Heq5 Pro RA tight after Hyperune

[Shanorton (Shannon)]

Hey all, I recently followed an online video on hypertuning my Heq5 Pro where I did a full tear down, replaced all bearings and put back together. Everything went well, the mount guides a fair bit better than pre hypertune, sitting around .35 - .60 with a 8" reflector. The problem I now have is if I loosen the RA clutch it is tight and seems to 'drag' when turning the axis while trying to balance. I pulled it apart again and narrowed the problem to the RA brass worm gear binding on the inside of the housing somehow. I put it back WITHOUT the brass worm gear in place and it was silky smooth, but back in its not good. I have sanded the worm gear with wet and dry paper and polished it with no change. I don't use any grease on the outside of the worm gear or in the housing, as this will effect the clutch. This tightness obviously doesn't effect the guiding because with the clutch engaged the brass worm stays in place.

Has anyone encountered this issue or something similar and know how to fix it? Did I somehow damage the brass worm gear or have I pushed it out of centre somehow causing it to rub on the inside of the housing? It seems to be worse when the rig is loaded up with scope and counterweights, but is still noticeable when nothing is on there.

Hoping someone can help! Thanks in advance!

[ChrisD (Chris)]

The first thing I would suspect is that there is not enough preload on the tapered bearing causing the RA shaft to move towards the casing when under load.

Try this. Without any scope or counterweights attached, extend the counterweight bar. Stand in front of the mount with the bar pointing down and push/pull the bar towards and away from you.

If you find any free play in the RA axis increase the preload on the tapered bearing using the slotted nut.

Chris

[Shanorton (Shannon)]

Originally Posted by ChrisD

The first thing I would suspect is that there is not enough preload on the tapered bearing causing the RA shaft to move towards the casing when under load.

Try this. Without any scope or counterweights attached, extend the counterweight bar. Stand in front of the mount with the bar pointing down and push/pull the bar towards and away from you.

If you find any free play in the RA axis increase the preload on the tapered bearing using the slotted nut.

Chris

Thanks for the reply Chris. I just tested this and there doesn't seem to be any play at all. I did play around with a few different tensions on the slotted nut when putting it back together and didn't seem to change much. Thanks

[ChrisD (Chris)]

ok, no freeplay.

I guess you've checked if the clutch is not dragging?

Maybe remove the clutch and brake button and see.

Chris

[Shanorton (Shannon)]

Originally Posted by ChrisD

ok, no freeplay.

I guess you've checked if the clutch is not dragging?

Maybe remove the clutch and brake button and see.

Chris

Thanks Chris, I have also tried with those removed too without much success. It's such an odd problem, I can't seem to figure out.

[ChrisD (Chris)]

Sounds like you've eliminated the obvious causes.

After I hypertuned my HEQ5 I found I was getting slight contact between the RA gear and the casing. I could hear a slight grinding when rotating the RA axis which got worse under load. Like you, I'd removed all that thick grease.
There was no obvious problems with the new bearings or my reassembly.

It was clear after working on the mount that it wasn't "high quality". My best guess was that the problem was the result of poor manufacturing and had always been there. The act of removing the thick grease made it apparent.

I identified the location from the visible scratch marks on the RA gear and I used abrasive to remove a small amount of the casing top edge and this fixed the problem.

Chris

[Shanorton (Shannon)]

Originally Posted by ChrisD

Sounds like you've eliminated the obvious causes.

After I hypertuned my HEQ5 I found I was getting slight contact between the RA gear and the casing. I could hear a slight grinding when rotating the RA axis which got worse under load. Like you, I'd removed all that thick grease.
There was no obvious problems with the new bearings or my reassembly.

It was clear after working on the mount that it wasn't "high quality". My best guess was that the problem was the result of poor manufacturing and had always been there. The act of removing the thick grease made it apparent.

I identified the location from the visible scratch marks on the RA gear and I used abrasive to remove a small amount of the casing top edge and this fixed the problem.

Chris

I'm getting the exact same noise that you describe. When rotating over the tight spot, it makes a slight grinding/binding noise almost like the sound of bad brakes on a bicycle. It looks like I need to pull it apart again and be a bit more aggressive with the sand paper on the inside of the casing, rather than just the worm gear itself. Thanks again for all of your suggestions and feedback - glad to know I'm not the only one that has had this issue.