Slow motion knob jammed

[Lazolaz]

Hello everyone! I'm a a complete beginner with telescopes, and I have one little issue with my celestron astromaster 130EQ. The DEC knob(I think, it's the one parallel with the telescope tube) is completely jammed and does not move. I've tried loosening the screw and making sure it's correctly placed, but it still wouldn't budge. On the other hand, the RA slow motion knob turns perfectly fine. The DEC knob worked well until last week, before it got stuck. Does anyone know what the issue could be?

[RT65CB-SWL]

Hi @Lazolaz and welcome to SGL. 

Many EQ mounts will only turn so far and have limited movement before they fully lock. Have you 'unlocked' the shorter one? (i.e. the short bolt one that is on the right of the flexi-DEC shaft).

[AstroMuni]

50 minutes ago, Lazolaz said:

he DEC knob(I think, it's the one parallel with the telescope tube) is completely jammed and does not move. I've tried loosening the screw and making sure it's correctly placed, but it still wouldn't budge.

Welcome to SGL

I have the same scope. As has been already mentioned by Philip if you move it too far it locks. Another reason could be that the black knob that holds the axis in place is too tight. Suggest you loosen it, move the scope about that axis and retighten the black knob. Now try and see if the slow motion knob moves.

Edited August 20, 2021 by AstroMuni

[Lazolaz]

Thanks for the replies everyone. I loosened the black knob, moved it around a bit, and then tried it again, but its still jammed. I can still move the telescope around manually in the DEC axis, but when I try to do it with the slow motion knob it won't move.

1 hour ago, Philip R said:

Hi @Lazolaz and welcome to SGL. 

Many EQ mounts will only turn so far and have limited movement before they fully lock. Have you 'unlocked' the shorter one? (i.e. the short bolt one that is on the right of the flexi-DEC shaft).

Which one is it? I'm a bit confused. Do you mean the black knobs which hold the axis in place?

[RT65CB-SWL]

29 minutes ago, Lazolaz said:

Thanks for the replies everyone. I loosened the black knob, moved it around a bit, and then tried it again, but its still jammed. I can still move the telescope around manually in the DEC axis, but when I try to do it with the slow motion knob it won't move.

Which one is it? I'm a bit confused. Do you mean the black knobs which hold the axis in place?

Yes - I should have explained that one! 

[AstroMuni]

40 minutes ago, Lazolaz said:

I loosened the black knob, moved it around a bit, and then tried it again, but its still jammed. I can still move the telescope around manually in the DEC axis, but when I try to do it with the slow motion knob it won't move.

Take a look under the area marked with a circle in this image. Its driven by a worm gear and sometimes the plastic covering on the scale can get tangled in it.

[bobro]

EQ2s have a tangent arm on the DEC axis for adjustment rather than a worm gear. That is why there is a limited range of movement. If too much force is used on the control rod it's possible the drive spindle connected to the control rod can bend slightly against the tangent arm and jam.

This thread shows the EQ2 in detail https://stargazerslounge.com/topic/319273-meade-large-equatorialeq-2-hyper-tuning/

I suggest loosening the nut as shown by the yellow arrow in the below image from the thread. That should free the drive spindle and allow it to be checked.