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Losmandy Counterweight on AP mount. Sacrilege?

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#1 Cotts

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Posted 15 October 2012 - 09:18 AM

My mach 1 GTO currently holds a 1988 6" f/8 refractor. It takes three of the 9 pound counterweights to balance this. (two of the weights are at the end of the travel and one could be slid out about two more inches) I'd like to add my 80mm William Optics as a guide/finder. With rings etc. it is close to another 10 pounds.

Another 9 pound AP weight may not be enough. But a Losmandy 11 pounder might be enough and a Losmandy 21 pound would be excessive, allowing me to remove a couple of the 9#'s.

The AP shaft diameter is 1.125" while the Losmandy shafts are 1.250" so the Losmandy weight could fit. With the locking bolt the Losmandy C. W. won't flop around. Or will it?

Musings over Monday morning coffee.

Especially the 'sacrilege' bit......

Dave

#2 orlyandico

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Posted 15 October 2012 - 09:44 AM

You could put the Losmandy weight on top, supported by one AP weight...

incidentally i always wondered if the Losmandy and AP weights were interchangeable. You just answered my question. :D

#3 skybsd

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Posted 15 October 2012 - 10:48 AM

Hi,
"Sacrilege" would be a matter for the owner more than anything else..,

One thing to consider is the fact that temperature variations may well contribute to the Losmandy counterweight flopping (even if slightly) as the tighning loosens over time..,

Regards,

skybsd

#4 Cow Jazz

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Posted 15 October 2012 - 10:57 AM

Could you add a sleeve to the Los CW? That may solve all issues.

#5 rmollise

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Posted 15 October 2012 - 11:40 AM

If the counterweight is tightened down, it will be fine, end of story. Sacrilege? I'll tell you what has served me well in this sort of conundrum in the past, Bubba...

"All Cats are Black in the Dark." :lol:

#6 bobhen

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Posted 15 October 2012 - 11:43 AM

My mach 1 GTO currently holds a 1988 6" f/8 refractor. It takes three of the 9 pound counterweights to balance this. (two of the weights are at the end of the travel and one could be slid out about two more inches) I'd like to add my 80mm William Optics as a guide/finder. With rings etc. it is close to another 10 pounds.

Another 9 pound AP weight may not be enough. But a Losmandy 11 pounder might be enough and a Losmandy 21 pound would be excessive, allowing me to remove a couple of the 9#'s.

The AP shaft diameter is 1.125" while the Losmandy shafts are 1.250" so the Losmandy weight could fit. With the locking bolt the Losmandy C. W. won't flop around. Or will it?

Musings over Monday morning coffee.

Especially the 'sacrilege' bit......

Dave




I’ve been using a 21-pound Losmandy weight and a 9-pound AP weight for My C11 and AP155 OTAs – works fine (less weights to employ) and no flopping around. The Mach 1 has the standard shaft.

Bob

#7 skybsd

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Posted 15 October 2012 - 12:04 PM

Could you add a sleeve to the Los CW? That may solve all issues.


I imagine it should work - though what material to use + effectiveness may well vary with local conditions..,

Best..,

skybsd

#8 Cotts

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Posted 15 October 2012 - 12:58 PM

Thanks, folks for the timely replies. It seems buying one 21# Lsmandy will do the trick. Apparently no sleeve will be needed. As far as interchangeability, the Losmandys will fit on the AP but not vice versa....

Dave

#9 RAKing

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Posted 16 October 2012 - 06:34 AM

Dave,

I get my counterweights from Robin Casady and they all look the same.

Try it - no one will know! :roflmao:

Cheers,

Ron

#10 Cotts

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Posted 16 October 2012 - 08:37 AM

I just went to the Casady website and his counterweights are for the 1.875" shaft so I won't be able to use them...

Thanks for the tip, nevertheless. He shows many other interesting products...

Dave

#11 EFT

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Posted 16 October 2012 - 10:11 AM

The problem with mounting a counterwieght with a larger diameter is that it will throw off the DEC balance to some extent since the counterwieght is not centered on the shaft. Some counterwieghts are already off balanced due to the knob and if that is the case with the Losmandy counterwieght, then it will be excentuated by pushing the knob side of the counterwieght further from the shaft.

#12 RAKing

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Posted 16 October 2012 - 10:51 AM

I just went to the Casady website and his counterweights are for the 1.875" shaft so I won't be able to use them...

Thanks for the tip, nevertheless. He shows many other interesting products...

Dave


Actually, I was suggesting one of his Losmandy counterweights. The 15 pounder might be a perfect compromise. You could sandwich it between two A-P nine pounders and no one would notice. :cool:

Sorry for the confusion,

Ron

#13 jmiele

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Posted 16 October 2012 - 03:35 PM

I just went to the Casady website and his counterweights are for the 1.875" shaft so I won't be able to use them...

Thanks for the tip, nevertheless. He shows many other interesting products...

Dave


Dave, I think A-P sells a standard 1.875" A-P 900/1220 bar for the Mach1GTO.

Best, Joe

#14 orlyandico

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Posted 17 October 2012 - 01:05 AM

Yes they do..

#15 andysea

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Posted 19 October 2012 - 07:21 PM

I must have committed the ultimate sacrilege. I sandwich two 10lb gym plates between my two Tak weights on my NJP!.....Am I going to astronomy hell? :)

#16 Dan Finnerty

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Posted 22 October 2012 - 11:36 PM

I must have committed the ultimate sacrilege. I sandwich two 10lb gym plates between my two Tak weights on my NJP!.....Am I going to astronomy hell? :)


You practice astrophotography in the dark with barbell weights. Indeed, you are already there! :roflmao:

#17 andysea

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Posted 23 October 2012 - 12:31 AM

Oh dear!! you might be right Dan:) It's just that at close to $400 a pop those Tak weight aren't cheap....and they rust!
On a different note I am going to try a Meade LX80 weight on the Mach1. I should have the weight by the end of the week. I will report back and let everyone know if it fits.

#18 andysea

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Posted 25 October 2012 - 07:34 PM

I can confirm that the Meade LX-80 counterweights will fit nicely on the Mach1 standard counterweight shaft. They are 11lbs each and they are probably the cheapest counterweights available on the market. They are also painted a nice silver finish.

Andy

#19 Starhawk

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Posted 26 October 2012 - 09:50 AM

The only point I'd look out for is if the alternate weights are going to scar up the counterweight bar. AP weights have bronze bushings and noses on their set screws.

The 1.25" diameter of a Losmandy weight would leave room for a bushing.

What would be really cool is a 40 amp-hour 12V battery weight.

-Rich

#20 andysea

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Posted 26 October 2012 - 03:57 PM

Good point RIch!
I bought a 12" bronze rod of the right diameter to replace the Meade steel plugs that press against the counterweight shaft. I will cut the rod in pieces of the correct length, one per each counterweight. It came up to a whopping 5 dollars :)

#21 kyang

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Posted 01 May 2014 - 03:00 AM

Just dig out this old thread... :D
Orion now offers 22lb CW for the HDX110.
http://goo.gl/ltku4R
It looks similar size as the one offered by Losmandy.

Stupid question, will this work ?
AP's CW is much more expensive... ;-)






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