Feathertouch Focuser

[+Bino-viewer]

One of the best upgrades i made to my telescope was the purchase of my Starlight Instruments Feathertouch 3545 focuser.

 

I purchased my William Optics FLT 132mm refractor towards the end of 2008.

Despite the fact it was marketed with a hefty price tag, which i had to save up for a long time for, it had a few issues. (i won't go in to them all now...)

 

The main one was the focuser. TBH, it was pretty poor quality.

It visibly sagged with the weight of a heavy 2" eyepiece when fully racked out.

Every review i read of the scope slated the performance of the focuser.

A year or so later Starlight Instruments made an upgrade available in the form of their much applauded Feathertouch 3.5" rack & pinion.

It was also machined with the correct sized thread to enable it to go straight on the FLT.

One problem (inevitably) cost. These things retail at 800 - 900 $USD over in the States. Way out of my price range at the time.

 

A few of them started to drift over to these shores, and then at the 2010 Astrofest show in London, i got lucky.

I arrived there first thing at 09:00hrs as the show opened, and was one of the first through the doors.

By chance i spotted one at Ian King Imaging, and to my surprise it was an FLT132 upgrade focuser !!

Ian King was / still is a William Optics dealer, and had not sold this particular focuser (probably due to cost)

I made him a cheeky cash offer (over a third less than advertised) and although reluctant, he agreed to sell it 

I was 'as pleased as Punch' 

 

I'll state now that i personally believe that this focuser is THE finest telescope focuser available on the market. Period.

The level of engineering, the quality of the materials used, the finish, everything, is at a level above anything i have ever seen or used before.

Now i know why they cost so much. And no matter what i put on the back of it, it doesn't even flinch. Its absolutely rock solid.

 

But anyway........the purpose of this post is to show you a little upgrade i've just done.

When i first brought the focuser, there was no endcap.

I simply used the one off my William Optics focuser ; the thread was the same.

It had a 2" opening, and a compression ring clamp, tightened by 2 decent sized thumbscrews placed 120 degrees apart.

 

It worked well. The Feathertouch has a generous 115mm of travel so i was able to accommodate most (but not all) accessories.

But over the last few years the weight i put on the back of it has gone up. And up.

Although i've not had any mishaps, the 2 thumbscrews have reached their limit and i have to really tighten them hard to keep things secure.

One night last winter i nearly came a cropper. My icy cold gloved hands didn't tighten the thumbscrews enough, and my diagonal, binoviewer,

and eyepieces slipped round a full 180 degrees where i found them facing downwards after i'd been fumbling about in my case for something.

Luckily no damage was done this time.

 

I immediately ditched the Baader 2 inch T2 nosepiece.

I felt it was way too shallow (only around 25mm) for the amount of weight i was putting on it.

It also had a recessed 'safety' undercut. Now i personally don't like these at all. Reason being, i find that you have to really over tighten the 

compression ring to get a good purchase on it. BUT, all things considered, it was the undercut that stopped my whole binoviewing rig from slipping out.

I'm now using a Moonlight 'smoothbore' that has a much deeper nose.

I don't need to tighten the compression ring as much and i've had no more mishaps.

 

But the weight issue remains. If i ever go down the Tv Delos route i'll be looking at nearly 2Kg in weight held secure by the aforementioned thumbscrews.

 

I've just purchased a new endcap from Starlight, that uses a collet style tightening ring. I also got the matching desiccant plug to keep dust etc at bay.

It works very well. I've tried a few combinations to see how it performs.

I think it will be much easier and quicker to use once i'm out in the field with half frozen hands.

Check it out......

 

Heres the old end cap (with FLO purchased end plug) Note the 2 thumbscrews.

 

 

Finally, i tested the collet tightening ring with various loads.

Firstly, my large 2" WO diagonal with heavyweight 31mm Nagler.

I them moved things 45 deg to see how it would cope with this 1350g load under strain. 

Pleased to report no movement was detected.

Them the final test with prism diagonal, binoviewer & 24mm Pans weighing 1500g.

Still good. It's passed its first test.

Hopefully, it will perform just as well out in the field. 

 

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[Doc]

I have the red dessicant cap as well Rob. it seems to work excellent and has already collected some moisture as the crystals have changed colour.

 

I do like the focuser though, looks awesome.

 

What size are those chrome plated screws holding the cap on, I have bent one of mine slightly are they M4.

[philjay]

They are good arent they?

I had one on an Flt98 and it was impressively smooth even with a heavy imaging train on it.

I am not a fan of WO mechanics, especially focusers, the idea is there but not the practicality.

The best thing you can do to upgrade a WO is change the focuser

[+Bino-viewer]

The desiccant end cap has 3 little sachets in it.

In these sachets are tiny little blue coloured pin head sized balls.

 

They apparently change from blue to a red colour if they absorb moisture.

Like the numpty i am, i thought you had to open the sachet and tip them in the endcap.

Doh......

They all fell through the minute holes.....

And they bounce amazingly well ! 

Once i'd gathered them up i chucked them down the loo.

And they pop if you submerge them in water.......

I have plenty of spare sachets though, and brought 10 extra on the order.

 

 

Re the thumbscrew........i'm not exactly sure of the size ?

I measured the thread at 4mm wide, and 12mm long. Not sure if this is M4 ?

 

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[Tweedledee]

Those items are very nice Rob

[Doc]

Thanks Rob.

 

They make a Feathertouch 3545 for my scope as well but it's nearly £700.

 

I don't think I'll bother yet, get some use out of the standard one.