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Last updated: 31 August 2012

Welcome to the AutoStar feedback page. This page is intended to provide user comments on using the Meade Autostar #494, #495, #497, #497EP, AudioStar, cables, and AutoStar updater software. See the AutoStar Info page for information from Meade and other users on the AutoStar, cables, and software. Send your comments and tips to for posting. Please use an appropriate Subject Line on your message per the Site Email Etiquette. Thanks. Remember, tips described on this site may invalidate the warranty on your telescope or accessories. Neither the submitter nor myself are responsible for any damage caused by using any contributed tips.

Subject:	Audiostar handset
Sent:	Thursday, August 30, 2012 15:42:39
From:	James Cunningham (
I have an Audiostar handset.  When it is inactive for about 10 minutes,
it goes dark.  Pressing any key will bring the display back.  Is there
anyway to override this?  Thanks.
James V. Cunningham
Mike here: This is the normal power-conserving mode. No adjustment to the delay is available.


Thank you.  I did find one way to get around it.  I set the timer for 8
minutes and when it beeps, I set it again for 8 minutes.  Do all of the
functions of the Autostar keep going when the handset is dark.  I ask
because I use Astroplanner software and it was fine until the handset
went dark and then it stopped slewing.
Mike here: The AutoStar continues to control the telescope when the display is dark. I don't recall any problems when I used Astroplanner with the AutoStar #497 and having the display turn off. Perhaps something is different with the AudioStar.


Thank you.  Maybe it is something different.
Mike here: If you are using a USB-serial adapter, be aware that not all adapters work reliably with the AutoStar. See the article "AutoStar and USB" on the Helpful Information: AutoStar Info page. (I recommend Keyspan adapters.)


That is the one that I use.
Mike here: Then perhaps it is something unique to the AudioStar and Astroplanner.

Subject:	Re: Clive and Terry Update Audiostar for ETX Problem
Sent:	Friday, August 24, 2012 15:51:20
From:	Clive and Terry (
Good news, finally had a clear night and after a full reset and
calibration etc. I locked onto the moon and the scope tracked
beautifully and stayed on target.
Thanks to you all I am one happy newbie.
Keep up the good work.
Clive Smith

Subject:	re: Hi there  (Sun Warning on ETX-125)
Sent:	Thursday, August 23, 2012 20:36:54
From:	richard seymour (
To get past the "Don't Point At Sun" message, you're supposed to press
the "5" key.

You can slow down the message to readable speed by tapping the scroll
down key a few times.

have fun

Subject:	Hi there
Sent:	Sunday, August 19, 2012 09:33:46
From:	Philippe Bissonnette (
I bought a nice used meade EXT 125 model Now teh autostar turns on and
powers up but It wont do a search or setup  But the part that that tells
you not to stare at the sun with the scope comes on....  can anyone tell
me what the problem might be .. I dont want to send it back I bought it
for a good price and I wouldloose if I sent it back  or should I order
another controller??? thanks ...phil
Mike here: PLEASE read the Email Etiquette item on the ETX Site home page; your message was originally deleted UNREAD as SPAM due to the subject line. Thanks for understanding.
Need more info on the symptoms. Do you mean the display just locks up at the sun warning? Do the slew arrows work to slew the telescope?


no the slew arrows do not work the scope
Mike here: Starting breakfast. I'll get back to you in about an hour. Apologies for the delay.

And: no problem I really appreciate the feedback ... thanks l8ter then .
Mike here: So the display is locked at the sun warning and the slew arrows don't work. Some possibilities: weak or incorrectly inserted batteries in the ETX, bent/dirty/too depressed pins on the HBX connectors or jacks, corrupted software in the AutoStar. Check the easy ones and if nothing there, try reloading the AutoStar software. You will want version 4.3Eg (from Meade's web site or the AutoStar Software Archive on the Helpful Information: AutoStar Info page on the ETX Site). You will also need a #505 serial cable (easily made; see the AutoStar Info page). If your computer has only USB you will need a USB-serial adapter, however, not all work reliably with the AutoStar; I recommend Keyspan adapters. You can use Meade's AutoStar Update Application or StarPatch (from, both for Windows, or AutoStarX (see the AutoStar Info page).


Hi again thank you very much for the information I think I will have to
get a hold of the cables in town .. I will try all of this and see what

And an update:

..Hi again ok it 's all good . I was doing something wrong obviously I
took all of the batterries out and chequed the leads, and put them all
back in turned it on pressed mode again for the aloted time and presto
it came up.. so whatever you said and I did worked out so thanks again..
man I did not want to return this piece .. now I wait for my
tripod..from the   thanks again...

Subject:	Re: Clive and Terry Update Audiostar for ETX Problem
Sent:	Wednesday, August 15, 2012 16:42:44
From:	Clive and Terry (
Sorry I have gone quiet on my problem, but I was waiting on the delivery
of the RA motor form BINTEL in Australia (Andrew, thanks for directing
me there). Anyway it arrived yesterday and was pleasantly suprised with
not only the motor being delivered but the gearbox and motor card as
well. All this for 25AUD. Great service and great value.

Originally I was going to split the gearbox in situ and remove the old
motor as:
1. I didn't feel confident in going down the path of removing the fork
of the scope etc to eventually gain accessand removal of the bracket
holding the worm shaft, thus enabling me to undo the hex screw holding
the gear wheel on that shaft.
2. Couldn't find or make a gear puller small enough to work in the
confined space of the scope base.

So, I decided to undo the nut holding the worm shaft onto the bracket
and proceeded to remove the gearbox, motor and worm shaft out as one
unit. I decided not to muck around with replacing the motor alone and
refitted the replacement, Some gentle pressure was needed to get the
bushes of the worm shaft back into place in the bracket, but eventually
all fitted nicely.

After tightening everything in place, the moment of truth. Switched on
the scope and after initialization tried the various speeds in both
directions and all works perfectly. When there are some clear skys I
will go through a complete reset and recalibration etc and see if the
scope works as it should. As a side issue before all this problem
appeared, I did have differculty in tracking correctly. Hopefully this
will be fixed as well. Time will tell.

Anyway, I wish to thank you all for your support and advice on my motor
failure. I have learnt a lot.
I will let you know how the scope performs after the setup - hopefully
it will be good news.


Clive Smith


From:	richard seymour (

Good luck with the "Sky Truth" testing...

have fun

Subject:	re:  etx 70 AT controller problems
Sent:	Wednesday, August 15, 2012 09:40:46
From:	richard seymour (
If the eyepiece is trying to go "under" the scope (i assume you mean the
scope is pointing "too high" and going "over the top"?), you may have
the wrong Gear Ratio set for the telescope.   Meade produced two
different models of ETX-70, and the Alt ratios differ.

First, make sure that you have ETX-70 selected as the
Setup/Telescope/Telescope Model
... if you didn't, that may be the source of your problem.

If it was set to ETX-70, then:
On the Autostar, menu to Setup/Telescope/Alt Ratio  (enter)

The two models used 1.36889 and/or 1.01500

If you have 1.0150, try changing that to 1.36889 (enter)
..and then test it again (after re-aligning)

You can test this indoors in the daytime... just tell it to align,
and tap Enter when it asks to center.  Then try "GoTo" ing various targets.

I'm (more than) a little surprised that it was willing to *align*
without revealing this problem... i would have thought that the
alignment slews (when it first goes to the stars) would have been
equally wildly "off"

good luck
From:	Gunter (
to set up the scope in alt-az mode, the scope must be fully

at my scope, the scope was at the direction of the pole 51° in

i think that was the problem..?
Mike here: The telescope does need to start out in the proper HOME position for the telescope type, mounting mode, and alignment type. In Alt/Az, the base and OTA need to be level and the OTA of the ETX-70 pointed towards True North before starting the AutoStar alignment.


" In Alt/Az, the base and OTA need to be level "

i think that was the problem.....the scope was pointed to the north, so
that was ok, but also 51° up....and it should be 0° level
Mike here: That would cause a problem.

Subject:	Audiostar compatability with early model ETX 105 EC
Sent:	Wednesday, August 15, 2012 08:04:45
From:	Paul Smit (
I would like to know if the current Audiostar controller will work with
a 2002 vintage Meade ETX 105 EC.  The 497 Autostar controller was an
expensive optional extra at the time, but I could use Alt-Az tracking
capability now. Meade replied with a "we think it might, ...", I'm sure
someone in the community knows?

Mike here: I'll let the AudioStar experts respond.
From:	richard seymour (
The Audiostar is an (almost) direct "port" of the original 497 firmware...
but translated to a different CPU's data structures, with (too many)
occasional bug introductions.  The "audio" features are supplied by a
"daughter board" inside the handbox.

But, overall, Yes, it works (it works on my older-than-that ETX-90).

Andrew has created a patch kit for A1F7 (the French-as-2nd-language)
Audiostar firmware that corrects many of the new bugs.  StarPatch is
happy to patch an Audiostar.

Meade's current Audiostar firmwares are A1F7 (English/French) and A3S2

have fun

Subject:	FW: etx 70 AT controller problems
Sent:	Tuesday, August 14, 2012 07:33:43
From:	Gunter (
i've just recieved a controller and al the problems are gone...

is there also on your site a good exemple for aligning the scope?




after i do a star alignment, and i go to   X object, the scope go in the
reverse direction (i mean that the eyepiece will go unther the scope....) is
that normal?
Mike here: There are several alignment tip articles on the Helpful Information: AutoStar Info page. As to the "rubberbanding" you are seeing, that is usually cured by doing a CALIBRATE MOTOR and then TRAIN DRIVES (on both axes).


what do you exactly main.....can i find some information about that on your
site to?
Mike here: CALIBRATE MOTOR is located in the SETUP: TELESCOPE menu on the AutoStar. Just select it; it will briefly run the motors. It measures the power output of the encoders and adjusts accordingly. TRAIN DRIVES is also in the TELESCOPE menu; just follow the onscreen help prompts. Training counts pulses from the encoders so that the AutoStar will know how far to slew when GOTOing and slewing. There are several articles on TRAIN on the AutoStar Info page.

Subject:	RE: Question
Sent:	Tuesday, August 7, 2012 16:23:58
From:	Jean-Marc (
I would like tive you some news about my problems with LX90.

It's not your firmware which cause my troubles: i reload it (v4.28 with
sideral speed to 33%), do an reset, calibrate motors and train motors

I'have always drifting west to east, i tried to adjust speed i need to
up it to 65 but after drift begin again in the other way : i can't correct my
trouble with custom speed.

I have tried PEC, i do a pec train then i put pec ON, this time object
move to west and go out ... It seems that PEC doesn't run correctly on my
scope (maybe first LX90 doesn't support this function)

It's not your firmware it's same with meade's firmware. I should have a
serious troubles with mechanics AND electonics.

I don't understand why in your country you doesn't seems to have too
troubles than you in europe. In France many lx90's users needs to buy
another wedge (eq6 or cgem) to practice correctly their hobby.

In the next day i will buy another wedge, may be a cgem DX and keeps th
lx90's optic.

Thanks for all, esxcuse me for my poor english ...

Jean-Marc BAILLE 
Mike here: Interesting. Wish I knew a solution. Have you tried the LX90 Yahoo Group?


I nerver heard about a lx90 groups, i just followed lx200 yahoo's group 

Thanks ...

Jean-Marc BAILLE
Mike here: It is mentioned on my LX90 web page, along with some other links.

Subject:	Re: Update Audiostar for ETX
Sent:	Wednesday, August 1, 2012 02:21:44
From:	Clive and Terry (
First let me say a big thanks for your quick and informative response.
Richard to anwser some of your questions:
1.    Before I attempted te upgrade the Audiostar version was displaying A256.
1.    My location that I have placed into the scope is Waikanae (about
60km north of Wellington) - 40:53:00 S and 175:04:00 E  (exact spot of
my telescope)
2.    Time and Date of updating the software/test - 31 July around 2pm
3.    Which stars? - I had accepted the automatic alignment method
4.    Other methods? - I have tried the 1 star alignment tonight
(following your communications) and I have got the same result, reboot
as soon at the motors start to move.
5.    Skip the alignment - no, reboot as before.
6.    Previous 497 - I am not sure what happened. Working one day, next
evening dead.

Tonight I did a reload of the BuildAUA1F7 using Starpatch (unregistered
copy) and after turning the scope off and back on, I got the same
It seems strange that if  the cause of my problem is a wiring issue,
that it should happen straight after a software update.

Hope this info is useful.
Once again thankyou for all your assistance on this issue.

Clive Smith


From:	Andrew Johansen (
Im still suspecting wiring or a shorting motor
based on what you have posted so far.
Just for info, if you dont start an align, it happily sits there.
What happens if you then set the speed to max and try and slew using the
slew keys???



Thanks for the response. Yes it will  boot up and sit at the alignment
display quite happy.
I will try the speed tomorrow and let you know the results.



From:	richard seymour (
A reminder that it powers up in "speed Max",
so you can run a number of variations on Andrew's theme:
(a) after powering, just try all 4 slew keys, one at a time.
(b) if that survives, change the speed (any key other than "9") and try the 4 slew keys

(c) if (a) didn't survive, power off, power on, and try (b)

As well as a shorted motor, it could also be a blown (to a shorting
condition) power MOSFET, which is the final bit of semiconductor
circuitry before the motor(s).

If you'd like to revert to unpatched A2S6, i can send a copy.
Meade has updated the Spanish version to A3S2 to handle the LX80 scopes.

I cannot explain why the patch and the failure were apparently
simultaneous (or at least related)... my supposition is that whatever
blew the original 497 weakened the motor unit (or vice-versa) and
eventually the motor unit died, too.

That said, there certainly *are* ways for the physical act of connecting
a PC to the Autostar to cause problems... but they require a
house-of-cards such as:
(a) power laptop and telescope from same battery
(b) using a laptop power adapter that carries the positive (+) battery
post through the adapter as a wire, instead of the more typical negative
(-) post.
(c) doing that moves the laptop's "ground" to a -6 volt potential
compared to the telescope's "ground"  (laptop adapters turn 12v to 18v)
(d) the serial cable (from Autostar 2nd socket to PC or via PC's
USB-to-serial adapter) then tries to reconcile that 6 volt difference
along the length of its "ground" wire.
(e) something along that circuit gets very very hot.

I've only directly heard of that full sequence (a through e) happening
twice in my 12 years of Autostar involvement (not involving patching,
the LX200gps scopes were being hooked up in the field (hence the
external car battery for the laptop) in preparation for auto-guiding
during astrophotography).

It's also possible for the physical act of plugging/unplugging/plugging
the handbox cable to cause the wires in the sockets to touch each other
(or get jammed, bent) or the handbox cable to have filaments of the
internal wires bridge adjacent pins at the connector pins.
Ohmmetering the handbox cable (looking for pin-to-pin connections) is
the safest way to seek such, whereas the quick "swap end-for-end" can
lead to other problems (but may change the symptoms... for better or

good luck
Mike here: The unplugging/plugging is something I've always worried about (but not a lot). It does add some "risk". Of course, leaving the cable connected also has "risk", in keeping the pins depressed all the time. (I'm glad I don't lose any sleep over worrying about this!)

And more:

Hi Richard,
Thanks for the advice, I will try what you and Andrew have suggested
tonight and let you know the results.
Your offer of sending the unpatched A2S6 is appreciated and accepted,


And an update:

Progress, following yours and Andrews things to try this is the result.
1    Powered up the scope - Press 0 to align etc is displayed.
2.   Pressed the up and down slew keys without changing the speed. The
scope responded correctly.
3    Pressed left slew key and the scope immediately rebooted.
4    Press right slew key and the scope rebooted again.
5    Following reboot I set the speed to 6, pressed all slew keys in
turn and the scope responded correctly.
6    Repeated process through all speed (except 9 Max) and scope
responded correctly.

So the prolem would appear to be with movement in the horizontal plane
and speed set to max.
From your expert opinion what is the conclusion.



We have a smoking gun.
The fact it works at all speeds except Max pretty much excludes possible
cut/shorting wires.

Up to speed 8, the system uses PWM ( pulse width modulation )
to drive the motors at a set "controlled" speed.
At "Max" it just opens up the motors to raw voltage.
If the motor is suspect, or the power supply is too weak,
this may have a large enough current draw
to pull down the supply voltage enough to reset the handbox.

What is the rating of your power supply?
Do you have/can you use a multimeter/bench power supply?
Ie can you watch the current draw when the
azimuth axix is being slewed, to see what happens??

Also, just to see if its mechanical
How tight is the RA axis when declutched??
Have you ever opened the base and looked at the gearing to see
how tight it is??



The power supply is an AC adapter 12v 1.5A. Unfortunately I do not have
any way of watching the draw on the current.
When I unlock the RA and turn the scope by hand, it is quite free and
smooth and yes I looked inside the base sometime ago and checked the
gearing. It all looked and felt OK.



1.5A should be heaps for an ETX.
We really need to get a current reading
to see whats being drawn,
as it is currently pointing towards a power supply problem.
( ie faulty lump or low resistance short in the RA motor drive.
I am loathe to suggest trying batteries, as they can produce massive current
in a short burst, and hence may overheat whatever is
causing the problem ( if thats the case ).
Maybe time to open the base again so you can feel the motor
to see how hot it gets when you slew at say speed 8
with the clutch released.



Will attack the base tomorrow during the day. Thanks for your help and
will keep you all posted.


Mike here: Might be worth another test: unlock the horizontal axis and see if max speed left/right slew reboots. If something physical is causing the large current draw, the AutoStar might not reboot.


This isn't a fix, but it may be a workaround:
You can set the Autostar to operate in "Quiet" mode...
that limits the MAx slew speed to 8 (even if you key "9")

It's under  Utilities/Quiet Mode(enter)  .. scroll to Yes (or On), tap Enter.

The unpatched copy of A2S6 will be in the next message (but not CC'd to Mike and Andrew)
If the problem is with the motor card or motor, the firmware won't change the symptoms.

If you do open the base, (and if they've gone to a single card for both motors)
you could connect the Alt motor to the AZ card (and vice versa)...
and see if the symptom moves with the motor-swap.
If it does, it's the motor.
If it doesn't, it's the card.

good luck

And this update:

Just to satisfy myself I reloaded thehandbox with A2S6 ROM and tried the
slew keys. Yes it failed at max speed in the horizontal plane OK in the
vertical. Next I set the quite slew to on, thus giving the max at 8.
Vertical plane OK, but the horizontal again failed at max(8). Ok at 7
and under. Tried an alignment and failed, first slew (max speed) it

I had a look in the base (as suggested by Andrew) and I can only see one
card around the motor area and one card for the control panel. On the
card around the motor there is a 4 wire connection back to the control
panel card and a further 2 wire connection that appears to go up one of
the forks.

When trying the slew process with the base plate off and the scope
unlatched everything moves freely and the motor doesn't seem to be hot.

If all this means that the electronics/motor has failed I really don't
know what to do. Support in New Zealand for Meade telescopes leaves a
lot to be desired.




Gday Clive

Do you have any access to TV repairmen, HAM radio enthusiasts,
members of local astro societies, who could do a few tests????
Ie simplest test to check for motor is disconnect the
black/red wire harness from the motor card ( remember orientation ).
Then feed it 12V directly from a bench power supply to see
what current it draws.
I suspect the motor card itself is OK based on the fact that
both directions work correctly.



If there are only two wires heading up the central axis, then the motor
card in the base is handling both motors (those two wires are to the Alt
You could be doubly sure by opening the motor fork and looking to see if
there's a card in there, too.

Assuming there's not, does the Az motor have a two-wire connector, too?
(or is it soldered directly to the card?)
If there's a connector (and you've verified that there's no 2nd card up
the fork), you could try swapping the connector for the up-the-shaft
wire pair with the one for the Az motor.  Then test.  If Az slewing
still crashes it, it's the motor card.

Another way to test the pair heading up the shaft is to check them with
an ohmmeter.
If the resistance is very low (less than 100 ohms, more like 5 or 10),
they go to the motor.
IF the resistance is higher, they're signal lines, and you should not
swap them with the Az motor's leads.

As for service, if this is a new scope, what *does* your warranty
document (and local laws) say?  Can you "simply" work it out through the
In Australia, Binocular and Telescope are an authorize Meade
warranty/repair shop, but they may only cover warranty work for products
sold *in* Australia.

Andrew may have a better idea of what you're facing in NZ.
I also recommend joining the Melbourne Meade Telescope Yahoo group..

good luck


I'm still surprised that it survives at speed 8 ... the PWM doesn't
interrupt the current flow for very long ... but it certainly looks like
it's the motor at fault (the semiconductors usually flat-out die)

good luck

And this:

> If there are only two wires heading up the central axis,

Then he's in trouble. :-)
If its an ETX-125PE, as noted earlier
there are a minimum of 4 wires going
up through the central bolt.
If it has an integrated LNT, there will be 6 wires.

ALL the RA motor card wiring is in the base
for the 125PEs, none goes into the forks.

In the 497s, its not the PWM that matters but the feedback speed control loop.
Ie Full speed with 13V is approx 8deg/sec
Speed 8 is only about 1.5deg/sec, so much lighter current draw.



Isn't Speed 8 three degrees per second?
(i'm in bed, my autostar isn't)

have fun
--dick (too many autostars dancing on his brain...)

And this:

My previous email referring to the wires I got wrong. On checking the
base again, I have 6 wires going up through the middle and a black/red
coming off of the circuit board to the motor.
I am now getting the failure on all speed settings.
Your comments below referring to 12v directly and see what current it
draws. Are you saying apply the 12v direct to the motor bypassing the
motor card or are you saying check the current drawn from the motor card
motor terminals when turning the scope on and using the slew keys.



> I am now getting the failure on all speed settings.

Not good

> Your comments below referring to 12v directly and see what current it 
> draws. Are you saying apply the 12v direct to the motor bypassing the 
> motor card

Yes, though it may pay to measure the motor resistance first
 if its now dying at all speeds.
Another simpler option is to unplug the motor from the RA card.
Now start the unit as per usual and try speed max.
If it doesnt reset, then that also points towards the motor.
( You may get a motor fault message and thats OK,
we want to see if the Hbx stays alive )



Have tried again. Without the motor connected through all speeds no
problem with the #497, as it should be.
I measured the voltage across the motor terminals on the RA card and for
each speed it measured 12.13v (I borrowed a meter from my neighbour)
If all this is correct, then yes I think the motor is suspect, what do
you think?
Do you know where I can get a replacement motor from.

Thanks for your help


I assume you saw the voltage change from +ve to -ve
when the keys changed direction.
If so that is sounding good.

> then yes I think the motor is suspect, what do you think?

Its almost 100% sure to be that now.
Again, running the motor directly off a seperate
 12V supply will confirm that.

> Do you know where I can get a replacement motor from.

I dont know of any third party suppliers, but your best bet will
probably be BINTEL in Sydney. Ask for Don

From:	Jeff Hyde (
When reading the problems Clive has been having and the suggestions to
help him, brought to mind a similar problem I had with erratic alignment
problems with an Autostar and ETX-125. I admit to having no experience
with the Audiostar but thought it worth suggesting the possibility of
insufficient voltage.
My problem turned out to be of my own making, in that I was attempting
to run an ETX-125 with a 3 metre handbox extension cable that had
excessive volt drop due to the conductor size when the motors activated
causing all sorts of unpredictable alignment problems.
So, as a thought, it may may be worth checking the telescope power
supply, i.e.
- if using internal batteries, rechargable NiMH or Nicad, unless they
are all good and fully recharged, they may not have sufficent voltage.
Try using a new set of good brand alkaline cells. 
- if using an external battery or mains power adaptor, check it can
supply adequate current capacity at 12 volts, (the Meade power supply is
rated at 1500mA). Ideally, a mains power supply should provide a
regulated voltage output
- if using an external power supply, check that the power cord going to
the telescope is not too long or too thin which may also cause voltage
drop at the telescope and Autostar when the motors run.
If, like me, you are not using the original handbox cable, try
substituting the original cable and see if it then works, (assuming the
power supply or batteries are correct as previously).
If you decide to use an external power supply, make sure the polarity of
the connecting plug is correct. Failure to have correct polarity will
fry your controller, telescope or both!!  See Mike's site under
Technical Tips, Power Supplies for information on external supplies and
correct polarity for your telescope.
Hoping this may provide an easy fix for your problem (if only......)
A fellow Kiwi
If, like me, you are not using the original handbox cable, try
substituting the original cable and see if it then works, assuming the
power supply or batteries are correct as previously.


Thanks everyone for the ongoing support.
Jeff, I am using the supplied cables with the Audiostar (have even
swapped with my original #497). The power supply is external 12v 1.5a
correct polarity and regulated. I have built a shed specifically for the
telescope with 240v house supply. The outlet for the 12v is dedicated
off of the shed switchboard. (If any interest I can supply photos of my
shed. I struggled withe the best way to slide the roof off. Tried all
different options, but finally used a garage door opener and it works

Andrew, my previous email to you, I indicated that at any speed setting
the scope initiated a reboot and therefore on the surface indicated the
motor was suspect. Well I tried it again this morning and it spits the
dummy at speed 8 or 9.  Anyway I managed to put 12v supply direct to the
motor (bypassing the card) and the motor ran, slower than I expected but
not knowing how the speed is controlled I don't know if this is normal.
So now what is wrong in your opinion - the motor or the card not
handling the speed control correctly. I am totally confused.
I sent am email off to Don at BINTEL in Sydney yesterday, so am looking
forward to his reply.
Jeff are you aware of any support for parts in New Zealand.

Regards and thanks again for all your efforts



Normally, the motor card puts out PWM ( pulse width modulation )
for controlled speed and raw voltage for full speed.
With proper diagnostic tools, this can be checked easily.
However, not having them handy,
If you put 12V directly into the motor,
it should literally scream along at say 10,000rpm.
To check this roughly,
the ETX has a 60 tooth wormwheel, so say 6deg/tooth
At approx 8 deg/sec max speed ( at 12V ),
by putting 12V directly into the motor,
you should see the worm turn
a bit faster than one rev per second.
It should do that in both directions.

See what the speeds are based on above test.



Andrew is correct... the motor should have *screamed*... (10,000 rpm is
not an exaggeration)
If one of its coils was short-circuiting, it wouldn't.
If you can measure current draw on the "12v direct", it *should* be
about one amp (or less).
If it's higher... well, the motor card components are only rated to 3

On the bright side: it's the RA motor, so it's easier to reach...

good luck


My testbed ETX RA drive draws 100mA when running full speed
Even with me putting a load on it ( by grabbing the output shaft )
it only goes up to 140mA with a 13V supply.
So those are the values you would be expecting for a good motor.


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