Rough rotating rings scratching my telescope.

[N3ptune]

Hi, I have this minor issue about my rotating ring, one of the 2 is damaging the paint of my telescope over time has the pictures bellow and I wish to find a way to mitigate that problem. I thought about replacing the textile by something else a bit thicker and softer (If i can find anything).. Do you think it can be worth the effort and what should I use if you already had a success story with a specific type of textile.

Thanks.

[Stu]

The pads shouldn't scratch the paintwork, so can you identify anything which is protruding through? A rough bit of casting or overlong bolt? If you can find exactly what is causing it perhaps you can deal with it with a file or an extra washer etc?

[SkyGibbon]

I have used stickyback craft felt and also the soft strip (loop?, hook?) of velcro. Both have worked well.

[N3ptune]

@stu

I didn't see anything unusual when I looked the last time, I will investigate again later today.

@SkyGibbon

You used something like this?

https://www.michaels.com/black-adhesive-felt-sheets/D010834S.html

 

[SkyGibbon]

12 minutes ago, N3ptune said:

@stu

I didn't see anything unusual when I looked the last time, I will investigate again later today.

@SkyGibbon

You used something like this?

https://www.michaels.com/black-adhesive-felt-sheets/D010834S.html

 

Exact stuff.......yes

 

[N3ptune]

@stu

I think there were metal particles from the thumbscrews or the rings on the felt.

The felt installed inside the ring is very thin too, I don't know why they didn't put anything with more thickness.

[N3ptune]

@Stu and @SkyGibbon

I found some adhesive felt at a local store. I bought a few thickness but the one with the adhesive must be almost 3x the thickness of the original black one from Skywatcher. I am proceeding to the upgrade right now and frankly it will be a superior job I think. They had like 50 different colors too.

-- > I am pimping my telescope with cool red color accessories.

 

[Stu]

Looks good  

[wimvb]

I had a similar problem when my 150PDS was new. I frequently rotated it in its rings, and this caused serious scratches in the paint work. It turned out that the rings had burrs left after machining. After removing these and gentle sanding of the inside of the rings, the problem was solved. No need to add any extra felt. I assume you've run your fingers along the edges of the rings to make sure these are smooth. Unfortunately, Skywatchers quality control isn't always as it should be ...

[N3ptune]

@wimvb  yes i touched the whole thing all around and i could not see a thing, no burrs. I removed most metal particles almost 2 years ago but more damage occurred anyway, probably smaller particles I can't see, the painted ring itself is quite soft all around. I think the new felt will be much better with particles with a better thickness, I also know it has no metal particles in it...

I am testing that.

I found that putting the rings inside the freezer will greatly help to remove the original strips of felt.

[N3ptune]

Ok my project is finished, took some time but I am really proud of the result and there is a notable difference in the rotation fluidity, it's much smoother. The increased thickness has no apparent negative effect.

Final result

Previous thickness

New thickness (The red one is more then twice of the original)

Difference with the original vs the new.

I think it's going to work.. and hopefully if it can help others prevent their tube from being scratched.. The sockets and screws were cleaned too with oil and Q-tips to make sure they don't contain anymore metal scrap from the tapping process.. I am pretty sure that was the initial problem.

[SkyGibbon]

Very nice. Much better than the original.

 

[dph1nm]

Had the same problem with my 12" Skywatcher Quattro. In fact the "felt" just came off the rings completely it was stuck down so badly.

NIgelM

[N3ptune]

On 2/21/2018 at 13:51, SkyGibbon said:

Very nice. Much better than the original.

 

I think so to (: its much thicker too, a better product.

@dph1nm

Ok that,s an expensive telescope too  12" Quattro. Did you replace it like I did

[N3ptune]

I tried the new rings and it's much much better then before. I don't need to tighten the thumb screws like 15 times to seize the telescope like I use to, now it's 5 6 times max. much faster. The telescope will roll in the rings with better fluidity too.

It's a top upgrade, it tried it for 3 hours and it's has good has it can be considering the tube is not completely round.

I encourage people to replace the original felt...

[F15Rules]

On 20/02/2018 at 20:45, N3ptune said:

The felt installed inside the ring is very thin too, I don't know why they didn't put anything with more thickness.

Cost, pure and simple. The paint is very thin, the felt is cheap and thin. 

Siywatcher scopes are great value for money, but the corners have to be cut to get the price down.

Thankfully, the optics are usually where the money goes, and are normally very good. 

That's why an equinox refractor costs much more than a DS pro..identical optics, very different hardware quality.

It's also why budled accessories tend to be low rent on the cheaper scopes: nothing is for nothing?.

You've done a great job on your re-felting!!

Dave

[N3ptune]

@F15Rules

Cost, pure and simple. The paint is very thin, the felt is cheap and thin. 

Siywatcher scopes are great value for money, but the corners have to be cut to get the price down.

I noticed that, the tube itself is far from a perfectly round too. I would not mind if that tube cost was 100$ more to improve the overall quality starting by having a very round tube, better felt inside the rings, a different paint inside to blacken the interior, something harder and less powdery.  Overall I think it's pretty good scope like you said about the optics and the dual speed crayford focuser is impressive.

--> Only If it was easier to rotate...

I found out disassembling the instrument, while looking at the front plastic ring. If you look carefully at the picture, telescope is oval, thats its biggest flaw by far. Perhaps this can prevent me from getting perfect collimation too (but thats pure speculation speculation)

If i had only one suggestion to Skywatcher: Find a way to make the tube rounder so it's easier to rotate.