Telescope weights (OTA)

[daiwelly]

Hi Not sure if this is correct place to put this post But I am sure the Mods will move it if not correctly placed this is a post aimed at the Suppliers really.

Is it possible to put the tube weights in there descriptions. so it will make it easier to match a mount I notice the mounts have suggested payload but that information is pretty useless if you don't know the OTA weight. just a thought?

[szymon]

What we could do is create a master list of known OTA weights here on SGL in a sticky post somewhere...

Sent from my iPhone using Tapatalk

[RichM63]

But they do, at least TS does, don't know about others.

[ronin]

Many do supply the weight and if not I find that the manufacturers site will usually list them.

I have at times seen a scope on retailer A then gone to retailer B to read the weight. Some seem to supply it others do not.

Also many cut and paste the manufacturers blurb, then it depends on how much they make use of.

What may happen is the manufacturer has a description and a specification, a retailer may only reproduce the description and not give the sprcification.

One small aspect is that the the OTA will be just that, no diagonal, no eyepiece no tube rings etc.

So whatever the OTA weight you may need to add a pound or two to it by the time it is on a mount.

[happy-kat]

FLO started to add weights as this was asked when ideas were suggested.

[baggywrinkle]

I agree you often have to go scratching around to find the tube weight, and then it does not state if this is a tare weights( weight without fittings) but one assumes so, as to include fittings etc would be a manufacturers nightmare.

I would also like to see manufacturers fess up on the load a particular mount can take and state the visual load and the AP load.

In my work I have to read many engineering specs for various types of sensors and few manufacturers will publish clear and unambiguous specs.

[Bizibilder]

As said the OTA weight may only be a small part of the total weight of someone' s set-up.  If you add cameras, guidescopes, finders etc the total may well me considerably more than double (or more) the weight of the "main" OTA.  Having said that a guide would be useful!!

One way of deciding is to look at the catalogues and see what the suppliers sell - they often sell combinations where the OTA is only just within the capacity of the mount they provide!  For example Skywatcher sell their 200P reflector on an EQ5.  This is barely adequate and you really shouild be considering at least "one up" from that - an HEQ5 sized mount for that particular scope (or even an EQ6 if you intend photography).

[Feral Rabbit]

Celestron do. My OTA is 13lb or 5.9kg in new money. It's on the box it came in, in the manual that came with the OTA and it's not too difficult to find out the info on the interweb either. Obviously it doesn't include the sundries that are fitted to be able to use the OTA mind.

Can't comment on other companies though.

[daiwelly]

Checked Skywatcher site they don't say but they are sending me a list of their weights. It was just a thought but with people doing  a mix n match for example someone has HEQ5 and wants to use it with a borg etc (just a example)

[Feral Rabbit]

Not sure if this is your OTA daiwelly but may help.

Linky

[daiwelly]

Thanks Feral

I have started a spreadsheet so I am searching & collecting data

this is what I have got so far its a start. it needs to be opened with MS excel.

OTA WEIGHTS.xlsx

[ollypenrice]

We do need to know the tube weights plus other bits. However, the weight of the payload is not the only issue. The two other big ones, which can change everything, are;

1) The polar moment of the OTA. If it is long and has heavy glass at both ends (Eg MNI90) it is effectively 'heavier' than a short OTA of the same weight so far as tracking accuracy goes.

2) For DS imaging, the pixel scale. The fewer arcseconds per pixel you are collecting the more accurate your mount needs to be under autoguiding. Anyone taking up imaging needs to read this ten times and make sure they understand the significance. It is way more important than weight.

Olly

[daiwelly]

We do need to know the tube weights plus other bits. However, the weight of the payload is not the only issue. The two other big ones, which can change everything, are;

1) The polar moment of the OTA. If it is long and has heavy glass at both ends (Eg MNI90) it is effectively 'heavier' than a short OTA of the same weight so far as tracking accuracy goes.

2) For DS imaging, the pixel scale. The fewer arcseconds per pixel you are collecting the more accurate your mount needs to be under autoguiding. Anyone taking up imaging needs to read this ten times and make sure they understand the significance. It is way more important than weight.

Olly

Hi Olly

I can see what you are saying but none of the manufacturers give this information or am I missing something. The idea of the list sprang from what would be a suitable mount for my 200 dob if I decided to change the mount. to a tracking one. If what you are saying is true then this list would be a dead duck I don't doubt what you are saying with your experience  so how do we decide which mount without this information. ? or could suppliers list what the mount is compatible with! I doubt they will do that.