Effect of temperature on backlash


Richard Kinsey
 

I can detect a small amount of backlash in both the RA and Dec axis of
my recently received AP1200. I am wondering whether this could be
caused by a change in temperature from the factory to the mount's
present location in my observatory where it is presently around 10
degrees C. If such a change of temperature explains the slight backlash
I can feel, perhaps I should leave it in readiness for warmer days. Any
advice would be gratefully received. Richard


Roland Christen
 

In a message dated 10/26/2007 1:23:41 PM Central Daylight Time,
richard.kinsey@... writes:


I can detect a small amount of backlash in both the RA and Dec axis of
my recently received AP1200. I am wondering whether this could be
caused by a change in temperature from the factory to the mount's
present location in my observatory where it is presently around 10
degrees C. If such a change of temperature explains the slight backlash
I can feel, perhaps I should leave it in readiness for warmer days. Any
advice would be gratefully received. Richard
Change in temperature will not cause a change in backlash. Adjust it and the
mount should work at all temperatures.

Rolando


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Roland Christen
 

In a message dated 11/2/2007 2:34:57 PM Central Daylight Time,
reseavey@... writes:


The following, winter when the temperature was about 5F, the engagement of
the RA worm and worm wheel seemed to be much tighter; in fact I had to
re-adjust the worm mesh so that the RA motor wouldn't make strange noises
while slewing.
I think you might have seen the effect of thickening of the grease, not worm
mesh.

Rolando


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Richard Seavey
 

Rolando
I adjusted the RA worm mesh on my AP1200 mount in the summer of 2006 when
the ambient temperature was about 85F.
The following, winter when the temperature was about 5F, the engagement of
the RA worm and worm wheel seemed to be much tighter; in fact I had to
re-adjust the worm mesh so that the RA motor wouldn't make strange noises
while slewing. I don't think voltage is an issue since the 13.8V mount
power supply is located in my house. Do you know what might have caused
this effect?

Richard

At 02:20 PM 11/2/2007 -0400, you wrote:

In a message dated 10/26/2007 1:23:41 PM Central Daylight Time,
<mailto:richard.kinsey%40tiscali.co.uk>richard.kinsey@... writes:

I can detect a small amount of backlash in both the RA and Dec axis of
my recently received AP1200. I am wondering whether this could be
caused by a change in temperature from the factory to the mount's
present location in my observatory where it is presently around 10
degrees C. If such a change of temperature explains the slight backlash
I can feel, perhaps I should leave it in readiness for warmer days. Any
advice would be gratefully received. Richard
Change in temperature will not cause a change in backlash. Adjust it and the
mount should work at all temperatures.

Rolando

**************************************
See what's new at
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sreilly <sreilly@...>
 

And voltage drop may be an issue for a long run. The only way to know for
sure is to take a reading at the mount end.



Steve





_____

From: ap-gto@... [mailto:ap-gto@...] On Behalf Of
chris1011@...
Sent: Friday, November 02, 2007 3:51 PM
To: ap-gto@...
Subject: Re: [ap-gto] Effect of temperature on backlash



In a message dated 11/2/2007 2:34:57 PM Central Daylight Time,
reseavey@verizon. <mailto:reseavey%40verizon.net> net writes:

The following, winter when the temperature was about 5F, the engagement of
the RA worm and worm wheel seemed to be much tighter; in fact I had to
re-adjust the worm mesh so that the RA motor wouldn't make strange noises
while slewing.
I think you might have seen the effect of thickening of the grease, not worm

mesh.

Rolando

**************************************
See what's new at
http://www.aol. <http://www.aol.com> com


Richard Seavey
 

Steve
I did measure the voltage and it was about 12.8 Volts under a slewing load.
But that reminds me of something else. I would find it very useful if
there were a 12 volt test point available on the mount so that the actual
mount voltage could be measured. I don't know of an easy way to measure the
mount voltage on the mount side of the power connector. Measuring at that
point is important because that power connector can sometimes fit loosely
which adds resistance with the attending voltage drop.

Richard

At 06:00 PM 11/2/2007 -0400, you wrote:

And voltage drop may be an issue for a long run. The only way to know for
sure is to take a reading at the mount end.

Steve

_____

From: <mailto:ap-gto%40yahoogroups.com>ap-gto@...
[mailto:ap-gto@...] On Behalf Of
<mailto:chris1011%40aol.com>chris1011@...
Sent: Friday, November 02, 2007 3:51 PM
To: <mailto:ap-gto%40yahoogroups.com>ap-gto@...
Subject: Re: [ap-gto] Effect of temperature on backlash

In a message dated 11/2/2007 2:34:57 PM Central Daylight Time,
reseavey@verizon. <mailto:reseavey%40verizon.net> net writes:

The following, winter when the temperature was about 5F, the engagement of
the RA worm and worm wheel seemed to be much tighter; in fact I had to
re-adjust the worm mesh so that the RA motor wouldn't make strange noises
while slewing.
I think you might have seen the effect of thickening of the grease, not worm

mesh.

Rolando

**************************************
See what's new at
<http://www.aol.>http://www.aol. <http://www.aol.com> com






Howard Hedlund
 

Here's a 12 volt test point: On your GTOCPx control box; on the five
pin receptacle for the keypad's plug; number 2 is negative and number
4 is positive. The pin numbers are visible on the receptacle itself.
You may need to rig up some thinner lead probes, but I have even gotten
accurate enough readings with two paper clips inserted into the
receptacle.



Mag. 7 skies!



Howard Hedlund

Astro-Physics, Inc.

815-282-1513

________________________________

From: ap-gto@... [mailto:ap-gto@...] On Behalf
Of Richard Seavey
Sent: Friday, November 02, 2007 6:27 PM
To: ap-gto@...
Subject: RE: [ap-gto] Effect of temperature on backlash




Steve
I did measure the voltage and it was about 12.8 Volts under a slewing
load.
But that reminds me of something else. I would find it very useful if
there were a 12 volt test point available on the mount so that the
actual
mount voltage could be measured. I don't know of an easy way to measure
the
mount voltage on the mount side of the power connector. Measuring at
that
point is important because that power connector can sometimes fit
loosely
which adds resistance with the attending voltage drop.

Richard

At 06:00 PM 11/2/2007 -0400, you wrote:

And voltage drop may be an issue for a long run. The only way to know
for
sure is to take a reading at the mount end.

Steve

_____

From: <mailto:ap-gto%40yahoogroups.com>ap-gto@...
<mailto:ap-gto%40yahoogroups.com>
[mailto:ap-gto@... <mailto:ap-gto%40yahoogroups.com> ] On
Behalf Of
<mailto:chris1011%40aol.com>chris1011@...
<mailto:chris1011%40aol.com>
Sent: Friday, November 02, 2007 3:51 PM
To: <mailto:ap-gto%40yahoogroups.com>ap-gto@...
<mailto:ap-gto%40yahoogroups.com>
Subject: Re: [ap-gto] Effect of temperature on backlash

In a message dated 11/2/2007 2:34:57 PM Central Daylight Time,
reseavey@verizon. <mailto:reseavey%40verizon.net> net writes:

The following, winter when the temperature was about 5F, the
engagement of

the RA worm and worm wheel seemed to be much tighter; in fact I had
to
re-adjust the worm mesh so that the RA motor wouldn't make strange
noises
while slewing.
I think you might have seen the effect of thickening of the grease, not
worm

mesh.

Rolando

**************************************
See what's new at
<http://www.aol.>http://www.aol. <http://www.aol.com
<http://www.aol.com> > com






Joe Zeglinski
 

How about using the +6v port? Plug in an audio cable and measure the voltage
at it's pigtail (or use an unwired audio jack and use it's tangs. I assume it
is tapped off the main 12V input, and might be representative of the cable
power coming in.

Joe

----- Original Message -----
From: "Howard" <howard@...>
To: <ap-gto@...>
Sent: Friday, November 02, 2007 7:46 PM
Subject: RE: [ap-gto] Effect of temperature on backlash


Here's a 12 volt test point: On your GTOCPx control box; on the five
pin receptacle for the keypad's plug; number 2 is negative and number
4 is positive. The pin numbers are visible on the receptacle itself.
You may need to rig up some thinner lead probes, but I have even gotten
accurate enough readings with two paper clips inserted into the
receptacle.



Mag. 7 skies!



Howard Hedlund

Astro-Physics, Inc.

815-282-1513

________________________________

From: ap-gto@... [mailto:ap-gto@...] On Behalf
Of Richard Seavey
Sent: Friday, November 02, 2007 6:27 PM
To: ap-gto@...
Subject: RE: [ap-gto] Effect of temperature on backlash




Steve
I did measure the voltage and it was about 12.8 Volts under a slewing
load.
But that reminds me of something else. I would find it very useful if
there were a 12 volt test point available on the mount so that the
actual
mount voltage could be measured. I don't know of an easy way to measure
the
mount voltage on the mount side of the power connector. Measuring at
that
point is important because that power connector can sometimes fit
loosely
which adds resistance with the attending voltage drop.

Richard

At 06:00 PM 11/2/2007 -0400, you wrote:

And voltage drop may be an issue for a long run. The only way to know
for
sure is to take a reading at the mount end.

Steve

_____

From: <mailto:ap-gto%40yahoogroups.com>ap-gto@...
<mailto:ap-gto%40yahoogroups.com>
[mailto:ap-gto@... <mailto:ap-gto%40yahoogroups.com> ] On
Behalf Of
<mailto:chris1011%40aol.com>chris1011@...
<mailto:chris1011%40aol.com>
Sent: Friday, November 02, 2007 3:51 PM
To: <mailto:ap-gto%40yahoogroups.com>ap-gto@...
<mailto:ap-gto%40yahoogroups.com>
Subject: Re: [ap-gto] Effect of temperature on backlash

In a message dated 11/2/2007 2:34:57 PM Central Daylight Time,
reseavey@verizon. <mailto:reseavey%40verizon.net> net writes:

The following, winter when the temperature was about 5F, the
engagement of

the RA worm and worm wheel seemed to be much tighter; in fact I had
to
re-adjust the worm mesh so that the RA motor wouldn't make strange
noises
while slewing.
I think you might have seen the effect of thickening of the grease, not
worm

mesh.

Rolando

**************************************
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Richard Seavey
 

Howard
Thanks for the tip! Sounds like a good solution. By the way, It was a nice
talking with you at AIC2007 last Saturday.

Richard

At 05:46 PM 11/2/2007 -0600, you wrote:

Here's a 12 volt test point: On your GTOCPx control box; on the five
pin receptacle for the keypad's plug; number 2 is negative and number
4 is positive. The pin numbers are visible on the receptacle itself.
You may need to rig up some thinner lead probes, but I have even gotten
accurate enough readings with two paper clips inserted into the
receptacle.

Mag. 7 skies!

Howard Hedlund

Astro-Physics, Inc.

815-282-1513

________________________________

From: <mailto:ap-gto%40yahoogroups.com>ap-gto@...
[mailto:ap-gto@...] On Behalf
Of Richard Seavey
Sent: Friday, November 02, 2007 6:27 PM
To: <mailto:ap-gto%40yahoogroups.com>ap-gto@...
Subject: RE: [ap-gto] Effect of temperature on backlash

Steve
I did measure the voltage and it was about 12.8 Volts under a slewing
load.
But that reminds me of something else. I would find it very useful if
there were a 12 volt test point available on the mount so that the
actual
mount voltage could be measured. I don't know of an easy way to measure
the
mount voltage on the mount side of the power connector. Measuring at
that
point is important because that power connector can sometimes fit
loosely
which adds resistance with the attending voltage drop.

Richard

At 06:00 PM 11/2/2007 -0400, you wrote:

And voltage drop may be an issue for a long run. The only way to know
for
sure is to take a reading at the mount end.

Steve

_____

From:
<mailto:ap-gto%40yahoogroups.com><mailto:ap-gto%40yahoogroups.com>ap-gto@...
<mailto:ap-gto%40yahoogroups.com>
[mailto:ap-gto@... <mailto:ap-gto%40yahoogroups.com> ] On
Behalf Of
<mailto:chris1011%40aol.com><mailto:chris1011%40aol.com>chris1011@...
<mailto:chris1011%40aol.com>
Sent: Friday, November 02, 2007 3:51 PM
To:
<mailto:ap-gto%40yahoogroups.com><mailto:ap-gto%40yahoogroups.com>ap-gto@...
<mailto:ap-gto%40yahoogroups.com>
Subject: Re: [ap-gto] Effect of temperature on backlash

In a message dated 11/2/2007 2:34:57 PM Central Daylight Time,
reseavey@verizon. <mailto:reseavey%40verizon.net> net writes:

The following, winter when the temperature was about 5F, the
engagement of

the RA worm and worm wheel seemed to be much tighter; in fact I had
to
re-adjust the worm mesh so that the RA motor wouldn't make strange
noises
while slewing.
I think you might have seen the effect of thickening of the grease, not
worm

mesh.

Rolando

**************************************
See what's new at
<<http://www.aol.>http://www.aol.>http://www.aol.
<<http://www.aol.com>http://www.aol.com
<http://www.aol.com> > com










Richard Seavey
 

Joe
Thanks for the suggestion. I had thought of using the + 6V port but I
believe the voltage is obtained from the +12V by using a 6V regulator, so
that idea would not work.

Richard

At 08:47 PM 11/2/2007 -0400, you wrote:

How about using the +6v port? Plug in an audio cable and measure the voltage
at it's pigtail (or use an unwired audio jack and use it's tangs. I assume it
is tapped off the main 12V input, and might be representative of the cable
power coming in.

Joe

----- Original Message -----
From: "Howard" <<mailto:howard%40astro-physics.com>howard@...>
To: <<mailto:ap-gto%40yahoogroups.com>ap-gto@...>
Sent: Friday, November 02, 2007 7:46 PM
Subject: RE: [ap-gto] Effect of temperature on backlash

Here's a 12 volt test point: On your GTOCPx control box; on the five
pin receptacle for the keypad's plug; number 2 is negative and number
4 is positive. The pin numbers are visible on the receptacle itself.
You may need to rig up some thinner lead probes, but I have even gotten
accurate enough readings with two paper clips inserted into the
receptacle.



Mag. 7 skies!



Howard Hedlund

Astro-Physics, Inc.

815-282-1513

________________________________

From: <mailto:ap-gto%40yahoogroups.com>ap-gto@...
[mailto:ap-gto@...] On Behalf
Of Richard Seavey
Sent: Friday, November 02, 2007 6:27 PM
To: <mailto:ap-gto%40yahoogroups.com>ap-gto@...
Subject: RE: [ap-gto] Effect of temperature on backlash




Steve
I did measure the voltage and it was about 12.8 Volts under a slewing
load.
But that reminds me of something else. I would find it very useful if
there were a 12 volt test point available on the mount so that the
actual
mount voltage could be measured. I don't know of an easy way to measure
the
mount voltage on the mount side of the power connector. Measuring at
that
point is important because that power connector can sometimes fit
loosely
which adds resistance with the attending voltage drop.

Richard

At 06:00 PM 11/2/2007 -0400, you wrote:

And voltage drop may be an issue for a long run. The only way to know
for
sure is to take a reading at the mount end.

Steve

_____

From:
<mailto:ap-gto%40yahoogroups.com><mailto:ap-gto%40yahoogroups.com>ap-gto@...
<mailto:ap-gto%40yahoogroups.com>
[mailto:ap-gto@... <mailto:ap-gto%40yahoogroups.com> ] On
Behalf Of
<mailto:chris1011%40aol.com><mailto:chris1011%40aol.com>chris1011@...
<mailto:chris1011%40aol.com>
Sent: Friday, November 02, 2007 3:51 PM
To:
<mailto:ap-gto%40yahoogroups.com><mailto:ap-gto%40yahoogroups.com>ap-gto@...
<mailto:ap-gto%40yahoogroups.com>
Subject: Re: [ap-gto] Effect of temperature on backlash

In a message dated 11/2/2007 2:34:57 PM Central Daylight Time,
reseavey@verizon. <mailto:reseavey%40verizon.net> net writes:

The following, winter when the temperature was about 5F, the
engagement of

the RA worm and worm wheel seemed to be much tighter; in fact I had
to
re-adjust the worm mesh so that the RA motor wouldn't make strange
noises
while slewing.
I think you might have seen the effect of thickening of the grease, not
worm

mesh.

Rolando

**************************************
See what's new at
<<http://www.aol.>http://www.aol.>http://www.aol.
<<http://www.aol.com>http://www.aol.com
<http://www.aol.com> > com















To UNSUBSCRIBE, or for general information on the ap-gto list
see
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