HEQ5 Pro bearings/plastic washers

[AdamSutton]

Hi all,

I have a secondhand HEQ5 pro, that I bought without knowing much!  I have since learned it needed a fair bit of TLC and over two years of ownership have stripped it down twice, the first time got things moving properly as it was stalling a lot, the second time after more reading I got things much improved and I used better grease.

It still isn't great though and I think the bearings could do with being changed, everything just feels too tight though I know I haven't over tightened anything.  I had contacted darkframe last week but not heard anything back, and am also thinking with the age of the mount rather than spend out money to that degree to just have a go at changing the bearings myself.

I have found various posts on the bearings, but does anyone have a definitive shopping list of what is required to replace all HEQ5 Pro bearings?  The other thing I have noticed is that from astro-baby's guide it mentions plastic washers on the RA and DEC axis, and I know for a fact that these are missing on my mount, were they always provided and present?  If so does anyone know if replacements are available anywhere?

Thanks!

[drjolo]

In HEQ5 there are following bearings:

• 6x  6006 2RS - these are main RA and Dec shafts bearings
• 2x  30205  - tapered rolled bearings
• 4x  689z  (or 618/9) - these are small bearings for worm shafts

I used EZO bearings for worm and SKF/Timken for others.

As for plastic washers - these are used for precise placement of worm at worm wheel. There probably should be some washers already, because if you want to replace them, you need to use new one with the same thickness. I cut out proper dimension washers from teflon foil.

Edited March 28, 2018 by drjolo

[AdamSutton]

21 minutes ago, drjolo said:

In HEQ5 there are following bearings:

• 6x  6006 2RS - these are main RA and Dec shafts bearings
• 2x  30205  - tapered rolled bearings
• 4x  689z  (or 618/9) - these are small bearings for worm shafts

I used EZO bearings for worm and SKF/Timken for others.

As for plastic washers - these are used for precise placement of worm at worm wheel. There probably should be some washers already, because if you want to replace them, you need to use new one with the same thickness. I cut out proper dimension washers from teflon foil.

Thanks drjolo, that is a massive help!

[spillage]

You might find if you regrease the larger bearings that they will be okay and just replace the worm bearings. If you use astrobaby's hypertune sectioin (not sure if its on the heq5 but is on the neq6 section) then you will know what thickness of teflon to order. I also found if you do not have the washer on the top of the brass worm gear then the axis will be too tight as the outer collar can rub against the mount.

 

ps I have asked about teflon washers here before in the wanted section and a very kind member sent me a few for free. I should have some hanging around. If you let me know what sizes you need I can try to find them and you can have them foc if I have the ones you need.

[AdamSutton]

41 minutes ago, spillage said:

You might find if you regrease the larger bearings that they will be okay and just replace the worm bearings. If you use astrobaby's hypertune sectioin (not sure if its on the heq5 but is on the neq6 section) then you will know what thickness of teflon to order. I also found if you do not have the washer on the top of the brass worm gear then the axis will be too tight as the outer collar can rub against the mount.

 

ps I have asked about teflon washers here before in the wanted section and a very kind member sent me a few for free. I should have some hanging around. If you let me know what sizes you need I can try to find them and you can have them foc if I have the ones you need.

Thanks spillage.  I will check out the neq6 guide, not sure of the size of the washers as they are missing but I will see what I can find and may be in touch.  Really appreciate the offer.

[Stub Mandrel]

If they are using washers to set the clearance for a worm gear, they will almost certainly need to be selected to suit the individual setup - if they could machine it accurately enough to always need the same size shim, they could do it accurately enough not to need a shim...

You can get thin shim in many materials and build up the exact thickness that gives you minimum backlash with no binding.

I plan to do this with my EQ3 to replace the 'push-pull' screw adjustment.

[newbie alert]

Look up these videos that Martin has done with his eq6..should be similar ish to a degree..this is part 4 but I'm sure you can find the others..

 

[AdamSutton]

Update:  I feel a bit of a fool.  As the weather is rubbish this bank holiday, I just spent a couple of hours fully dismantling the mount and the washers were there. Doh!

Seems to be a lot of play in the tapered bearings, so this is going to be interesting to see how things work out.  Going to order the bearings this week and hopefully get things back together next weekend.

Thanks again for the replies all.

[KemalOz]

if you can find any you might wanna try angular contact bearings on the worm. They are both good for radial load as well as axial. I couldn't try them on my mount because they only exist in certain sizes.

[Stub Mandrel]

5 hours ago, AdamSutton said:

Seems to be a lot of play in the tapered bearings

The end loading of taper bearings is critical to their performance. For this application you need the absolute minimum of preload, just enough to make sure they don't come loose when you mount a telescope. I would suggest doing up the adjusting nut until all shake disappears and then just a tiny fraction of a turn, perhaps 10-15 degrees.

<edit> with taper rollers in this application, I would be tempted to us no preload at all unless you can detect movement in use.

Those taper rollers should NOT need replacing at any point in the lifetime of the mount, unless they get corroded. Those bearings arte big enough to take the loads associated with a good sized lathe and would be expected to last millions of revolutions under difficult conditions and heavy loads while keeping their basic accuracy. A telescope mount might make hundreds of revolutions in its lifetime.

Edited April 2, 2018 by Stub Mandrel

[Thalestris24]

Here's Astrobaby's wonderful heq5 strip down and adjustment guide  

HTH

Louise

[AdamSutton]

On 02/04/2018 at 22:35, Stub Mandrel said:

The end loading of taper bearings is critical to their performance. For this application you need the absolute minimum of preload, just enough to make sure they don't come loose when you mount a telescope. I would suggest doing up the adjusting nut until all shake disappears and then just a tiny fraction of a turn, perhaps 10-15 degrees.

<edit> with taper rollers in this application, I would be tempted to us no preload at all unless you can detect movement in use.

Those taper rollers should NOT need replacing at any point in the lifetime of the mount, unless they get corroded. Those bearings arte big enough to take the loads associated with a good sized lathe and would be expected to last millions of revolutions under difficult conditions and heavy loads while keeping their basic accuracy. A telescope mount might make hundreds of revolutions in its lifetime.

I hear you, but I am just not convinced with what has been done to this mount in the past and it is at least 10 years old.  One of the odd things I have found is that one of the worms has 2 bearings on one end of the shaft! so there are five in total.  My thinking is that if I have everything apart I may as well replace them all with higher quality ones.

[AdamSutton]

19 hours ago, Thalestris24 said:

Here's Astrobaby's wonderful heq5 strip down and adjustment guide  

HTH

Louise

Thanks Louise, I wouldn't be attempting this without that great guide 

[spillage]

Looks like a good time to install the belt mod??

[AdamSutton]

12 hours ago, spillage said:

Looks like a good time to install the belt mod??

I was tempted, but when looking into it the older HEQ5 like mine also require drilling to get the new pinion shafts to fit.  I may come back to that later.

[Dan13]

On 02/04/2018 at 16:58, AdamSutton said:

Update:  I feel a bit of a fool.  As the weather is rubbish this bank holiday, I just spent a couple of hours fully dismantling the mount and the washers were there. Doh!

Seems to be a lot of play in the tapered bearings, so this is going to be interesting to see how things work out.  Going to order the bearings this week and hopefully get things back together next weekend.

Thanks again for the replies all.

hi did you find the "clear washer" thats mentioned ? The one asteo baby says sits on top of the brass wirm gear. I have the two red ones but def can't find this clear one and now starting to worry