HEQ5 Pro Rowan Belt Mod

[juno16]

Good day all,

I plan to upgrade my HEQ5 soon (possibly as early as tomorrow) with adding the Rowan Belt kit.

I’ve watched several videos and the process seems fairly straightforward. I have also read post on astro forums about upgrade problems

Seems that I need to be careful with belt-pulley alignment and belt tension. Also, I read that good neutral balance is necessary.

I am sure that there are some here on the forum that has performed this modification.

Any tips or guidance?

 

 Thanks, Jim

[Padraic M]

Good luck with that upgrade Jim; it's relatively straightforward, and well worth doing. You have nailed the main areas that can cause problems. Belt alignment is important as is belt tension. There are plenty of posts offering guidance on how to do both here and on YouTube. If you've bought the gear puller, removing the old gears will not be an issue. You will also need to spend some time resetting the backlash on your worm gear when you're finished. Neutral balance is important, but that's not specifically related to the belt mod - you need to do that anyway if there's any weight in your payload.

Don't overtighten any bolts (especially those holding the motors to the chassis) as the threads in the aluminium body can be stripped easily.

Be careful removing the wiring looms as I've heard of people lifting the connectors off the motherboard.

[City9Town0]

Agree with Padraic re gear puller... take your time and take photos as you go to help when putting it back together.

Re-setting the worm backlash took longer than the belt-mod! (but was done, again following guides).

[juno16]

@Padraic M

@City9Town0

Thanks to you both for the guidance. 
I hadn’t considered the backlash and thanks for that too! 
Need to go over the backlash adjustment procedure a few times first. 
I did order the pinion gear puller.

Photos are a great idea!

 Thanks for the tips!

 

Jim

 

 

[KP82]

I did the upgrade myself also when I had my HEQ5. It took me a whole afternoon (4 - 5 hours). While all the points raised above are valid, I'd also like to say that pinion gear removal was not as easy as the instructions might suggest even with the original pinion extraction toolkit.

Edited March 18, 2022 by KP82

[juno16]

11 hours ago, KP82 said:

I did the upgrade myself also when I had my HEQ5. It took me a whole afternoon (4 - 5 hours). While all the points raised above are valid, I'd also like to say that pinion gear removal was not as easy as the instructions might suggest even with the original pinion extraction toolkit.

I really appreciate your input KP82.

I did the upgrade this morning. Took 2.5 hours and some of that was loosing some parts due to droppage. Also, the DEC idler shaft was extremely tight  in the bore and I had to drive it in and out many times so that it was movable by hand. Other than that, it went smoothly.

I have only adjusted the DEC worm so far and I tried many times to get zero backlash ( I used a long dovetail bar to check it), but never got it to zero without binding the axis. I hope that it is as good or better than before. 
I also backed off in the DEC collar to still allow zero up/down clearance, but to release some friction on the DEC axis to allow easier balancing. 
Still need to adjust the RA worm and give it a trial run.

It is really nice and quiet!

 Thanks for everyone’s input!

 

Jim

[juno16]

I just want to report back on results that I have seen after the Rowan belt upgrade so far. 

The moon has been blowing out the sky the past few days, but after doing the Rowan belt mod and then adjusting the DEC worm I also added a "back off" of the DEC bearing collar to allow easier DEC balancing. There is still a good bit of RA worm backlash, but I did not want to introduce too many variables. I decided to give it a go with the new changes. 

Very pleased with what I have seen so far. I set up tonight just to test things out. Total RMS guiding error averaged between 0.5-0.6 no matter what part of the sky I was guiding in. I would previously get numbers like this only in the northern part of the sky and only after awhile of settling down. I tried north, east, and southern targets with the same 0.5-0.6 average total rms guiding error in PHD2. 

PHD2 reported backlash at 200 ms compared to 3 seconds previous to the adjustment. Huge difference!

I hope to get out later this week to image the Markarian's Chain, then on to the RA backlash adjustment. 

Just want to report the substantial improvement note so far.