New dual speed skywatcher crayford doesn't fit

[Steve Clay]

I was going to upgrade the focuser on my ED 80 with the Skywatcher crayford dual speed.

Orderd from FLO and next day delivery.

Its a heavy CNC machined bit of kit.

The problem is the holes in my tube don't align with the holes on the focuser flange.

Also it doesn't seen to go all the way into the tube. There is about a 2mm gap.

Disappointedly it will have to go back.

 

Edited February 1, 2020 by Steve Clay

[John]

That is a shame. I've fitted those to a couple of Skywatcher achromat refractors and an ED120 refractor and they went on just fine.

I'm sure FLO will sort it out for you though.

 

 

[Steve Clay]

16 minutes ago, John said:

That is a shame. I've fitted those to a couple of Skywatcher achromat refractors and an ED120 refractor and they went on just fine.

I'm sure FLO will sort it out for you though.

 

 

Yep I'm sure they will.

[johninderby]

When you say the holes don’t align is it because the flange doesn’t fit into the tube all the way? 🤔

Have had to sand the inside of the tube to remove excess paint before in order to get the flange to fit all the way into the tube.

[joe aguiar]

Is it possible to just drill the holes to the next size drill bit which is just 1mm more?

The head of the screws are abit thick I think I done it b4 and it worked

Joejaguar 

[John]

4 hours ago, johninderby said:

When you say the holes don’t align is it because the flange doesn’t fit into the tube all the way? 🤔

Have had to sand the inside of the tube to remove excess paint before in order to get the flange to fit all the way into the tube.

The black dual speed ones can be a tight fit I agree. I assume that is because they are machined to tighter tolerances than the stock focusers.

 

[Steve Clay]

12 hours ago, johninderby said:

When you say the holes don’t align is it because the flange doesn’t fit into the tube all the way? 🤔

Have had to sand the inside of the tube to remove excess paint before in order to get the flange to fit all the way into the tube.

No John they are offset laterally.  If I drilled out the holes 1 of them would be huge. 

[johninderby]

Unusual that the holes would be drilled incorrectly but the replacement should be OK. 🙏🏼

[Ronclarke]

I fitted a Moonlite focuser directly onto my ED80, everything lined up but I also had to sand of some excess black paint in the tube assembly.

Cheers

Ron

[Steve Clay]

1 hour ago, johninderby said:

Unusual that the holes would be drilled incorrectly but the replacement should be OK. 🙏🏼

Agree, would be a computer controlled process I would have thought. Regarding sanding the tube I assume some rag was stuffed down to keep dust out?

[GazOC]

31 minutes ago, Steve Clay said:

Agree, would be a computer controlled process I would have thought. Regarding sanding the tube I assume some rag was stuffed down to keep dust out?

I'd be inclined to play it safe and unscrew the lens cell

[johninderby]

Unscrewing the lens cell also helps when fitting the focuser flange as you can then stand the tube on end and tap the flange down gently with a rubber mallet if needs be. 

 

[FLO]

We replied to Steve's email then noticed his discussion here at SGL so will reply here too. It might benefit others who experience the same problem. 

The focuser is CNC machined so its flange diameter and hole spacing is unlikely to be wrong. It is more likely the Evostar 80ED tube's inner diameter and/or hole spacing is a little different from the norm. Sometimes the focuser can be encouraged to fit, otherwise it is best to simply return it for refund. (That is what we have advised Steve to do in this instance). 

HTH, 

Steve 

[Steve Clay]

1 hour ago, FLO said:

We replied to Steve's email then noticed his discussion here at SGL so will reply here too. It might benefit others who experience the same problem. 

The focuser is CNC machined so its flange diameter and hole spacing is unlikely to be wrong. It is more likely the Evostar 80ED tube's inner diameter and/or hole spacing is a little different from the norm. Sometimes the focuser can be encouraged to fit, otherwise it is best to simply return it for refund. (That is what we have advised Steve to do in this instance). 

HTH, 

Steve 

Totally agree with what you have said Steve.

I wasn't prepared to remove the lens cell and sand down the inner tube or indeed persuade the focuser in with a mallet. A simple return is the best way ahead.

Thanks

Steve