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My new focuser & adapter


T A WOW
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So after living with the stock rack & pinion focuser on my bresser for a while, and having done shed loads of over time I decided to treat myself to a new focuser. It took me awhile to decide which one to go for, a toss up between a baader steel track, moonlite, and revelation hyperfocus. in the end I went for the revelation 3" hyperfocus, it was in the middle price wise and I personally liked the look of it the most.

now I knew that these new focusers don't just fit on as standard and you need an adapter to make them fit. I had no idea at all what these look like so being able I designed my own. I had a bit of spare aluminium lying around for one bit and enlisted our very own graham to make the other bit for me.

I designed it in two parts, one which goes on the inner bore of the OTA which fits super nice around the focuser body with about 0.001' clearance. the second part fits around the outer diameter of the OTA tube and then some nice bolts I made screw through the two parts into the focuser and some standard SS bolts screw it to the inner part.

time for some pics.

the two parts together.

12523739385_5a4af7d0fa.jpg

Focuser stuff by tobias_lunt, on Flickr

12523867903_890304de4d.jpg

Focuser stuff by tobias_lunt, on Flickr

painted up the outer ring to match the main focuser.

12561824573_25d7857ec1.jpg

Focuser adapter by tobias_lunt, on Flickr

with the focuser in place.

12562184004_4ca86772a0.jpg

Focuser adapter by tobias_lunt, on Flickr

so to fit it the OTA I needed to drill some holes through. I did this by using the outer piece of the adapter as the template, before I painted it mind. I put some kitchen towel down the tube to stop any bits of swarf getting down the business end of the scope.

12561817423_bd72b8bf6e.jpg

Focuser adapter by tobias_lunt, on Flickr

forgot to take the flaming stuff out though first didn't I!!! :lol:

the little thumb screws I made to hold it in.

12561701745_6e3fc5893a.jpg

Focuser adapter by tobias_lunt, on Flickr

next to the old focuser.

12561697985_c70c5b8bd5.jpg

Focuser adapter by tobias_lunt, on Flickr

with everything else in place. I took the opportunity to paint a couple of the standard trimmings black to match the new look.

12562168244_e0e2f6094d.jpg

Focuser adapter by tobias_lunt, on Flickr

12561799723_220e606008.jpg

Focuser adapter by tobias_lunt, on Flickr

12561794833_61a66594e0.jpg

Focuser adapter by tobias_lunt, on Flickr

I'm really happy with this focuser, its a lot heavier than the stock one which is good as it aloud me to move the OTA forward by about 2" in its rings for easier observing. I also designed it to sit about an inch further forward than the stock focuser so with a 1.25" diagonal hopefully I'll be able to use some bino viewers (I'll need to borrow somebodys to test that though :D )

now all I need is some clear skies.

Big thanks to graham for making the outer part of the adapter for me and to philj for helping me out at the start with how to get the stock focuser off and explaing to me what I needed.

Edited by T A WOW
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Looks very pro Tobias.

I see you emulated the bresser way of sandwhiching the tube in the back casting. As discussed in my pm re this, that bit is the achilles heal of the bresser design in that the tube is not firmly fixed that is why they stick it in with tape and goo. Eventyally these work loose and droop especially with heavy loading on the back.

Make sure you clamp that tube solid on the adaptor otherwise you will loose collimation, Ive had to refurbish 2 of these in the past and know of another with the same problem. I drilled and tapped the tube and fixed the back casting solidly to the tube,

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Phil. Yeah that tape stuff made getting the stock one off a bit of a job, but my one fits very nicely inside so it should hold collimation well. I had no idea what "normal adapters" look like so I basically copied and improved the stock method. It'll probably need a bit of adjustment to start with but I expected that.

Ron. Yeah it does rotate. The little thumb screw in front of the EP does that.

Edited by T A WOW
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So if I put my flex 250 and my Bresser 127/635 on a Sky Tee 2 i should have no problem - Didn't you build your own tripod?- i was thinking of using 2 inch scafford poles for a sky tee tripod or just putting a fixed mount (plus lots of concrete) in the center of my garden. Is the sky tee 2 too heavy to move in/out ?


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Yeah the skytee would handle that fine. My set up is a 250pds and a bresser 152. The skytee itself weighs about 10kg with the counter weights. I did build my own tripod yes. That'll easily hold 100kg

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The 250 Flextube is 15kg (rocker box 13kg), and the Bresser 127/635 is 7.7kg.


 


The Skytee-2 is rated for 2 scopes up to 15kg each side. :)


 


(I'm putting mine on an EQ6 tripod with the 2" legs)


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What about ground clearence (or lack of it!) At what height is your Skytee2 sitting - Trying to lay down on freezing/wet ground (even using 90 d) is not my idea of fun - unless I am missing something !


 


The mount that came with the Bresser uses 2 inch steel legs(looks like EQ6 tripod) but its so low down when viewing even the finder that I would end up in A&E with a bad back or at least a stiff neck.


 


In process of building a simple a frame adjustable "chair"  but just wondered at Tobias tripod height.

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The legs do extend on the EQ6 and Tobias's tripod - raising the Refractor eyepiece to a more useable height. But then you need a ladder for the Newtonian Eyepiece. I find a 200P and a Tal 100RS are enough for me. You can also use a pillar extension if required.


 


But there's nothing to stop you putting bigger scopes on if it suits you. :)


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I very rarely use both scope at the same time but when I do I dont use the bresser for anything above about 50° altitude. And use a little camping chair when I am using it.

If I'm just using the bresser then I extend the tripod legs and it puts the EP at a decent level.

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Thanks for the info.


 


Kim you make a very valid point about the Newt level and ladders  - needed the obvious pointing out - thanks.


 


More thought needed me thinks - Maybe the Skytee2 only comes into its own when using two refractors of different abilities and Tobias indicates that "very rarely use both scope at the same time" means it may not really be worth it for a Newt and a refractor for me at least.


 


One last question - do either ever of you take your Skytee2 off site or is it "home" based ?


 


Again many thanks for your input.


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May take you up on that Tobias as I find my tripod,even extended, is a pain in the neck/back (literally). That's why I was asking about the height of your tripod up to the mount. And I am only short so god help anyone a bit taller. I was going to the W on the 8th but hope to turn upat another W - Belper is just a bit far for me.


 


Again many thanks


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HI Ron,


 


Its not the distance as much but the roads. Have you got a post code so I can see where it is.


 


Suppose the roads to BF aren't much better.


 


As you said W is easy down the A46 which makes all the more disappointing for March 8.


 


Hope you are over your bug.


 


Still trying to thaw out from being out till late the other night but it was clear for once but the wind was like a knife.


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