Meade 10" SN refurb

[traveller (Bo)]

I am now half way through my refurbishment of a Meade 10" f4 Schidmt Newtonian OTA.
When I picked it up, it was in very poor condition, even had a spider living inside the tube.
After taking the scope apart and giving it a good clean, I flocked the inside of the tube, and replaced two of the weakest components. The focuser has been upgraded a to Moonlite unit, so smooth and rigid. I also upgraded the finder to a RACI finder (with vixen foot) so I can swap over to my 50mm guider once aligned. Also upgraded the vixen bar to a 40cm D plate for more ridgidty and better balancing.
Next stage will be collimination. A rough look with a laser late last night showed minor adjustments needed.
The next stage will be adding a cooling fan and build a dew heater for the corrector plate.
But hoping to put it on my eq6 later to test it first. It's already tipping the scale at 15kg, so by the time I add guidescope/OAG, mpcc and camera, I will be pushing the mount to the limit.
Here is a pic of stage one.
Enjoy.
Bo

[peter_4059 (Peter)]

Nice - I'm on the lookout for one of these. I'll be interested to hear how it goes.

[traveller (Bo)]

Will do Peter,
My main concern is the weight, I will be pushing 16-17kgs by the time I get a camera OAG and mpcc on the rig. I tried to balance the scope yesterday with 3 counterweights but still top heavy.
So I plan to get a longer cw bar and see if I can balance it.
Bo

[peter_4059 (Peter)]

Yep - I ended up with 4 counterweights and an extension bar for my 10" Newt+guidescope. I've now upgraded the EQ6 cw bar to 1.25" and I've got a 10kg EQ8 cw so more of the mass is at the bottom of the bar.

[traveller (Bo)]

Update 2 of the refurb of my 10" f4 SN.
The mirrors are now aligned and collimated, but not tested under the stars yet.
I hit a snag when my 15kgs of counterweight cannot blance the OTA (17kgs). I managed to get a counterweight extension bar to see if an extended bar would help. I then hit the second snag when the extension shaft is bored m12 and my existing bar has a m6 female thread for the counterweight retaining nut.
I contacted a member here who has a lathe (thanks Stefan Buda!) and re bored the existing bar to a m12 female thread.
I can now balance the scope with 15 kgs.
So far so good, just waiting for the clouds to lift in Melbourne.
Seriously tempted to take this baby to snake valley
Bo

[peter_4059 (Peter)]

Hi Bo. I went to change the focuser on mine tonight to a Moonlite but hit a snag when I tried to remove the corrector plate. Do you know what size button head cap screws yours has? My mirror cell screws seem to fit a 3/32 Allen key but nothing I have fits the screws holding the corrector plate cell in place?

Peter

[mariner10 (Steve)]

Hi Bo, I've owned a 10" LXD55 SN for years, brought the whole package when they first came out and it was probably the worst decision I've ever made. The mount was complete rubbish so that eventually went but I still have the OTA which optically is very good which is why I still have it.
Actually your OTA looks pretty good and has come up a treat from the photo. I took the corrector plate off once to clean inside the tube and the metal flexed so badly it caused a lot of the powder coating to flake off, something that still occurs every now and again.
I like the look of the Moonlit focuser so will have a look at that myself.
One problem I have at the moment is movement in the secondary mirror arrangement. Every time I try to adjust for collimation the whole assembly rotates about a quarter of a turn.
What did you do to the bottom end if anything and when you've fitted the fan can you post another pic of it please.
Steve.

[carlstronomy (Carl)]

Steve, I also had movement in the secondary mirror, it is due to the shrinkage of the gasket material. If you have not fixed it this is what I did.

1. Due to the two holes being too small for right angle cir-clip pliers in the holding ring, I bought a very large pair of grips from Bunnings.
2. I cut out a cardboard sheet to protect the corrector plate.
3. Manufacture a wooden fork device to hold the star points during tightening.
4. Use two people, one to hold the fork device and one to tighten the ring

This does work but does damage the ring cosmetically. I am going to have a new ring manufactured with proper cir-clip holes soon. When this is fitted I shall also replace the gasket material with new.

Carl

[Exfso (Peter)]

I had one of these a few years ago, the first thing I replaced was the crap focuser, that really was rubbish. I suspect mine was 2nd hand even though it was purchased new from the local Meade dealer here in Adelaide. The reason was that when I removed the corrector to install the new focuser, the ota was rusted where the screws attached to corrector to the ota and someone had obviously tried to spray over the area. I was not impressed and gave the dealer a real spray, he threatened to sue me. When I showed him what I meant he shut his mouth big time. All that aside the optics were pretty good. In my opinion a mongrel to collimate. It sure as hell did not go with the LXD55 mount, and that was as useless as boobs on a bull. I reckon they were the worst mount Meade ever produced. It worked well on my Losmandy G11.
Eventually sold it.