LXD75 with 10"?

[EzyStyles]

Hey Guys,

Read plenty of reviews and it seem the best mount within my budget is the Meade LXD75 with AutoStar. Was wondering if it will support a 10" scope 1200mm fl? Not exactly sure how many kg my scope is.

Thanks.

[ving]

did a quick search of the cloudy nights forums and found that some sugested the max payload for this mount was considerably less than what your 10" would weigh. this is of course just an opinion. the meade site has the lxd75 with 6-8" scopes tho

[[1ponders]]

It will support it but whether it would be suitable for imaging is another question. If you are thinking of imaging then maybe have a look at these http://meade.com/catalog/lxd75/index.html Particularly the 10" f/4 Schmidt Newtonian. I think (but don't quote me on this 'cos it was dark) that Itchy uses one of these????? Maybe drop him a pm and see what he thinks. Anyway you're looking in the price range of @4200-$2800 8"-10" Not saying they are ideal but maybe it is a start.

[Striker]

Yep Itchy use the LXD 10" F4.....nice and fast for imaging.

[EzyStyles]

thanks all. The Meade website shows their 10" mounted on the LXD75. But im just going to get the mount itself instead as i have my own skywatcher 10". Since the skywatcher is longer than the meade's 10" newtonian, was wondering if the mount itself can manage my 10". Im not sure what the skywatcher 10" weight compared to the meade's 10". :)

Many thanks.

[[1ponders]]

The extra weight will make a bit of difference (though how much heavier it is I don't know), but the biggest difference will be in the increased lever arm movement. Because yours is an extra 400mm longer it will be more prone to wind movement and any movement in the mount will be amplified by this longer length. Also balancing the tube fore and aft will be more critical as well. Not saying it won't work, just something to be aware of.

[Robert_T]

Hi ezistyles,

I have the LXD75, acquired about 3 months ago. I use it separately with a 6kg DK cassegrain tube about 600mm long and a 9kg C9.25 Smit Cassegrain of the same tube length. It handles both well for planetary imaging. The real problem you'll ahve with the 10in skywatcher is it has it's weight a long way either side of the mount so it will wobble about at the touch of a hand - should settle quickly enough. Wind weill be a problem. When I use the C9.25 with a large dew shield it has similar size as your 10in and the wind gets it and whips it about a bit.

If you do get the LXD75 insist on 2inch diam tripod legs - these are great and should be standard on the new ones.

cheers,

[EzyStyles]

thanks guys. hmm wind movement , i have fencing around the telescope which blocks some wind at my place not all though. What other mount would you guys recommend for a 10" scope besides the EQ6?

[[1ponders]]

An Eq6 :shrug: You might try a HEQ5 which is a beefier EQ5
http://myastroshop.com.au/products/details.asp?id=MAS-042

[EzyStyles]

but for $500 more, i can get LXD75 with go-to :) :)

[[1ponders]]

True. Do a google check and see if you can find any information about the periodic error of both the mounts. Just out of interest.

[EzyStyles]

thanks Paul but what is periodic error? as in with the drive system error?

[Miaplacidus]

Sorry, Ezy, please don't take this the wrong way, but I think you are asking for the impossible. There just ain't a cheap stable goto mount that'll accommodate your ten inch ota (imho). Else we all would have one.

Personally, I wish someone would come up with a good quality ALT-AZ goto mount that could accept a large range of otas. Shouldn't be that hard, you'd reckon, but no one has done it yet.

[[1ponders]]

Irregularities in the gears that prevent tracking at a consistant rate. The smaller the pe the better, but you usually pay for it.

[EzyStyles]

hey Miaplacidus, no need to apologise. :) .
Ok ignore the price, what is the best mount for a 10" 1200mm newtonian?

thanks paul. been googling around on the LXD75 but can't find proper info on it.

[Robert_T]

A Losmandy G11 would handle it well, but ~$3500 without goto and ~$5000 with.

I belive the HEQ5 Pro Series with Goto may be being sold by some retailers as a separate mount - looked at one of these recently at Sirius Optics in Brisbane. Very nice!

[RAJAH235]

FWIW. My Meade 10" (254mm), f4.5, (1140 mm), sonotube dob is the same one that is in the Meade cataldog. Being sonotube it is much heavier than the thin 'steel' tubes. (has more mass). The diff in length I think you'll find is just 60 mm.. :shrug:
As Paul has mentioned, you may have a few probs with the breeze...mainly due to it's lighter mass...
HTH.. :D L.

[JohnG]

I don't know if this is relavent to your thoughts or not but in 30+ years of observing I have come to learn that you should always get the heaviest mount you can afford, yes, it may seem an overkill, but, with the telescope you have you need the stability, what you don't want is the thing vibrating and moving around with the slightest touch. Do you really need GOTO, why not spend the extra money on the mount itself, you can always learn to use Setting Circles, that was all I used until a couple of years ago, once you learn it is easy or think along the lines of an Argo Navis and encoders. Just a bit of food for thought. Geez, now I think about it, it is more like 40 years.
Cheers
JohnG

[g__day]

I believe your GoTo mount options stack up like

CG5 - $1,400 (probably work) Andrews Communications
LXD75 - $1,600 (probably work) Bintel
Skywatcher EQ6 Mount with Skyscan Go-To Upgrade $1,700 - Andrews
Skywatcher HEQ5 PRO Series SkyScan Go-To Mount $2,100 - Andrews
Vixen Sphinx + Starbook $2,400 - $2,600 (love the look of these) - Astronomy Online, Astro Optical or centre.net.au
Losmandy G8
Losmany G11 (circa $4,950 wow) - telesccope-astronomy
Losmand HGM Titan - expensive!

[EzyStyles]

G11, G8 is wayyy out of my price range. Max willing to spend will be $2000.

Thanks g__day, really helped me out on the sort of mount/price im looking for.

So my options are:

CG5 - $1,400 (probably work) Andrews Communications
LXD75 - $1,600 (probably work) Bintel
Skywatcher EQ6 Mount with Skyscan Go-To Upgrade $1,700 - Andrews
Skywatcher HEQ5 PRO Series SkyScan Go-To Mount $2,100 - Andrews

SOmehow im still leaning towards the LXD75. Whats wrong with me? because i like Meade? or because i have a DSI so i can use a Meade mount to auto guide?. Not sure guys, still need help to make up my mind. Thanks. hate to waste $1500-$2000 on a mount and i get disappointed from it.

I heard EQ6 have problems with the gear? not exactly sure.

[EzyStyles]

another question, can i use the Meade Autostar hand controller on for say EQ6?
Still new but auto guiding is when you select an object and the telescope follows it until you press the stop button? which of the above has auto guide?
many many thanks.

[EzyStyles]

another question, can you fit the meade autostar controller on an EQ6? with auto guiding, that is when you selected an object and the tele just follows it until you press the stop button? like tracking? which of the above has auto guiding?

many many many thanks.

[JohnG]

Auto guiding is used in photography, you need another smaller telescope attached to the mount and a guider and associated software etc, it has nothing to do with visual, with GOTO you send the telescope to the desired object and it "should" be in the eyepiece, normal siderial tracking then takes over until you send the telescope somewhere else.

BTW I would not even contemplate a GM-8 for your setup, just to heavy, you will have a lot of weight hanging there.

JohnG

[EzyStyles]

thanks johnG. stupid me and auto guiding. just learning :)

Anyway, came to the conclusion to get the EQ6 with Skyscan $2150. opinions on this?

thanks

[cjmarsh81]

When you have your new mount and have used it, please post your opinions. I have the same 10" skywatcher and will be going down the same track in a year or so.

[EzyStyles]

hey cjmarsh81, what mount have you got your skywatcher 10" on currently? it should come standard with the EQ6.

[ving]

if its the pic in his avatar, then its a dob...

[EzyStyles]

*slaps face* miss that and even in his signature too.

so EQ6 with skyscan guys? yes/no? im going down to my local astroshop very soon. or LXD75?

[ving]

i'd say the eq6 would be more stable... and i believe stability is a key concern in imaging....
iI am sure an expert will tell you whats what tho.

[JohnG]

Hi EzyStyles

I also would say the EQ-6, it is rated for a heavier load, similar to the G-11 I believe. The problem of stability will be addressed by not extending the legs, the lower to the ground you get a tripod the better with a Newtonian. That has always been the problem of mounting a Newtonian on a GEM mount, you will also need to address the counterweight issue, conventional thinking is to get enough weight and try and place it close to the head as possible. As far as imaging is concerned, the general rule of thumb is try not to exceed 2/3 the weight capasity of the mount. That is why I said in an earlier post, try and get the best mount you can afford, it will save a lot of tears in the future.

Have fun
JohnG

[cjmarsh81]

Yeah guys it is a Dob. I soooo need tracking.

Where did you find the EQ6 with synscan for $2150. Myastroshop has the EQ6 for $1600 and the synscan upgrade for $1100

[g__day]

Talking to BinTel yesterdau on auto guiding they said:

"Auto guiding can be done with a seperate telescope piggybacked onto a larger one and a CCD that picks a pixels and keeps your star there, but more recently this can be done with newer CCDs that stack and autoguide (interleveling between the two 10 - 100 times a second).

So you tyoically do segments of 10 - 100 exposures of length 5-10 seconds during each exposure the CCD is flipping between recording all pixels and then next round monitoring a target one to keep a guide star in view"

Gives you more options!

[[1ponders]]

This is all true g_day, there is one downside I can think of though and that is that it will take you twice as long to take each image. So a 5 minute image becomes a 10 minute image.

That in itself mightn't be too bad but will this now increase the amount of noise in your image (because you are effectively taking a ten minute image) or not? I don't know but I have a feeling that it will. If so then any darks you take will have to be 10 minutes long as well, thereby doubling your dark capture time as well. so a normal 10 minute shot then becomes 20 minutes. Ok not so bad until you start looking at taking what would normally be an hour of 5 minute shots (12 shots). goes from 120 min to 240 min.

I think the Starlight Express range work as you are describing and there are many people using them and singing there praises as a very good imaging/guiding tool. Unfortunately there is a trade off.

M2CW in case you weren't aware of it.

[g__day]

Personally I think that algorithm or hardware is very limited if that is how it is used. It should be simplicity itself for a simple subprocessor to choose say 3 brightest spots on image, triangulate them and as brightness data is gathered keep those reference spots calibrated.

I believe low light CCD's pixels don't fire per every photon packet arriving but possibly accumulate then give results when pooled. Surely you could just check every 5 seconds within your frame buffer your reference points were stable, and if not translate the data back to a zero delta, whilst correcting the telescope too!

[[1ponders]]

:lol: too technical for me g_day :lol: Maybe it is possible to do that, I wouldn't even begin to understand how, but I'm pretty sure that they operate as I've described, collect - dump to "buffer", collect - dump and guide, collect - dump and add to "buffer", Collect -dump and guide etc til time is reached and "buffer" is cleared to laptop. Hopefully I'm describing the process correctly if not using the right terms.