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Losmandy's new high-speed motor

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#1 Raginar

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Posted 17 March 2013 - 06:08 PM

They're very VERY loud. I purchased one to replace my RA motor that I burned out after missing a limit. This thing is nearly 2-3x as loud as my declination motor. It's downright ridiculous.

On the plus side, it moves around 50# like there isn't anything on the mount.

#2 herrointment

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Posted 17 March 2013 - 08:55 PM

Why is this? You can buy motorized anythings and most I can think of, either in industrial or consumer applications are for the most part almost silent. Is it due to the huge speed differences between tracking and slewing?

#3 orlyandico

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Posted 17 March 2013 - 10:56 PM

the Mach1 is also surprisingly loud, louder than my CGEM.

it's probably the gearbox. reducing the periodic error in the gearbox means using a fine-toothed gear set with very tight tolerances. that tends to make it noisy..

#4 Raginar

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Posted 18 March 2013 - 09:37 AM

Orly,

You think if I bought McClaren gearboxes the noise would go down? It's like using a power drill.

#5 SteveProcter

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Posted 18 March 2013 - 09:53 AM

My friend has a new G-11 with the new motors installed. He also was very concerned about noise of the new high-torque motors. however, as we listened more carefully, we soon realised that the extra noise was emanating from the gearbox and not the motor itself. The higher torque of the new motors (the torque is supposedly higher than the Maxon motors) seems to be putting more strain on the gearbox and in my opinion the design of the gearbox is less than adequate. I previously changed the standard gearboxes on my MI-250 with the Maxon motors installed for their McLennan counterparts and the noise was reduced.

#6 SMigol

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Posted 18 March 2013 - 01:26 PM

You can set the max slew speed on the hand controller and it will make them a bit quieter at the expense of speed of movement.

#7 contraf15

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Posted 20 March 2013 - 11:24 AM

I completely disassembled the gearboxes on my new (in Jan) G11, cleaned them, and greased them with SuperLube before bolting them back together. The change in noise level when slewing the mount was astounding. It didn't even sound like the same mount, it was that much quieter. It is quite tolerable now, much quieter than my old CGEM (which wasn't the case before). Those gearboxes are ridiculously noisy without any modification.

Jeremy

#8 orlyandico

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Posted 20 March 2013 - 11:43 AM

Interesting...... my Mach1 is noisier than my CGEM, even when speed-reduced to 600X (the stock is 1200X).

But the CGEM gets noisier when the worm to worm wheel mesh is too tight. Maybe that's what happened Jeremy?

#9 contraf15

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Posted 20 March 2013 - 11:53 AM

Trust me, it was the gearboxes. After troubleshooting literally every component on this mount I have no doubt about the cause of the change in noise. I also did RA and DEC gearboxes at different times and was able to compare the slewing noise directly. Changing the worm mesh changes the pitch of the motor whine, but not the fast rattling noise of the gearboxes which on my mount ended up being noisier than the motors.

Jeremy

#10 Footbag

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Posted 20 March 2013 - 12:04 PM

I was surprised at how loud the Mach 1 motors are. Of course, I couldn't care less about the noise as long as they perform well.

#11 Startraffic

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Posted 22 March 2013 - 03:19 PM

Jeremy,
If you pack the gear boxes full of Lube, the noise is radically reduced.

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#12 Hilmi

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Posted 22 March 2013 - 11:15 PM

If you pack the gear boxes full of Lube, the noise is radically reduced.


Only for a while till the lube redistributes evenly. After that the noise will come back. Honestly I think the only long term solution is to reduce slew speed. Maybe a thin layer of rubber under the gearbox to dampen the vibrations, but I haven't tried that one.

#13 contraf15

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Posted 22 March 2013 - 11:23 PM

I only applied a thin layer of Superlube to the wheels inside the gearboxes. They aren't and have never been packed with grease, and they have been used more than enough to evenly distribute since I overhauled them. They're still just as quiet. I have some short slewing videos showing the difference, I'll put them online when I get a chance (currently traveling)

#14 Raginar

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Posted 23 March 2013 - 08:36 AM

Contra, I'll give that a run when I get a chance. Are you using the high-speed motors?

Chris

#15 David Pavlich

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Posted 23 March 2013 - 08:43 AM

I'm not sure that I get the reason for having high speed motors anyway. I have my MI250 slowed way down. I use it for imaging, but once in a while, I'll throw in an ep and view. With it slowed down, it takes, say, 15 seconds to get to an object instead of 10 seconds. :shrug: I would think that keeping the slew speed at a slower rate would reduce wear.

David

#16 Raginar

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Posted 23 March 2013 - 08:51 AM

David,

Honestly, I only got one because they don't see the normal motors anymore and I fried my RA motor not being careful with my safety limits. I agree there really isn't a 'point'. The only thing I thought after putting it on is that it probably works 'better' than the original motor would with a heavier load? So if/when I get a C14 for this mount, maybe it won't strain as much. :D

I think, later, I'll replace the gear boxes as suggested above. But for right now, it seems like the gear boxes are holding up find.

Honestly, if I could've bought an old one, I would've! 225 bucks is alot of money!

#17 neilson

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Posted 23 March 2013 - 08:53 AM

Hi,
I took each gearbox apart then cleaned and coated the teeth of each gear and axles with tripleguard, its
blue grease. Its very thick and made for the gearbox of outboard motors. I use it on everything in my mount. But I live where it gets hot in south Texas and regular grease melts. This does not.

This makes my mount very very quiet. This grease stays on the gears even after alot of use. I open it up and theres still grease on the teeth. I would only recomend it on the gearbox and maybe the worm gears but not on the bearings if you live in cold climates.
I mix triple guard and super lube for my bearings otherwise theres a little stiction when trying to balance my mount.

I have been using this on all my mounts for years.

neilson

#18 hottr6

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Posted 23 March 2013 - 03:00 PM

You think if I bought McClaren gearboxes the noise would go down? It's like using a power drill.

I think McLaren gearboxes are dog boxes, meaning straight-cut teeth, meaning LOTS of noise. But you won't hear it over the noise from the manifold pressure.

Oh, this is an astronomy forum. I'm guessing that in order to cut down on PE the gear teeth need maximum contact area, which means straight-cut gears. Which means noise.

#19 Raginar

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Posted 23 March 2013 - 06:50 PM

Hottr6, funny :).

Neilson, interesting idea. Maybe I'll try it when I get them. Until then I'll just wake my neighbors up :).

#20 David Pavlich

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Posted 23 March 2013 - 09:37 PM

McLennan Gearbox Upgrade. It takes a bit of work. :p

David

#21 Dan McConaughy

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Posted 23 March 2013 - 09:43 PM

I have Maxxon motors and McLennen gear boxes on my Byers mount, and they are quieter than the Losmandy gear boxes. I run my mount at 500X and at 18 volts and it's not very noisy. The motors are a bit noisier at 18 volts than 12 volts. It does get noisier if the worm is a bit sloppy with the worm gear and the mount is out of balance in favor of the direction that the mount is slewing - it's actually quieter when it's driving out of balance against the counter weight and working harder. If you burn out motors going to the limit, use less pressure on the clutches - you don't really need that much tension on the clutch if the mount is balanced. I use as little pressure on the clutches as I can get away with.

#22 Raginar

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Posted 24 March 2013 - 12:26 AM

David,

Besides trimming the driveshaft to match my current gearboxes, is there anything missing from the tutorial on how to replace them?

Dan,

I agree completely. I test my safety limit each time now just to make sure, and I've loosened my clutches as much as I can without getting slippage.

#23 David Pavlich

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Posted 24 March 2013 - 04:53 PM

I don't know, Chris. I just happen to have this in my bookmarks. I've never done it. Truth be known, my mount works so well as is, I've decided to leave it alone. Also, I'm not sure what I would have to do since I run my 250 with SiTech.

David

#24 Raginar

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Posted 24 March 2013 - 10:52 PM

David,

That's right, you're running the SiTech. Honestly, they're plug-n-play for the Gemini gearboxes minus shortening the driveshaft to make it match whatever your particular mount is cut for. I dunno what your mod entailed.

BTW, I love my MI-250. This mount is fantastic!






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