To go flextube or rigid?

[twotter]

I've started thinking about a 12"+ dob, possibly a 300P Synscan, so this thread has been an interesting read. Now to spend some time with my friend, the 'search' button

[bomberbaz]

I've started thinking about a 12"+ dob, possibly a 300P Synscan, so this thread has been an interesting read. Now to spend some time with my friend, the 'search' button

get a 300p goto, its the next step on the ladder.

(before you go for a 400p, lol )

[Optical Dob]

get a 300p goto, its the next step on the ladder.

(before you go for a 400p, lol )

I dont think many people will need a ladder for a 300

[Jase_v2]

Just got back off my hols to the TT - thanks again for the replies and great advice. I hadnt thought of a 12" as Id heard it was too big for a beginner. Here we go again !

[Sky Clad]

Excellent thread - that's a "thanks" from me too.

My situation is likely to have young children getting involved with whatever type of telescope I eventually purchase, and one of my concerns of the flextube or truss type was the increased possibility of accidentally dropping something onto the primary mirror which is something that has not really been mentioned here (other than dirt migrating onto the mirror) though I do realise that a shround should be used. Am I just paranoid, or is it likely to be a realistic problem?

It would also stand to reason that flocking the tube on a truss/flextube would be hugely easier to do.

At this point in time I'm fairly undecided, but as I am looking for a secondhand 10" instrument I'm likely to choose/buy whatever turns up at the time - be it flextube or not. Either way, this thread has been a very interesting read, so my thanks to all

[scarp15]

Hi

The shroud should offer protection to the primary. Something to consider would be the careful use of a screw driver when collimating the secondary screws. Might be an idea to attach to a wrist strap to avoid accidentally dropping into the tube. Better still change them for Bobs Knobs, which are tool free. The main hazard from open tubes though might derive from birds, bats and insects rather than children. Where children are concerned, eyepieces and the objective lens on binoculars are a bit more vulnerable to say finger prints.

Concerning flocking, yes it is quite straight forward to fully flock the secondary cage. I also flocked the first six inches around the primary.

Good luck with your choice.

[Sky Clad]

Sorry if I am labouring this a lttle, but regarding collimating - with a flextube design would this be required literally every time the tube is collapsed and extended?

The reason I ask is that I am almost 100% certain that I read a review suggesting that this was actually not such an issue, as during the test the telescope was repeatedly extended and collapsed during the course of an evening with negligable loss of collimation.

I'm not fearful or daunted by the collimation procedure, just trying to get an idea of what to expect and simply trying to get a clear picture of what I would be taking on if I chose a flextube design over a solid tube.

[scarp15]

Yes, the flex tube will require some attention to collimating each time, between collapsed and extended. This may apply more to the primary than the secondary though. As mentioned the secondary screws may benefit with replacements anyhow, such as Bobs Knobs or similar, which makes collimating easier than with the allen key type bolts. Collimating is quite straight forward to learn and apply and does not take up much time. I use a cheshire collimating tool, in addition some people like to make and use a cheshire eye cap for the secondary.

Once collimated it should hold out for the duration of the session.

[Sky Clad]

Thanks for that clarification Iain. I did suspect that would likely be the case!

Along with the lazy Susan bearing modification, the Bob's Knobs mod will be one of the first jobs I will carry out be it flextube or otherwise.

Sorry Jase if I hijacked your thread a little, but your original question was a good one, and rather than repeat the question in a new thread I just thought I would ask a little more about it!

[bomberbaz]

I check mine everytime. Doesn't always need any attention but when it does, it takes two minutes. I bought a laser and use this in conjunction with a cheshire as i like to be extra sure it is right.

Still haven't bought bobs nobs yet though but i had a scope with them once and they are brilliant

[andyman]

just collimate mine with a colli cap for secondary and barlowed laser for primary works for me

[MorningMajor]

Just got back off my hols to the TT - thanks again for the replies and great advice. I hadnt thought of a 12" as Id heard it was too big for a beginner. Here we go again !

Totally off topic but I'm just back from the TT as well - awesome weather last week wasn't it!

Ok, back to the debate............I've got a flex and love it!

[RikM]

I have the solid tube 10" and it's just right. Any bigger and I would want a flex/truss design.

[Bart]

I think I'd go for the solid tube. I have one and it is excellent as for moving it in and out of the garage, I have it on a sack truck and either go straight out the bid door or if the garage is cluttered (ahem) and I have to take it out the normal door I have bits of wood to make up the gap between the steps if you know what I mean

Here a pic if it sitting on the sack truck next to its big brother the 16"

[Optical Dob]

Good idea with the sack truck. Is that dew a cover you've made for the eyepiece holder?

[Bart]

Good idea with the sack truck. Is that dew a cover you've made for the eyepiece holder?

Sure is, works a treat. It's just a piece of camping mat above the EP holder.

[Jase_v2]

Cracking idea with the sack trolley - and hadnt considered a goto either! Want to learn my way around the sky on my own first before I go down that route ! Thanks again for the help and advice !

[Moonshane]

all newts need to be checked and (sometimes) tweaked before each session. just the same as all guitars need to be tuned slightly. it's part of owning a newt and takes seconds once you 'get it' (the process I mean).