My RX80-L Refractor

harlequin2902 · Post by **harlequin2902** » Fri Apr 02, 2004 1:19 pm

Yeah ! The mounting rings and tripod adapter finally arrived today and the RX80-L can be mounted properly on a mount at last. The Skywatcher 3.5" tube rings fit perfectly. I hope to be able to test it this Sunday evening.

Here are some more pictures to share :

The RX80-L taking it's place in the living room

The RX80-L on a Manfrotto 410 head

Post by **Airconvent** » Sat Apr 03, 2004 12:09 am

mm...Sam...the scope looks pretty decent aesthetically!
maybe if cost is low, you can make a few and sell them!
btw, how much would it have cost to make the scope based on your retail price for the components?
looks like I would have to consult you as to how to convert my surplus shed 50mm freak scope into something more presentable...

rich

harlequin2902 · Post by **harlequin2902** » Sat Apr 03, 2004 1:18 am

mm...Sam...the scope looks pretty decent aesthetically!
maybe if cost is low, you can make a few and sell them!
btw, how much would it have cost to make the scope based on your retail price for the components?
looks like I would have to consult you as to how to convert my surplus shed 50mm freak scope into something more presentable...

rich

The breakdown of the costs for the complete RX80-L OTA based on M.S.R.P (manufacturer suggested retail price) :

Imported :

80mm objective with cell - S$150.00
2" R&P focuser - S$100
Mounting rings & tripod adapter - S$90.00
1.25" prism diagonal - S$45.00
Red dot finderscope - S$50.00

Shipping is an estimated S$120.00 for all the above items. UPS rate.

Locally available :

Those silver coloured rings - S$2 each. Used 6 of them so it's S$12 in all.
A can of Ivory spray paint (Nippon) - S$5
3.5" diameter, 75cm long PVC pipe - S$5

S$577.00 total. Still can't beat the prices of factory mass produced scopes, but the fun of putting your own scope together and the sense of achievement that comes with seeing it work (Saturn at 150x is still Saturn with the rings, a hint of the Cassini Division and banding around the equatorial region) is absolutely priceless.

kayheem · Post by **kayheem** » Sat Apr 03, 2004 8:17 am

harlequin2902 wrote:
mm...Sam...the scope looks pretty decent aesthetically!
maybe if cost is low, you can make a few and sell them!
btw, how much would it have cost to make the scope based on your retail price for the components?
looks like I would have to consult you as to how to convert my surplus shed 50mm freak scope into something more presentable...

rich

Still can't beat the prices of factory mass produced scopes, but the fun of putting your own scope together and the sense of achievement that comes with seeing it work (Saturn at 150x is still Saturn with the rings, a hint of the Cassini Division and banding around the equatorial region) is absolutely priceless.

Welcome to the world of Amateur Telescope Making (ATM)!

An ATM-ed scope will always be unique. You will be using *your* scope and the feeling is great , especially if it performs well. Only problem is getting people to see the 'beauty' of the scope when you are trying to sell it.

Kay Heem

ChaosKnight · Post by **ChaosKnight** » Wed Apr 07, 2004 9:12 pm

Ya know....if you used 6061 aluminium, the error in the angle of incident light from the objective on the eyepiece is reduced to 0.06 that when PVC is used?

Post by **weixing** » Wed Apr 07, 2004 9:23 pm

Hi,

Ya know....if you used 6061 aluminium, the error in the angle of incident light from the objective on the eyepiece is reduced to 0.06 that when PVC is used?

I just wondering what do you mean??? And also what is that 0.06???

Have a nice day.

Debash · Post by **Debash** » Wed Apr 07, 2004 10:01 pm

Weixing, you have hit the nail on its head with a good sense of humour

can't stop laughing after reading your questions!!

ChaosKnight · Post by **ChaosKnight** » Wed Apr 07, 2004 10:20 pm

For an optical system to perform optimally, the light along the principal axis from the objective must be normal to the lens of the eyepiece. Any deviation from such a 90 degree angle can be considered an error.

Because telescope tubes flex, such an error is always present. The only way to improve optical performance is to reduce flexing through choice of materials or geometry of the tube.

By replacing a PVC tube with a geometrically identical aluminium tube, this error can be reduced to 0.06 of its former value.

Sorry Debash, but what's so funny?? i don't geddit......

Post by **weixing** » Wed Apr 07, 2004 11:31 pm

Hi,
Hmm... But how do you get that 0.06... I mean how do you know that with an aluminium tube, the error can be reduce to 0.06 of its former value?? Also, what is the unit for the 0.06?? I hope you can give more explanation when you give such numbers...

Have a nice day.

Post by **zong** » Thu Apr 08, 2004 12:16 am

yes, I'm quite curious at how you arrive at 0.06 too. There's no one lens and tube combination in this world that can achieve such perfection in the first place, so on what basis are you giving your comparison? and .06 of its former value, as i understand, is .06 of the error caused by using PVC instead of aluminium tube, which is indeed a great claim! Can you try to explain a little more at how you arrived at that number. Thank you.

Yea I don't understand what's so funny about weixing's question, too... It's afterall perfectly logical to question the illogical, right?