11 replies to this topic

[ssagerian]

All this time I ve been thinking I needed two v-groove rails for my ROR with V-groove wheels  but in a recent post I read the  poster suggesting using a rail system consisting of one v-groove track and the other track just (what?) a flat bar stock. This would mitigate the situation where the two rails were not parallel. Is that what most people are doing (those that use a V-groove track and wheel system)

Obviously you would use the same wheel type on both tracks, what about the difference in heights between the flat track and the v-groove track? Resistance differences between the two tracks?

 

Seems like this allows you to be somewhat sloppy in constructing your gantry, on the other hand, it would allow the roof to roll off even if the tracks are somewhat skewed.

 

HELP!

 

Steve

[Couder]

Don't know about everybody else but my ROR has two v grooves (angle iron with point up) and heavy duty castors (I cut the wheels in a v shape on my lathe). It has been in service for close to 12 years no problems.

[greenstars3]

My RoR also has 2 V tracks and wheels, if you string line the tracks when you install them and check them for square before the castors, trusses and roof go on you should not have any alignment problems. The roof rolls off easy considering its weight and closes just as easy (I use a rope tied to both ends and pull it open and closed without any power source) , be sure to have some method of securing the roof on the track when closed, I use chain boomers on each corner.

The reason I used 2 V tracks is to keep the roof from becoming misaligned  (with guidance from both tracks).  I also have seen in CN differing methods and their are more ways to "skin a cat".

More wheels will make rolling the roof easier whatever method you chose. (I used 3 on each side of a 12X12 ft building and wished I had used 4 per side. 

Grainger sells grooved wheels with grease fittings on them in 4 and 5 inch size. 

 

Robert 

 

edit: make sure to string line the angle iron before you weld it to the flat steel, cold roll steel is not straight, best practice is to snap a chalk line 

Edited by greenstars3, 05 October 2020 - 12:31 AM.

[ssagerian]

Hi Robert and Couder,

could you (and anyone else who joins this discussion) comment on what materials you used in your gantry rails (2x6 fir, 4x4s, pressure treated, etc) and how do you keep them aligned years later?

thanks

SteveS

Edited by ssagerian, 05 October 2020 - 03:41 AM.

[HunterofPhotons]

You haven't said what your roof is going to be made of but let's assume that it's wood or some material that is subject to movement, seasonal or otherwise.

V-tracks are particularly suited to this application and you can easily use two.

As noted before, make sure that one side is mounted securely and straight.  When fastening the other, following v-track loosely snug it down so that it can move to accommodate the sideways movement of the roof.

Flat surfaces exposed to the elements are not ideal.  They will collect snow, rain, and whatever blows around your observatory.

Angled surfaces naturally shed these.

Here's an example:

 

 

Note the v-track in this image is galvanized.  Materials made for outside use should be used in an outside application.

 

dan k.

[Dick Jacobson]

I used v-groove on one side and flat on the other. Seven 6-inch v-groove casters on 1.5" stainless steel angle on the south side. Seven 8-inch phenolic casters on 4" by 1/8" stainless bars on the north side. The bigger the better for wheels, friction is inversely proportional to wheel diameter. My 2000-pound roof needs only 10-20 pounds of force to roll. No problems yet after almost 3 years. South wall is about 4 feet lower than north wall; upper half of south wall rolls along with the roof.

[greenstars3]

My rails are angle iron welded to1x4x1/4 cold roll steel. The building is 2x6 and the supports outside the building is 4x4x1/4 I beam. Treated lumber is prone to warp and twist at a rate that stagers the imagination (look at the reject pile in a real lumber yard). The I beams weight is not for the weak, the rails have remained straight and parallel and the thing may be over built but the cost of replacement for twisted rails will never be an issue. And the cost was not much higher that making a beam out of treated lumber.

The track is 25ft long and is screwed to the building and bolted to the I beam, 12 ft of building and 13 ft of I beam.

 

Robert 

[ssagerian]

My rails are angle iron welded to1x4x1/4 cold roll steel. The building is 2x6 and the supports outside the building is 4x4x1/4 I beam. Treated lumber is prone to warp and twist at a rate that stagers the imagination (look at the reject pile in a real lumber yard). The I beams weight is not for the weak, the rails have remained straight and parallel and the thing may be over built but the cost of replacement for twisted rails will never be an issue. And the cost was not much higher that making a beam out of treated lumber.

The track is 25ft long and is screwed to the building and bolted to the I beam, 12 ft of building and 13 ft of I beam.

 

Robert 

Hi Robert, something about your numbers that is confusing..you have a 1x4x 1/4 flat bar cr steel on top of an I beam?

The building is 2x6?

 

Can you send a picture of the I-beam?

thanks

SteveS

[greenstars3]

ssagerian

 

I was in error about the cold roll flat steel the 1 1/4 x 1 1/4 inch angle iron is welded to. It is 4 inches wide and 1/4 inch thick and is 25 ft long (don't know where the 1" came from). The building is 12 ft and the standard 4x4x 1/4 inch I beam is bolted to the building and is 13 ft long. The top of the wall is at the same elevation as the I beam so the flat steel and angle "rail" is one long piece. The run is smooth to the end with stops welded on each end of the track to keep the roof from rolling off. Sorry about the confusion, I have no photos of it but could take some and send you a PM if you want.

 

Robert    

 

edit: I framed the building using 2x6 studs and wall plates.

Edited by greenstars3, 05 October 2020 - 05:30 PM.

[555aaa]

I did one V groove and one flat. My rails themselves are A500 steel rectangular tube, two pieces attached with a splice plate per rail, so each is about 20 ft long. I think I used 3 x 5.

[Starhawk]

I've wondered if garden railway wheels (miniature railway wheels) would work, since they are not degree of freedom over-constrained and can just run on aluminum angle with the flat bolted straight down- I haven't tried, this, though.

 

-Rich

[Stevegeo]

I have a friend who built a r and r and had me weld up the rails .

We used 2 in sched 40 pipe for rails , and wheels bought off mcmaster car cheap made for rails though v grooved . Welded stops on the ends and each section supported by 2 by 2 steel tubing . His building is 10by 12 ft .

Consider pipe ..it sheds outside elements.