TheSkySearchers

I had converted my Z12 to a collapsible using carbon fiber poles a couple years ago. I was never really happy about it because it was a bit bulky and the balance was off due to the loss of a piece of metal tube. Also, the struts were fastened with 6 small screws which was not ideal to say the least.

This weekend I replaced the carbon fiber poles with square aluminum trusses, replaced the tube with a smaller section of the part that I had taken out last time, fixed the balance and shortened the base by 2 inches. This should make it much easier to put in the car and take to star parties. The fasteners are now a bunch of wing nuts, much easier to use than the old system. The balance and focus are perfect. I drilled some extra holes for AP to push the focal plane further out.

I tried it tonight, it works great. It takes about 4 seconds for the image to settle after a bump but that's OK. I know it's because I attached the struts straight on the tube and did not add wooden rings for stiffness. It doesn't bother me so I'm happy.

Oh and I cleaned the mirror too while I was at it.

Nice work Henk. Sounds like a real pleasure to use.

helicon wrote: ↑Wed Jul 07, 2021 8:19 pm Nice work Henk. Sounds like a real pleasure to use.

Thanks Michael. It's much better now, I just deal with 3 wingnuts mostly. It is now more of a truss design than a collapsible because the aluminum poles are longer than what one would choose for a collapsible. The Z12 is great but in its original form it takes up 3 car seats. After my first conversion it took up 3/4 car seat and it was a hassle laying it down on its side. Now it should fit straight up if I put the top plus trusses in the trunk. I can remove the trusses from the top as well if I run short on space.

In retrospect of course I should have got the Skywatcher 12" collapsible, it would have saved me a bunch of work. I could not resist getting the Z12 for $630, its price it back in the days when they were competing to push Apertura out of business.

Sweet rig

Good for you. I'm thinking through a process for compactifying my own Z12.

Good job Henk - does it have a significant weight loss?

KingNothing13 wrote: ↑Thu Jul 08, 2021 12:04 am Good job Henk - does it have a significant weight loss?

The base is now 15 kg, the tube 19 kg. That's about 75 US lbs. Hmm that's still the regular weight. Maybe my scale was off because the aluminum struts should weigh less than the piece of steel tube that I took out but not by a whole lot. Weight was not ghe main goal, size was. It indeed fits on the back seat straight up.

SkyHiker wrote: ↑Thu Jul 08, 2021 3:45 am

KingNothing13 wrote: ↑Thu Jul 08, 2021 12:04 am Good job Henk - does it have a significant weight loss?

The base is now 15 kg, the tube 19 kg. That's about 75 US lbs. Hmm that's still the regular weight. Maybe my scale was off because the aluminum struts should weigh less than the piece of steel tube that I took out but not by a whole lot. Weight was not ghe main goal, size was. It indeed fits on the back seat straight up.

Ahh, I see - that makes sense.

I don't have a problem with the weight or size of my AD10 - but I am not getting any younger (sadly).

At nFA's request, here are more detailed pictures some with a tape measure so it can be used to perform similar surgery:

Mirror section: Side view to get an idea of the clearance (I believe the alt bearings are at the lowest position), with a strut hole to the right. The center part that was cut out. A strut, square from ACE. Square struts have the advantage of being flush with the tube so they can be fixed much better than a round strut, using wingnuts. The 2nd hole from the top was a mistake (not used). The bottom hole is for regular viewing, the one above it is for AP (to get the focal plane out far enough). Bolt with wingnut, inner scraggly keep-in-place washer (don't know the name), Belleville washer for tensioning. The bolt is 5/8" x 1.5" IIRC. Top view. Note that the struts are not placed in an equilateral triangle because they have to have clearance around the Alt bearings. Focuser section. I hope this makes it clear enough. It's a pretty rough conversion but it works. Note that the tube ends that were cut are bare so you can cut yourself on it. I intend to put some trim on it, some day.

It is best to mark the struts and the holes with colored tape (different colors, to be clear) so you know which one goes where.

The weight distribution is such that the Alt bearings must be in the lowest position. I had been thinking about moving the bearings 1" down so the bearing position can be 1" higher so they are not in the extreme position anymore. But there is no need, this works.

I am not going to advise how to drill the holes such that everything is straight and vertical. If you don't know how to do that then maybe this is not for you. I did it in place, used painter's tape IIRC, just some simple tricks but this has to be done with care of course.

Thanks for the update. I probably could do something similar with the Z10, though it's not so heavy and for now, the tube fits in the backseat of my SUV.

helicon wrote: ↑Fri Jul 15, 2022 12:32 pm Thanks for the update. I probably could do something similar with the Z10, though it's not so heavy and for now, the tube fits in the backseat of my SUV.

Very true, I could do the same with my 10" Coulter Odyssey - no conversion needed, and the views from a 10" are not a whole lot worse. So maybe I should never have got that Z12, I could just not pass it up when it was on sale for $630 when Zhumell was running Apertura into the ground. The difficulty of handling a scope goes up with the cube of the diameter while the views only go up with the square! Oh well it gave me something to do.

Nice mod Henk!

Hi Henk. Sorry to come in late. You did a wonderful job on your Z12 conversion and upgrades. This is some great craftsmanship on your part. And, I agree with your analysis about the scope diameter; "The difficulty of handling a scope goes up with the cube of the diameter while the views only go up with the square!" My largest telescope which gives me fantastic views is my XT12i. However, over the years as I age, it seems to be getting heavier and I now need help to carefully get it out and use. Thanks for this wonderful report and the excellent photos about your Z12 handy work Henk and the best of regards.

@SkyHiker how large a hacksaw do you recommend? What size did you use?

notFritzArgelander wrote: ↑Thu Jul 21, 2022 5:07 am @SkyHiker how large a hacksaw do you recommend? What size did you use?

I used a jigsaw IIRC. Easy to control and to make it go straight mark the cutting line with painter's tape.

SkyHiker wrote: ↑Thu Jul 21, 2022 6:30 am

notFritzArgelander wrote: ↑Thu Jul 21, 2022 5:07 am @SkyHiker how large a hacksaw do you recommend? What size did you use?

I used a jigsaw IIRC. Easy to control and to make it go straight mark the cutting line with painter's tape.

Quite so. I misremembered hacksaw instead of jigsaw as you posted on the other thread. I need to check about availability I think. I think I just might have one lying about.

Any postive news nFA, or total destruction? I'm curious how things worked out.

SkyHiker wrote: ↑Tue Aug 02, 2022 2:50 pm Any postive news nFA, or total destruction? I'm curious how things worked out.

Things are moving at glacial pace. The only positive news is that I’ve located my jigsaw. But I’m still mulling over conversion trade offs between a metal tube truss and a wood work collapsible. I’m still dealing with the aftermath of my plumbing problems.