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Re: GM-8 Oldham coupler alignment

Keith N
 

Greg:

To one of your original questions, the only way is to remove the cover while leaving the two bearing blocks secured by the 2 screws underneath, thereby potentially altering the alignment.? Perhaps Losmandy has determined the alignment of the gearbox shaft to the worm gear, and hence Oldham, is not that important. I'm curious how they do this in the factory.

Keith
Re: GM-8 Oldham coupler alignment

 

drift has nothing to do with the mount - it's usually polar alignment drift

That data was really hard to interpret and didn't seem to reflect any periodicity of the mount.?

have tried out the first three PEC tutorials i posted here?

Brian

On Sun, Jul 26, 2020 at 1:26 PM Gregory Latiak <glatiak@...> wrote:
Thanks, Brian. It was that data as we have had nothing but clouds since then. One question, though. Given the structure of the mount, what is drift?

greg



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Brian?



Brian Valente
portfolio

Re: GM-8 Oldham coupler alignment

 

Thanks, Brian. It was that data as we have had nothing but clouds since then. One question, though. Given the structure of the mount, what is drift?

greg
Re: GM-8 Oldham coupler alignment

 

Hi Greg

that may be drift. If it's the data you recently uploaded to PEMPro support, i think there are a number of issues with that data collection that may not?

if it's a different log you are referring to, happy to look at it.?

On Sun, Jul 26, 2020 at 8:24 AM Gregory Latiak <glatiak@...> wrote:
Question... is there any decent way one can check if the oldham coupler is actually properly aligned when reassembling the drive? Not a lot of clearance between the worm block and the gear housing. When looking at my PEC data there are a number of anomalous peaks, like a big one at 1022 sec that bothers me. ANy thoughts or suggestions?

Thanks,
greg latiak
avalon observatory



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Brian?



Brian Valente
portfolio

Re: GM-8 Oldham coupler alignment

 

Hi Greg,

Ok...you have an RA OPW, so the blocks are supposed to be well aligned.??

You must then determine if the 1022 sec glitch really does repeat at that same period.? If it does....I think it has to be a bad worm bearing.? They are not very expensive...about $12 each from Boca bearings.

(If non repeating,...any chance something bumped the mount?? )

If non repeating, points to some burr or a speck of dirt...maybe a damaged gear thread on the ring gear (if an abrasive hard particle got ground in).? I guess clean, inspect and relube.? You can generally swap the RA and DEC components to try too...worm and ring gears maybe.??

Best of luck on unraveling this puzzle...

Michael



On Sun, Jul 26, 2020, 9:24 AM Gregory Latiak <glatiak@...> wrote:
Thanks, Michael.

I do have the OPW assemblies. The separate bearing blocks were more of a challenge to pinch together and align -- I just don't have enough dexterous appendages to manage. Don't have a lot of actual measurements as yet -- our skies have been so cruddy its been like one or two nights a month. And hot.

greg

Re: Losmandy presentation: achieving <1" performance, July 22 2PM PDT

 

That large T style handle looks impractical because there are 2 Alt bolts on each side that must be secured and the large handle can easily block one of them (the lower one in the picture).? To me that's a non-starter unless I am missing something?

BTW I have often found that tightening them can easily throw off the polar alignment.? I tighten them a bit one at a time until they are all tight.
Re: GM-8 Oldham coupler alignment

 

Thanks, Michael.

I do have the OPW assemblies. The separate bearing blocks were more of a challenge to pinch together and align -- I just don't have enough dexterous appendages to manage. Don't have a lot of actual measurements as yet -- our skies have been so cruddy its been like one or two nights a month. And hot.

greg
Re: GM-8 Oldham coupler alignment

 

Greg,

That's an interesting puzzle: a glitch at 1022 sec....and you say it is repeating at the time period?? ?That is like 4.26 x as slow as the G11 worm period.

Nothing in the front section (motor, gearbox, Oldham coupler) of the RA drive train is that slow.??

The Oldham revolves exactly at the same ~240 sec as the worm. Since it can wobble in the front and back slots where the metal rods insert, I think it could cause a speedup or slowdown either 2x or 4x per period.??
Even if one of the metal rods "slips" or gets "caught" in the plastic center part, it would happen at some period matching the RA drive rate.

The gearbox gears revolve faster than 240 sec, and only the output gear rotates at that speed. So cannot be the gearbox.? The motor is 25x as fast...can't be that (it's a 25:1 gearbox).??

That leaves something at the back end of the drive: it's possible that you have a ball bearing getting pinched in one of the worm bearings.? There were 8 balls in the bearing I disassembled once.? I can't tell what rate those balls pass a certain position in the race, but if you have maybe one bad ball bearing that is slightly larger than the others, perhaps it takes many center axis rotations for that bad ball bearing to get to the pinch point.??

So my guess is:
If the 1022 sec is repeating, I think you should replace your two R4ZZ worm bearings with new ones.? I prefer the ABEC-7 quality rated R4ZZ ones.? Get a bunch like 5 and hand test them each yourself for smoothness...pick the two best and put them in the RA worm drive, closest to the worm teeth.? (Some older G11 OPWs have 3 R4ZZ bearings.)??

The Worm Blocks are required to be lined up to prevent pinching a ball bearing.? Getting an OPW will ensure the worm blocks are lined up by the OPW case.? Lining the blocks up by hand requires using a metal straightedge and very hard to do for one person alone without an OPW.??

If the 1022 second is not repeating....say it's a sporadic glitch...I'd suspect some speck of dirt on the Ring gear.? I'd take out the ring gear, and scrub the teeth clean with an abandoned toothbrush.? Same with the RA worm teeth...make sure there is no hard particle stuck in the grease.??

Best of luck, Greg!!!

Michael



On Sun, Jul 26, 2020, 8:24 AM Gregory Latiak <glatiak@...> wrote:
Question... is there any decent way one can check if the oldham coupler is actually properly aligned when reassembling the drive? Not a lot of clearance between the worm block and the gear housing. When looking at my PEC data there are a number of anomalous peaks, like a big one at 1022 sec that bothers me. ANy thoughts or suggestions?

Thanks,
greg latiak
avalon observatory

Re: Losmandy presentation: achieving <1" performance, July 22 2PM PDT

 

You can use them all over the mount and tripods for things that need regular adjustment and additional leverage. The great thing for those who don't know it is that the levers can be repositioned as needed to make access easier for adjustment or to clear mechanical interference.?

There are also metal versions available as seen on the Berlebach tripods. I use them on other tripods for locking the legs too. Great stuff.?
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Chip Louie - Chief Daydreamer Imagination Hardware
GM-8 Oldham coupler alignment

 

Question... is there any decent way one can check if the oldham coupler is actually properly aligned when reassembling the drive? Not a lot of clearance between the worm block and the gear housing. When looking at my PEC data there are a number of anomalous peaks, like a big one at 1022 sec that bothers me. ANy thoughts or suggestions?

Thanks,
greg latiak
avalon observatory
Re: Losmandy presentation: achieving <1" performance, July 22 2PM PDT

 

>>> The adjustable knobs in the drawing were meant for the elevation lock on the sides of the base NOT for attaching the Gemini control box to the tripod!?

that's what I thought they were for - mostly because I have a pair (from losmandy) and use them in exactly the same way :)


On Sat, Jul 25, 2020 at 12:20 PM Chip Louie <chiplouie@...> wrote:
Michael and gang,

The adjustable knobs in the drawing were meant for the elevation lock on the sides of the base NOT for attaching the Gemini control box to the tripod! If you read my note it says for those who need "extra leverage" and the size should tell you this. There are very similar adjustable knobs that come with the mounts but they are much smaller with smaller threads and a shorter stud length. I also use them on Losmandy and other tripods.? ?

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Chip Louie - Chief Daydreamer Imagination Hardware



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Brian?



Brian Valente
portfolio

Re: Losmandy presentation: achieving <1" performance, July 22 2PM PDT

 

My error, Chip.

I have those same looking levers on the Gemini-1 to attach it to the "ears" on the tripod vertical riser.? When I saw the photo I only thought of the Gemini side mounting bolts.? The bolts on that application are 1/4-20, length is 5/8 inch.?

The bolts you show with levers for the elevation lock would likely be 3/8-16 thread.? That would be a good place for the leverage and you don't need to remove them.??

Stay well,
Michael



On Sat, Jul 25, 2020, 12:20 PM Chip Louie <chiplouie@...> wrote:
Michael and gang,

The adjustable knobs in the drawing were meant for the elevation lock on the sides of the base NOT for attaching the Gemini control box to the tripod! If you read my note it says for those who need "extra leverage" and the size should tell you this. There are very similar adjustable knobs that come with the mounts but they are much smaller with smaller threads and a shorter stud length. I also use them on Losmandy and other tripods.? ?

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Chip Louie - Chief Daydreamer Imagination Hardware

Re: Losmandy presentation: achieving <1" performance, July 22 2PM PDT

 

Michael and gang,

The adjustable knobs in the drawing were meant for the elevation lock on the sides of the base NOT for attaching the Gemini control box to the tripod! If you read my note it says for those who need "extra leverage" and the size should tell you this. There are very similar adjustable knobs that come with the mounts but they are much smaller with smaller threads and a shorter stud length. I also use them on Losmandy and other tripods.? ?

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Chip Louie - Chief Daydreamer Imagination Hardware
Re: Losmandy presentation: achieving <1" performance, July 22 2PM PDT

 

Thanks David,
I didn't realize those were 3/8" diameter. I only have G2 and the mount ears to G2 controller wingbolts seem thinner than 3/8".?
I guess I don't understand why that connection needs to be really tight.
Perhaps there is some confusion as to where these lever bolts are to be used?
Only on the RA Alt hold down, right?
Thanks,
Astronut Tim
Re: Losmandy presentation: achieving <1" performance, July 22 2PM PDT

 

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Nah ¨C it¡¯s the one to secure the G1 to the ears on the mount base.

?

From: [email protected] [mailto:[email protected]] On Behalf Of Astronut
Sent: 25 July 2020 18:19
To: [email protected]
Subject: Re: [Losmandy_users_io] Losmandy presentation: achieving <1" performance, July 22 2PM PDT

?

Hi David,
Is this knob meant for the Altitude Lock on the RA Axis?
Thanks
Astronut Tim

Re: Losmandy presentation: achieving <1" performance, July 22 2PM PDT

 

Hi David,
Is this knob meant for the Altitude Lock on the RA Axis?
Thanks
Astronut Tim
Re: Losmandy presentation: achieving <1" performance, July 22 2PM PDT

 

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I can attest to that given the number of G1s I have had in for repair with PCB damage caused by over long bolts.

?

David

?

From: [email protected] [mailto:[email protected]] On Behalf Of Michael Herman
Sent: 25 July 2020 16:58
To: [email protected]
Subject: Re: [Losmandy_users_io] Losmandy presentation: achieving <1" performance, July 22 2PM PDT

?

Beautiful levers...I could not find them anywhere, so thanks, Chip!

?

However...beware!

?

Those bolts on that link item are way too long. They will go all the way into the G1 and impact the circuit board, and will break the PC board in a Gemini-1.? The bolts should be cut (a hack saw will do) to be 5/8 inch long.? ?

?

?

?

Best,

Michael
Re: Losmandy presentation: achieving <1" performance, July 22 2PM PDT

 

Hi Chip & Michael,
Just to be sure Chip, you mentioned these knobs for the Altitude Lock on the G11, is that correct ?

I am using the Losmandy FHD tripod top knobs (very similar but with threaded nut, instead of bolt) foy my Azimuth Lock down and they really do make it easier to tighten carefully while doing PA, especially for long FL.

Thanks,
Astronut Tim
Re: Losmandy presentation: achieving <1" performance, July 22 2PM PDT

 

Beautiful levers...I could not find them anywhere, so thanks, Chip!

However...beware!

Those bolts on that link item are way too long. They will go all the way into the G1 and impact the circuit board, and will break the PC board in a Gemini-1.? The bolts should be cut (a hack saw will do) to be 5/8 inch long.? ?



Best,
Michael



On Fri, Jul 24, 2020, 1:13 PM Chip Louie <chiplouie@...> wrote:
I have not had any issues using the Losmandy AKS knobs but for those folks who need a little extra leverage these are nicer and under $6 each. Put a plastic washer under the handle and you are GTG but check the fit though as I have not used them yet. I use something similar on my Losmandy LWT and they are great.??



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Chip Louie - Chief Daydreamer Imagination Hardware

PHD2 simulation

daniel vrolijk
 

I am wondering if it is possible to setup PHD 2 so I can simulate guiding. So sorta like PEM pro where it shows the graph. I need the graph data to see how the worm gear is performing. If anyone knows a tutorial on how to do this let me know.

Daniel V

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Clear skies?

Daniel V
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