EQ6 dec axis 'tight'

[tooth_dr]

11 minutes ago, newbie alert said:

What's the red grease please?

It's synthetic grease with added teflon, used for bikes. 

[LightBucket]

Just now, tooth_dr said:

It's synthetic grease with added teflon, used for bikes. 

Hmmmm, bike grease.... not a good idea.... well from what I have read anyway.

[tooth_dr]

The same stiffness is felt with bearings removed, with just the brass cog inserted into the DEC head/shaft.  I can't do much about that ?

[ronin]

Where the rod for the weights slides in there is a "cone" cover. This cover effects the Dec movement.

You can undo the 3 grub screws a little  - do not take them out as the fall into the over. The unscrew the conical cover a little - sort of 5mm rotation. Then check the Dec movement by hand for tightness.

It seems that when the cover is screwed on it pulls the Dec unit and this gets tight against something - not sure what exactly and I do not intend to pull my mount apart to find out.

The other one I found is that when you retighten the 3 grub screws do the first do it just makes contact, then do the next the same then the third, then go round again and add a further small increase - sort of one flat or less of the allen key on each grub screw. Looking at the arrangement it seems possible to tighten the first one too much and that could push the Dec shaft down at a slight angle, thus affecting the rotation.

[LightBucket]

1 minute ago, ronin said:

Where the rod for the weights slides in there is a "cone" cover. This cover effects the Dec movement.

You can undo the 3 grub screws a little  - do not take them out as the fall into the over. The unscrew the conical cover a little - sort of 5mm rotation. Then check the Dec movement by hand for tightness.

It seems that when the cover is screwed on it pulls the Dec unit and this gets tight against something - not sure what exactly and I do not intend to pull my mount apart to find out.

The other one I found is that when you retighten the 3 grub screws do the first do it just makes contact, then do the next the same then the third, then go round again and add a further small increase - sort of one flat or less of the allen key on each grub screw. Looking at the arrangement it seems possible to tighten the first one too much and that could push the Dec shaft down at a slight angle, thus affecting the rotation.

Yes we have been through all this earlier in the thread, his problem is the same with all that removed,

When you tighten the cone cover you talk about, you are pushing on the chamfered bearing, (which is its purpose) which is fine as long as it is not too tight, just tight enough to pull all together, and to take all the slack out of the bearings plus another 1/8 of a turn...there is no need to do up as tight as it will go...

[tooth_dr]

Should the brass cog/gear be stiff to turn in the metal housing I guess is what I'm asking!?

edit: rightly or wrongly I've concluded that this stiffness is not relevant to the functioning of the mount since when the clutch is tightened this movement doesn't apply?

[tooth_dr]

Figures from my calculations, only to 0.1mm accuracy:

so I need a 0.4 or 0.5mm shim

 

[tooth_dr]

The shim that's in is 0.5mm so I'm good with shims I hope:

 

[spillage]

I know its a pain to do but if you remove the clutch and the disc then how does the brass gear feel when its put back together. If its all slackened off the dec should be really loose.

shims look good so that's one idea put to bed.

[tooth_dr]

2 minutes ago, spillage said:

I know its a pain to do but if you remove the clutch and the disc then how does the brass gear feel when its put back together. If its all slackened off the dec should be really loose.

shims look good so that's one idea put to bed.

What do you mean? Sorry!

[tooth_dr]

All the bearings run really smooth, tried each one of the dec shaft, the only issue is the brass cog seems tight in the dec housing/bell. This is causing it to not spin when the clutch is disengaged.  Hopefully I'm right to assume this is irrelevant when mount in use as clutch is engaged? So just makes it harder to balance? 

[spillage]

33 minutes ago, tooth_dr said:

What do you mean? Sorry!

sorry if you remove the clutch does this help?

[tooth_dr]

18 minutes ago, spillage said:

sorry if you remove the clutch does this help?

 

Even with no clutch screwed onto the housing it's stiff! I'll reassemble tomorrow and test it out and see how it goes. I've a good idea how it all needs to be tightened. To be honest it looks like I had it right first time but does no harm to take apart and check all again. Thanks again Spillage. 

[spillage]

No problem at all. More than happy to help as much as I can.

[tooth_dr]

Back on the pier now and although not tested properly, it's slewing and sounds slightly quieter than before. It gives clear skies tonight so I'll do my first (I know) proper PA, and see how it tracks. 

 

Thanks to to all for your input. I actually ended up buying two new bearings 608 2RS for the RA worm gear as there was a slight hold when I rotated the gear at one point. And to be honest the new ones are so much smoother I'll probably end up changing them all next time I strip it (c. 2027).

 

Cheers all!

[Ishan Mair]

18 hours ago, tooth_dr said:

All the bearings run really smooth, tried each one of the dec shaft, the only issue is the brass cog seems tight in the dec housing/bell.

With the nut and tapered bearing  at the end removed, the brass cylinder will be tight. Because it supports the axis weight in the housing and this causes friction. Put the bearing and tighten the nut slowly and carefully by one turn at a time. Once it starts slightly pressing the tapered bearing, the axis rotation will get smoother. this is because now the bearing will also support the axis in the housing but its smoother than the brass cylinder. You must tighten the Allen set screws on the nut to fix it on the shaft before you check rotation of axis. DONT FORGET TO LOOSEN THE ALLEN SET SCREWS BEFORE TRYING TO ADJUST THE NUT OR THE THREADS MAY GET DAMAGED. Do such iterations - loosen screws, rotate nut, tighten screws, check axis rotation, repeat.  In my experience axis rotation will get smoother as you tighten the nut until a limit. Then the nut will press hard against the bearing and housing so axis might get stiff. Keep tightening the nut until the manual dec axis rotation starts getting tighter.

I had the same issue with heq5 pro ra axis earlier. Everyone says loosening nut makes axis rotation easy. Nope. Mine just shows opposite. I had just the same problem. Ra axis rotation was quite stiff. It doesn't affect mount rotation by motors directly. But makes balancing a little inaccurate (not that mount becomes a showpiece ?) . It will still track well.

[LightBucket]

40 minutes ago, Ishan Mair said:

With the nut and tapered bearing  at the end removed, the brass cylinder will be tight. Because it supports the axis weight in the housing and this causes friction. Put the bearing and tighten the nut slowly and carefully by one turn at a time. Once it starts slightly pressing the tapered bearing, the axis rotation will get smoother. this is because now the bearing will also support the axis in the housing but its smoother than the brass cylinder. You must tighten the Allen set screws on the nut to fix it on the shaft before you check rotation of axis. DONT FORGET TO LOOSEN THE ALLEN SET SCREWS BEFORE TRYING TO ADJUST THE NUT OR THE THREADS MAY GET DAMAGED. Do such iterations - loosen screws, rotate nut, tighten screws, check axis rotation, repeat.  In my experience axis rotation will get smoother as you tighten the nut until a limit. Then the nut will press hard against the bearing and housing so axis might get stiff. Keep tightening the nut until the manual dec axis rotation starts getting tighter.

I had the same issue with heq5 pro ra axis earlier. Everyone says loosening nut makes axis rotation easy. Nope. Mine just shows opposite. I had just the same problem. Ra axis rotation was quite stiff. It doesn't affect mount rotation by motors directly. But makes balancing a little inaccurate (not that mount becomes a showpiece ?) . It will still track well.

Sorry, but totally disagree with your first part of your post, you should NOT tighten the locking collar until the DEC axis gets tight,  you only need to tighten enough to take out the slack of the bearings, and maybe 1/8 of a turn more, that’s all it needs, anymore and you are just putting excess pressure on the tapered bearing, which is not needed.

[tooth_dr]

Good to hear different inputs! I sincerely appreciate all that advice 

[spillage]

Well at least you are now fully qualified in stripping and reassembling a eq6 mount for when you install a belt kit

[Ishan Mair]

8 hours ago, LightBucket said:

Sorry, but totally disagree with your first part of your post, you should NOT tighten the locking collar until the DEC axis gets tight,  you only need to tighten enough to take out the slack of the bearings, and maybe 1/8 of a turn more, that’s all it needs, anymore and you are just putting excess pressure on the tapered bearing, which is not needed.

oh yes agree. Sorry for that mistake. Follow Lightbucket's advice. ?

EDIT:

Quote

With the nut and tapered bearing  at the end removed, the brass cylinder will be tight. Because it supports the axis weight in the housing and this causes friction. Put the bearing and tighten the nut slowly and carefully by one turn at a time. Once it starts slightly pressing the tapered bearing, the axis rotation will get smoother. this is because now the bearing will also support the axis in the housing but its smoother than the brass cylinder. You must tighten the Allen set screws on the nut to fix it on the shaft before you check rotation of axis. DONT FORGET TO LOOSEN THE ALLEN SET SCREWS BEFORE TRYING TO ADJUST THE NUT OR THE THREADS MAY GET DAMAGED. Do such iterations - loosen screws, rotate nut, tighten screws, check axis rotation, repeat.

This part is correct. Now I'm not a mech. expert but that's what I had observed with my mount. Please correct me if I'm wrong.

[wimvb]

On 2017-09-15 at 11:34, tooth_dr said:

How do I go about testing amps being drawn?  Connect a multimeter across the terminals when its slewing?  Also the axis appears to be stiff when the worm gear is not in contact as far as I can see, but will double check later.

Just came across this part of your thread, and nobody seems to have addressed it.

To measure voltage, you put the volmeter across the power connectors (parallell), such that you get one closed circuit with power supply and mount, and one with power supply and voltmeter.

If you want to measure current draw, you need to connect the amp meter to the power supply (+ terminal of supply to + of amp meter) and + of mount power connector (- of amp meter to + of power connector). The amp meter is in series with the mount. The - of the mount power connector is connected to the - sude of the battery. You shoul have one closed circuit: + power supply ... amp meter ... mount ... - power supply.

If you connect an amp meter across terminals, you will short the power supply.

When the mount starts to draw amps from a power supply (especially a battery), you can expect a slight drop in voltage. Measuring voltage, and looking for that drop, is usually easier than inserting an amp meter in the circuit. My advice is to use that first, even if measuring amps is more accurate.

[tooth_dr]

Thanks @wimvb

ive a small voltage meter attached, I'll analyse it closely later. 

 

Can someone please tell me if this is correct. If I remove the worm gear and reassemble the DEC shaft, then engage the clutch, this is a true representation of the resistance/stiffness/binding of the shaft in its bearings.

IS THIS WRONG? --> The stiffness I'm experiencing is to do with the DEC bell housing being tight on the big brass cog. This isn't the stiffness that is experienced by the worm gear/ motor etc when the clutch is engaged since the DEC bell housing / big brass cog move as one.

I feel incredibly thick here guys by the way ?

[Ishan Mair]

3 hours ago, tooth_dr said:

The stiffness I'm experiencing is to do with the DEC bell housing being tight on the big brass cog. This isn't the stiffness that is experienced by the worm gear/ motor etc when the clutch is engaged since the DEC bell housing / big brass cog move as one

Yes correct. Balancing can be affected by that stiffness. So it could be way off when you think its balanced. That's the only thing this stiffness will affect. You said you will try it out. How did that  go?

 

[Ishan Mair]

4 hours ago, wimvb said:

When the mount starts to draw amps from a power supply (especially a battery), you can expect a slight drop in voltage. Measuring voltage, and looking for that drop, is usually easier than inserting an amp meter in the circuit. My advice is to use that first, even if measuring amps is more accurate.

Wonderful!!!! That's something I knew theoretically. Never thought could use it this way.

[tooth_dr]

57 minutes ago, Ishan Mair said:

Yes correct. Balancing can be affected by that stiffness. So it could be way off when you think its balanced. That's the only thing this stiffness will affect. You said you will try it out. How did that  go?

 

Thanks, I'll try it tonight when I get a chance. Although balsnce could be off, I'm familiar with where my scopes/camera setup balances normally so i knows it's close but it maybe be indeed upsetting the guiding.