EQ2 Mount

[AlexM]

Hi.

I'm musing over whether to get a cheapish f10(ish) refractor for planets as a more manageable option over the dob. I've already got an EQ2 mount attached to a smaller reflector. What are people's views on the max sensible aperture/weight the EQ2 could handle. I was thinking around 102.

Second bit, anyone got a view on which cheap and cheerful achromatic OTA I might consider?

Thanks.

Alex

[John]

I think an EQ2 would be fine for a short tube (F/5) 102mm but an F/10 might be a bit wobbly at higher powers - longer tubes cause more vibrations to be transmitted to the eyepiece because of a force called moment arm.

Skywatcher used to sell their 90mm F/10 refractor on an EQ2 though so I guess that was probably OK.

[John]

Another thought --- have you considered a Skymax 127mm Maksutov ? - as well as being very good for planets and the moon it's a short tube scope and would probably be fine on the EQ2.

[AlexM]

I'd thought about the skymax, perhaps the 90 or 102. You reckon the EQ2 could handly the 127?

[John]

I'd thought about the skymax, perhaps the 90 or 102. You reckon the EQ2 could handly the 127?

Celestron used to market their C5 SCT on the EQ2 mount - the C5 is around the same weight / size as a 127 mak I think. The 127 mak optical tube weighs just 8.5 lbs which is pretty light plus it's a short tube.

I've not actually tried it though so perhaps wait and see if someone else has before moving on this.

[Cornelius Varley]

Celestron used to market their C5 SCT on the EQ2 mount - the C5 is around the same weight / size as a 127 mak I think. The 127 mak optical tube weighs just 8.5 lbs which is pretty light plus it's a short tube.

I've not actually tried it though so perhaps wait and see if someone else has before moving on this.

The C5 weighs about 1kg less than the 127 Mak. C5 2.95kg, 127Mak 3.93kg. I think the 102 Mak would suit the EQ2 mount better than the 127.

Peter

[John]

The C5 weighs about 1kg less than the 127 Mak. C5 2.95kg, 127Mak 3.93kg. I think the 102 Mak would suit the EQ2 mount better than the 127.

Peter

Thanks Peter - thicker glass in the mak I guess

[PaulG]

Hi.

I'm musing over whether to get a cheapish f10(ish) refractor for planets as a more manageable option over the dob. I've already got an EQ2 mount attached to a smaller reflector. What are people's views on the max sensible aperture/weight the EQ2 could handle. I was thinking around 102.

Second bit, anyone got a view on which cheap and cheerful achromatic OTA I might consider?

Thanks.

Alex

I would be surprised if a long 102 sat on a EQ2 would be stable enough.

Sounds like you need a EQ3-2.

I quite like the Helios brand of achromatic refractors (same as the Skywatcher) but with a much more durable paint finish (thick black glossy paint).

From the 102 and upwards, it's quite easy to swap out the focuser for a nice crayford.

Paul

[step_hen]

Sitting in the garage at the moment i have several scopes, including both tube lengths of the Helios 102 frac an EQ2 and EQ3-2. The short tube F5 is fine on the EQ2, but the longer F10 Evostar version is right on the limit of the EQ3-2 due to its length. I wouldnt consider it on the EQ2 at all! A mid sized Mak would be better option for planets on the EQ2, or why not dabble in widefield with a Helios F5 102 frac- mines up for sale!

Stephen