Mesu Owners: Opinion - am I overloading?

[Merlin66]

I regularly use the C11 at f10 with Losmandy dovetail on an NEQ6 for spectroscopy and can easily hold a target star on a 19 micron slit indefinitely.

It’s amazing what can be achieved with standard equipment.

 

[JamesF]

1 hour ago, ollypenrice said:

Unfortunately the shifts could be due to almost anything but drive slippage can't be ruled out. It's good to see your scopes close together because that reduces one of the moments. I think I'm right in saying, also, that heavier counterweights closer to the fulcrum have a lower moment of inertia than lighter ones further out when both give the same balance factor. Years ago one member posted the equations.

I think that makes sense to me.  As far as I recall from school physics, achieving balance is just a matter of mass multiplied by distance from the fulcrum, whereas moment of inertia is proportional to the square of the distance from the fulcrum.

James

[ollypenrice]

4 hours ago, JamesF said:

I think that makes sense to me.  As far as I recall from school physics, achieving balance is just a matter of mass multiplied by distance from the fulcrum, whereas moment of inertia is proportional to the square of the distance from the fulcrum.

James

Yes, I think that's it.

Olly

[ollypenrice]

5 hours ago, Merlin66 said:

I regularly use the C11 at f10 with Losmandy dovetail on an NEQ6 for spectroscopy and can easily hold a target star on a 19 micron slit indefinitely.

It’s amazing what can be achieved with standard equipment.

 

OK, that's good news. the OP should ignore me. I've only used a Vixen sized rail on an SCT.

Olly

[tomato]

12 hours ago, ollypenrice said:

 I think I'm right in saying, also, that heavier counterweights closer to the fulcrum have a lower moment of inertia than lighter ones further out when both give the same balance factor. Years ago one member posted the equations.

Gorgeous setup, as aready noted!

Olly

Thanks for this tip Olly, I’ve got another 15 kg of Geoptik weights sitting in the study doing nothing, so I’ll have a go tomorrow to set up a better counter weight bar.

[kirkster501]

I'd be interested in how this progresses since I am also thinking of getting a C14 in a year or two and flogging the C925.  I'd want the TEC, C14 and the FSQ85 all on the MESU permanently configured.

[ollypenrice]

9 minutes ago, kirkster501 said:

I'd be interested in how this progresses since I am also thinking of getting a C14 in a year or two and flogging the C925.  I'd want the TEC, C14 and the FSQ85 all on the MESU permanently configured.

I'd say that's getting to be a big ask. If you are going to move the camera around between scopes the dynamic balance is going to change each time. If aiming to do DS imaging wth the C14 you'd need to use an OAG on that but it wouldn't work for guiding the others (risk of mirror movement) so it's all getting a bit fraught to my mind...

Olly

PS Paris Roubaix today, Steve!

[kirkster501]

Yep, just watched it live, a great win at the Paris-Roubaix and I won't mention it here in case anyone watching highlights on Eurosport later.  A brutal race on the pave...

Yes, could be a bit too much I guess, certainly going to be at the limit with the C14 as well.

[ollypenrice]

9 minutes ago, kirkster501 said:

Yep, just watched it live, a great win at the Paris-Roubaix and I won't mention it here in case anyone watching highlights on Eurosport later.  A brutal race on the pave...

Yes, could be a bit too much I guess, certainly going to be at the limit with the C14 as well.

I was asked if I'd like to add a third 106/11 meg to the dual rig in exchange for a share of the collective data but I declined because enough is enough.

Olly

[kirkster501]

Holy thread resurrection.

How are you getting on with the TOA150 and C14 ??????