r3i

IMy RC8 is not perfectly collimated at the minute - it is out slightly. I am waiting for a few collimation bits from Howie Glatter before I set out to fine tune it. I don't want to mess this up and get it into an unrecoverable situation. I want to make a tutorial or video when I do this since such info is thin on the ground.

I'll certainly look forward to any feedback you can give on using the Howie Glatter stuff on your RC8. I've so far just used a Cheshire eyepiece to collimate and I seem to get a reasonable collimation but would certainly be interested in any tools that may be able to really nail it down.

Couple of things things I have had to deal with right away is:

1. Finding the target at the longer FL - is more difficult than using a ED80 and requires better mount alignment.

2. The image scale, upon finding the target, is HUGE compared to the ED80!!

1. I tend to 'star hop' to a target rather than try to 'goto' it straight away. I set my camera up in the Nebulosity 'frame and focus mode' with an exposure time of around a second, then using CdC I goto a relatively near bright star then centre and synch it. From there I'll hop to a nearer star and so on until I've got to the target - usually only takes 2 or 3 hops. If I'm still unsure about what I have in the FOV, I'll take a relatively short exposure (10-30 seconds) then compare the resultant star pattern to an image of the intended object from somewhere like Google Images.

2. Yes, you'll find quite a difference in the FOV size to your ED80. If you haven't already got it, I'd recommend downloading CCDCalc which will help you get a feel for how objects will (or won't) fit into your FOV.

Sorry, flip-mirror? Not sure I know what you mean by one of those.....? I do knwo the misery of trying to get a planet onto a webcam sensor though - its a frustrating PITA. Only way I can do it, on a SCT, is to massively defocus so I have a huge airy disk and then hope to catch that disk at some point as I slew around since even if the planet is out of the field, the airy disk edge may pass though it.....

Something like one of these: http://www.widescreen-centre.co.uk/Products/Meade_Flip_Mirror_1_25.html

They allow you to flip between the light going to the webcam and the light going to an eyepiece at 90 degrees.

They take a little bit of initial setup to get the eyepiece parfocal with the webcam and also to adjust the position of the flip mirror so that when the object is centred in the eyepiece it is centred on the webcam chip. But you can do most if not all of that setting up in daylight.

An eyepiece with an illuminated reticle is also handy to assist in getting the target bang in the centre of the eyepiece. If your eyepieces are reasonably parfocal with each other, you can start with a low powered one and progressively swap to higher powered ones to get on target.

I strongly suggest you make sure you align the finder scope in daylight and you will be fine. I forgot once and what a waste of about 2 hours that was trying to even put Jupiter on the chip without a finder was a nightmare!!

If you're doing planetary imaging with a webcam, a flip mirror is a big help in getting the target onto the tiny webcam chip.

I've got the Orion OAG and have been very pleased with it. I've used iit with my RC at both prime focus and with a focal reducer. I've had no problems locating a guide star when using a Meade DSI 1 OSC as the guide camera - the ability to rotate the guide camera around the scope axis made it possible to locate a suitable star with not too much effort.

Great review John, thanks for putting it together.

Was wondering, how did you deduce that the primary was loose? I think the one on my 8" RC is okay but would like to check if that's easily done.

Welcome back and good to know that you're over your illness & injury - that looks like an excellent, well built pier.

RIP Sir Patrick. Like so many he has a huge inspiration to me, particularly his Observers Book of Astronomy, which I must have read dozens of times as a youngster.

A very very sad day.

Isn´t the Hubble a Ritchey - Chretien??

Yes I believe that is the case, but I don't think it was made my GSO Maybe they should've done and perhaps then the mirror shape would've been OK from the start.

I am very interested in this scope but what does the GSO mean in the name?

GSO stands for Guan Sheng Optical - they are the OEM company that makes the RCs that are subsequently sold under different badges such as Altair Astro, TS in Germany and Orion & AstroTech in the USA.

And when I'm out on the field, wich is not very often, I prefer not to have to do testing...

Understand that - clear nights are so few and far between, you want to make the most of them.

Since the CCD67 is NOT a reducer, do you think that train of gear could actually work out ?

Guess you meant to say that it's not a flattener?

Interesting post as I've just got the CCDT67 for my 8" RC. I did notice a fair bit of curvature on my first session at the weekend, but that's just one of many gremlins I need to address with my imaging processes.

I also have the SkyWatcher flattener that I got for my 70mm frac. Never really thought about whether it's feasible or not to use it in the RC image train with the reducer. Only only one way to find out - will have to give it a try at some stage.

If the Celestron tubes are bolted to the forks in a similar way to Meade then it will be a straightforward job - just take your time when separating the tube from the forks in order to prevent scratching the paintwork.

Then all you need to do is get yourself a dovetail from one of these suppliers: D Series Dovetails or Farpoint - Products - "D" Dovetails & Accessories

You shouldn't need to drill the OTA, they usually have the screw holes already in place.

r3i, There's no change to shaft dimensions.

The 12T pulley is re-bored to 5 mm, the 48T pulley to 12 mm. The 48T pulley also has 3 mm removed from its thickness.

Hi Francis,

Thanks for that. I did understand the re-boring and thickness reduction was the extent of the machining required, but such modifications are beyond my skills, which is why I was interested in Malc's idea. And I think it would be nice to the see the job go to a fellow SGL member.

Those hypertunes are an example of poor value, separately sourced items are so much cheaper and parts lists on this forum. ;-D

Just waiting for some clear skies to test the belt drive. Looks like it is performing similar to Georges at the moment.

Yes, there is indeed a hefty premium to pay in that instance for the convenience and reassurance.

Looking forward to finding out the 'scores on the doors' with your upgrade. It's been a great project to follow.

Didnt mean to sound annoying in that last message so appologies for that.

No need for apologies Neil

I was just hoping to provide encouragement for Malc in his idea to provide the bits pre-engineered as a way to fund his lathe purchase.

I'm sure you're right that it won't be difficult to source a machinist to do the work, but if someone is offering to provide a one-stop shop by both supplying and machining the parts then good on them.

This approach has already been done in other applications, for example whole kits can be bought for the EQ6 hypertune rather than having to separately source the tools, bearings, shims & grease. For sure it's not exactly rocket science to get hold of all the different parts, but some folks prefer the convenience of a single source of supply and also they have the reassurance that someone else has made sure that all the bits are the right bits.

The thread is a discussion on doing a belt mod to an EQ6 and te first post by George mentions the bits needed, how to do it and where you can possibly buy the parts pre-drilled.

It´s a very easy mod on the EQ6.

Malc is just trying to adapt it to the HEQ5 but the thread topic is for th EQ6 and I don´t think it would need a kit (I know nothing about the heq5 so couldn´t comment if a kit is usefull for that).

I should read all the previous posts before commenting...sorry...but I still dont think the eq6 needs a kit.

Hi Neil,

I've been reading this thread and George's original research thread since they began.

It was my understanding that for the EQ6 mod both gears need re-boring and the worm shaft gear needs reducing in thickness by 3mm. If this is correct, then the modification to the EQ6 is more than just an assembly exercise, it requires some machine work. This is why there is an opportunity for an enterprising person to supply the belt and the gears with the machining already done to them as a kit.

I'm going to look at pricing up some "kits", work out some costs for machine time, and then see if there is enough interest in this mod so that I could at least recover the cost of my outlay for a lathe.

Will you be looking into kits for the EQ6 as well as your HEQ5? There's possibly quite a few people like me who are okay with disassembly and reassembly work but lack the skills and tools for more hard core engineering. Whether there's enough to make it worth your while, we'll have to wait and see but I hope so. Wishing you well with it all.

What is the advantage of the belt drive conversion compared to the original gears? Is it noise reduction (as Malcom hinted at) or less backlash? or something totally different? ;-)

This was answered here in the original discussion thread.

Indeed.

Also, if you own a domain name for your website that lists all your equipment, make sure that your address is not listed as the domain owner in the publicly accessible WHOIS database...

Good point. Another potential vulnerability is dedicated amateurs who submit their observations to scientific organisations because some publish not only the data but also the lat/long and the equipment used.

One good idea is not to post your exact long and lat on this forum along with a list of all your expensive kit.

Cheers,

Chris

It's amazing how many people actually do this.

Looking good Darren.

What size MetPosts have you used to anchor the deck into the ground, the 3" or the 4"?

Looks like a marvellous observatory.

I noticed that your south facing flap folds inwards - just playing devil's advocate here: is there sufficient room so that when you fold it down it won't hit any part of the scope/mount?

Some other flaps that I've seen on observatories fold outwards to prevent that kind of incident but I guess they're short on space and your observatory looks quite spacious so I'm guessing yours will be okay? If it were me (and one day I hope it will be), I'd also prefer the flap to fold inwards, so that the hinges are not visible externally (i.e. better security).

My vote would be for geese of some description. We have a number of gravel quarries nearby that form an aquatic nature reserve and these are full of geese this time of year (I think they're Greylag and Canada geese). They often fly across us in the hours of darkness honking merrily away!