Project Mak.......a handle

[M40]

First off thanks to captain scarlet and his post Reverse Engineering the Skymax180 and to Martin Pyott and his youtube video supertune the planet killer. Both were a great source of information. 

A quick note about collimation. The secondary mirror position is fixed with no adjustment, so by shining a laser collimator through the eyepiece, the laser is going through the hole in the primary and reflected back to the collimator from the secondary. So this action tells you how aligned the secondary is to the eyepiece only. 

Adjustment is carried out on the primary only and this action centers the image at the eyepiece. I shall add to the post when I have sorted a good method for this, but I would say that unless you can fit the flocking material without knocking the primary mirror, expect to have to collimate the telescope. 

If the focuser section is left in place and flocking is not carried out, collimation should not be affected by fitting a handle.

So, the project, I turned this...

Into this.....

And at the same time I flocked the tube. As the existing dovetail conflicts with the tube rings it involves a touch of diy.

I  have tried to write it down in the steps I took, so I hope it makes sense to anyone thinking about it.

1. As I normally keep the telescope in the garage, brought it in to acclimatise it first, took about an hour.

2. Using an svbony sv121, I checked collimation of the secondary mirror before I started so I had an idea of what to expect, all good. Che king tbe primary mirror collimation is a slightly different process and once I have it sorted I will add to the topic but initially check using a defocused star.

3. I bought a pair of Orion Optics tube rings, ouch, simply put they are the only ones available unless you diy it. Check the tube rings provide a tight fit, mine didn't,  so I put some sticky back 1cm wide draught excluder on the tube rings and it worked a treat. 

4. Create a nice working space, you will need it.

5. If you are going to flock the tube, the flocking material will need rolling the other way so worth doing now. Note: If you are not flocking the tube, you do not need to remove the focuser section. 

6. Put a piece of tape on both ends of the tube and the meniscus lens and focuser sections. It makes it very easy when reinstating.

7. Have something handy to keep the screws in. 

8. Create a clear space for the meniscus section and the focuser section. The focuser section, in my case, requires 450mm clearance.

9. Remove the four screws at the meniscus lens end and remove the lens section. 

10. Remove the dovetail by unscrewing the two fixing screws. Note: the nuts and washers are not captured and as such you will need to hold them in place inside the tube to ensure nothing gets lost behind the mirror. 

11. Fit the tube rings and handle. I fitted the tube ring at focuser section end so that it covered one of the old dovetail screw holes. Fit the handle and then fit the second tube ring which is dimensioned by the handle. When you fit the handle, make sure the fixing screws are not too long so that they do not damage the tube.

If you are not flocking the tube, jump to number 17.

12. Place the tube so that it is standing on the meniscus end.

Remove the four screws and lift off the focuser section keeping it as straight and vertical as possible so as not to knock anything. Note: there is a lip on the inside of the focuser section so it will stay in position when all four screws are removed. Put the focuser section in a safe space.

13. I measured the flocking material at 350mm front to back and 665 internal diameter. I cut the material to 675mm so that it overlapped by 1cm.

14. At the meniscus end, the gap between end of tube and flocking material is about 19mm, to mark this, I used electrical tape as it was exactly the dimension I needed. Not wholely necessary, but just remember to remove the flocking material around the fixing holes.

15. Give yourself time, it can be a bit testing. At one point, I thought it would have been a wise move to buy a second piece of flocking material as you only get one go out of the length supplied, fortunately I did not need it.

16. Reinstate the focuser section. Check there are no challenges with the flocking material. 

17. Reinstate the meniscus section and again check the flocking material. 

18. Fit the dovetail.

19. Check collimation of the secondary. Check collimation of the primary using a defocused star.

20. Put the lens cap and finders back on and wait for the clouds to go.

21. This is the sum total of tools required 

It took about 3 hours beginning to end but that did include a dog walk in the middle.

During the focuser section removal and replacement, I did put mine out of collimation. There are various methods to collimate the telescope from purely using a defocused star, using a microdot torch, using a wholesky camera in the eyepiece section then following on with a defocused star and then there is the ocal collimator. When I have sorted the best way for me, I shall update the post according.

All the best and I hope that it proves useful to someone in the future. 

 

Edited January 9 by M40
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[Neil H]

Hi Les looks great mate what's the cost I bet tube rings were mega 

[M40]

Tube rings were a definate ouch at £318 but I couldnt find any other supplier. Flocking material from flo was £7.50, hence why I kicked myself not getting a spare roll and I got the handle used at £9 I think it was so all told about £335. 

Plus side, it is now very much easier to carry so in my mind well worth doing.

I also noticed that the inside of the tube was a slate grey colour with what seemed flecks of white in the paint. I was a little concerned in case it was caused by condensation, but it wouldn't rub off so who knows what that is all about.

Edited December 12, 2023 by M40

[Neil H]

I still have a roll of flock that I got from FLO a long time back so I can do that when I want