A versatility of the Askar FMA230 rings. Askar FMA230 · Vroobel · ... · 9 · 333 · 12

Vroobel
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Hi,

Everybody interested in the Askar FMA230 had to see threaded holes on each of the four sides of the rings. I decided to use them all.

All my scopes have the ZWO EAF attached, so I ordered the Deep Sky Dad's kit for the EAF as well. It's placed on one side. The FMA230 can be easily rotated in its rings, but not with the EAF attached. There is 120:1 gearing in the EAF, so rotating its axis is impossible. Therefore, if you rotate the scope, you change focus. It shouldn't be a big change, but rotating the scope 90 degrees means rotating the focuser ring 90 degrees in the opposite direction. 

After some experience with framing, I found that the best result (for me) is if the DSO fits the frame with the horizontal or vertical orientation of the camera. Here is the place for the extra dovetails. My ASIair Plus, home-made smart dew heater controller and also SW Evoguide 50ED are equipped with dedicated ZWO Vixen-style clamps. All my scopes have extra dovetails for ease of attaching the accessories. I figured out that if I screw the FMA230 on the saddle using the side dovetail, I can get the vertical composition and I'm still able to attach my accessories around. Yes, I know, that's crazy, but I'm... lazy...

To be able to screw the two extra dovetails you need some M6 and M5 bolts. Additionally, the side opposite the EAF requires a few mm thick spacers, because a timing belt pulley from the EAF kit makes the screwing impossible. I designed and printed the relevant spacer, so after applying it, everything is OK. 

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I'm hugely impressed by the EAF kit. I have a big experience with 3D modelling and prototyping, so I can appreciate the cleverness of the solution. The kit moves together with the focusing ring. I thought I can do it and safe £129, but not, I wouldn't do it so well with a significantly lower cost. Thus, well done, Deep Sky Dad!

There is something to do with the EAF kit, but first I have to do it and then will write about it. Deep Sky Dad should take it into account. 



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lpgc 0.00
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hey do you happen to know the specs for the bolts needed to attach to the side mounts on the FMA rings?

M? and length?
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Vroobel
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Hi smile

I'm sorry, I don't remember.  I can check it later, but the rig is in use at this moment so I don't want to disassemble it when the good weather may happen at any random time.
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afjk 3.58
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nice versatile solution!
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Vroobel
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Larry CABLE:
hey do you happen to know the specs for the bolts needed to attach to the side mounts on the FMA rings?

M? and length?

 Hi,

There are holes of two sizes: 2x M5 (8mm deep) and 1x M6 (7mm deep) on sides of each ring. Length of the bolts depends on a thickness of the addition which you are going to attach there. I hope you find it helpful. 

image.png
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lpgc 0.00
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Larry CABLE:
hey do you happen to know the specs for the bolts needed to attach to the side mounts on the FMA rings?

M? and length?

 Hi,

There are holes of two sizes: 2x M5 (8mm deep) and 1x M6 (7mm deep) on sides of each ring. Length of the bolts depends on a thickness of the addition which you are going to attach there. I hope you find it helpful. 

image.png

cheers @Vroobel just what I needed ... many thanks, you'd think Askar would mention this on their product description!

BTW I used my FMA230 for the 1st time last night ... I definitely think that the 55mm back focus as documented is wrong, I can definitely see some elongation of the stars in
the corners not too mention perhaps a hint of vignetting too!

apart from that very pleased with the little scope!

thanks again! much appreciated!
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lpgc 0.00
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BTW I plan to attach 2x Askar 90mm multi-connection finder plates using the central M6 I think
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Vroobel
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After many tests I stopped with 52.5mm of the back focus. I have no idea why it happens. Now I'm very close to round stars in corners.

Good luck. 🙂

CS, Martha
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lpgc 0.00
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After many tests I stopped with 52.5mm of the back focus. I have no idea why it happens. Now I'm very close to round stars in corners.

Good luck. 🙂

CS, Martha

I'll try that thx
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lpgc 0.00
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Screenshot 2024-10-22 at 7.36.51 AM.png
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