AstroEQ for EQ mounts

[booth_robert]

Defo 12v dc very hot and lot of smell by the power socket drivers warm

[TCWORLD]

Turn the potentiometers as far anti-clockwise as possible. Then power up again. Anything getting hot? (The motors will likely not be able to move as the current limit is too low now).

Connect to EQMOD with the case still open. On the main EQMOD screen near the bottom there are two boxes (labelled RA: and DEC:) in the Track Rate. Enter 50 in both of there and press the button which looks like a meteor. This will set EQMOD moving both of the axes.

If there is nothing hot, then very slowly turn the potentiometers clockwise until the motors start moving.

If there is still nothing hot, further increase the current limit a few degrees clockwise. This just ensures that the motors have enough torque. The motors should feel warm to the touch.

Let me know how you get on.

[tigger]

Hi all         I was going to spend £300 on goto for my EQ5 but now I don't think I need to ! However it has been mentioned about the slow slew speed using the SW motors. Is this down to AstroEQ or the motors? Would bigger motors give up to  800X slew? Thanks   Philip

[TCWORLD]

Its the motors. The dual axis motors have a massive gear ratio (120:1) which limits how fast they can go. 

With better motors/gearing, AstroEQ is capable of slews up to 200X the sidereal rate. With that you can slew from one side of the sky to the other in about 30 seconds. Even small motors (28mm sq by 45mm) are sufficient to get my relatively small 120mm refractor up to that speed. You can't get up to 800x due to limitations in the AstroEQ firmware.

[JamesF]

If you feel competent to use your own motors and make up the required brackets, I would.  As Tom says, the dual axis motors have a 120:1 reduction which is achieved using quite a large gear train.  That produces an astonishing amount of backlash that is pretty much impossible to get rid of.  I stripped one of mine down and rebuild it, but it still isn't even close to as good as I think is desirable.  I also removed the external DEC gearing and clutch on mine.

If you want something that just does simple RA/DEC control and don't want to have to think too much then the standard dual-axis motor kit probably makes sense.  In any other case I think AstroEQ and your own stepper motors is a much better choice.

James

[Oily]

If you use the SW motors,it gives you time to go and make a brew whilst it's slewing

[TCWORLD]

Just had a look at your gearbox stripdown/rebuild. It looks like the ones you got were slightly better than mine - I took them apart to count the ratios. In my one all the gears in the train are poorly made plastic ones. On mine you can turn the input shaft almost a quarter turn back and fourth before the output shaft even notices.

[JamesF]

Just had a look at your gearbox stripdown/rebuild. It looks like the ones you got were slightly better than mine - I took them apart to count the ratios. In my one all the gears in the train are poorly made plastic ones. On mine you can turn the input shaft almost a quarter turn back and fourth before the output shaft even notices.

Blimey.  That's really bad

James

[Quatermass]

interesting, if the back lash is bad due to the motors then this is going to effect guiding I suppose the idea of upgrading the motors for astroeq purposes is beginning to look like a smart move. Have to say I don't really mind the slewing speed being a bit slow it prevents me from crashing the scope into things but stronger motors for my 200p might be a better idea.

[Quatermass]

I remember last year taking my worm gears apart and dismantling my EQ5 to re grease the gears and tighten everything up I thought when I had done it that the mechanical parts where pretty basic really and there was not a high degree of precision. But then again you do get what you pay for and these mounts are at the cheaper end of the market compared with other mounts. I will be very interested to see what kind of performance you get with a different set of gears fitted.

[tigger]

If you use the SW motors,it gives you time to go and make a brew whilst it's slewing

I want to have friends round and show them the night sky. With a slow slew they'll drink too much beer and all their stars will be binaries!!        Thanks for the replies 

[Quatermass]

I want to have friends round and show them the night sky. With a slow slew they'll drink too much beer and all their stars will be binaries!!        Thanks for the replies 

WIth a fast slew they will more then likely get whacked across the back of the head, I think the slow slew is a safer option and I have no problem drinking beer 

[tigger]

Would these be any good http://www.omc-stepperonline.com/3d-printer-nema-17-stepper-motor-2a-45ncm64ozin-17hs162004s-p-16.html   There cheap enough. ps never done a link before so it may not be right.   philip

[Astropedro]

I believe the HEQ5 and NEQ6 mounts use a medium torque version of these if not the exact same ones.  Surely if theyre fitted on a superior mount than our EQ5s then they must be a good motor?

[booth_robert]

Theres a strip down of an eq5 by astroboy i think thats what i googled to take out any play in the mount

Tom will try that when i finish work tonight

[TCWORLD]

Well, I've got a webcam, just need to work out how to attach it to my finderscope and then I can try guiding.

A bit off topic, but does anyone know where I can get an o-ring for a 9x50 finderscope? Having just taken it out of the holder I've just found it doesn't have one around it and come to think of it, never has (I wondered what that left over bit that I've now lost was - and why it was always wiggling around).

[JamesF]

A bit off topic, but does anyone know where I can get an o-ring for a 9x50 finderscope? Having just taken it out of the holder I've just found it doesn't have one around it and come to think of it, never has (I wondered what that left over bit that I've now lost was - and why it was always wiggling around).

Allegedly the inside diameter of the O-ring is 46mm and the cross-section of the O-ring is 1.5mm diameter.  I haven't tried it for myself though.  I'd not be surprised if you can't buy them singly.

James

[TCWORLD]

Allegedly the inside diameter of the O-ring is 46mm and the cross-section of the O-ring is 1.5mm diameter.  I haven't tried it for myself though.  I'd not be surprised if you can't buy them singly.

James

What do you recon: http://www.polymax.co.uk/46x1-5-nitrile-rubber-70 ?

[JamesF]

What do you recon: http://www.polymax.co.uk/46x1-5-nitrile-rubber-70 ?

Certainly looks like the right kind of thing.  Be nice if someone else would confirm the size as well though.  I've just measured one of mine and it's actually about 50mm ID, but it's quite a poor fit.  (I had 46x1.5 scribbled down somewhere in case I needed some new ones myself, but I have no idea where I got the information.)  If someone else said it was actually 48mm x 1.5mm I'd probably go with that.

James

[Quatermass]

Well, I've not got a webcam, just need to work out how to attach it to my finderscope and then I can try guiding.

A bit off topic, but does anyone know where I can get an o-ring for a 9x50 finderscope? Having just taken it out of the holder I've just found it doesn't have one around it and come to think of it, never has (I wondered what that left over bit that I've now lost was - and why it was always wiggling around).

If you want to give guiding a try out your more then welcome to use my webcam and finder scope Tom. I am happy to carry on with taking short subs for the time being and if it would help you test out the guiding I can post it to you off to you.

[booth_robert]

hi tom tried what you have said and when i hit the meteor button the ra motor starts then 2-3 seconds later the dec motor starts now both motors getting very hot drivers very hot and on the circuit board D1 is red hot and a lot of burning smell both on minimum setting like you said 

[TCWORLD]

Do you have a multimeter?

[booth_robert]

yep

[TCWORLD]

On the attached picture, I have marked two places on the circuit board, one it blue (top right of image), one in red (middle left of image).

With the motors detached, measure the voltage across these two point with a multimeter (DC). What voltage do you read? [p.s. be VERY careful not to touch the chip with the multimeter probe when measuring]

[TCWORLD]

Then (with the motors still disconnected), turn the potentiometer fully clockwise and repeat the measurement. What voltage do you see now?