Re: G11 RA motor is stalls when tracking but not when slewing
Brendan's point of "motor drive energy is low" made me also think of this to check:
Make sure you are using a >12v power source for the gemini. it is rated from 12-18v but ideally you want 15-18v. 12v isn't going to be enough
[Edited Message Follows]
It¡¯s quote possible the motor is slightly bad for whatever reason.? Try swapping motors Ra to Dec etc
the reason it¡¯s bad at sidereal (I¡¯m assuming it¡¯s a G1) is the motor drive energy delivered is low.? At higher drive rates it¡¯s provided with more energy....it moves faster. it could be a bad ¡°H¡± bridge but I doubt it.? So try swap the motors over.?
If the system is a G2, you can enter the WEB interface and select¡±servos¡± page:
In this you can increase the servo motor tracking percentage ( increase energy) to the motor.? Try increasing it a little let¡¯s say 35%
it could also be as Michael said or a slipping motor pinion gear
If it is still failing....get back?
--
Brendan
-- Brian?
Brian Valente portfolio
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Re: G11 RA motor is stalls when tracking but not when slewing
Erik
i also should have said.....take that bad motor off and start run system like it¡¯s installed. ?You can run it on a bench (non installed) it¡¯s just the axes won¡¯t move. ?
So start it up.....if it¡¯s a Ra motor, it¡¯s pinion should feel tight on boot right up till the HC displays ¡°cold boot at xxxxxxx¡± ?At this point the pinion will start rotating at its specified sidereal rate. ?It will have resistance to your finger pressure on the pinion aka ¡°not weak¡±. If it¡¯s a DEC motor it won¡¯t move till you command it but from start it will feel tight and resist rotating by fingers.?
Don¡¯t worry if you¡¯re fiddling causes a stall warning they¡¯ll clear next boot.?
Test the above
--
Brendan
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More on worm bearings... types, prices, testing...
Hi gang,
Quick report on the R4ZZ worm bearings from 2 different sources...
I finally received the ? ABEC-7 R4ZZ stainless steel ball bearings. I tried them with a magnet, and compared them to a few from?
I find them both about the same magnetically... weakly able to be attracted. ? Therefore I think they are all a stainless steel. ? The comment from Bocabearings to me that the McMaster ones were not stainless was... ? incorrect. ?
Of course, you can order all kinds of bearings from McMaster, and from boca. Some will be stainless and some will not.? It's stated clearly in the website what you are getting.
The new ones I just got from boca have no name printed on them.? They are in a plastic shipping sleeve and a paper label says they are ? R4ZZ ABEC-7. ? ? They cost ~$9.75 each.
The ones from McMaster-Carr are listed at $8.60 each.? The ones that I have are I think the same units.? They are stamped on the bearing "NHBB USA" ?? The plastic package of each bearing says: ?SSR-4ZZR
Spec A7P25LY75P Mfr 50294 ? MVCSD30 Date 1.26.2018 NHBB Chatsworth USA
Now:? what about testing them on a 1/4 inch diameter worm shaft?
The new ones from Boca the center rotating part can shift very slightly left to right (along the rotating axis). The side enclosures holding the balls in are not "tight," like the ones I got many years ago from Boca. ? None of the bearings seemed "rough" on rotation, but they must be compressed axially to keep the balls in the smooth races.?
?To prevent this axial movement, these bearings must have a Belleville spring washer to compress the balls into the races properly, and the bearings must be lined up with the worm axis so there is not a "pinched" ball that will cause PE issues.? (That is what the OPW worm system does: keep the worm blocks lined up with the worm so the bearings are co-linear with the worm). Without an OPW, you can line the blocks up with a metal straightedge, and this also works. ?
The bearings from McMaster seem as tight or tighter.? I cannot tell since they are still in their plastic envelope.
Bottom line: I think the stainless steel R4ZZ ABEC-7 from McMaster are likely as good as the ones from BocaBearings.com.? They are both stainless steel. ? With shipping considered the price may be essentially the same. ? The McMaster ones are stamped with a name, which I like over nameless units. ?
All the best, Michael --
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Re: G11 RA motor is stalls when tracking but not when slewing
It¡¯s quote possible the motor is slightly bad for whatever reason. ?Try swapping motors Ra to Dec etc
the reason it¡¯s bad at sidereal (I¡¯m assuming it¡¯s a G1) is the motor drive energy delivered is low. ?At higher drive rates it¡¯s provided with more energy....it moves faster. it could be a bad ¡°H¡± bridge but I doubt it. ?So try swap the motors over.?
If the system is a G2, you can enter the WEB interface and select¡±servos¡± page:
In this you can increase the servo motor tracking percentage ( increase energy) to the motor. ?Try increasing it a little let¡¯s say 35%
it could also be as Michael said or a slipping motor pinion gear
If it is still failing....get back?
--
Brendan
|
Re: G11 RA motor is stalls when tracking but not when slewing
Hi Eric,
The most common reason is a loose Oldham coupler part.
Look at the drive metal parts of the RA Oldham coupler...see if one end is loose. They can get loose over time, and it might be temperature dependent.? If one of those ends gets loose, the motor will tell Gemini it is still turning (so no Lags message), but the worm will not be driven..so the axis will not move.
-----
I was going to say:
Try swapping the cables from RA to DEC (...the RA is shorter...might be difficult).
However, if the cable were faulty, I think the Gemini would say "Lags" or something like that.? I think the Oldham coupler is the most likely trouble.
Best wishes, Michael
On Sun, Sep 22, 2019, 12:27 PM Erik Nordberg < tierozi@...> wrote: Hi friends !
I have had a problem the last couple of years with the RA motor that stops working when tracking at star but when hitting the slew buttons on the hand controller the works as usual.
There is no stall warning in the display.
Often I can get it working again after pushing the buttons on the handcontroller but last night it did not work that way. I even shut down Gemini twice and after a restart the star was
OK and not drifting but when I center the star it immediatly starts drifting which means the RA motor has stopped. And never a stall warning in the display.
I know the that the stall warning does work when for example I adjust the wormwheel.
Is this a problem that any of you guys has encountered before ?
Rgds
Erik Nordberg
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G11 RA motor is stalls when tracking but not when slewing
Hi friends !
I have had a problem the last couple of years with the RA motor that stops working when tracking at star but when hitting the slew buttons on the hand controller it works as usual.
There is no stall warning in the display.
Often I can get it working again after pushing the buttons on the handcontroller but last night it did not work that way. I even shut down Gemini twice and after a restart the star was
OK and not drifting but when I center the star it immediatly starts drifting which means the RA motor has stopped. And never a stall warning in the display.
I know the that the stall warning does work when for example I adjust the wormwheel.
Is this a problem that any of you guys has encountered before ?
Rgds
Erik Nordberg
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For ASIair, connect a USB cable from the Raspberry Pi to the USB port on the Gemini. ?If my memory is working, it shows up as /dev/ttyACM0 (that's the 'device' you tell the ASIair to use to control the Gemini) and ASIair does support Losmandy mounts (just make sure you pick it as the mount type).
Clear Skies,
toggle quoted message
Show quoted text
On Sep 21, 2019, at 10:17 AM, Richard Paul via Groups.Io < rickpaul@...> wrote: I haven¡¯t gotten it yet. But I¡¯ve been buying the little stuff first!?
Would appreciate knowing how to setup the ASIair to work with the Gemini. Any special settings on either side? I love my ASIAir. I¡¯m actually a beta tester for it.?
--
Rick Paul
Tucson, AZ
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Ok Daniel.....Michael filled me in on the history of your issues. ?I¡¯m sorry to hear it¡¯s not going well.?
Scott has always been more than willing to assist users....as I said to Michael even upgrade old mount versions for free and much more. Replace old worms for free...
He¡¯s is not?intransigent, quite the opposite, so I am vexed. ?But I¡¯d admit I¡¯m out of this loop and best to stay out except to say are others having similar mount performance issues??
I have read of some of this previously, in the forums, but I haven¡¯t read nor seen enough to know. ??
Id like to so ill school up on this...
--
Brendan
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Re: Belleville washers and Oldham coupler
(Thanks to John Hobbs for his prompt...!)
Sounds like you want to get the CG11 to imaging level.? ?I have one and it's my workhorse, now having a 12 inch SCT for imaging. ?
? I upgraded it with the parts below...
...those parts below, plus an "original" (long version) Losmandy OPW on the RA axis, not listed below. Today, Losmandy sells a shorter OPW version today slightly different (shorter) in design, and less expensive than the original longer version.?
David Partridge in the UK got exceptionally low PE without an OPW... so though it may help, it's not an absolute necessity. ?
If you can get parts in Europe, that's great. ?
If not... I can get you parts from the US.? Here are some options to upgrade:
I have a small stock of the Belleville washers, and it's easy to just mail them in a standard letter, inexpensively.? Send me your mailing address and I can get you out a pair of them if that's all you want. ?
Any other stuff would need a package, costing a lot more to mail. ? Packages (larger than letters...limited in thickness) from the US can go to Austria, but require a customs form. It can be done.? Least expensive packages are now about $35 I think, using the US Post Office international rates. ?
So what else should go in a package?
The Oldham coupler you asked for... those should not wear out, but if yours is list or questionable, and you want some ordered, I can do that if you'll pay for shipping to me and then to you. I'm in California, so shipping from the LA McMaster-Carr website is not too bad.? Let me know how many, and what model you want.? Losmandy also sells them. ?(Note: the stock coupler is "short" but for the older longer OPW needed a "long" one. The new OPW used the original short Oldham coupler.? Best to measure the one you are replacing if you have it.)
More importantly, for the CG11 PE improvement, you should change the original steel worm (at minimum the one on the RA) to a new Losmandy precision brass worm.? They are $100 from Losmandy... I'd get 2 of them and test each in the RA drive.? Then use the one with lowest PE on the RA drive...the other on DEC.? I can get them from Losmandy if you tell me what you need.? Your system might already have brass worms... so look at them to see the material. ?
You may want to replace the RA worm bearings model R4 with higher quality ones. There is a rating system...ABEC from 1 to 9.? There are ABEC-7 rated R4ZZ bearings for about $11 available here in the US, but you might find these in Europe also.? ABEC-5 have also been used with excellent results.? If you are going to put in Belleville washers, it's possible you may damage a bearing getting it out of its tight cylinder.? Best to have spares available just in case or to upgrade. ?(McMaster Carr has some abec7 rated R4 for ~$6, but another bearing vendor claims those are not stainless steel.).?
For imaging, clutch slippage is eventually an issue, but it can be eliminated.? First clean all clutch mating surfaces. That will work for a period of time.? Eventually oils from the lubricants can migrate and coat the plastic clutch disk.? So I suggest you replace the plastic clutch disks: They can be from 3.5 inch OD to 4.25 inch OD in that system. Losmandy only sells 4.25 inch plastic disks, though they can be cut by a scissors to smaller OD. The OD is not a critical factor, and as long as it is approximate it will work just fine. ? I make these clutch disks of higher friction material that will help seal out oils and hold the driven plate with lower clutch know force. Let me know if you want those and what OD sizes you need.
Many people like the newer type of clutch knob that has 3 beautiful handles around the circumference.? Losmandy makes these, in order to increase force on the (somewhat slippery) plastic clutch disk material. ? If you are going to order other stuff from Losmandy, consider those beautiful knobs too. ?(The system works better, and the parts last (forever?) longer with lower clutch knob force, so using the higher friction clutch material is a benefit. )?
Finally, you should give the existing parts and the internal needle bearings that hold the 1.25 inch shafts, a thorough cleaning in something like a strong degreaser.? There is a product called Berryman B-12 here in auto parts stores that works great...requires a metal pan and solvent protection gloves and mask.? The old greases tend to gum up the tiny needle bearing rollers that hold the shafts, and it will all work better if you remove the old gummed up lubricants and re lubricate with a Teflon based ( or other modern) grease.? You'd have to buy chemicals locally, of course.? The solvents are toxic, so should be used outdoors in fresh air. ?
Have fun with your CG11!
Best, Michael
Hi all,
i got an older G11 Mount, made for Celestron.
Some parts are missing and the mount needs some upgrade.
I tried to order Belleville washers (Belleville Disc Spring for Ball Bearings, Bearing #R4, .406" ID, .618" OD, .0216" High) and Oldham couplers from McMaster-Carr but they canceled my order as they would not ship to Austria/Europe.
Does anybody knows where i can These parts somewhere in Europe?
Regards,
Wolfgang
|
Re: Belleville washers and Oldham coupler
If you email Micheal Herman : mherman346@..., he may be able to tell you about someone in England who might be able to help.
John Hobbs
hobbs_john@...
-----Original Message-----
From: vergolder <vergoldermeister@...>
To: Losmandy_users < [email protected]>
Sent: Sat, Sep 21, 2019 11:09 am
Subject: [Losmandy_users_io] Belleville washers and Oldham coupler
Hi all,
i got an older G11 Mount, made for Celestron.
Some parts are missing and the mount needs some upgrade.
I tried to order Belleville washers (Belleville Disc Spring for Ball Bearings, Bearing #R4, .406" ID, .618" OD, .0216" High) and Oldham couplers from McMaster-Carr but they canceled my order as they would not ship to Austria/Europe.
Does anybody knows where i can These parts somewhere in Europe?
Regards,
Wolfgang
|
Daniel Scott adjusts all the worms pretty much himself. ?He wouldn¡¯t throw or reject anyone with new mount issues. ? He stands by his products.?
If you have fiddled with it and it¡¯s not right I¡¯m sure he¡¯ll adjust it for you....you may have to pay shipping you won¡¯t need to send the whole mount.?
--
Brendan
|
HI Larry
how did you determine your RA 'drift' was due to the worm??
regarding watching the tucked in gears, the part there was less about watching them, and more about feeling the tension on the gear. In my experience, when the spring was too tight, the tucked in gearing rotation was stiff. as I slowly adjusted the spring mechanism, there was sort of a "cliff" where it suddenly freed up and spun easily in my hand. I don't know if that helps you at all, but it was really more about the feeling and finding that point, not about visual confirmation
Some might recall that about a month ago I asked about a problem with my mount "drifting" in RA for some time after I made a manual correction through the ASCOM interface.? It turned out that was due to a poorly adjusted spring loaded worm assembly.? I contacted Losmandy and in part due to that call, Scott made and posted a video on how to properly adjust the worm - apparently a number of people were having problems with adjustment, or simply ignored Scott's warning to not mess with it!? Unfortunately, that video describes adjusting the spring while watching the gears on a tucked-in motored G11.? On the older G11 without the tucked in motors, one cannot watch the gears mesh, at least not that I have figured out.? That aside, and adjusting as best as I can, I adjusted the right worm block (the one farthest form the motor) until it and the worm were tight, then tightened that block with the bolt coming from the rear - the bolt that can't be tight otherwise the whole assembly will not rotate as intended.? I figured out to first tighten that rear block mounting bolt then reattached the long worm cover piece and tighten that to both blocks firmly.? Then, loosen the rear block bolt just enough to allow it to move so the spring can do its job of keeping the assembly, which contains the worm, close to the main gear.? That worked and I saw very good tracking, for a while, but over a fairly short period of time the block slide outward a bit loosening the worm and the RA "drifting" problem returned.? Assuming I'm doing this correctly, the problem I see is that the bolt going through the cover piece that I'm using to keep the block adjusted relative to the worm can't be tightened enough to hold that block in place with the force from the lateral worm movement that exists anytime the mount is driven (tracking), or making RA corrections.?? I'm inclined to fabricate an end plate for the worm cover (somehow) and add an adjuster screw coming out the end (co-linear with the worm) so that that the right block can be adjusted with just the right amount of force on the worm but allowing the assembly to freely pivot around the left block rear bolt, rather than count on Scott's approach of "press on the block with your fingers while rotating the RA shaft, then screw it down", approach.?
Am I approaching this incorrectly, or does anyone have a better idea on how to ensure the right block, once adjusted, stays adjusted??
Larry
-- Brian?
Brian Valente portfolio
|
Mine is basically a useless piece of junk and losmandy does not want to service it because they blamed me for everything when I did nothing.
Yea mine has the same problem. I was told that I did something with the mount and I did not. Now if I send it back it's not under warranty. I adjusted the worm gear in the fashion that was shown in the spring loaded worm video. No luck at all.?
Daniel V
Some might recall that about a month ago I asked about a problem with my mount "drifting" in RA for some time after I made a manual correction through the ASCOM interface.? It turned out that was due to a poorly adjusted spring loaded worm assembly.? I contacted Losmandy and in part due to that call, Scott made and posted a video on how to properly adjust the worm - apparently a number of people were having problems with adjustment, or simply ignored Scott's warning to not mess with it!? Unfortunately, that video describes adjusting the spring while watching the gears on a tucked-in motored G11.? On the older G11 without the tucked in motors, one cannot watch the gears mesh, at least not that I have figured out.? That aside, and adjusting as best as I can, I adjusted the right worm block (the one farthest form the motor) until it and the worm were tight, then tightened that block with the bolt coming from the rear - the bolt that can't be tight otherwise the whole assembly will not rotate as intended.? I figured out to first tighten that rear block mounting bolt then reattached the long worm cover piece and tighten that to both blocks firmly.? Then, loosen the rear block bolt just enough to allow it to move so the spring can do its job of keeping the assembly, which contains the worm, close to the main gear.? That worked and I saw very good tracking, for a while, but over a fairly short period of time the block slide outward a bit loosening the worm and the RA "drifting" problem returned.? Assuming I'm doing this correctly, the problem I see is that the bolt going through the cover piece that I'm using to keep the block adjusted relative to the worm can't be tightened enough to hold that block in place with the force from the lateral worm movement that exists anytime the mount is driven (tracking), or making RA corrections.?? I'm inclined to fabricate an end plate for the worm cover (somehow) and add an adjuster screw coming out the end (co-linear with the worm) so that that the right block can be adjusted with just the right amount of force on the worm but allowing the assembly to freely pivot around the left block rear bolt, rather than count on Scott's approach of "press on the block with your fingers while rotating the RA shaft, then screw it down", approach.?
Am I approaching this incorrectly, or does anyone have a better idea on how to ensure the right block, once adjusted, stays adjusted??
Larry
--
Clear skies?
Daniel V
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Yea mine has the same problem. I was told that I did something with the mount and I did not. Now if I send it back it's not under warranty. I adjusted the worm gear in the fashion that was shown in the spring loaded worm video. No luck at all.?
Daniel V
Some might recall that about a month ago I asked about a problem with my mount "drifting" in RA for some time after I made a manual correction through the ASCOM interface.? It turned out that was due to a poorly adjusted spring loaded worm assembly.? I contacted Losmandy and in part due to that call, Scott made and posted a video on how to properly adjust the worm - apparently a number of people were having problems with adjustment, or simply ignored Scott's warning to not mess with it!? Unfortunately, that video describes adjusting the spring while watching the gears on a tucked-in motored G11.? On the older G11 without the tucked in motors, one cannot watch the gears mesh, at least not that I have figured out.? That aside, and adjusting as best as I can, I adjusted the right worm block (the one farthest form the motor) until it and the worm were tight, then tightened that block with the bolt coming from the rear - the bolt that can't be tight otherwise the whole assembly will not rotate as intended.? I figured out to first tighten that rear block mounting bolt then reattached the long worm cover piece and tighten that to both blocks firmly.? Then, loosen the rear block bolt just enough to allow it to move so the spring can do its job of keeping the assembly, which contains the worm, close to the main gear.? That worked and I saw very good tracking, for a while, but over a fairly short period of time the block slide outward a bit loosening the worm and the RA "drifting" problem returned.? Assuming I'm doing this correctly, the problem I see is that the bolt going through the cover piece that I'm using to keep the block adjusted relative to the worm can't be tightened enough to hold that block in place with the force from the lateral worm movement that exists anytime the mount is driven (tracking), or making RA corrections.?? I'm inclined to fabricate an end plate for the worm cover (somehow) and add an adjuster screw coming out the end (co-linear with the worm) so that that the right block can be adjusted with just the right amount of force on the worm but allowing the assembly to freely pivot around the left block rear bolt, rather than count on Scott's approach of "press on the block with your fingers while rotating the RA shaft, then screw it down", approach.?
Am I approaching this incorrectly, or does anyone have a better idea on how to ensure the right block, once adjusted, stays adjusted??
Larry
--
Clear skies?
Daniel V
|
Some might recall that about a month ago I asked about a problem with my mount "drifting" in RA for some time after I made a manual correction through the ASCOM interface.? It turned out that was due to a poorly adjusted spring loaded worm assembly.? I contacted Losmandy and in part due to that call, Scott made and posted a video on how to properly adjust the worm - apparently a number of people were having problems with adjustment, or simply ignored Scott's warning to not mess with it!? Unfortunately, that video describes adjusting the spring while watching the gears on a tucked-in motored G11.? On the older G11 without the tucked in motors, one cannot watch the gears mesh, at least not that I have figured out.? That aside, and adjusting as best as I can, I adjusted the right worm block (the one farthest form the motor) until it and the worm were tight, then tightened that block with the bolt coming from the rear - the bolt that can't be tight otherwise the whole assembly will not rotate as intended.? I figured out to first tighten that rear block mounting bolt then reattached the long worm cover piece and tighten that to both blocks firmly.? Then, loosen the rear block bolt just enough to allow it to move so the spring can do its job of keeping the assembly, which contains the worm, close to the main gear.? That worked and I saw very good tracking, for a while, but over a fairly short period of time the block slide outward a bit loosening the worm and the RA "drifting" problem returned.? Assuming I'm doing this correctly, the problem I see is that the bolt going through the cover piece that I'm using to keep the block adjusted relative to the worm can't be tightened enough to hold that block in place with the force from the lateral worm movement that exists anytime the mount is driven (tracking), or making RA corrections.?? I'm inclined to fabricate an end plate for the worm cover (somehow) and add an adjuster screw coming out the end (co-linear with the worm) so that that the right block can be adjusted with just the right amount of force on the worm but allowing the assembly to freely pivot around the left block rear bolt, rather than count on Scott's approach of "press on the block with your fingers while rotating the RA shaft, then screw it down", approach.?
Am I approaching this incorrectly, or does anyone have a better idea on how to ensure the right block, once adjusted, stays adjusted??
Larry
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Re: Screws on the CG-11... Saddle plate bolts.
Glad you got the stuff locally. ?
Similarly, getting metric sized product in the US is sometimes hard... always costly.
Very best, Michael
Hi Michael,
thank you for your help and for your offer sending me some bolts. With your info on the size, I found a store in Germany that ships them for 5€ including shipping. So there is no need for shipping them from the US.
Thanks again
Stephan
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Belleville washers and Oldham coupler
Hi all,
i got an older G11 Mount, made for Celestron.
Some parts are missing and the mount needs some upgrade.
I tried to order Belleville washers (Belleville Disc Spring for Ball Bearings, Bearing #R4, .406" ID, .618" OD, .0216" High) and Oldham couplers from McMaster-Carr but they canceled my order as they would not ship to Austria/Europe.
Does anybody knows where i can These parts somewhere in Europe?
Regards,
Wolfgang
|
I haven¡¯t gotten it yet. But I¡¯ve been buying the little stuff first!?
Would appreciate knowing how to setup the ASIair to work with the Gemini. Any special settings on either side? I love my ASIAir. I¡¯m actually a beta tester for it.?
--
Rick Paul
Tucson, AZ
|
Re: Screws on the CG-11... Saddle plate bolts.
Hi Michael,
thank you for your help and for your offer sending me some bolts. With your info on the size, I found a store in Germany that ships them for 5€ including shipping. So there is no need for shipping them from the US.
Thanks again
Stephan
|
nice, great to hear!
i use sky safari on ipad and it links right in. Don't need much planetarium software but when i do it's delightful to work with
On Fri, Sep 20, 2019 at 8:41 PM Greg via Groups.Io <gregmorris425= [email protected]> wrote: Just wanted to let those of you that have responded to my questions know I have gotten the kinks worked out on my tp-link. Randy was kind enough to help me on the phone and after a few minutes we found that the dns server values were not set right in the hand control. I bought this slightly used so maybe it was done by the previous owner. Anyway it was a joy to get it to respond to my phone. Now I may be in the market for an I-Pad. It never ends!! :) I appreciate the responses and maybe one day I can even be a help to someone else.
Greg
-- Brian?
Brian Valente portfolio
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Michael Herman
Timothy Campbell
vergolder
Richard Paul