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Alt-Az mounts for visual use?

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#1 SnaggS

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Posted 15 July 2009 - 02:17 AM

Hi,

I've just bought a FS-128 refractor.. and the $$$ for a EQ mount are high. I also find that the EQ mount I bought for my Sky 90 removes some of the compactness of the scope and is not as easy to point at objects in the sky.

So, I was thinking of getting a Pier put in my back yard and buying a Takahashi TG-LA Alt-Az mount.

I'm sure I can find cheaper Alt-Az mounts, but I like Takahashi, and it will be bullet proof.

What do you think? Is this doable for planets or am I going to find it a pain keeping things on track?

What does "Lapides Modified" mean?

Here is a pick I found of a 210mm Mewlon on the mount I'm looking at;

Posted Image

Posted Image

#2 TONGKW

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Posted 15 July 2009 - 08:48 AM

Herewith is an article describing the Lapides modification of the Takahashi Teegul AltAz mount.
http://www.cloudynig...php?item_id=599

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#3 highwood

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Posted 15 July 2009 - 09:40 AM

Snagg:

I use the modified Teegul (actually, I bought Richard Lapides's, the one shown in his Cloudy Nights article) on a Davis & Sanford tripod with an AP Traveler, and it tracks very nicely thanks to the slow motion knobs. Not a GEM, but a lot more convenient. I imagine the pier will make your rig much more stable, but I can't say how all this will work with the FS-128, which I believe may be lighter but longer than the Mewlon 210. One suggestion: if you can acquire the eyepiece holder (it's shown in Richard's article), you won't regret it. It was expensive, but it's a great piece of equipment.

Good luck.

Jim

#4 Scott99

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Posted 15 July 2009 - 10:33 AM

Hi,

I've just bought a FS-128 refractor.. and the $$$ for a EQ mount are high. I also find that the EQ mount I bought for my Sky 90 removes some of the compactness of the scope and is not as easy to point at objects in the sky.

So, I was thinking of getting a Pier put in my back yard and buying a Takahashi TG-LA Alt-Az mount.

I'm sure I can find cheaper Alt-Az mounts, but I like Takahashi, and it will be bullet proof.

What do you think? Is this doable for planets or am I going to find it a pain keeping things on track?

What does "Lapides Modified" mean?

Here is a pick I found of a 210mm Mewlon on the mount I'm looking at;

Posted Image

Posted Image


The picture of the M210 on the un-modified Teegul is a joke, believe me it would be unusable. Read Ed Ting's review of the original Teegul. Even the modified Teegul can't handle any bigger than M180.

The modified Teegul is great but it won't be able to handle an FS128 tube, too long & heavy. if you want to go alt-az you'd be better off with Discmount6.

#5 SnaggS

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Posted 15 July 2009 - 08:58 PM

Are you saying that all the Teeguls are the same? The TG-LA is the same as the TG-SM just one has a bigger arm on it?

I thought the TG-LA was a beefed up unit?

Daniel.

PS. The ED-Ting review I found was very positive?

#6 SnaggS

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Posted 15 July 2009 - 10:32 PM

The DM-6 looks amazing!! I think I'm sold.. anyone know of a good pier to use with it?

Regards,

Daniel.

#7 CESDewar

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Posted 15 July 2009 - 11:09 PM

I have the Lapides-modified Teegul as well as a DM6 along with Celestron C8 and a TeleVue NP-127 - both of which top out at about 20lbs fully loaded. The FS-128 fully loaded might be a pound or two heavier at most, so it's really in the same range weight-wise, but it's 46" long - a foot longer than the NP-128, and that creates far more shake on a mount.

The Teegul mount does work with my two scopes, but it's pushing the top limit and only acceptable because (a) I observe in an area with no wind, (b) I put vibration suppression pads underneath the legs, and © it's lightweight, so I'm sometimes willing to compromise on the settling time for less carrying weight and (d) I like slow-motion controls.

But if you are going to put a pier in the backyard, I would think it's a no-brainer to go with the DM6 as this is a mount spec'd to hold more than twice the load of the Teegul. It will do a good job on the FS-128 especially on a pier, and the longer length of the FS128 will actually be beneficial as it makes it easier to move the scope on the DM6.

#8 SnaggS

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Posted 16 July 2009 - 05:54 AM

Would you guys take a DM-6 over a EM-200 if cost were not a factor?

(for visual use).

Regards,

Daniel.

#9 Luigi

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Posted 16 July 2009 - 07:13 AM

How about a WO EZ-touch, or cheaper, the Orion AZ?

#10 SnaggS

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Posted 16 July 2009 - 08:02 AM

Well, I like the encoders, and the ability to mount a 6" on it at a later date. I just sold my P2Z so I'm cashed up and ready to go.

I'm just worried I'll spend all this money on a mount and not be able to track planet. I don't mind having to learn how gently keep track, I just don't want it to jerk around!

Daniel.

How about a WO EZ-touch, or cheaper, the Orion AZ?



#11 zawijava

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Posted 16 July 2009 - 08:03 AM

Would you guys take a DM-6 over a EM-200 if cost were not a factor?

(for visual use).

Regards,

Daniel.


You could really save some money and have an equally functional, if not better, Alt-Az mount if you buy a Giro III at $375. You could even add on a Tech 2000 drive [$750] to the Giro III later on! This is how I am setting up my FS-128.

Tim

#12 SnaggS

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Posted 16 July 2009 - 09:55 AM

I've read other posts which consider the DM-6 better? It would also enable a 6" apo to be mounted one day.

Can the Giro III take a 6"?

Daniel.

#13 zawijava

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Posted 16 July 2009 - 10:34 AM

I've read other posts which consider the DM-6 better? It would also enable a 6" apo to be mounted one day.

Can the Giro III take a 6"?

Daniel.


Daniel,

What I've read from Giro users is that the 28 pounds [per side] rated capacity is very conservative. Giro users have stated they have loaded these mounts with 35 to 40 pounds per side with no degradation of function. As with any alt-az mount in this class, balance of loads is the key. Successfully hanging a 6" refractor on the Giro [or other alt-az mount] would depend more on focal length than weight, in my opinion. Perhaps others who have done so could give you more specifics.

In regards to the EM-200, it would be an awesome mount for the FS-128, yet pricey.It carried my Mewlon 250 with ease. It is one of many Tak mounts I have owned and I loved it but it has some substantial weight to it....I would not consider it a grab and go mount by any means.

Tim

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#14 Tamiji Homma

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Posted 16 July 2009 - 11:26 AM

Would you guys take a DM-6 over a EM-200 if cost were not a factor?

(for visual use).

Regards,

Daniel.


Hi Daniel,

I use DM-6 for fully loaded 6" refractor, 44lb. I can track at 300x. You need a little practice to get used to it. I use the setup as "drag-n-go." I think total weight is over 100lb. If you want to mount 6" in the future, you need solid tripod/pier. I use Losmandy FHD tripod with DM-6.

If you go over 200x regularly, I would consider EM-200 as primary mount if you choose either EM-200 or DM-6.
I use G11 mount/HD tripod combo for that purpose.

I have been considering this mount for a while for 5" refractor.
http://www.universalastronomics.com/
The DoubleStar Mount

Good luck in mount hunting :)

Tammy

#15 Scott99

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Posted 16 July 2009 - 12:49 PM

Are you saying that all the Teeguls are the same? The TG-LA is the same as the TG-SM just one has a bigger arm on it?

I thought the TG-LA was a beefed up unit?

Daniel.

PS. The ED-Ting review I found was very positive?


Daniel - sorry, I was thinking of a different review.

The un-modified Teeguls use a long arm to hold the scope - this introduces lots of instability & vibration in all but the smallest scopes. Mr. Lapides and his friend with machine shop came up with an easy way to eliminate the arm, hence the "Lapides modified" version that is now purchased by the vast majority of users. It is much more stable without the arm.

However, I think a 5 inch refractor or Mewlon210 is beyond what the Teegul can handle. The DM6 can handle much more weight but you give up the slow-motion knobs.

I would definitely take the EM200 over a DM6. It's hard to set up but you get stability and high-power tracking. The FS128 will easily get up over 200x for planetary observing and that's when you really appreciate the tracking. Also for mid to high power work on DSO work on planetaries, globulars, galaxies, etc.

You really have to try this out, some people cannot tolerate alt-az mounts at all. I enjoy using them because using my equatorial mount pretty much triples the amount of equipment I have to load in the car and bring to the observing site. It's worth it for my 6 inch refractor, but for my smaller 4 inch one I end up using the Teegul 99% of the time.

#16 SnaggS

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Posted 16 July 2009 - 07:34 PM

Sigh.. its very difficult.. the EM-11 I can get for A$6.9k with Takahashi pier like below all in green paint :)

Posted Image

or its A$3.7k for a DM-6 on tripod.

Problem is, no one around has a decent Alt-Az to try.

Daniel.

#17 spmv

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Posted 16 July 2009 - 09:02 PM

Daniel, I feel your pain. I also bought a beautiful FS 128 and am weighing my options on buying a mount. I've been so close to calling Tom at Discmounts but have held off thinking a G11 would suit me better. I had a new Atlas, but it died on me, literally.
If I could afford the EM 200, it would be my first choice for the 128.
It sure would be easier to be able test drive a mount before buying wouldn't it?

#18 SnaggS

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Posted 16 July 2009 - 09:50 PM

Yes!!! and damn that green paint.. its like a drug.. imagine a whole pier painted that colour :)

Daniel.

#19 crazyqban

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Posted 17 July 2009 - 12:43 AM

Snagg I have the three mounts that you are considering. I believe that the Teegul will be too small for your needs. Especially when you add the mounting hardware, diagonal, eyepieces, etc... I really like the DM6. I am set up and running in about 5 minutes. I use a Losmandy HD tripod and it is super stable with my TOA-130F. The EM-200 I got because I got it at an excellent price (used) and because kids tend to move the DM6 really easily during public events. When I am not doing a public event and just viewing with friends or alone I used the DM6. I really like how the whole system works with the encoders and the Sky Commander. Oh and did I mention the super quick setup/breakdown times? My EM-200 takes a while longer to setup. I like the quickness of the DM6. Hope this info helps...

Sergio

#20 SnaggS

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Posted 17 July 2009 - 12:57 AM

Thanks Sergio is does help, but maybe not my wallet.. makes me want to get both :)

The one advantage of the EM-200, is that I am looking at putting a Sirius observatory in the bush somewhere. This means I could just have a pier here, and a pier there and lug the mount and scope back and forth.

Daniel.

#21 CounterWeight

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Posted 17 July 2009 - 01:34 AM

Maybe I missed it... do you have the original long tube FS-128 or what is called the NSV (new Short Version) ? Either way enjoy the terric scope - love mine :)

#22 SnaggS

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Posted 17 July 2009 - 02:27 AM

Hey.. I don't have it yet, its this one.

Posted Image

#23 moynihan

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Posted 17 July 2009 - 08:41 AM

... As with any alt-az mount in this class, balance of loads is the key. Successfully hanging a 6" refractor on the Giro [or other alt-az mount] would depend more on focal length than weight, in my opinion. Perhaps other
s who have done so could give you more specifics.


It would be i guess a different class, (both as to scopes and mounts :), but i am strongly considering right now an Orion AZ with a dual mount of a 6" f/8 newt and an Orion 80mm ED.
Would those balance ok, if anyone knows...

#24 Luigi

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Posted 17 July 2009 - 08:54 AM

The main issue with balance on the Orion AZ is fore-aft. If you can position the scope in it's rings and the dovetail in the saddle appropriately to achieve reasonable longitudinal balance with diag, EP, etc.. on the scope, you're good. The motion is very smooth when the friction is light. If you need to tighten friction due to being out of balance (say chaining from a light to heavy EP), the motion becomes less smooth. I put either or both of the 16+ lb OTAs on it and find it works well. With light friction, it's smooth enough for planetary.

The secondary balance consideration is perpendicular to the the scope axis. Point the OTA straight up. If there is a heavy load (finder?) on one side of the scope it'll tend to rotate toward that load. In use, the top heaviness caused by a finder will cause the scope to want to tip upward as you look closer to the zenith and will require adding a bit of friction. If you can arrange it so the finder is in the plane of the OTA and alt axis, then this effect goes away. I don't use a finder on my 120ED. The finder on my MCT is close enough to the right place to not have a significant effect.

#25 SnaggS

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Posted 17 July 2009 - 10:04 AM

Ok, made the decision.... I'm going the DM-6 complete with tripod and a case of Zeiss Abbe II eyepieces!

The DM-6 is so much cheaper than a EQ mount of similar quality due to its simplicity. It can take a 6", and a mount for a 6" like the EM-4000 is four times the price.. it means I can get some more quality aperture alot sooner.

I'll leave a good EQ until I have a Dome setup somewhere. Thanks all for your help.

Daniel.






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