16" Lightbridge Set up

[DarkerSky]

Hello...

After many nights of deliberation I have decided on getting a 16" Lightbridge. This is the set up I am going for with the scope...

Light shroud

26mm Meade QX Wide Angle Eyepiece 2" barrel

17mm Nagler Eyepiece 2" barrel

Televue 2x Barlow 2" barrel

Argo Navis with Lightbridge Attachments from Wildcard

Cheshire collimating eyepiece

That's it for now. Later I am looking to get some sort of Poncet / Equatorial platform, either custom built or commercial. But I have to save a few more pennies for that!

Does this seem like a reasonable set-up for the 16" Lightbridge for me to get stuck in to the sky with it for a bit??

Any advice on extras or alternative accessory stuff is welcome

[red dwalf]

Doc, has one of these and i`m certain he`ll be able to help you out alot if you PM him, he loves his and i don`t blame him

[John]

Just one question at the moment - is this your 1st scope or have you owned others before this ?.

John

[pvaz]

A telrad finder, if you don't already have one. Other then that, you have my "dream gear" on that list.

[moocher]

Get the base water proofed!!!!!! Its the only weak link. Unfortunately though thats a big link!!!! Great scope otherwise!!!

Alan:)

[Doc]

Welcome to SGL.

I have had my 16" LB for over a year now and they are great, but to fully appreciate it you need dark skies and quite a few mods.

Your list is very good but I would like to add.

1) Strengthen the base as without it the base will flex.

2) Wheelbarrow handles I think are a must.

3) Blacken the truss poles to reduce scatter

4) Flock OTA's.

5) Counterweight system for larger eyepieces.

6) Milk carton washer mod for Secondary mirror helps collimation.

7) Handles on OTA's.

8) Fit Telrad

http://stargazerslounge.com/members-equipment-gallery/79900-updated-photos-my-lb-dob.html

http://stargazerslounge.com/members-equipment-gallery/67312-my-lightbridge-16-a.html

[ZOG]

I use the Argo Navis on a 12" flextube. My advice would be, unless you're going to mount it on some kind of stalk, buy the longer encoder cable. It is very disconcerting when you turn around with the Argo in your hand to find that the cable is too short and is trying to pull the unit out of your hand. You REALLY don't want to drop it, as I found out to my cost.

[DarkerSky]

Hi Guys,

Thanks so much for all the feedback, and thanks for the list of mods Doc. I'll look into finding a source for the Telrad and wheelbarrow handles and getting the base strengthened and waterproofed in the first instance. They all sound like pretty important mods.

Zog - thanks for the heads up on the Argo Navis. I know Wildcard have put together an encoder and mounting "package" for the lightbridge, so I will ask them about cable lengths

Hi John - this will be my third scope

Thanks again for all the info.

[John]

.....Hi John - this will be my third scope...

That's great - I don't think a Lightbridge 16" would make a good 1st scope.

As a 12" LB owner I reckon a lightshroud was my #1 priority, especially as I'm viewing from a site with some light pollution. My LB was virtually unusable without it.

John

[MartinB]

I use a Baader laser collimator. Not everyone is a fan of these but I wouldn't be without mine. With my 12" Skyliner I use it before every session, it takes just a couple of minutes and is very accurate.

To avoid moisture problems on the base I sit the scope on some plastic sheeting. Wet lawns are the big problem

[Euan]

I use a Baader laser collimator. Not everyone is a fan of these but I wouldn't be without mine. With my 12" Skyliner I use it before every session, it takes just a couple of minutes and is very accurate.

To avoid moisture problems on the base I sit the scope on some plastic sheeting. Wet lawns are the big problem

I can second that, I use mine all the time and couldn't go back to the cheshire method.

[johninderby]

I used to have a 16" Lightbridge before I upgraded to an Orion Optics UK 14" with 99 Strehl 1/10PV optics. The 16" Lightbridge is a big and heavy beast and does require quite a few mods. A year ago you could pick up a new one for about £1,000.00 when on sale, but with the price having gone up to about £1,800.00 new I'd certainly wouldn't buy one new but would be looking for a used one.

Here's a few brief notes on some of the mods I made (fortunately I still had the notes on file)

Blacken Truss Tubes

The truss tubes were covered with heat shrink woven covering. This is a heavy duty abrasion and chemical resistant covering usually used to cover pipes and wires in industrial applications. After applying sprayed the tubes with Ultra Matt black paint to hide any trace of the silver showing through. If I was doing it again I would have painted the tubes first.

Flocking Etc.

Used ProtoStar light trap sheets to cover the inside of the tube. Painted the end rings with black hammer finish paint and them sprayed the inner surfaces with Ultra Matt black paint. The spider vanes and the secondary mirror holder and the back and sides of the secondary mirror were also sprayed with Ultra Matt black paint.

Counterweights

I had seen some commercial counterweight sets for the Lightbridge that replaced the collimation lock screws but I wanted to keep the lock screws. I had some Astro Engineering 1 pound weights that looked as if they would be ideal. Drilled three holes in the base and inserted three 12mm Allen head bolts from the back to hold the weights. each "foot" consists of a stack of four large diameter body washers, three 1 pound weights and a knurled lock nut on the end with a felt pad glued in place. Very simple but works beautifully. I needed a bit more weight and found the ideal Lightbridge balance weights. They are 1 kg Go Cart lead ballast weights, cheap and fit the Lightbridge perfectly. One can be seen just barely poking out behind the bottom foot in the photo below left, held in place with Velcro. If hadn't already had the 1 pound weights I would have just used the go cart weights.

Base Mods

The standard base isn't really stable enough for the 16". The simple answer was to add two stiffing pieces to each side. These were cut down from a white melamine shelf and screwed in place from underneath and from the inside of the box. I also added a handle on each side. This was simply two lengths of broom handle turned down at each end on the lathe to fit into holes in the stiffening pieces and secured with small screws at each end. Some of the heat shrink woven covering was used to cover the handles. I added some 5 inch swivel locking castors which work really well. They are fine on hard surfaces and make it so easy to roll the scope over to wherever I want to observe from. Trees that used to get in the way are no problem now. Surprisingly I have found that it isn't usually necessary to lock the castors and also vibration is not a problem. Usual procedure is to place the base just outside my workshop door and lift the OTA through the doorway and into place on the base, then roll the whole scope into position. Takes a good 30 seconds to get the scope from indoors to observing position.

Other Bits and Pieces

Astrozap light shroud, Astro Engineering Light Cap and two industrial handles.

Last But Not Least

In the category of one of the most useful mods (and zero cost) are the guides for setting the OTA down into position on the base. These are simply two of the rubber feet that came with scope. They have been bolted into place on the aluminium altitude bearing, just far enough round the housing so that there is about an 1/8 inch clearance. Simple but makes setting the OTA in place so easy.

John

[calibos]

If you really want tracking then I would not get an Eq platform for your LB16. Because the base is so big and the scope so heavy, one would have to order a huge one to take an LB16. I have a 28" diameter reinforced Brian Reed EQ platform that I had used with my last scope. I tried my LB16 on it once. Dangerous is not the word! Not a fault of the Brian Reed RTP, just the oversized LB16. The problem is that even larger platforms are very expensive and now that Brian Reed has retired there is no one catering to the middle of the Market.

My suggestion is to save up for a Servocat drive system to go with the Argo Navis Dsc you have/intend to get. Even compared to Brians RTP the choice was a hard one with a servocat coming in a few hundred more. Now with suitable Eq platforms for your LB16 coming in a lot more expensive it's a no brainer. Servocat will be the same price. Add no extra weight nor take up space like a big platform. With your Argo you'll have Goto as well as tracking.

[albedo0.39]

Good choice (I would say that though). A Highly tweakable scope and one that rewards with immense views when set up with the right EP.

Doc's got most of the mods covered but I'd add:-

• Modify the seconday collimation screws to stop them rotating.
  
• Add a "direct heating" seconday dew heater (costs a few pounds)
  
• Seal the base - use waterproof wood glue to stop any chance of moisture entering into the "grain" of the MDF. If not, it will / can bubble and cause stick AZ movement
  
• ensure that the mirror clips on the primary are not in actual contact with the mirror or you may get astigmatism
  
• Add some handles to lift
  

The Meade QX is average and gets murdered by the F4.5 ratio, so once you've seen any sort of decent EP in the Lightbridge, you'll not look back

Oh and leave some ££ for a decent field map.

Keep us informed and welcome aboard !

Steve

[DarkerSky]

Thanks again for all the advice and the mod suggestions. I'm really looking forward to getting this scope now, playing with it and tweaking it. Plan on ordering it this weekend.

I will definately keep you all informed and post some of my sketches from the eyepiece as I go along.

Calibos - thanks for the advice on the EQ platform. ServoCat is probably the way I'll go with this. The other one I looked at was the Track n Train system from JMI I think it was. But that seems only to hold the eyepiece view for about 10 mins

[John]

This piece has just appeared on the Cloudynights web site:

Meade LightBridge 16" - Review

Very timely !.

John

[albedo0.39]

Interesting review - it sums up the LB quite well. Good optics let down by a load of poorly thought out design features (all of which can be fixed) around the mirrors.