Jump to content

sgl_imaging_challenge_2021_annual.thumb.jpg.3fc34f695a81b16210333189a3162ac7.jpg

Flocking a 6SE


Recommended Posts

asked on here about a month ago but was advised against it

I'm afraid I'm a bit more adventurous than that myself, much prefer to investigate then go for whatever it is I'd like to do rather than do nothing.

Link to comment
Share on other sites

Hi I did a C90 Mak, photos attached.

I also stuck some flocking on black paper and lined the focuser tube, not sure if a 6SE has one of these, is it the same as a baffle?

post-13264-0-52695100-1367248593_thumb.j

post-13264-0-68499200-1367248602_thumb.j

post-13264-0-86016200-1367248610_thumb.j

A noticeable improvement in contrast was noted, especially in the daytime as it was mainly used a a spotting scope.

Not too much of a slouch at night either.

Edited by moriniboy
Link to comment
Share on other sites

Hi,

Just last weekend I had the chance to check a Celestron SC 6SE OTA. It was returned because the costumer found the mentioned halo rings from bright stars near the edges of image - now he's a happy owner of a 5" f/9 achromatic refractor. I tested the telescope with several eyepieces and star diagonals. The halo rings appeared with every star diagonal I tried, from the original 1,25" prism supplied by Celestron to 2" SC-threaded dielectric mirror and 2" refractor-type dielectric mirror, using 2" wide angle eyepieces from 22 mm to 40 mm and also the 6SE's standar 25 mm 1,25" Plössl.

By the way, I believe I can recall the same type of halo rings in the 8" SC OTA of my CPC 800 when looking through some long focal lenght wide angle eyepieces. I'll test this again as soon as the sky gets clear.

Regards,

Leo

Link to comment
Share on other sites

A Celestron Nexstar 6SE OTA.

post-20192-0-03217600-1367354994_thumb.j post-20192-0-90986500-1367355054_thumb.j

First thing to do is to remove the rubber bung from the front of the Dovetail bar.

post-20192-0-09166600-1367355176_thumb.j post-20192-0-01154600-1367355192_thumb.j

Now slide out the manufacture label plate, this is NOT easy, mine appeared to be slightly glue so had to tap it to free it.

Once the plate is removed it reveals an allen screw at the front end of the dovetail bar, their are 2 more allen screws at the rear of the dovetail bar.

post-20192-0-24154200-1367355266_thumb.j post-20192-0-89269000-1367355382_thumb.j

Link to comment
Share on other sites

Next thing to do is to remove the dovetail by removing the 3 allen screws holding it on.

You now have access to all 4 screws (3 are highlighted) that hold the entire front corrector plate assembly to the tube.

post-20192-0-47450000-1367355831_thumb.j

After removing those 4 screws the whole front assembly just pulls away.

post-20192-0-45378100-1367355953_thumb.j post-20192-0-15437600-1367355904_thumb.j

Link to comment
Share on other sites

The baffle around the secondary mirror looks quite shiny on the inside, even though it's painted matt black.

post-20192-0-93341400-1367356116_thumb.j post-20192-0-10800000-1367356190_thumb.j

The inside of the main tube also looks quite shiny (again painted matt black).

post-20192-0-76202600-1367356346_thumb.j

Should have added these photos before hand showing the internal shininess. Better late than never.

post-20192-0-09923200-1367356570_thumb.j post-20192-0-09843600-1367356586_thumb.j

Edited by Cath
Link to comment
Share on other sites

Removed rear assembly (complete single unit) by removing the 4 rear screws around the tube.

Cut the velour to size - one piece 54.5cm * 23cm.

post-20192-0-94904000-1367360995_thumb.j

Before flocking (left) .. after flocking (right)

post-20192-0-70574100-1367361170_thumb.j post-20192-0-55534900-1367361012_thumb.j

Note. Their are no nuts on the inside of the tube (the tube is threaded for the 8 screws) unlike the larger Celestron tubes, which means removing the 2 ends can be done without removing the corrector plate and primary mirror separately.

Edited by Cath
Link to comment
Share on other sites

I left a thin unflocked edge right at the front of the tube, you can see the difference between the matt black painted tube and a flocked tube.

post-20192-0-93573200-1367365745_thumb.j

I also flocked inside the secondary mirror baffle by unscrewing the plastic baffle off and using a 166mm * 26mm piece of velour.

Before flocking (left) .. After flocking (right).

post-20192-0-81875300-1367366059_thumb.j post-20192-0-34102700-1367366016_thumb.j

Finished OTA.

Before flocking (Left) .. After Flocking (right).

post-20192-0-75351900-1367366153_thumb.j post-20192-0-58699400-1367366164_thumb.j

The tools I used were an allen key (dovetail removal - 3 bolts), a philips screw driver (front and rear assemblies - 8 screws), a pair scissors and a very sharp modellers blade - for cutting the velour.

The hardest bit was removing the Celestron label plate at the beginning!

Edited by Cath
Link to comment
Share on other sites

Very nice Cath, can't wait for the results

Well, time will tell !

I couldn't flock inside main baffle that goes through the primary mirror as that is just too long and narrow. Not looked inside the diagonal - yet.

I'm not expecting an enormous improvement but ort to be a bit better I would have thought.

Link to comment
Share on other sites

I found the biggest improvement was doing the long baffle tube, mind you the C90 was very shiny.

Just cut some paper to fit the tube exactly, then flock it, stick the long side together with a permanent type sellotape (not the degrading cellulose based stuff) and insert into the tube. As you have pre-measured it a friction fit is all you need, sorry I don't have any photos.

Link to comment
Share on other sites

Thanks moriniboy.

I'll have another look at it again then, see if I can do similar.

I'm also going to flock the outside of the secondary mirror baffle, so will look at doing the long rear baffle as well then if I can.

What they ort to do is make these baffles from semi-stiff flocking material rather than solid plastic/metal. Would be cheaper for them as well I'd have thought.

Link to comment
Share on other sites

good point cath, but in the summer when your ota gets hot in storage it could bend if its made of something soft

I'm sure with today's material knowledge they could sort out a suitable base material for the flock to avoid bending in hot conditions. In the mean time we'll just have to flock what we have I guess ourselves.

I'm glad I've done it anyway, it's good to have learnt the internals of my scope. It doesn't seem scary now the thought of opening up an SCT.

  • Like 1
Link to comment
Share on other sites

Good job on the flocking Cath.

re materials today, I doubt you need a recent material that does what you say. It's just a price/profit thing. Bending sheet metal or extruding is probably cheaper and more consistent than working with resins.

Link to comment
Share on other sites

I found the biggest improvement was doing the long baffle tube, mind you the C90 was very shiny.

Just cut some paper to fit the tube exactly, then flock it, stick the long side together with a permanent type sellotape (not the degrading cellulose based stuff) and insert into the tube. As you have pre-measured it a friction fit is all you need, sorry I don't have any photos.

You could be right there!

Here's a quick photo, eyepiece and diagonal removed, looking into the rear, camera focussed halfway down the long baffle that goes through the primary mirror ..

post-20192-0-34362600-1367428630_thumb.j

The baffle is quite long, so it's going to be a real fiddley job I think. But it's got to be done, I can't leave the worst offender untouched after having done everything else.

Edited by Cath
Link to comment
Share on other sites

OK, I've now flocked everything.

Just done a quick test, although I need to smooth the velour a bit more that I've simply rolled up (left the backing paper on) and pushed into the main long baffle that goes through the primary mirror. I had to use 2 pieces as the last 2 to 3 inches inside the baffle is slightly tapered.

Before rear long baffle flock (left) .. After rear long baffle flock (right)

post-20192-0-05740900-1367434905_thumb.j post-20192-0-10498600-1367434927_thumb.j

Before any flocking (left) .. After complete flocking (right)

post-20192-0-15495600-1367435071_thumb.j post-20192-0-46058200-1367435083_thumb.j

The above two images of the houses a mile away were taken at around 8pm +- 15mins (last night and tonight) with the scope in the spare bedroom looking through the double glazing.

What do you guys think? .. I'd say it's been worth doing.

Edited by Cath
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.