HEQ5 belt drive kits

[m37]

Hi all

I've been reading with much interest the threads on belt mods for the HEQ5 mount. I am looking at this one 

http://www.beltingonline.com/eq5-telescope-belt-mod-drive-kit-12097?zenid=mjbk8po2bfqdn46ug9efb4uvo4

and just wondering if anyone knows:

1. Would this invalidate the warranty on my mount? (I could check this with FLO I guess...)

2. Would replacement belts be easy enough to find?

3. What is the life expectancy of the belts?

4. Can I put the original gearing back in place?

cheers

Christoph (eager to get rid of handset!!!)

[m.tweedy]

try this one.

http://rowanastronomy.com/productsa1.htm#heq5beltkit

the heq6 ones are very good and no tinkering with handset. 2 and 4 yes. 3. replacement belts can be bought but should last a LOOOOOOOOOOOOONG time.

1 . dont know answer

[JamesF]

This is on my list of things to do with mine though I've not got so far yet.  If the mount is mainly for visual use and it's desirable to leave the handset working then I'd be tempted to go with one that preserves the original gear ratios.  For imaging I think I'd go with the kit that changes the ratio to 4:1 (I think) as EQMOD can handle the altered ratios and I believe the simpler gear ratios should make PEC simpler.

James

[m37]

Cheers guys, will look into that a bit more. Lots of cloud = lots of potential for tinkering

[JamesF]

Cheers guys, will look into that a bit more. Lots of cloud = lots of potential for tinkering

Quite so.  This afternoon I have been making a new white light solar filter on the grounds that any additional cloud that arrives as a result will be barely noticeable

James

[sbooder]

The Rowan one does allow the HC to still be used, which gives you the best of both the HC and EQMOD worlds.

[chrisshillito]

The Rowan one does allow the HC to still be used, which gives you the best of both the HC and EQMOD worlds.

The price you pay for sticking with a handcontroller compatible gear ratio is a Periodic Error signal that is not truely periodic over a single worm period. So while you may get the 'best of both worlds' in so far as you can easily switch between handcontroller and EQMOD, you won't get the best PEC performance possible. Quite how important PEC, EQMOD or the handcontroller is will vary from user to user.

Chris.

[sbooder]

The price you pay for sticking with a handcontroller compatible gear ratio is a Periodic Error signal that is not truely periodic over a single worm period. So while you may get the 'best of both worlds' in so far as you can easily switch between handcontroller and EQMOD, you won't get the best PEC performance possible. Quite how important PEC, EQMOD or the handcontroller is will vary from user to user.

Chris.

Most of us with non permanent setups do not even bother with PEC, it a time consuming a pointless pursuit as we would have to perform it every time and not use a replay.  I tend to use PAE more.

[chrisshillito]

Of course it is up to each individual to decide what is worth bothering with within the context of their own astronomy. However using PEC on a non permamently sited mount is actually no more hassle than on a permanently sited one. You only have to park to retain PEC synchronisation - it doesn't matter if you then slacken clutches or re-site the mount. Even if you forget to park there is a mechanism with EQMOD to resynch the encoder/worm position, you only need to find a way to index the worm shaft/pulley whilst at the home position (or indeed any other conveinent park position).

With the later test releases of EQMOD the capture of PE and generation of PEC has become much easier and can be done in the background whilst guiding/imaging.

Just because most folks don't bother with PEC doesn't necesarilly mean it has no value - it could be those folks are missing out on a potentially useful technique, particularly if imaging at longer focal lengths or on targets where guide exposures are long.

Chris.

[sbooder]

Of course it is up to each individual to decide what is worth bothering with within the context of their own astronomy. However using PEC on a non permamently sited mount is actually no more hassle than on a permanently sited one. You only have to park to retain PEC synchronisation - it doesn't matter if you then slacken clutches or re-site the mount. Even if you forget to park there is a mechanism with EQMOD to resynch the encoder/worm position, you only need to find a way to index the worm shaft/pulley whilst at the home position (or indeed any other conveinent park position).

With the later test releases of EQMOD the capture of PE and generation of PEC has become much easier and can be done in the background whilst guiding/imaging.

Just because most folks don't bother with PEC doesn't necesarilly mean it has no value - it could be those folks are missing out on a potentially useful technique, particularly if imaging at longer focal lengths or on targets where guide exposures are long.

Chris.

But that does not take into consideration dismantling and rebalancing where the scope and counter weights will not be in the same position every time. 

Plus I am not sure how having the belt conversion at the same ratio will affect the worm at all the rotation on the motors stays the same?

[1parsec]

Plus I am not sure how having the belt conversion at the same ratio will affect the worm at all the rotation on the motors stays the same?

Hi Simon,

I think the only time you need a 4:1 ratio is if the motor pulley is running eccentrically which can then be corrected by EQMOD.

If the motor pulley is machined accurately and runs true any error contributed from it is insignificant and the standard 9:47 ratio will perform as well as 4:1

Dave.

[chrisshillito]

The position of the scope and counterweights will not affect the periodicity of the periodic error - maybe the amplitude.  Usually majority of PE comes from eccentricities in the worm, worm gear, gear teeth, pulleys and support bearings, all of which remain the same. It may well be that PEC on a permanently sited/equipped mount performs better over many sessions but regardless of this a non permanent mount running will still track better with PEC applied than with it disabled.

If I recall correctly the HEQ5 gearing is by default 47:9 so  the stepper pulley rotates 47 times in order for the worm to rotate 9 times. 47 and 9 have no common factors and as the stepper pulley error is modulated by the worm errors the true period of the periodic error for such a system is 9 worm cycles! Neither EQMOD or the handcontroller have a PEC mechanism capable of supporting such a long period, and even if it had few would spend that much time recording PEC anyhow. Use a 4:1 ratio (or 5:1, 6:1) and the period of the stepper pulley becomes a harmonic of the worm so the resulting modulated waveform can be accurately captured withing the period of a single worm cycle.

For me the belt mod of my EQ6Pro was simply a means to change the gearing to one that offered the best possible PEC performance. I would not have considered it worth it without the gear change - but that is just a personal view and I appreciate others use their equipment differently and have different aims.

Chris.

[lensman57]

Hi all

I've been reading with much interest the threads on belt mods for the HEQ5 mount. I am looking at this one 

http://www.beltingonline.com/eq5-telescope-belt-mod-drive-kit-12097?zenid=mjbk8po2bfqdn46ug9efb4uvo4

and just wondering if anyone knows:

1. Would this invalidate the warranty on my mount? (I could check this with FLO I guess...)

2. Would replacement belts be easy enough to find?

3. What is the life expectancy of the belts?

4. Can I put the original gearing back in place?

cheers

Christoph (eager to get rid of handset!!!)

Hi,

I just managed to mod my HEQ5 Pro with a kit from Rowan engineering. I have to wait untill I image with it but first impressions are very good. They dispatched  the kit within 24 hours even though I ordered just after boxing dayand I got it on  SAT   morning. Excellent printed instructions, written in English that we all speak and read. Well packed and labelled including the  Allen keys, just in case you don not the right ones, all is needed is a phillips screw driver about an hour of daylight. The pinion extractiotool is necessary if you are not into model engineering butthe cost was reasonable. £105.00 including postage. Most importantly it retains the use of the SynScan handset which I use for now untill get the chance to get the EQMOD, CDC going.Hope this helps.

Regards,

A.G

[m37]

Hi,

I just managed to mod my HEQ5 Pro with a kit from Rowan engineering. I have to wait untill I image with it but first impressions are very good. They dispatched the kit within 24 hours even though I ordered just after boxing dayand I got it on SAT morning. Excellent printed instructions, written in English that we all speak and read. Well packed and labelled including the Allen keys, just in case you don not the right ones, all is needed is a phillips screw driver about an hour of daylight. The pinion extractiotool is necessary if you are not into model engineering butthe cost was reasonable. £105.00 including postage. Most importantly it retains the use of the SynScan handset which I use for now untill get the chance to get the EQMOD, CDC going.Hope this helps.

Regards,

A.G

Thanks for that mate, very helpful info.

Sent from my Nexus 7 using Tapatalk 4

[TimC]

With the later test releases of EQMOD the capture of PE and generation of PEC has become much easier and can be done in the background whilst guiding/imaging.

Chris.

Hi Chris - I was curious about this comment.  How does one capture PE and generate PEC while guiding/imaging and can you average multiple cycles this way?

[chrisshillito]

Hi Chris - I was curious about this comment. How does one capture PE and generate PEC while guiding/imaging and can you average multiple cycles this way?

EQMOD simply keeps tags on the RA motor position. It knows how this would vary if traking at sidereal so any extra variation must be due to a guiding correction (doesn't matter what type of guiding you use, pulse, st-4 or even manual) . By analysing this correction data, any periodic signals can be extracted and thus the PE of the RA axis determined. EQMOD will log this data to file and can additionally combine multiple worm cycles of data (up to 5) to build a PEC file that is also saved to file and optionally loaded/executed.

There is a dedicated interface within EQMOD to setup, initiate and monitor the process of the AutoPEC process.

Please note this feature is currently only available in the test release made to the EQMOD yahoo group. Within the files/documentaion section of that group you will also find an updated VS-PEC document that includes details of the new user interface.

Chris.

[sbooder]

EQMOD simply keeps tags on the RA motor position. It knows how this would vary if traking at sidereal so any extra variation must be due to a guiding correction (doesn't matter what type of guiding you use, pulse, st-4 or even manual) . By analysing this correction data, any periodic signals can be extracted and thus the PE of the RA axis determined. EQMOD will log this data to file and can additionally combine multiple worm cycles of data (up to 5) to build a PEC file that is also saved to file and optionally loaded/executed.

There is a dedicated interface within EQMOD to setup, initiate and monitor the process of the AutoPEC process.

Please note this feature is currently only available in the test release made to the EQMOD yahoo group. Within the files/documentaion section of that group you will also find an updated VS-PEC document that includes details of the new user interface.

Chris.

Funny you should bring this up.  I have just finished hunting for discussions from around the web on guiding Vs PEC with the EQ6 with original ratio.  Mainly because I wanted to know if for a temp setup it would be better to guide or use PEC.  From what I have read the majority seem to be for guiding (of course with perfect polar alignment and no cone error).

[TimC]

Hi Chris - I was curious about this comment.  How does one capture PE and generate PEC while guiding/imaging and can you average multiple cycles this way?

Wow! I am behind the times.  Just getting back into this after a 2-3 year hiatus and I didn't realize my EQMOD version was out of date (124g).  I forgot that the latest releases are on the yahoo group... it's all coming back to me now .  Just read some of the documentation on Autopec and sounds very interesting.  Will be fun to play with at least.  thanks!

Tim

[chrisshillito]

Funny you should bring this up.  I have just finished hunting for discussions from around the web on guiding Vs PEC with the EQ6 with original ratio.  Mainly because I wanted to know if for a temp setup it would be better to guide or use PEC.  From what I have read the majority seem to be for guiding (of course with perfect polar alignment and no cone error).

If considering Guiding Vs PEC then surely guiding wins every time. PEC on these mounts is unlikely to give you a sufficient exposure length for imaging deep space objects. For long exposure imaging you are always going to need to guide. PEC only removes periodic errors - but there can be plenty of sources of non periodic errors,  or very long period errors that for effectively appear non-periodic over your imaging session. There are also linear drift effects caused by slight polar miss-alignment (perfect polar alignment is rarely achieved or indeed necessary) or flexure that will also need correction and for all of this you really need a closed loop system i.e. guiding.

To my mind, for this class of mount at least, PEC really only adds anything when used in combination with guiding. PEC keeps the mount roughly on track during the guide exposure, and will effectively act to adjusts the guiding signal using its knowledge of what is about to happen. Guiding can correct those non-periodic errors the PEC doesn't cover as well as mopping up any residual periodic errors (a PEC Profile is usually an average response so will never provide a perfect fit).

Chris.

[bodtwo]

Curious newbie, what's the advantage of upgrading the belts?

[JamesF]

Curious newbie, what's the advantage of upgrading the belts?

It's more of a replacement than an upgrade.  Normally the RA and DEC axes are driven by the motors through a gear train that has unavoidable backlash.  Replacing the gears with a belt reduces the backlash meaning that the mount is more responsive and guiding/tracking can be more accurate.

James

[Spookylight]

It also makes it a lot quieter and removes those awful sounding chatter mesh sounds from the inertia.

[lensman57]

It also makes it a lot quieter and removes those awful sounding chatter mesh sounds from the inertia.

Hi,

I have changed the HEQ5 to belt drive and I still have the use of the handset. Quieter it certainly is and the grinding  noise is somewhat reduced too. I have not noticed any improvements in guiding accuracy as the imaging conditions have neither been present or have been awful to the least. I am waiting for one of those rare clear nights when I can do 15~20 minutes exposures and see what happenes. I am not going to do a PEC analysis either. The Rowan kit is excellent though.

Regards,

A.G