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#1 Patrik Iver

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Posted 04 January 2012 - 01:16 PM

Hi!

I've never heard anything bad about the DM tripod extensions, but to my eyes, the design looks like it might be less torsionally rigid than for example a similarly sized tube section would. I've never used or seen a DM mount in person, and I'm not a structural engineer, but I am in need of a higher capacity alt-az mount, and the DM6 is high(est) on my list.

Anyone owning a DM6 tripod extension who has compared the az stability with/without the extension?

I would use the mount mostly with a 130 mm f/6.3 refractor and with a 235 mm SCT (AP130GT and C9.25). I am apparently relatively picky about mount stability.

Any and all feedback is most welcome.

Thank you!

#2 Wayne W.

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Posted 04 January 2012 - 01:41 PM

Hi Patrik. I used two extensions stacked on a CPC tripod for my DM-6. They are very ridged and there is no flexure. I would recommend them. Their very nicely made and quite substancial. Clear skies

#3 gillmj24

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Posted 04 January 2012 - 05:38 PM

I think the three struts are solid (they sure feel solid) and are thicker than the tube of say, an orion atlas/sirius extender.

It's quite solid and I don't feel I've lost rigidity by adding it.

#4 mountain monk

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Posted 04 January 2012 - 05:45 PM

The thing is bombproof. I tried it without the extension but the handle hit my Planet tripod. So I went to the extension plus a two-inch aluminum block and I haven't had a sign of rotation. A great system.

Dark skies.

Jack

#5 gatorengineer

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Posted 04 January 2012 - 05:52 PM

rock solid but expensive...... Your load out would be trivial for a DM6... I would have no qualms throwing a Meade 14 on it. With your load out, even if you put it on a Dual saddle plate, and mounted it simultaneously no worries. The real issue is the tripod, that will be your weakest link. If you want maximum stability, try a Berlebach, thats what I carry my DM6 on, big differnce between it and the highly regarded Stellarvue Stabilock, which I use for my medium duty pod. The Stellarvue was a HUGE upgrade over a CG5 Pod....

I think Mountain Monk is referring to a Berlebach Planet if I am not mistaken.....

#6 mountain monk

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Posted 04 January 2012 - 08:48 PM

Yes, I was.

Dark skies.

Jack

#7 Patrik Iver

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Posted 05 January 2012 - 02:52 PM

Thank you all!

Kind of confirms why I've never seen any negative comments about the extensions.

If I choose a DM6, I would most likely mount it on a Berlebach Planet. My current most solid tripod is a Berlebach UNI18L (no longer in production, but pretty close to the current UNI28, I think), but even if it atleast somehow carries a Giro II with a C9.25 and plenty of counteweights, it does not support the (ligher, but longer) AP well enough to feel comfortably usable. I'd guess this is more due to the Giro II than the tripod, since the tripod is quite usable with the same load on a GP-DX equatorial head.

Beside the DM6, the other contenders are the T-Rex and possibly the AYOdigi.

#8 mountain monk

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Posted 05 January 2012 - 04:29 PM

Patrik:

I will add that Tom Peters is a gem of a man to deal with. Fast responses by e-mail or phone. No bull, great support. Very expensive that Berlebach Planet and the DM-6, but it is a lifetime system. Buy once, cry once, etc.

Dark skies.

Jack

#9 M44

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Posted 05 January 2012 - 05:47 PM

Beside the DM6, the other contenders are the T-Rex and possibly the AYOdigi.


Patrik,

Like you, I am very picky about the mount/tripod stability. I have a Super Halfhitch on order for almost a year, so I went ahead and purchased AYOdigi from Beat Kohler of Aokswiss. Beat is a great guy to deal with and it was a one of the best purchasing experience. I took few months to decide but I am very happy with AYOdigi mount/Berlebach planet and APD 130EDFGT. When using Arognavis, the backlash is only 1/100th i.e, when I zero-in on an object with Argonavis, the mount moves back (backlash) only 1/100th point on Argonavis display.

The motions are rock solid and like any alt/az mounts, it responds well with a well balanced load, I usually balance it 45-50 deg angle. One con is it is very heavy with two Robin Casady dove tail saddles and d-plates at ~15 lbs.

One of the picture of AYOdigi (with TSA 120 and AP130EDFGT) you see on aokswiss is mine used with my permission.

Good luck with your mount hunting!

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#10 Patrik Iver

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Posted 09 January 2012 - 04:01 PM

Buy once, cry once, etc.


Decided to go with the DM6 (with extension) - placed the order earlier today.

I'm waiting for a quote from Berlebach for a Planet with a larger 50 cm tray in place of the 37 cm spreader in order to give a wider spread angle and thus better stability with the offset load. I'd like a large tray without EP-holes, like the one I have on my 10 year old UNI18L, but that tray is no longer listed. I have a feeling they might be willing make one for me, but let's see what they reply...

A big "THANK YOU" to everyone who shared their opinions and ideas during the process.

#11 Mark9473

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Posted 09 January 2012 - 04:12 PM

Your C9.25 has a relatively short OTA. I don't know where the balance point is on that scope, but I hope it's significantly more forward than on my Mewlon 210, otherwise your knee will hit the tray.

#12 Patrik Iver

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Posted 09 January 2012 - 04:28 PM

Probably true.

Frankly I haven't yet quite decided when to get a Vixen to D-type rail adapter for the SCT to mount it on the DM6. When I take out the SCT it is for longer sessions, and then I usually mount it on the GP-DX equatorial head I have on a permanent pier, which nicely solves any knee-/chair-clearance problems, as well as giving me tracking to really be able to concentrate on high power views.

#13 Patrik Iver

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Posted 10 January 2012 - 03:08 PM

Your C9.25 has a relatively short OTA. I don't know where the balance point is on that scope, but I hope it's significantly more forward than on my Mewlon 210, otherwise your knee will hit the tray.


Still further on this topic:
How about turning the diagonal outward? Makes hand-tracking a bit trickier, and perhaps navigating a bit more challenging, but on a GEM you would anyway constantly be adjusting the diagonal rotation depending on where you are pointing.

#14 Patrik Iver

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Posted 10 January 2012 - 03:23 PM

I'm waiting for a quote from Berlebach for a Planet with a larger 50 cm tray in place of the 37 cm spreader in order to give a wider spread angle and thus better stability with the offset load. I'd like a large tray without EP-holes, like the one I have on my 10 year old UNI18L, but that tray is no longer listed. I have a feeling they might be willing make one for me, but let's see what they reply...


Berlebach did not recommend to replace the spreader with a clip-on tray on their high capacity tripods to increase the leg angle. The logic was that for a heavily loaded tripod with a wide leg angle on a slippery surface (I requested plastic feet instead of spikes) an accident like inadvertedly kicking up the tray so that a clip releases might lead to a leg swinging out and the tripod falling over.

Logical, but I guess it could be prevented with a safety chain.

Instead they suggested that they supply a tripod with the spreader installed without the screws in place, whereby I could choose and adjust the leg angle (by varying the spreader assembly height on the legs) until I'm happy with it, and then finally lock the spreader with the screws.

They did also say that if I wanted a bigger clip-on tray without EP-holes, they could make one.

Responsive and considerate, I think. :)

#15 Mark9473

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Posted 10 January 2012 - 03:36 PM

How about turning the diagonal outward? Makes hand-tracking a bit trickier, and perhaps navigating a bit more challenging, but on a GEM you would anyway constantly be adjusting the diagonal rotation depending on where you are pointing.

That certainly works I've recently extended my Planet's legs a bit further so as not to have to crouch down too much when viewing the zenith, but of course when viewing at low altitude I now have to look sideways into the diagonal.

It is not as intuitive to move the scope in this orientation, but I suppose it's just a matter of getting used to it a bit more. But using the handle it wasn't really all that hard either. Perhaps the DM-6's tension settings can be adjusted to help in this.

The main reason why I don't like doing this, though it is unavoidable, is that I don't like looking at Jupîter and the Moon laying on their side.

#16 Mark9473

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Posted 10 January 2012 - 03:40 PM

I don't really understand Berlebach's comments. Must be a different tray as the one I have, which is secured with a large screw at the center. Quite frankly I much prefer the spreader that came with mine. I think their suggestion to leave the installation of the spreader to you, to fine-tune the leg angle as you wish, is the best option.

#17 Patrik Iver

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Posted 10 January 2012 - 04:20 PM

The main reason why I don't like doing this, though it is unavoidable, is that I don't like looking at Jupîter and the Moon laying on their side.


I'd have to agree on that one...

But comfort is still #1, you see so much more when sitting comfortably in a relaxed position without straining.

#18 Patrik Iver

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Posted 10 January 2012 - 04:28 PM

I don't really understand Berlebach's comments. Must be a different tray as the one I have, which is secured with a large screw at the center. Quite frankly I much prefer the spreader that came with mine. I think their suggestion to leave the installation of the spreader to you, to fine-tune the leg angle as you wish, is the best option.


It is a different tray. Before the spreader (as used on the Planet and Sky), the trays had (and still have, for the UNI) a clip at each corner, which clips around a pin between the lower end of the upper leg sections. Your remove the tray by pushing it upwards - the clip opening is facing downwards. You can see how the trays look on their website.

I just ordered the tripod with the stock tray and spreader, but unfastened, as they recommended. It has been an expensive couple of weeks...

#19 mark8888

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Posted 11 January 2012 - 12:09 AM

(I requested plastic feet instead of spikes)


They will most likely also send the spikes, in a separate little baggie. At least, they did for me. You might want to mention it, I think I did.






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