Latest Project - 18" f3.9 Truss Dobsonian

[Rustysplit]

That is the same as the ply I used in my UTA. Really nice to work with and a perfect match to the other thickness birch ply panels.

[Moonshane]

The mirror box is now pretty much complete. need to make the cell and the truss clamps and it will be completed. should start on the rocker first though, probably next weekend.

the construction is fairly standard with rebated butt joints in the corners, nailed and glued and with gussets and fillets in the corners to add further strength. I did the gussets last weekend but when I looked again before starting today, they looked a bit bulky so I used the jigsaw to remove the bulk and then a small saw to clip the corners before rubbing back to a shapely corner piece. I then added some further gussets which were a bit more shapely. this adds further strength to the mirror box which is now really quite robust. once the cell and truss clamps go in it will be pretty good. note the curved front / leading edge which allows the scope to sit a couple of inches lower as the rocker can be shorter (and stiffer).

I had previously drilled the holes in the sides from the alt bearing template and these were also transferred to the bearings themselves today. as I often do, I added two sets of holes. one for the anticipated balance point (the top of the mirror box) and one a little lower in case the scope is too bottom heavy. with an f4 scope this is a possibility as the leverage of those heavy eyepieces is 20% lower than an f5 scope. doing this now is less tricky then when the scope is built!

there are some pics below showing the mirror box and with the side bearings place on loosely with bolts (no handwheels at this stage.).

It's starting to look more like a scope than a pile of wood in my loft!

[Rustysplit]

Coming along nicely Shane. I really like the look of the alt bearings.

[swamp thing]

Nice going Shane. Are the side bearings going to be removable then?

[Moonshane]

hi Steve

to some extent although I'd envisage them being more or less permanent once the preferred setting is established.

[estwing]

looking very good Shane,that curved leading front edge is very clever is that your own idea?

[Moonshane]

not at all matey - Kriege and Berry have the credit for that (well, Kriege and Berry and of course Pythagoras ).

[estwing]

haha..sorry mate with your telescope making skills I wouldn't of been surprised if it was your idea!

[Moonshane]

I do have my own ideas of course but like most I 'stand on the shoulders of giants' to get started. usually the issue is getting the eyepiece a little higher but with this scope it's getting it a little lower that counts.

[estwing]

ok now the cat's out of the bag...i'll confess this is going to be my scope..

[swamp thing]

Any updates???

Pics would be really nice

[Scott]

hmmm, just wondering how I'm gonna get that in my car, might have to leave passengers at home

you don't mind do you calv?

[estwing]

yes mate if shane see's anything tonight he's going to cut the truss poles to focus?..you'll know what I mean..pics yes tomorrow I maybe able to pics it up and bring it home!...it's not been a bad week for me.

[Moonshane]

hi all

been working like a slave to get this finished by tomorrow and have been too tired to take pics in truth! it's outside now with makeshift trusses to allow me to properly gauge the proper length so I can cut and make them tomorrow which will be it completed subject to a final test tomorrow night (I hope). I am sure Calv will add pics soon after he takes it home :0).

the amount of work in these scopes if heavy if you work full time and have a family and I will only be making them for myself in future I think; although I hardly went into full scale production anyway!

[Moonshane]

indeed, just need one (only one will do) star to focus tonight to allow a finish tomorrow.

[estwing]

hmmm, just wondering how I'm gonna get that in my car, might have to leave passengers at home

you don't mind do you calv?

..don't worry mate the Telementor will fit in no worries

[swamp thing]

Tell me about it Shane.

It's a lot of evenings and weekends when there's so much else to do.

[faulksy]

hope you get lear skys shane for your final test, good luck mate

[estwing]

will take pics tonight..more soon

[Sfarndell]

Any updates?

[Moonshane]

and

[faulksy]

loved that build as well, thought the part were calv says ill confess its my scope was dead funny, he couldnt resist good on you boys