Reattaching primary cell to Skywatcher 130

[johnfosteruk]

So I've whipped the primary off the SW 130 to centre spot it and flock the tube, I'll also obviously be removing the secondary as well.

The 4 screws around the OD of the cell are affixed to nuts on the inside of the tube which was easy enough to get off - I just did a little light prising to as I unscrewed the screws, but I don't anticipate it being an easy job to get the nuts and screws talking to each other again when I'm done.

I could hold the bolt in grips with my arm down the tube while someone else does with the screw end of things, but I don't anticipate that being very easy to achieve and if I drop the grips.....

I also thought of glueing the bolts in place for complete ease but obviously glueing a flat surface to a curved surface would prove difficult.

Anybody here got their primary screwed back onto their SW 130 easily? If so how? 

[GaryHenderson]

Hi,

I stripped my dad's 130/900 at the weekend and all I needed to do to remove the primary cell was remove the 3 screws next to the collimation screws - from memory they are screwed into a ridge attached to the band around the end of the tube. There weren't any nuts. I didn't remove the end band. Don't have any pics unfortunately

[johnfosteruk]

ah right, I didn't want to disturb the collimation screws or locking screws, just to make life a little easier when I was done. But I suppose a little bit of collimation required isn't that much easier than a lot of collimation required..

[GaryHenderson]

true, and it all went back in no problems. you could try marking the orientation when you take it out, and if you put it back in the same way you might not upset it too much. If your's was like my dad's then removing the spider moved the secondary all over the place so collimation was inevitable. It was the first time I'd stripped a scope fully down (he'd been storing it in a shed, upright with the end cap off  and it was full of dust and spiders), and I had to make a film canister collimation cap, but in the end it was easier than expected. I could even see stars afterwards

 

[brantuk]

Stick a bit of insulating tape vertically across the join between the mirror cell and the tube and slice horizontal along the join - then you can line the tape back up when reattaching the two together.

[johnfosteruk]

Good tip, I made a mark with a sharpie before I took the outer ring off the tube, so it should all be good in that respect. I'll do the same with the main cell section before I take that out to reattach the outer ring to the tube.

And as I'm flocking the tube I'll be taking the spider off so collimation will be inevitable now that I think about it out loud.

cheers both

 

Clear skies.