Constructing a dob

Although I've been quiet on this thread for a few days now, progress has continued a pace. Below are two images of the near-completed scope:

www.astroshot.com/Dob/17.jpg

www.astroshot.com/Dob/18.jpg

The items which remain to be done are:

1-Stiffen up the bearings with connector struts between them
2-Level off the truss clamps. One of the struts appears to be slightly off from the remainder of them.
3-Glue washers above the truss collars on the secondary cage so that the wood doesn't get marked when the upper truss clamps are tightened.
4-Attach metal or timber onto the inside of the rocker box to form a track for the bearings to sit around. At the moment, they could easily fall off the bearings.
5-Fix the length of sling.
6-Insulation to the truss poles.
7-Length of steel plate to attach to the struts which carry the truss clamps - to stiffen it up.
8-Bars on the mirror cell to hook over the mirror to ensure it doesn't fall out.
9-Any other suggestions???

Many thanks to Dave L this evening for talking me through the installation of the upper truss clamps.

Cheers,

Michael,
she is looking good !! I though you said the primary mirror is a foot of the ground, it certainly looks alot lower in your pic. !
I think you have all the bases covered so here are a few more minor things to consider.

1,A shroud of some sorts, I guarantee the mirror will fog over at WSP otherwise, even a partial shroud for the lower 2 or 3 feet of the truss poles would do.

2, A viewfinder, a telrad would be ideal.

3, double sided tape for the primary mirror + belt.

To me its looks like you could have knocked off a few inches off the height of the UTA as the focuser is soo far down towards the primary mirror? Is there any particular reason why its that high/long.?

In your pic, either the focuser is on upside down or the UTA is sitting 180degrees rotated, a minor detail :lol:
Now there is a question, which side of the scope do you prefer the focuser to be on?

Dave,
Thanks for the feedback.
I had forgotten about the shroud. That won't happen any time soon though. Need to get something made up.
I have a red dot finder but forgot to mention it. I need to put this on.
Going shopping for some double-sided tape today. Although, if I do that, I'll need to leave the mirror in the cell at all times, otherwise the glue on the tape will just wear off. Any other suggestions?
The UTA is only as long as it needs to be. It's designed around the height of the spider and secondary mirror. I didn't see much point adding another few inches to it.
As for the focuser, I'll bring a screwdriver with me to Birr and we can fix that there. Didn't know which way to turn it to be honest.
Cheers,

Lookin' good Mike. Bringing any more pics to the TAS meeting tonight?

1-Made up a simple three piece H-section of timber. Treated it and let it to dry overnight. I'll attach this to the bearings tomorrow evening.
2-Truss clamps now levelled
3-Washers glued to the UTA
4-I've attached a few metal plates to act as a track.
5-Sling length now fixed. Will tweak this at Whirlpool.
6-I have the insulation but won't bother with it for the mo until the pole lengths are perfect
7-WOn't bother with this till after Whirlpool. I reckon it's the least I'll need. I'll get some feedback first and decide what to do then.
8-Won't finasise these till after Whirlpol. Will get the length right first.
9-Double-sided tape is not onto the mirror and I'll simply attach it to the sling when it get's installed onto the mirror cell.
10-Will try and work up something up tomorrow evening but may not get time before Whirlpool.
11-As for the focuser, I rotated it 90degrees, just to be on the safe side and cover all my bases.

Michael,
The shop here in Limerick where I was going to get the shroud material doesn't have it it stock, maybe you'd have better luck in the Dublin shop.