Trouble with M2.5 x 20 screws installing Mount Adapter Plate for Polar Finderscope EXOSPF #iEXOS-100 #polaralignment


Ade Ashford <macuserade@...>
 

Hi Kent,

Sorry for the late response on this thread as I've been away. Yes, there were instructions included, as well as the two oversized nuts that Pavel mentioned that I also took to be used as washers.

In the end, I obtained some replacement M2.5x20 screws with Phillips heads from the local hardware store. I cut these down to a length of 15mm with a small hacksaw and now it all fits perfectly.

Regards,

Ade


Pavel
 

Yes, that is obviously the meaning of the nuts. Otherwise I would probably strip the threads. The screws are just too long.

Is there no explanation for the marking in the reticle available? The marking for the Southern Hemisphere is quite self-explanatory - there are clearly marked crosses for "σ Oct" and "χ Oct". But for the Northern Hemisphere, there are just three lines with gaps for both "δ Umi" and "51 Cep" (probably "OV Ceph"), no crosses. (Actually, no full cross for Polaris either.) See the first attached picture.

I also wonder about the role of the rubber washer/gasket that came with the polar scope. The only place I can imagine it could meaningfully fit would be to fill the gap between the bracket and the pivot collar for collimation (see the second attached picture). Is it possible that someone "forgot" to pull it there while assembling the scope? Considering the fact that the scope came mounted "backwards" to the mount adapter, I am not sure if the person assembling the whole thing was well conscious about the proper state of things. Of course, I may just as well ask Bresser, as you suggest, but I was hoping to get some explanation faster from someone here, as the subject has just been opened.

 


Kent Marts- Explore Scientific Customer Service
 

NEVER hard tighten screws that go into ANY kind of plastic. That is a sure recipe for stripping the threads.

I have no idea what the nuts are for. Those are not shows in the parts list included with the directions.

Again, please contact Bresser customer support.

We have a draft document for using the finder. But is has not published

In a nutshell:

1) Look in the sky and find Cassiopea and the Big Dipper (The Plough in Europe, I believe).

2) Rotate the Polar Finder Scope to match what you see in the sky.

3) Adjust the mount in azimuth and altitude to get Polaris in the location on the reticle.

The other marking are for use in the Southern Hemisphere.

The procedure outline above is done once the Polar Finder Scope is aligned with the polar axis of the mount.

Note that the only way to ensure a perfect polar alignment is to use the Drift Alignment method.

Camera alignment programs like Pole Master, Sharp Cap, etc., provide extremely close polar alignment. The Drift Method makes it absolute.

--
Kent Marts
Customer Service
Explore Scientific

Gear: Anything in the store!


Pavel
 

No printed directions. I just found the manual online on your website.
Is there anything else available in printed form?

Those slightly oversized nuts were placed in a small plastic bag
together with the screws (actually pulled "demonstratively" on them!)
and a 2mm hex wrench. Without the nuts used as washers, I wasn't able to
tighten the screws on the mount (well, I probably didn't use _all_ of my
power, but it seemed to be dangerous to try any further).

Best regards,
Pavel

Pavel,

The packages from Explore Scientific do not have nuts. The box does
contain two screws referenced in my answer to Ade.

Did your package contain printed directions?

Please contact Bresser customer support regarding your issues. Bresser's
customer portal is https://www.bresser.de/c/en/support/


--
Kent Marts
Customer Service
Explore Scientific

Gear: Anything in the store!


Kent Marts- Explore Scientific Customer Service
 

Pavel,

The packages from Explore Scientific do not have nuts. The box does contain two screws referenced in my answer to Ade.

Did your package contain printed directions?

Please contact Bresser customer support regarding your issues. Bresser's customer portal is https://www.bresser.de/c/en/support/


--
Kent Marts
Customer Service
Explore Scientific

Gear: Anything in the store!


Kent Marts- Explore Scientific Customer Service
 
Edited

Ade,

I checked email but found nothing from you on this subject.

The specifications on the replacement screws are M2.5x20, with thread M2.5x0.45mm, using a hex/Allen tool that is 2 mm.

The part in question is McMaster-Carr Part No. 91292A019

On the units I have assembled things fit perfectly.

Did you receive a set of printed directions?

--
Kent Marts
Customer Service
Explore Scientific

Gear: Anything in the store!


Pavel
 

Hi,

I have just received the Polar Scope yesterday from Bresser/Germany and
also was a little bit puzzled by several things:

From the package, the scope was loosely fixed to the mount adapter
plate, but the other way around than it should be, as I found out
quickly. The people in the factory obviously do not care much and let
you solve the puzzles youselves.

The two small screws were accompanied by two oversized nuts without any
obvious purpose. I also found out that the screws are just too long, so
the nuts are obviously expected to be used as washers (underlay)? Even
so it was very tight to get fully fixed, but fortunately nothing got
broken. I guess it would be more appropriate to shorten the screws by
cutting them or just to buy shorter ones, but as a workaround it is OK.

I am also puzzled by the role of the rubber washer or gasket (or how
should it be called?) just loosely pulled around the scope...?

The reticle would also need some explanation that I have not found
anywhere. I suppose that Polaris should nowadays fit exactly into the
gap in the line between the marks "2000" and "2030" - and in the
following years maybe behind the line and closer to the mark "2030"? (As
the Earth axis slowly drifts... But it should drift slightly *pass* the
NCP, not directly *towards* it, I think.)
A similar explanation would also be useful for the triple line/gaps for
"δ Umi" and "51 Cep". Why triple?
Anyway, I have not really found "51 Ceph" in any catalog nor sky map. Is
it possibly the star marked as "OV Cep" or "HD 51802"?

I hope to actually try looking at the sky with the finder tonight. Last
night was rather cloudy.

Best,
Pavel

Hi all, has anyone else installing the iEXOS-100 EXOSPF Polar Finderscope?

The two mounting screws provided are supposed to be M2.5 x 20 according to the Instruction Manual, but appear to have a smaller nominal diameter than 2.5mm.

Thankfully, the smaller diameter means that they are tight replacements for the two smaller screws in the front of the declination drive's cover, but at 20mm they are too long to thread all the way in.

One of the longer screws was so tight that I couldn't remove it with the Allen key and had to resort to cutting the screw's head off and removing the threaded portion with pliers.

If the supplied screws are indeed M2.5 (they look no more than M2 in the accompanying image of the only good one remaining), would two 15mm-long screws be better?

Many thanks,

Ade



Jay Sanchez
 

I had the same problem -- ES sent out (2) longer screws. Ask Kent (customer support).


--
Jay Sanchez

Home: Bortle 8, Norfolk VA
Camera: Canon t2i, ha modded
Guide Camera: ASI224MC & ASI mini guidescope
Imaging scopes/lens: Pentax 300mm f4, WO Z61 w/ FF, Vivitar 90mm; 70-200mm f/2.8, Tokina 11-16mm f2.8, Nikon 50mm f1.4
Filters: HA 12nm astronomik clip in, SVBony 2"CLS, 2" L-Enhance
Mount: iEXOS-100
APT, CDC, PHD2, Sharpcap, DSS, PS


Ade Ashford <macuserade@...>
 

Hi all, has anyone else installing the iEXOS-100 EXOSPF Polar Finderscope?

The two mounting screws provided are supposed to be M2.5 x 20 according to the Instruction Manual, but appear to have a smaller nominal diameter than 2.5mm.

Thankfully, the smaller diameter means that they are tight replacements for the two smaller screws in the front of the declination drive's cover, but at 20mm they are too long to thread all the way in.

One of the longer screws was so tight that I couldn't remove it with the Allen key and had to resort to cutting the screw's head off and removing the threaded portion with pliers.

If the supplied screws are indeed M2.5 (they look no more than M2 in the accompanying image of the only good one remaining), would two 15mm-long screws be better?

Many thanks,

Ade