Skywatcher EM130 Is this okay?

[Flounder]

Hi Everyone

Just got started with my new scope and I'm enjoying it a lot!

There is one thing that has been bothering me since I unpacked my new scope. The end cap with the mirror in doesn't quite fit correctly all the way round, it's like there is a flat spot in the tube.

Most of the way round there is a 1mm gap which opens out to about 3mm. Box seemed to be undamaged so I've got to assume it was manufactured like this. I've attached a picture.

Will this effect the optics?

Should I return the Telescope?

Is this normal?

Thanks for your help and advice.

Paul

[paul schofield]

Personally if I received a scope with that problem I would return it post haste for a replacement. Whether this affects the optics I could not say. You paid good money for a scope & it should be in perfect condition. I am assuming this scope was new ? If used, I am sure this would be pointed out ? The scope may perform perfectly but I would not be happy with it. Hope you get it sorted.

[Bizibilder]

Either the tube or ring (or both!) is slightly out of round. Take the tube out and reclamp the rings then put a ruler sacross them - you'll soon see if it is the rings. They are castings so I would not be surprised if they were not truly round!. A bit trickier to do with the tube but you may be able to carefully roll it on a table or similar and see if it is out of round. The tube is rolled steel sheet (I think!) and again it is very difficult to make that perfectly round in the thin gauge material used.

It should not really make any difference to the scope as the shape of the tube is immaterial - all it does is hold all the important bits (mirrors and focusser) in the correct relative positions. Overall it should not affect the performance of the scope at all.

[Flounder]

That's sort of the feeling that I get. It was new and it came from the Astronomy & Nature Centre.

[Flounder]

Either the tube or ring (or both!) is slightly out of round. Take the tube out and reclamp the rings then put a ruler sacross them - you'll soon see if it is the rings. They are castings so I would not be surprised if they were not truly round!. A bit trickier to do with the tube but you may be able to carefully roll it on a table or similar and see if it is out of round. The tube is rolled steel sheet (I think!) and again it is very difficult to make that perfectly round in the thin gauge material used.

It should not really make any difference to the scope as the shape of the tube is immaterial - all it does is hold all the important bits (mirrors and focusser) in the correct relative positions. Overall it should not affect the performance of the scope at all.

It's the tube you can feel the flat spot. it's not a dent as it has no edge to it.

[Bizibilder]

Sounds as if they rolled it "out of round" - Its up to you whether you decide to live with it or return it.

[Peter Drew]

It's about what you would expect from a mass produced item. A rolled steel sheet will have a flat on the leading and trailing edge which results in a flat portion when the seam is welded. To make a good round tube requires either to roll an excess width and then crop off the flats before welding or beat out the flats on a former, either method would probably not be economic at the price. As already mentioned, it will not affect the performance.

[LukeSkywatcher]

Personally if I received a scope with that problem I would return it post haste for a replacement. Whether this affects the optics I could not say. You paid good money for a scope & it should be in perfect condition. I am assuming this scope was new ? If used, I am sure this would be pointed out ? The scope may perform perfectly but I would not be happy with it. Hope you get it sorted.

I agree. If the scope was new then i would not expect to see this. I really cant say if it wil have any effect on the overall image.

I am a bit OCD about stuff like this. If i know its out by a couple of mm this would annoy me to no end and i would return it.

Thats just me though. Even if optically it was 100%...............the "kink" would annoy me.

[Flounder]

I agree. If the scope was new then i would not expect to see this. I really cant say if it wil have any effect on the overall image.

I am a bit OCD about stuff like this. If i know its out by a couple of mm this would annoy me to no end and i would return it.

Thats just me though. Even if optically it was 100%...............the "kink" would annoy me.

Me too, I think in retrospect I probably wouldn't have ask if it wasn't annoying the hell out of me!

[Flounder]

It's about what you would expect from a mass produced item. A rolled steel sheet will have a flat on the leading and trailing edge which results in a flat portion when the seam is welded. To make a good round tube requires either to roll an excess width and then crop off the flats before welding or beat out the flats on a former, either method would probably not be economic at the price. As already mentioned, it will not affect the performance.

Strange thing is the flat spot isn't anywhere near the seem it's about 160 degrees around from it. The flat spot starts to develop about 3-4 inches from the end.

One things for sure, if the clouds clear slightly more tonight it will be getting some more use before it goes back!

[LeeB]

Looks like its been packaged with to much weight on it rather than a tube manifacture error, while a little out of thrue is expected that looks worse than that. I would return ..

[LukeSkywatcher]

My fear is that it may allow moisture inside the OTA.

[Flounder]

It's a bit of a shame because I got some really good views of Jupiter and moons the other night. Bet we have 2 weeks of cloudless nights the moment it leaves!

[8kids]

I wouldn't worry my 300pds tube has a flat spot all the way down the tube where the edges are welded together. I can't see how it can affect the scopes performance.

[Moonshane]

All my Orion Optics UK scopes have a slight (sometimes not so slight) flat on the tube as they use rolled ali and fold rather than weld the seam. I has absolutely no affect on anything, there's a large hole at the top end (the aperture) which is more likely to be a source of moisture ingress (unlikely generally). It's entirely up to you whether or not you want the hassle of returning etc. I seriously doubt it's a problem as such but I understand if you would want to return it.

[John]

All my Orion Optics UK scopes have a slight (sometimes not so slight) flat on the tube as they use rolled ali and fold rather than weld the seam......

My 10" Orion Optics has that "flat spot" along the seam too. The £1,500 TAL Apolar refractor that I was loaned a while back had something rather similar along it's welded seam. The tube on that one was actually somewhat egg shaped in profile !

It's aestheticlly annoying but I've no evidence that it affects optical performance one bit.

If the flat spot is not on the seam though it does sound like something has pressed against the tube at some point, possibly in transit.