Gina's Observatory Roll-Off-Roof Automation

[Gina]

Hope you get your new house sorted out soon Jake   This is not a good time to be without heating

The grass has kept growing here James but the goats are keeping it short

[Gina]

Hope you get your new house sorted out soon Jake   This is not a good time to be without heating

The grass has kept growing here James but the goats are keeping it short

[Gina]

Arrrgghh - had connection problems last night so gave up trying to post.  Now I see "3 came along at the same time" early this morning while I was asleep   Guess it held my tries until BB was up again then sent it 3 times   One of the "joys" of country living - rubbish BB

[SnakeyJ]

Hope you get your new house sorted out soon Jake This is not a good time to be without heating

The grass has kept growing here James but the goats are keeping it short

Thanks Gina - all in now, bar the lathe, washing machine and tumble drier! I have some work to do at the old house, but taken a week off to sort! Might even get internet tonight if the router arrives from bt :-)

We used to have goats, white saracen? And Anglo nubians - or anglo neurotics as Dad affectionately called them :-) We used to sell goats milk for asthma sufferers and eat the billy goats.

They were good company and affectionate animals, but more intent on escaping and eating the trees and flowers, or climbing on to the farmhouse roof. The sheep were better grazers, but much harder work!

[Gina]

White Saanan I think you mean which we used to breed.  British Saanan and British Toggenburg   Lovely animals.  Just 3 left now one Saanan (white) and two Toggenburg (brown and white).

[Gina]

Ordered some new wheels and track from FH Brundle for the ROR a few days ago - I decided the plastic V wheels were not really the best option for an automated roll off roof even though they could handle the weight alright.  I concluded that the friction would be less with steel wheels and track as recommended by several other members.  Also likely to be more reliable in the long run.

The track and wheels arrived this afternoon.  Looking good   I ordered slightly bigger wheels The 120mm wheels fit the track perfectly (maybe too perfectly unless I can get the wheel carriers mounted precisely on the ROR carriage - should be alright), but the 100mm wheels are a bit wider than the track and run on the top.  I don't think this will be any problem for the lighter north side which currently has no guiding - just rubber tyred wheels on timber track.

Editing please wait...

Edited March 16, 2015 by Gina

[Gina]

Must have taken too long to edit my post as the BBS software wouldn't let me post the edited text (even though it didn't stop me editing it!).  So I'll re-post the edited vserion - here it is...

Ordered some new wheels and track from FH Brundle for the ROR a few days ago - I decided the plastic V wheels were not really the best option for an automated roll off roof even though they could handle the weight alright.  I concluded that the friction would be less with steel wheels and track as recommended by several other members.  Also likely to be more reliable in the long run.  These new wheels and track are round rather than V profile with a 20mm diameter section.

The track and wheels arrived this afternoon.  Looking good   I ordered slightly bigger 120mm wheels for the heavier and more critical south side and smaller, 100mm wheels. for the north side where the weight is much less and the alignment less critical.  The 120mm wheels fit the track perfectly (maybe too perfectly unless I can get the wheel carriers mounted precisely on the ROR carriage - should be alright), but the 100mm wheels are a bit wider than the track and run on the top.  I don't think this will be any problem for the lighter north side which currently has no guiding at all, just rubber tyred wheels on timber track.

[Gina]

Sorted out some wood for the wheel frame supports and sawn through a piece of track to make up the required track length of 4.3m.

Here is a screenshot of a SketchUp model showing  a wheel frame and support blocks.  I have omitted the wheel, axle, ROR carriage and bolts etc. for clarity.  The reason for the length of the blocks is so that I can get two bolts through the blocks and ROR carriage.

Edited March 17, 2015 by Gina

[Gina]

South side roof propped up on blocks and aluminium track removed.  Steel track in place but I need to pull out a few nails before I lay it.

Later...  Nails pulled out and steel track put back.  Prop blocks removed and roof lowered onto track still with the plastic V wheels.  The roof now runs very easily on the round steel track - much easier than on the aluminium V track

Now with the roof closed the next job job will be to swap the wheels over.  I'll start by attaching the wheel frames to the blocks as accurately aligned as I can.  Then prop the roof up again, locate the new wheels and drill the fixing holes for the mounting blocks.

Edited March 17, 2015 by Gina

[Gina]

First 120mm wheel fitted and now working on the second

[Gina]

Second wheel now fitted   Needed adjusting and I left one side not bolted to the support block so that it could self align.  Roof is now running very freely   I shall need to guide the north side as the roof is quite flexible and the wheels tend to come off the timber runner.

[Gina]

The new south side track and wheels are now completed and the roof moves very easily - I can move it with one finger.  The track join is fine with just wood screws to fasten the track to the support timber rail.  There is just a slight click as the wheel rolls over the join in one direction but is noiseless in the other.

Next job will be the north side.  The original rubber tyred wheels with needle roller bearings are starting to make graunching noises as the roof is moved.  I don't think these wheels are suitable for a damp environment   It needs guiding anyway so replacing these rusty wheels with the gate wheels is definitely a good idea

[Gina]

Working on north side track and wheels.  Old wheels and axles removed and bigger part of track put in place.  Now lining up the new wheels and support blocks ready for fixing.  Nice sunshine but a cold NE wind.

Edited March 19, 2015 by Gina

[Gina]

Wheels mounted on ROR carriage on 3m length of track and track slid to adjust the roof so that the storm safety pins and holes lline up   Need to screw the track down now I have it in the right position then measure and cut the extra piece to complete the running track - about 1.5m but need to check.

Tried giving the roof a little push from half open towards closed and it just continued to roll on its own until it hit the end stop in the fully closed position!   WOW    What a difference

[dazza1639]

You can come and do mine next [emoji56][emoji51]

Darren

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Twitter: @SalAstroSoc @Astronut1639 www.salfordastro.org.uk

Nexstar 8 GPS ADM MDS Rings & Counter Weights, Skywatcher ST80 & Synguider, Canon EOS 1000d,

Dew Heaters & 4 Channel Controller, Orbit Wedge, Observatory and not enough clear nights

[Gina]

You can come and do mine next [emoji56][emoji51]

Darren

------------------------------------------------

Twitter: @SalAstroSoc @Astronut1639 www.salfordastro.org.uk

Nexstar 8 GPS ADM MDS Rings & Counter Weights, Skywatcher ST80 & Synguider, Canon EOS 1000d,

Dew Heaters & 4 Channel Controller, Orbit Wedge, Observatory and not enough clear nights

I'm afraid Manchester is just a bit too far

Edited March 19, 2015 by Gina

[dazza1639]

[emoji20]

Darren

------------------------------------------------

Twitter: @SalAstroSoc @Astronut1639 www.salfordastro.org.uk

Nexstar 8 GPS ADM MDS Rings & Counter Weights, Skywatcher ST80 & Synguider, Canon EOS 1000d,

Dew Heaters & 4 Channel Controller, Orbit Wedge, Observatory and not enough clear nights

[Gina]

Track now all finished, all fitted and screwed down   Now have full run of the roof.  Tried a push from closed and it ran on its own right up to the fully open stop.  I can open and close it with my little finger   Main push is to get the mass moving   Now that the north side is guided the storm safety pins just slide into their holes with no effort - there is a small clearance and the accurate alignment means that they don't touch the sides at all.  Only thing left now is to refit the draftproofing brush pieces to provide a good weather seal.

I am extremely pleased with these new wheels and track

[Gina]

Been working on the east wall flap/window.  Now timber cut to size, brackets and bearings 3D printed, aluminium channel for ends of polycarbonate sheet, cut to length, drilled, slid onto poly sheet and screwed to the timber uprights.  Finally, all partes assembled and screwed together.

Here's a photo.

[Gina]

Slight change on the East Wall Flap/Window - polycarbonate window pane now on the inside of the frame.  Weight will be balanced by arm and weight on the north side with bias towards closed so window will be pulled open.

Here are a couple of SketchUp screenshots.

[Physopto]

Gina,

 Just out of interest, have you tested the printed parts for strength in any way. I'm afraid I look at them with some suspicion. The printed parts are usually well fused in the x-y plane but because of the necessary time taken to return to the same position in the next layer the fusion strength is not the same. I.e. the bond strength is less in the z axis. Over a period of time the strength may deteriorate and basically the layers could possibly split apart. The cold weather may also hasten the process! The material could be very brittle in our climes especially at low temperatures when being subjected to shear stresses.

It would be a great shame as the amount of effort you are putting is something to behold.

I speak as an ex engineer.

Regards,

Derek

[Gina]

Yes, I have tested the strength and I over-engineer to allow for cold weather and aging.  I arrange the print orientation so that the weak Z dimension is not where it matters so much.  To test the main support bearing brackets I got a loop of bailing twine threaded through the hole and the other end round one of my feet and tested it with my not insignificant weight - it passed   The window unit plus balancing weight will be very much less

The only think I'm not quite happy with is the counter balance - I might yet change my mind on that.  It has to turn the aluminium tube which in turn would turn the end brackets on the window frame.  I might have something inside rather than outside and connect to the actual window frame.

Edited March 22, 2015 by Gina

[Physopto]

Well!!!

I aint going to put myself in the position of any comment on a ladies weight  I value my life too much! I learned the hard way, married and poor you know.

Derek

[Gina]

The new window fits well   I think I'll go back to the rope/cord method of closing the window.  I have some Marlow yacht rope of 6mm diameter with a breaking strain of about a tonne - it's good stuff, I used in in my sailing days.  Rot proof and very low stretch.

[Gina]

From inside the scope room.