View Full Version here: : advice on roll off roof tracks and wheels setup?
09-06-2010, 06:33 PM
I have built a roll off roof observatory. The roof does not roll off very well.
I used 100mm C purlin on its side as the track and 75mm wheels on an M10 axle bolted through 100x 40mm 3mm steel section.
There is very little clearance for the wheel inside the purlin and I think that is the problem.
I am thinking I will lay the purlin in its back and see if that works better.
Greg, I put some comments in the cdk17 thread. Do you have photos?
09-06-2010, 07:41 PM
here Greg here is some pic of my observatory building,tha rail is upside down angle iron,the castors come from big castor shopa in Brisbane I will get details for you
09-06-2010, 07:44 PM
I will try and get some better pics,uploads very slow tonight,IIS security is popping up so slowing things as well.
hope the one pic I got up helped
09-06-2010, 07:48 PM
Here is a photo of the current setup:
The axle is an M10 bolt with a domed head. It isn't a proper fit in the wheel which seems to need something like an M12 or 14. The wheel itslef is wider than I would like as the C purlin only has 45mm of clear space. The dome head bolt end has a little squared off section as it is designed to bolt timber together. The wheel has roller bearings.
Chris how do prevent the roof from blowing off in heavy winds?
Some sort of lockdown system?
Your getting a sideways shift. This is common to most c perlin designs. Stop you side shift, and you stop to friction.
I can recommend some suppliers that have a track and wheels to suit, that are designed to stop sideways shift and hold the roof securely and runs smooth as a babys butt.
09-06-2010, 08:39 PM
Very simple,'L' bracket on roof with hole in bottom,'L' bracket on inside of wall,with hole (half inch) a bolts goes through,a wing nut attaches underneath.there are 8 of these,very,very simple
I will post pics tommorow,too cold to go outside now.
Its a very simple system,with the bonus of adjustment for ground slippage,see the pic again,note the bolts and nuts,I can 'tilt' the roof if needs be about 5mm either way,(does this mean I have a 'tilt' train in my yard:lol:)
also,the castors have 5mm 'play',not that I have ever needed to call on any of this,never had an issue,never had any maintanance,a bit of CRC to stop rust colour.
Cant go wrong with this design,I have seen a set up like you mention,I nearly went that way,then we figured this was more simple,less likely for lproblems,Hope this helps,
09-06-2010, 08:49 PM
I use something similar to Chris, except my angle iron is laid flat to the bearer so the pulley sits on the edge of the angle. It works a treat. The angle is 4mm thick and the pulley is 5mm in the center. A bit of grease on the angle and its a smooth as butter. If any spots are tight a quick brush with an angle grinder or even just a rub with some sandpaper soon frees up any tight spots.
The only disadvantage to this is some form of hold down has to be used to secure the roof.
09-06-2010, 09:02 PM
Hi Greg, I use C channel on my roll off roof observatory. As well as the 8 wheels that take the weight of the roof, I fixed 4 wheels at each end that run at 90 degrees to the others stopping any sideways friction.
You could do this with your set up also.
09-06-2010, 09:15 PM
Yes I agree that is the problem. Who would you recommend for the track and wheels?
09-06-2010, 09:17 PM
Yes, well you were right.
That is a possible change. I think that could be plan B and a more simple mod to what I already have is plan A.
Some sideways wheels could work although mine is only 100mm C purlin whereas yours looks like 150 or bigger.
09-06-2010, 09:34 PM
Yes Greg, mine is 150mm C purlin. Even very small wheels would help minimise any friction from side ways movement. Small roller bearings would do the job also.
All the best.
09-06-2010, 10:29 PM
Thanks for the tip Lester.
I will look at how I could add some sideways wheels as I think that is definitely what is happening. It is possible the trusses I have made flex down. The 2 steel 100 x 40mm x 3mm are pretty heavy. Add the roof and trusses and you would have about 175kg.
The trusses though are only holding the roof up and that would weigh about 80kgs or less.
Richmond wheels and castors seem to have a huge range. There is one in particular PU350 which is 75mm in diameter, ball bearing, 1/2 inch axle and only 29mm wide including the ball bearing housing. It also can take large weight loads. These guys are in Wetherill Park.
10-06-2010, 08:24 AM
Heres some pics of my roll of roof observatory,if anyone want design,I will give it to you.
The roof weighs around 500 Kg.the Richmond castors are very good.
hope this helps
10-06-2010, 06:00 PM
Thanks for the advice I rearranged it today and believe I have it working now.
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