup. What generally happens is a "dome" of snow forms around the runner where the heat doesnt reach and then the building bulldozes it off when it opens. I turn the heat on and off via a Karas Smart Plug strip, see my article here on my SubStack for details on how it works.

Edited by gordtulloch, 07 March 2024 - 10:55 AM.