dob shroud

[astrokat]

in need of a shroud for new 14" skyarcher dob any ideas please

ive no idea what im doing though mother in law is very handy with sewing machine

[brantuk]

Try Astrozap - they do the 12" but don't know if they've introduced the new 14" ones yet. Or ring FLO for advice on that

[Talitha]

Hi Toby.

I made the shroud for my 16" LightBridge. Be sure to measure the material long enough in length to allow for two 'hems' which your securing cord or elastic will run through at top and bottom, and also measure the material wide enough in girth to allow for an overlap where the material will be joined together (i used velcro).

You may need to make a few 5" wide 'stiffening' rings (think barrel hoops) for the outside of the truss poles if your scope has a six truss design like mine does. The six truss design leaves gaps which the shroud tends to sag into, blocking the lightpath to the mirror. I used strips of a camping mat for mine (the same material we make dew shields from). If your scope has an eight pole truss design though, i don't think you need the rings.

The material i used is a very tightly woven thorn-proof material used on the front of hunting and camping pants. Water runs off of it when poured directly on, but the slow dewing process soaks it all the way through although i've never had a problem with water pooling on the interior and running into the LTA or dripping onto the primary mirror. After the session, undo the velcro and hang the shroud up to dry. Hope this helps.

[rowan46]

If you make it yourself you may find these useful Pennine Outdoor - Outdoor Fabrics, DIY Clothing, Walking Gear and Sports

[WayBig]

That's a great idea Carol - I can remember feeling underwhelmed when unpacking my £50 astrozap dew shield, and thinking I'm sure I could have knocked up something myself much more cheaply.

[astrokat]

astrozap are not making yet i think i will have a go at making my own thanks for all the good advice i will post my results when finished

[Talitha]

I know what you mean, Chris... an Astrozap for the 16" LightBridge is about $90... IIRC, it was only $20 for the material, velcro and elastic. I was tempted to try a plastic shower curtain, but my winters are too cold and it might shatter when touched. Out of curiosity i might give it a try after the Spring thaw, though.

Looking forward to seeing the finished product, Toby.

[WayBig]

but my winters are too cold and it might shatter when touched.

...Ouch

[sixela]

Don't forget to also consider a light shield to extend the front as well.

Depending on exactly where the focal plane is, stray light can enter the scope from the front opposite the focuser if you don't extend the tube there.

[Space Cowboy]

I used camping mat..keeps its shape and so far had no problem with dew on the secondary. Only problem is small gaps at the top caused by the truss bulging out...need something to cover those over for it to be completely stray light free.

[bcfcciderhead]

i use the 10" lightbridge type for my 8" dob, i use the 10" so the extra 2" helps it go around the truss's, it was longer then i needed so cut off about 8" and use this as a dew shield, i had to trim the ends a bit to make it fit around tidy but it works really well and only cost £10 from astro buy and sell, but after looking at different types and what they are made from i would go and make your own and save a few pound.