200P Modification

[DRT]

In another thread I discussed the OOUK F4 VX12 that I have on order that will be used both as a Dob and as a Newt on my AZ-EQ6. I expect it to take a few months to arrive and saw a bargain on Astroboot that I couldn't resist so that I can enjoy some observing with GOTO over the summer. The bargain was the OTA from a SW Skyliner 200P Dob for £130. It is absolutely brand spanking new and just didn't have the Dob base. An brand new 8" F6 Newt for £130? I don't mind if I do!

As soon as it was ordered my mind turned to whether or not I saw this as a long term proposition given that the 12" F4 is incoming. I quickly decided that the 8" was much more practical for travel (i.e. Skye in August!) so decided a few upgrades were justified:

• Moonlite CR-1 Focuser
• ADM Losmandy Dovetail
• Skywatcher 8" Tube Rings
• Carry handle
• Flocking behind the secondary
• White sticky back plastic to cover the holes left by the Dob bushes once removed (very Blue Peter!)

So, all the boxes were here when I arrived home last night and after a few hours putting it all together I now have this lovely beast ready and waiting for the next clear night

 

 

This OTA is roughly the same length that the VX12 will be so the first good news is that unless it is pointing at zenith the eyepiece is in a very comfortable position and no ladders or steps will be required. Even at zenith it is only a couple of inches above my natural eye line which can easily be sorted by dropping the tube down in the rings a little when I want to point it straight up.

The next bit of good news is the collimation. I removed the primary cell and the secondary to do the flocking and drill holes to fit the focuser and handle. When I put it all back together the Hotech beam was hitting the dead centre of the primary it only took a very small tweak on one collimation screw to have it bouncing back through the centre of the target. If it holds collimation as well during use as it does through disassembly and re-assembly I will be very happy!

I am very happy with this - a brand new 8" scope with some nice upgrades for £350

 

 

 

[Ricochet]

Very nice. Where did you get the handle from?

[A McEwan]

I had an 8" f6 a while ago. I think I had to collimate it once a year or so... Very practical scopes, specially with those User-Friendliness Upgrades!

[DRT]

28 minutes ago, Ricochet said:

Very nice. Where did you get the handle from?

It is one of these: http://www.wdsltd.co.uk/product/3851/bridge-handle-with-steel-or-brass-insert-wds-8532/

I have used these handles on a number of scopes, including my 16" Flextube Dob, and they are very sturdy. You have to source some M8 bolts separately.

[Moonshane]

Looks fab mate. Don't forget that with a heavier mirror the eyepiece will possibly be lower with the 12" - even better!

[rockystar]

very nice. I'd be interested to hear how you get on with the new focuser, it's an upgrade I've been thinking about.

[DRT]

4 minutes ago, Moonshane said:

Don't forget that with a heavier mirror the eyepiece will possibly be lower with the 12" - even better!

I had been wondering if it would actually be the other way around, Shane, in that the VX12 mirror and cell will probably be proportionately heavier than that of the 200P so I might have to have the tube further up in the rings to achieve balance? Even if that is the case I think zenith is the only part of the sky I might need to find a solution to, which with this scope will be at most a 2" thick board lying on the patio.

[DRT]

Just now, rockystar said:

very nice. I'd be interested to hear how you get on with the new focuser, it's an upgrade I've been thinking about.

I have had quite a few Moonlites and loved every one of them. You will not regret going for it

[rockystar]

did you buy the installation kit too? It's something in the the FLO website that had confused me about this product. It's in the "often bought together" bit, but can't see that it says you will definitely need it.

[DRT]

44 minutes ago, rockystar said:

did you buy the installation kit too? It's something in the the FLO website that had confused me about this product. It's in the "often bought together" bit, but can't see that it says you will definitely need it.

I already had one from a previous scope so didn't need to buy one this time. When replacing a SW standard Crayford the installation kit plus the focuser puts the minimum in-travel point at almost exactly the same distance from the secondary - i.e. it makes the two focusers the same length. It is not essential to buy one but if you don't you will probably need an extension tube to reach focus. That could end up being quite a long tube so I think the installation kit is the better option as it provides a much more stable stet-up.

[rockystar]

Thanks DRT, I already have a couple of extension tubes, as I can't reach focus with the Morpheuses in 2" mode without them, but I think I'll get the kit anyway.

Did you not feel any desire to get the dual speed version, or is it not worth it for visual? I did think it would be a nice upgrade for the standard focuser, but maybe the Moonlight is of such a better quality that single speed is smooth enough.

[DRT]

37 minutes ago, rockystar said:

Thanks DRT, I already have a couple of extension tubes, as I can't reach focus with the Morpheuses in 2" mode without them, but I think I'll get the kit anyway.

Did you not feel any desire to get the dual speed version, or is it not worth it for visual? I did think it would be a nice upgrade for the standard focuser, but maybe the Moonlight is of such a better quality that single speed is smooth enough.

I already have a Moonlite CR-2 dual speed on my 16" Dob and to be honest I rarely use the fine tuning. Even at just single speed this is a major step-up from the standard crayford.

I was trying to keep the cost of this scope down given what I have just spent on the OOUK VX12 which is mainly why I went for the CR-1. If it is your main scope and you have heavy eyepices or camera equipment I would recommend the CR-2 as it takes a much heavier payload than the CR-1.

[Moonshane]

2 hours ago, DRT said:

I had been wondering if it would actually be the other way around, Shane, in that the VX12 mirror and cell will probably be proportionately heavier than that of the 200P so I might have to have the tube further up in the rings to achieve balance? Even if that is the case I think zenith is the only part of the sky I might need to find a solution to, which with this scope will be at most a 2" thick board lying on the patio.

LOL

Well done you passed the test I carefully set for you. In my defence I have been chipping out flag pointing most of the day. ....

[CraigT82]

Smashing tube for the price! I'm have on which I use for visual and a bit of planetary imaging and I'm beginning to think it is the ultimate do-it-all scope. It just does everything well (and it only cost me £50... Third hand at least)

My own one has a 44mm secondary (fitted be a previous owner) with DIY secondary dew heater, cooling fan in neoprene 'panel', CR2 with SW motor and thumbscrews/strong springs in the primary. All my mods are very Heath Robinson but the seem to work well so I'm not bothered how it looks! 

Dont think I'll ever get rid of this scope. 

[spaceboy]

Result Derek  

I have to say I think the white tube with black accents assembly looks far more telescope like that the peacock livery they have on the black diamond series. Why they felt the need to gloss up scopes with metallic paint that are often used in the dark I will never know ?? and black of all colours to choose

[DRT]

12 hours ago, spaceboy said:

Result Derek  

I have to say I think the white tube with black accents assembly looks far more telescope like that the peacock livery they have on the black diamond series. Why they felt the need to gloss up scopes with metallic paint that are often used in the dark I will never know ?? and black of all colours to choose

I completely agree, but as someone who came to this sport/hobby/pastime/belief system relatively recently I have to say that the marketing department at Synta hit on a gem when they conceived of "Black Diamond". A mass market dream, which is mainly where they sell to.

However, now that I have spent time with the enlightened I know that white and simple is best

 

[rockystar]

Hi DRT,

After reading this, I decided that putting on a carry handle is the way forward. So I've got one from the link you posted. A question though: how did you go about drilling the holes in the tube without the drill bit going all over the place and scratching or denting it?

The flock is also on the way - so this will be my (scary) weekend project: taking my telescope apart!! Eeek.

Cheers, Lee.

 

[DRT]

Hi Lee,

The way I do it is to stick some masking tape over the area you want to drill and then use an awl to make a small dent at the centre of the intended hole. Make sure your scope is held firmly in place and that the position of the hole is in a place where you can position your drill comfortably. Place the point of the drill bit in the hole with some firm pressure on the drill and pull the trigger gently. If you don't put some pressure into it the drill bit will scuttle away across your paintwork and leave a nasty scratch so you need to commit and be brave

Good luck!

Derek

 

[rockystar]

Thanks Derek. Commitment is the key. I'll post up my success when it's done

 

[DRT]

I picked up an OO UK Dob base from @dobbie yesterday for the 200P and they seem to sit very well together

[dobbie]

Hi Derek now that looks good .. shall I get rid of my observatory and start again ... mmm .

[Mark at Beaufort]

Derek I missed this thread when it was started - 3 weeks on the narrowboat. Anyway you have done a brilliant job modifying this 8" scope. Even though I have a 12" Dob I love the quick grab and go of the Orion VX8. Getting the Dob mount from Dobbie makes this a great scope to take on outings - good luck in Skye. I wonder if WDS know how many handles they have sold to DIY astronomers - I bought 4 just recently for various modifications - never mind the ones I bought several years ago.

Looking at your scope makes me want to change the poor focuser on the Orion VX8 - I had a Moonlite CR1 on my old 10" Dob and it was excellent for just visual.

[DRT]

Thanks, Mark. I must confess that the focuser tends to be the first thing I go for when pimping up any scope. Luckily some of the newer non-SW scopes I have bought recently have had good focusers as standard but I hate those wobbly things they put on SW scopes, especially given the cost and weight of the things I hang from them. The Moonlite CR1 is a great way of upgrading to a solid focuser without spending the earth.

I really like this little scope now - a definite grab-n-go prospect and also good for moving around the garden easily when my larger set-up is rooted to the spot.