ZWO latest Electronic filters has 12 mount holes - but no bolts supplied to plug them

[g__day (Matthew)]

I bought a new 7x36mm ZWO filter wheel and it is working brilliantly - but I notice the design has changed to allow mounting large cameras or adapter plates with 12 threaded holes.

Only the product didn't come with the bolts to block these 12 points of dust and dew and light leaks from entering the filter wheel.

Nor did come with any installation nor operating instructions - I guess everyone thinks go online and look at the (partially out of date materials)!

Does anyone know what thread and pitch bolts are needed to seal these 12 holes in the filter wheel body itself? I have asked Bintel the suppliers for this information - but if anyone knows I can just pop into Bunnings tomorrow and get a dozen stainless steel bolts and cut them to the correct size and paint them black to prevent stray light leaks or light bouning around.

Stunned for a product that costs close to $500 delivered they skimped on supply 12 measely bolts!

[JA]

I haven't seen the filter wheel, but it would almost certainly be a standard metric size. Try M2, M2.5, M3, M4, M5 or M6. I'd be surprised if it wasn't one of those.

Best
JA

PS... On inspection of some drawings they may even be plain holes.

[ronson]

The four holes on the camera side should be M2.5 threads. The 8 holes on the telescope side do not have threads, they are plain holes. Easiest might be to just tape them.

[g__day (Matthew)]

Many thanks all - will use black electricans tape until I can find the correct bolts. At least I did the right thing and put the darkening slides around the holes.

I found this thread on Cloudy nights

https://www.cloudynights.com/topic/7...-which-screws/

But this drawing explained to use the darken inserts the way I had. Wonder why ZWO just didn't provide black rubber or Silicon plugs as multiple folks seem upset by light leaks.

[joshman (Josh)]

I've got one of the new EFWs with all the holes. One side is bolted straight to the 2600MM, for the scope side with the 4 holes, I ended up 3D printing a round disc so that I could use a darkening ring. The 4 holes are standard M2.5 screws.

The mechanical drawing on the ZWO site shows all relevant dimensions.
https://astronomy-imaging-camera.com...5020449435.png

The attachment is what I printed: