Downsizing from DM6/Planet ?
Posted 19 April 2013 - 04:15 AM
The thing is, my back yard doesn't exactly have wide open views so I need to be able to carry the 30 kg rig around to look in different directions, and it's really taking a toll on my back. There are a few narrow passages so wheels are not an option.
Is there an alt-az mount / tripod combination avalaible that would be close to my current set-up in capacity, stability and ease of operation, but weighs something like 10 kg less?
Don't mention Rob Miller's tripods as these are not available.
I have a Giro-3 and that is not quite up to the task. For starters I'd need a counterweight with my Mewlon on it and that defeats my purpose. It's also quite frankly not in the same league on stability.
Posted 19 April 2013 - 06:55 AM
You might give Tom Peters a call and see what he thinks.
I am going through a similar thought process because of my medical issues.
Posted 19 April 2013 - 07:11 AM
I've found the HAL130 to be an extremely portable tripod. When carrying the HAL130 in the field with the mount head and scope sitting on it, you can leave the legs extended but easily collapse the tripod leg set by lifting on the center spider and then carrying the whole assembly over your shoulder using the leg set to grab and counterbalance the scope and mount head.
The HAL130 tripod is undervalued in the astronomy world for some reason, but I've found it to be a real workhorse. The HAL130 tripods are the one's sold with Vixen's GP and GPD2 mounts. The GPD2 is rated to carry a 35 lb payload.
For car transport, the HAL130 tripod collapses to a package size of about 6" x 30".
At any rate, I don't think you'll be very happy losing your DM6, especially compared to any of the other alt/az mounts out there (except the T-Rex of course ).
Posted 19 April 2013 - 01:21 PM
Kunama, that DSV-3 looks like a Giro3 class mount; I'll look for reports from people that have compared the two.
Ron, the Mewlon is actually over the rated limit of the DM4 but I know there are numerous reports it's been rated too conservatively. I still think it's more an option for when I decide to downsize the scope too.
Patrick, I've followed your thread about your magnificent T-Rex set-up. The tripod is a surprise. I'm curious how that HAL130 tripod differs from the Vixen tripod that came with my Super Polaris mounted 90mm achromat I bought in '89. I didn't like that tripod. It was certainly strong enough but very prone to vibration.
You're right about one thing, I will hate to ever give up the DM6. I still kick myself over being able to buy that whole set-up used for a steal.
Posted 19 April 2013 - 02:36 PM
I'm wondering why the HAL130 is so much more stable.
Posted 19 April 2013 - 03:00 PM
I'm curious how that HAL130 tripod differs from the Vixen tripod that came with my Super Polaris mounted 90mm achromat I bought in '89. I didn't like that tripod.
It's a completely different tripod. The aluminum Super Polaris "AL" tripods were a split design with a sliding center piece similar to many wooden tripods today (and also similar to the Porta mount leg sets). The HAL130 upper leg is a hollow extruded member that the similar hollow extruded lower leg slides within. My guess is that the hollow extruded legs are much stiffer than the split design.
Personally I hate a shaky setup, so if it wasn't sturdy, it would be gone!
Posted 19 April 2013 - 03:12 PM
Could you let me know the diameter of the top of the tripod (the part your T-Rex mounts to)?
I'm also thinking about doing some landscaping in the garden so that I could use wheels under the Planet.
Posted 19 April 2013 - 03:24 PM
Biggest question will be how to mate it to the DM6's flat bottom.
On the T-Rex there is a special bottom plate to accomodate the polar axis post. I believe the flat on the base is about 5" with a recessed area about 1.5-2" in diameter for the bottom of the GP2 mounts to fit in.
Perhaps the DM folks have some kind of adapter for use with tripods with the polar axis posts?
Posted 19 April 2013 - 03:55 PM
The simplicity of a DiscMount I prefer to the DSV-2 that I previously owned. No backlash adjustment, no altitude locking/unlocking, no rebalancing, no levelling. Just plunk the scope in the saddle and observe.
Ecstatic DM4 owner, Keith
Posted 19 April 2013 - 05:58 PM
Patrick has me thinking about a HAL130 and removing the pin. That would be a light, apparently solid, setup for my little TV85.
Posted 20 April 2013 - 01:29 AM
Posted 20 April 2013 - 02:00 AM
Posted 20 April 2013 - 03:26 AM
Posted 20 April 2013 - 05:08 AM
That said, I am usually too lazy to bother and put up with a little imbalance. The friction discs compensate well enough for my tastes.
Posted 22 April 2013 - 09:34 PM
The Gitzo 5541LS weighs about 6.5 pounds. There is a big difference in the DM4 (5.2 pounds) vs DM6 (16.2 pounds). I think these weights are without saddle and the 8 inch extension would be more. I think you could have a DM4 on a Gitzo and still be under 14 pounds with the saddle. I have no shake/steadiness issues on the Gitzo. Just keep an eye on it around people because all the weight would be at the top of the tripod. It would take quite an effort to knock over my Planet. I prefer the Planet when doing outreach because of the lower center of mass.
Posted 23 April 2013 - 04:09 AM
That Gitzo tripod is a lot more expensive even than the Planet.
Posted 23 April 2013 - 05:45 AM
Posted 23 April 2013 - 07:35 AM
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Posted 24 April 2013 - 12:24 PM
Posted 24 April 2013 - 06:10 PM
Posted 24 April 2013 - 07:56 PM
I would recommend the GT5532S for $1050 as the best Gitzo tripod for astronomy. It is rated at 88 pounds and weighs 6.2 pounds. It goes to 51 inches maximum height. The legs are in 3 sections so they are quite thick. My 5541LS has legs in 4 sections and goes higher but I only use the 3 thickest sections for astronomy.
Posted 25 April 2013 - 02:23 AM