fwm891

Well the model has progressed if nothing else... Please excuse the panel pin axles, and the brace round the wrong way and... (anything else)

You need another scope to cut out complicated decision making...?

No, the Flat 73A is set to 11.4 (on the WO scale - probably mm but not sure?) then the 48mm T camera adapter. Total. If your using a cooled camera (CCD or CMOS) then some adapter will be needed to make up the difference between a dslr and short back focal plane cameras. My pic's above were without the flattener in place - Han Solo has a flattener. Mine with guide scope. Flat 73A and D5100 on Star Adventurer

I have a lathe and some small lenses...

I have to say I hate Sketch-up. Never got on with it even the basics...

Decided to try building a model at 10th scale - nowhere near finished, braces to add, sleepers, cladding, etc., etc...

If your testing something the set-up must be as tight as possible otherwise the test is pointless. Even if you are intentionally off-setting your PA, off-set it a good amount so you can clearly see errors.

They were curved but no bright spots along the length - sorry dumped them.

Hi James - If it is a serious error and the drive wheel is a little eccentric then there may be a speed variation causing the brighter patches...?

First do a good PA with the weight of the camera/lens etc on the SA then try your exposures again. My first results were similar because I 'had to use it' but never took the time or care over the initial set-up. Mine works fine now with a 430mm fl scope mounted and DX format camera. These images were taken with mine when reviewing a WO ZS 73 APO:

I turned mine through 90° putting the fine focus knob on top where it's easy to get to.

Well I for one am not happy about the iOptron CEM60 problems - been waiting 6-7 weeks now. My iEQ45 Pro guided extremely well whether I used a separate guide scope or OAG, it's only that I want to put a heavier scope on a mount and tandem mount two smaller scopes that I'm going for the CEM60. I've seen a friends results directly with his CEM60, OAG guided with a 9.25" Edge HD on board and the results are superb - one reason I hit the buy but with FLO for a CEM60 - come on iOptron fix it quick. Seems TS have the EC version in stock...

Awkward with the high heels though!

Yes. I ran a bead of bitumen sealer around the edge of the ground board (read sleeper) / slabs before and could find no evidence of water ingress when I had to dismantle the thing. New sleepers have an expectancy of 10-15 yrs, I'm just about 68 now so if they rot in 15 yrs time I'm not sure I'll be too worried...

That's essentially what I did with my previous obsy. I used a plastic DPC as a skirt running from under the lower shiplap and down over the sleeper.

Thanks All for the track input. Looking at the wall/bearer cross sections hopefully self explanatory. Not a great deal of loading as the obsy will be quite small. Footings: scalping's with a very liquid cement binding. Paving slabs over the footings with treated sleepers spreading the loading across the slabs. Waterproof membrane comes next with the floor joist bearer's pinning the membrane to the sleepers. Joists to support the T&G flooring. Walls sit on a weather board to take water away from the structure, Treated shiplap cladding over a CLS frame - internal cladding in 12mm OSB...

Looking at the tracks/wheels from Brundle's I'm trying to decide on which wheel size to choose. I'm thinking the 200Kg per wheel is way OTT but that's the loading option I'm looking at with a 20mm round top galvanised track. The wheel options are either 60 or 80mm diameter. https://www.fhbrundle.co.uk/groups/13SWR200__200_kgs_Weighthttps://www.fhbrundle.co.uk/groups/13SWR200__200_kgs_Weight Any thoughts welcome

Thanks Steve - not what I wanted to hear re CEM60's but...

Looks superb but on dew laden nights isn't the carpet going to act like a sponge which will need a dehumidifier running during the day to remove the water - especially when a wet day follows a damp night...?

No James - it got dismantled because people viewing the house were put off by it. The observatory was built in sections apart from the roof and it ended up being a posh chicken run for a guy in the village...

My earlier obsy while in Devon

Pondering whether to carry the cladding right across each elevation, mitre the corners and hide the corner posts...?