$200 Lunt LS50 w/ 2''Baader Steeltrack focuser mod.

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soulvagabond
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$200 Lunt LS50 w/ 2''Baader Steeltrack focuser mod.

Post by soulvagabond » Sat Jul 15, 2017 9:55 am

Hey guys!
If you are looking for a cheaper Lunt50 focuser upgrade, here's my solution.
The total cost of the project, around $200, but that depends on the cnc milling cost in your area. Typically, I pay around $10-15 for an adapter.
Pre Diamond Baader Steeltrack 2'' focuser, was purchased from a famous UK store, which has the stock of the older model, for around 120GBP (tax deducted). Diamond edition, could be a better option, I believe, it would also give more travelling distance after the modification, but the price was too high for me.

So, once the focuser was delivered, I took all the measurements, to preserve the original 62mm distance in between the Lunt's etalon and the body of the B600 diagonal. There's also a possibility, to modify it for more in-focus, compared to the stock focuser. Around 7mm extra of in-focus can be achieved. But that would limit the focus travel to 15mm. But, since I don't have any issues with all of my eyepieces, I have chosen longer focus travel option.

Then, I designed 2 adapters, one to connect the focuser to the Lunt's diagonal and the other is for 2'' tube, for the Lunt's diagonal and brought it to the local cnc shop.

After I received the adapters, I had to shorten the Baader's focuser drawtube, for 15mm and add a 6mm focuser stopper, to avoid the focuser slipping out, after shortening the tube.

Here's the result:

Image
Image
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To mention, the 2'' tube is a must, since it allows the diagonal to be fully sunk into the focuser.
The stock design of the diagonal is wasting quite a bit of the in-focus:

Image


With the 2'' tube, this problem is eliminated.

Tested today, works great. Needless to say, zero play on the optical axis.

And the final image of the focuser on 80mm achomat

Image

Have a good sunny day, everyone!

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marktownley
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Re: $200 Lunt LS50 w/ 2''Baader Steeltrack focuser mod.

Post by marktownley » Sat Jul 15, 2017 4:11 pm

Funky stuff! Which shop did you buy the focuser from?
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http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!

soulvagabond
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Re: $200 Lunt LS50 w/ 2''Baader Steeltrack focuser mod.

Post by soulvagabond » Sat Jul 15, 2017 4:25 pm

365astronomy

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