Dew shield support?

[DazC]

I recently made a dew shield for my dob.

I made it from a camping mat, secured it to the scope and taped the join together.

This is all good....until I lower the scope to near horizontal at which point, after a short while the end of the dew shield starts to 'sag'.

I've looked through the eyepiece and can't see the shield in the FOV, it is not obstructing views.

I just have a couple of questions.

Will this be affecting the amount of light entering the tube?

And

Is there a lightweight way of supporting the end of the shield so it keeps its circular shape?

I hope that all makes sense.

D.C

[NGC 1502]

Hi D C.   If the dew shield is sagging, it's possible that it could be reducing the light entering the tube, without that being apparent when you look into the eyepiece.

You could probably get a better idea by looking from the front end.

A lightweight method of keeping the front end of the dew shield circular is to use a narrow strip of thin aluminium.  The ali is easily formed by hand to the curve needed. It could be fixed to the outside of the shield with strong duct tape.  I expect there are other methods, perhaps better suggestions will come from others.

HTH, Ed.

[DazC]

That was the kind of method I was thinking only I thought of using a wire coat hanger.

Thanks for your input Ed.

I'll give it a go.

D.C

[CPR1969]

Hi,

I used some old bike spokes taped to the outside of the roll of camping mat, did the trick without having to bend them too.

[michaeldurban]

I used foam for my dewshield...

And I strengthened it with steel wire from the local hardware store.

I made to circles from the wire, and fitted those on opposite ends

of the dewshield, the I took two strips of leftover foam and glued

that over the rings to secure them into place.

Then I took four straight steel wire cuts and fitted those around the

dewshield (north,east, south, west) and secured them to the top and

bottom circular steel wire, bit like a steel cylinder.

That does the job perfectly..