Re: Needle bearings and axial play, is this a significant performance problem and how difficult is it to fix?
On Sun, Jul 18, 2021 at 01:24 PM, Brian Valente wrote:
but here we are talking about TVC and guiding which are two software systems for backlash compensation. They will fight with each other if not handled properly. This is the recommendation of Losmandy and openPhD.?
?
Brian
Brian, They should only fight if you are in the unstable zone per my sketch. Peter 
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Re: Needle bearings and axial play, is this a significant performance problem and how difficult is it to fix?
Brian,
As a representative of the manufacturer I appreciate that you responded to my two posts, but I would ask that you please read them carefully as you are in part providing your customers with I feel incorrect/imprecise information. ?The backlash was measured via the Allen key method outline previously and did not involve PHD2.
If gravity plays a role then it in likely due to the needle bearing problem I outlined in earlier postings. I.e. Shifting of the Dec Axis due to a slop in the needle bearings sure to the weight and position of the scope. The shaft is out of spec for these bearings. These bearings where designed to be pressed into place. When done correctly the bearing ID is reduced slightly. The bearings are a light press (Scott himself has said as much). I pressed them in with my fingers! The shaft needs to be exactly 1.25". Mine is 0.004 to 0.006 under size this makes a big difference.?
Did you read read my explanation for how PHD2 works? Yes it does issue a single large pulse when reversing compensation, but it takes that amount of time to take effect. It does not matter if it dynamically adjusts through the night or session to session. It's irrelevant. If the backlash reversal pulse is longer than the guide imaging rate you have a big problem. This will undoubtably lead to instability within PHD2.
Lastly, you absolutely do not want to use a conservative value for TVC, you want to use the correct value. What do I mean by that? For those who use auto focus there is a curve where the minimum point on the parabola is the point of focus. This is true of TVC. Too small a value and backlash remains. Too large and backlash increases but in a negative way, which no doubt leads to the instability you noted. I think it's your job to study this in a precise meaningfull way. Replace my Allen key with a timing circuit. This way you can precisely measure TVC as a function of backlash. I see no reason why thus is not a fixed function. I take your point about being conservative as you do not want to be on the wrong side of the parabola. But setting an arbitrary, often too small a value, makes no sense in my opinion.
Look the backlash problem in my setup was due the excessive pressure put on the thrust bearings. This resulted in too much force needed to move the ring gear. This in turn forced considerable pressure to build in the gearbox and coupler resulting an uncorrectable large backlash. This was resolved with new thrust bearings and determining the correct value for TVC. Until I built my open worm assembly, where I had access to the various elements, I struggled to understand what was really going on, and certainly did not appreciate how important TVC was to eliminating backlash.
Peter
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Re: Needle bearings and axial play, is this a significant performance problem and how difficult is it to fix?
Keith
I agree regarding hardware adjustments.?
but here we are talking about TVC and guiding which are two software systems for backlash compensation. They will fight with each other if not handled properly. This is the recommendation of Losmandy and openPhD.?
Brian
I think as much as possible, considerations of DEC backlash on the mount should be de-coupled from PHD2's backlash compensation which is a feature of a particular piece of software.? DEC backlash, whether with the SLW or not, can be objectively measured using whatever method (but apparently not using PHD2 for some reason from what I've read).? Reducing DEC backlash by mechanical means is obviously the best route, followed by software compensation (i.e. not everyone uses PHD2 to guide, though likely the majority).
Keith
-- Brian?
Brian Valente portfolio
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Re: Needle bearings and axial play, is this a significant performance problem and how difficult is it to fix?
I think as much as possible, considerations of DEC backlash on the mount should be de-coupled from PHD2's backlash compensation which is a feature of a particular piece of software.? DEC backlash, whether with the SLW or not, can be objectively measured using whatever method (but apparently not using PHD2 for some reason from what I've read).? Reducing DEC backlash by mechanical means is obviously the best route, followed by software compensation (i.e. not everyone uses PHD2 to guide, though likely the majority).
Keith
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Re: Needle bearings and axial play, is this a significant performance problem and how difficult is it to fix?
>>>
I would suggest he try a setting in the order of 120 to 150.?
I caution using? too large TVC and trying to get this to?"zero backlash"
I spent about 3 months dialing in perfect TVC value to get zero backlash in the mount. The result was zero backlash when measured in PHD. However when I was guiding, DEC was a mess. It often overshot the correction and created oscillating patterns
First, the amount of backlash varies as you move across the sky: gravity, equipment shifting, etc. all play a role in this. So there isn't "one" backlash value
Second the DEC auto backlash compensation in PHD is adaptive. It measures the amount of backlash and number of steps required for reversal, and adjusts itself to the point where a reversal takes just one pulse. However, it adjusts this dynamically throughout the night, and this amount will absolutely vary based on the above factors
I posted some months back that the better approach is to use a conservative TVC value to minimize backlash (that's why it's there) and then use the auto backlash compensation to finish it up.?
Brian
Think I've cracked and eaten this nut. Here is what I did:
1. Renamed the observatory to Sheep Field Observatory.
2. Replaced the two thrust bearings. The ring gear now moves much more easily when the clutch is tightened down.? Also the center point of the ring gear was raising by about 1 thou relative the plate. The worm is now better centered on the ring gear. This change is a big deal, as very effort is now needed rotate the worm.
3. Set the worm mesh using a feeler guide while measuring the backlash. It's important to make sure there are no hi/low spots. This is a periodic error problem and can be felt easily by rotating the coupler back and forth.
4. Installed the motor and measured the backlash with TVC set to zero. I made this measurement using using an Allen key, see pictures. This is very precise way to do it, but I have gone over to an open worn design per the pictures. I counted roughly a 2s backlash, perhaps a bit less. I then set the TVC value. Set to 100 I had no perceivable backlash. It's quite a sensitive thing to set. I have a feeling that folks are using too small a value. There is a chap here (Dave A.) whose mention his backlash was about 3.5s. I would suggest he try a setting in the order of 120 to 150.?
-- Brian?
Brian Valente portfolio
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Re: Needle bearings and axial play, is this a significant performance problem and how difficult is it to fix?
Derek,
I think you misunderstood what I said. Using the Allen key method, I measured the backlash at around 2sec by counting. I then found the appropriate TVC value to completely eliminate the backlash per what I could see. The Allen key method is very precise. Even a fraction of rotational movement is detectable visually. There is no involvement of PHD2. For the record, The 2.5s measured backlash in PHD2 was from last week before I changed out the thrust bearings and devised the Allen method to make measurements during the day and figured out the correct TVC value.
I'm think this argument that PHD2 cannot measure the backlash on the SLW is highly dubious. Backlash is backlash after all.??I would suggest to Losmandy they create a TVC compensation curve that precisely relates the measured backlash value to the correct software compensation value. This way folks can measure their backlash in PHD2 and set the optimal TVC value.
Why it's important and why you should worry about it.?
I could be wrong on this, but If your backlash is say 2.5s and TVC = 0, PHD2 sends out a large 2.5 backlash pulse + guide pulse. It takes the mount 2.5s to respond and take up the backlash. If your guide interval is say 1s, PHD2 will see no movement in Dec and send out another guide pulse. It will then send out a third guide pulse before it registers any movement. It has now sent out a guide pulse 3 time the amplitude of what was intended, and it will then look to compensate for this over correction in the opposite direction. I think this is why the Dec plot can often look so erratic. If say the backlash is under 1s, then it should register the guide pulse and not send out any further unnecessary pulses.?
If the TVC value is set to the correct value, there entire 2.5s backlash will be compensated for almost instantly (I assume because Gemini moves the Dec motor at a faster than guiding rate). However, I have often seen suggested a TVC setting of 10 or 20. Thus is too small a value for this backlash value. It more likely has to be set to between 120 and 150. Really, this has the be properly studied and should be the responsibility of the manufacturer.?
If you are happy with what works for you that great. I'm more focused on getting to the route cause of some of these problems. I do this so you don't have to?
Peter
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Re: 1st time buyer: Recommended knobs other than CKS?
Michael
Herman¡¯s power supply is far superior, though It would still acquire the
Losmandy adapter as a backup..
?
Derek
?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Oberon510
Sent: Thursday, July 15, 2021 4:43
PM
To: [email protected]
Subject: Re: [Losmandy_users_io]
1st time buyer: Recommended knobs other than CKS?
?
I picked up the following
extras for my G11 (check GM11 equivalents - and I got the large tripod so TKS
may not apply also) - if you don't have a power adapter buy one also as they
don't come with the mount.
ACDC?? POWER ADAPTER - 120VAC TO 15VDC @
4.3Amps
CKS??? CLUTCH KNOB SET (2) W/THREE (3) HANDLES, GM-8, G-9 &
G-11 MOUNTS
TKS??? TRIPOD KNOB SET (3) MOUNTS GM-8 OR G-11 TO TRIPOD W/ NO
TO
AKS??? ?? ALTITUDE LOCK KNOB SET (2)
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Re: Needle bearings and axial play, is this a significant performance problem and how difficult is it to fix?
see no visible backlash, yet I still measure 2.5s in guiding assistant.
***
1a)
Stiction and/or 1b) PHD2 is no good at measuring backlash.. They posted an
update earlier this year to make it better, but before that, and on advice I
received from this group, I stopped even worrying about it.. I set my (two
piece / old style) worm to worm wheel mesh at just slightly more pressure than
the weight of the worm and don¡¯t over tighten my clutches and ¡°just guide¡±..
?
Derek
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From: [email protected] [mailto:[email protected]] On Behalf Of pcboreland via groups.io
Sent: Wednesday, July 14, 2021
7:06 AM
To: [email protected]
Subject: Re: [Losmandy_users_io]
Needle bearings and axial play, is this a significant performance problem and
how difficult is it to fix?
?
Alen,
first what a great great piece you wrote on backlash. From the graphs you
posted I might be too tight? Second, you mentioned going to I think guiding
rate and counting. You say you counted 2a before any movement in the worm. When
I do this test it moves immediately and a see no visible backlash, yet I still
measure 2.5s in guiding assistant. What might be going on here?I looks like a
possible clear night so I'm anxious to get this sorted.
Peter?
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Re: Periodic DEC oscillations
Alan, I tried to search on ¡°forward lash¡± and all I got was links to custom eyelash extensions !?
What physical cause are you describing with this term??
--
Edward
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Re: At some point, I may begin commenting on the G11 DEC axis...
Allen,
You can set the step size on he brain/algorithm form. Default is 500ms.
Are you imaging or viewing with this scope. I have a 12" F4 truss Newtonian. I figure with all the added gear for imaging it has got the weight at least 65-70lbs. The focuser and motor weigh in at 5lbs or more. I can go OAG and drop the guide scope to reduce weight a bit, and improve center of balance. Would love to see a picture of your final setup.
Also, what TVC value are you using? I found that I can reduce backlash to the point of not being able to visually see any per my Allen key trick. If you are at 1s, I would think the value ought to be 50 or a bit more. A graph needs to be plotted perhaps to set the right value. I.e. Measure backlash in guiding assistant and set TVC accordingly per a graph.
Peter
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Re: Needle bearings and axial play, is this a significant performance problem and how difficult is it to fix?
Think I've cracked and eaten this nut. Here is what I did:
1. Renamed the observatory to Sheep Field Observatory.
2. Replaced the two thrust bearings. The ring gear now moves much more easily when the clutch is tightened down. ?Also, the center point of the ring gear was raising by about 1 thou relative the plate. The worm is now better centered on the ring gear. This change is a big deal, as very little effort is now needed to rotate the worm.
3. Set the worm mesh using a feeler guide while measuring the backlash. It's important to make sure there are no hi/low spots. This is a periodic error problem and can be felt easily by rotating the coupler back and forth. Alignment of the two bearings black is critical, see picture below.
4. Installed the motor, make sure it is aligned, and measured the backlash with TVC set to zero. I made this measurement using using an Allen key, see pictures. This is very precise way to do it, but I have gone over to an open worn design per the pictures. I counted roughly a 2s backlash, perhaps a bit less. I then set the TVC value. Set at 100 there was no? perceivable backlash.? I will measure using guiding assistant in near at first opportunity. It's quite a sensitive thing to set. I have a feeling that folks are using too small a value. There is a chap here (Dave A.) whose mentioned his backlash was about 3.5s. I would suggest he try a setting in the order of 120 to 150.?
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Re: Needle bearings and axial play, is this a significant performance problem and how difficult is it to fix?
John,
Alignment was not an issue with the third bearing. I estimate the shaft if 3-5 thou undersize. I think this was done intentionally by Losmandy for various reasons. Chrome plating might be an option, but I'm not going to spend anymore time on this as the slop as Alen137 has pointed out had no perceivable impact on backlash, but it would appear in the FFT analysis as a large low frequency component, which I think it does, but guides out.
Peter
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Re: Runaway slew while using PHD2
Alan?
You are thinking it's a software conflict.? Your mount is selected in Stellaium as ASCOM and your chooser comes up. Make sure that shows the correct mount type.? If it defaults to Titan, I think it will slew further than a G11.?? I doubt that is wrong because you do get the correct position sometimes.?
I wonder if this is an intermittent hardware issue...either of 3 causes:
DEC cable.? ?Try switching cables and see if the problem switches to RA. ( I'll be home on Tuesday and I have a spare new DEC cable you can try.)
Bad DEC motor encoder ? ?Try switching motors ? ?(I have a spare new HiTorque motor you can try)
Bad Gemini input socket. (Brendan Smith mentioned this affecting some G2 he has repaired.)? There have been reports of a week solder connection at the G2 board to DIN socket.? You might look for such a thing....maybe a crack in the soldering or crack in the socket itself.? Your system is from March 2021 so you'd ask the factory for a new G-2 replacement.??
Best of luck tracing the problem.
Michael
OK, it happened again.? This time, that PHD2 checkbox was clicked.
All I did was GOTO (under stellarium) a nearby star to center in the field of view for focusing.
Then the mount started running away with no STOP button.
I ran over and shut off the mount.
Then warm restart.
Reconnect under Stellarium.
The mount knew where it's new position was, so therefore I don't blame an uncontrolled motor.
Manually slew back to original position.
Plate solve.? Yup, the reported position was correct.? However, the DEC axis didn't move, only the RA, during the runaway.
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Re: Runaway slew while using PHD2
OK, it happened again.? This time, that PHD2 checkbox was clicked.
All I did was GOTO (under stellarium) a nearby star to center in the field of view for focusing.
Then the mount started running away with no STOP button.
I ran over and shut off the mount.
Then warm restart.
Reconnect under Stellarium.
The mount knew where it's new position was, so therefore I don't blame an uncontrolled motor.
Manually slew back to original position.
Plate solve.? Yup, the reported position was correct.? However, the DEC axis didn't move, only the RA, during the runaway.
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Re: Needle bearings and axial play, is this a significant performance problem and how difficult is it to fix?
Peter,
If I am understanding what you are doing here you now have 3 bearings with less play replacing the looser original 2. Each of the new bearings has less freedom for the shaft to rock up and down or back and forth, or any direction. Therefore each bearing needs to be more perfectly centered on axis to allow free shaft rotation. The present bearing seats may not have that level of alignment precision, one could be off center from the rest, or perhaps tilted at an angle. Therefore when you are locking down the clutches, you are further pulling in any axially play. Now you could have a situation where the shaft is being pressed in from the sides by the needles being at different distances from shaft axis center and you are creating pinch points. I agree with Alan that you should be testing shaft rotation by hand with no worm engaged to see if you can still rotate with normal forces, and not binding up under pressure. You might be reducing shaft play, but don't have enough tolerance left for normal shaft rotation.
Just thinking out loud. You would need to test torque values to confirm what your adjustments/modifications are actually doing.
Best regards.
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Re: Needle bearings and axial play, is this a significant performance problem and how difficult is it to fix?
On Sat, Jul 17, 2021 at 04:36 PM, <pcboreland@...> wrote:
I think I may have discovered something interesting regarding why it is so difficult to both reduce and get a consistent backlash value for Dec.
After changing out the needle bearings, and adding a third, I noticed how stiff the worm gear was to turn after I had tightened the clutch. When I later measured my backlash I had actually gone from 2500ms to close to 4000ms, even though a visual inspection of the mesh seemed good. Actually, I set the mesh with the clutch undone, using finger feel to sense if the alignment was good (no high-low spots) and little to no blacklash. The loading placed on thrust bearings seem to be were the problem resides. I ordered new clutch plates and just received new thrust bearings from McMaster- Carr. I'm concerned by the stiffness and I think this means considerable pressure has to build up before there is any rotational movement in the worm. This pressure (force) has the created in the gearbox and coupler. This is both bad for the gearbox and means a large backlash.?
Peter
This is totally expected. Remember I said there were three concentric parts of the DEC axis: a) the saddle and 1.25" shaft b) the assembly that holds the ring gear (which I have never taken apart, so I don't know much about it) c) the black outer anodized body Part b) rides on it's own set of bearings that you don't see.? When everything is put together, tightening the clutch knob pulls a) downwards against c).? The clutch pad itself pushes b) downwards relative to c).? Well, c) holds the worm and b) holds the ring gear, so you'd expect the ring gear to move down a LITTLE bit, depending on what the bearing preload characteristics are.? With that said what's important for low backlash is that the axis still turns freely when the clutch is engaged.? To test the b) bearings, remove the worm (or push it out of the way), loosen the clutch knob all the way, push down hard on the saddle dovetail with your palm, and see if the axis still rotates freely.? All bearings should rotate with minimal friction, and even the innermost needle bearings because they aren't loaded by the weight of the scope and counterweights. Next, with the worm still out of the way,? Pull UP hard on the dovetail and try to rotate it.? Now you are testing the needle thrust bearing that is part of the clutch knob assembly.? BTW, did you rearrange the spacers so that there is a thick spacer between the wavy washer and the thrust bearing?? Because that would be pretty dumb to have the wavy washer pushing against the bearing surface.? (There should be a set of rollers and two thin plates for the bearing assembly, and a correct orientation) Next, start to tighten the clutch knob and see if the friction increases.? On my G8 DEC axis, it increased a little bit, but on the G11 it is still fairly free to turn even with moderate clutch pressure. Finally, with the worm still out of the way, load up the counterweights and a sacrificial scope ;) to see if the DEC spins freely with the clutch tightened somewhat.? NOW you are testing out the inner needle bearings with a realistic radial load. With all that said, adjust the worm pressure / spacing with the clutch engaged the "usual" amount.? Also, yes, too tight worm mesh can increase backlash.? Also, too much axis friction can increase backlash.
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Re: Needle bearings and axial play, is this a significant performance problem and how difficult is it to fix?
Peter,
Glad to read your last posting, not your "hit by lightning" obituary!? ?What a story!
You may need a lightning rod near your observatory.??
On to the question: why does your clutch force affect your worm to ring gear spacing?? Ideally, it should have no effect, but you are not the first to report that it does have an effect. I always wondered what's causing this effect, as it is not observed on my systems.
So let's think it through.? Something on your system is getting distorted by the tightening of your clutch knob. The distortion is changing the worm to ring gear mesh.? What piece is distorting causing the worm to tighten or loosen on the ring gear teeth???
In worm drive systems, one critical setting is the center of the worm gear axis (center of the worm long axis) to the center of the ring gear teeth (center plane of the ring gear.)
Like this:.? --- ((((o ---- with the (((( being the ring gear and the o being the worm seen end on.? The center of these is supposed to be equal height on the center level I indicated with? dashes? ----
Looking from the top down, the axes are composed of:
Upper part of axis ...dovetail if DEC say Bottom of upper clutch surface Clutch disk (soft) Ring gear ((((( upper surface? ? ?is the top of the lower clutch surface Top race of the thrust bearing (thicker plate) Rotating center of the thrust bearing Bottom race of the thrust bearing (thin plate) Thick mounting plate, holding the worm gear bearing blocks. Mount axis body (thick aluminum cylinder) Bottom thrust bearing Bottom clutch knob
From that construction it seems impossible to shift the ring gear to worm gear height just from axial compression.?
But the ring gear is a metal disk and is being pulled from the center.? ?Can that ring gear disk curve down in the center from the high force, and curve up at the outer edge?? That must mean the upper flat surface is distorting also.? Seems unlikely....but all those arts are aluminum.? If the worm gear gets tight all the way around 360 degrees rotation this may be what's going on.
Or else something else must be shifting.?? ?I think you found you have a slight gap between the 1.25 inch shaft and the needle bearings.? If that were present, consider another possible movement:? We now know there can be a gap between the 1.25 inch steel shaft and the tubular needle bearings inside the mount axis body.? It is therefore possible that the axial force causes the ring gear to shift or? "tilt" in the axis body.? The ring gear could tilt toward or away from the worm.? That is, the axial force causes the 1.25 inch shaft to go slightly non perpendicular.? As you rotate the axis around 360 degrees you would find one side would go "tight" and the area 180 degrees would go loose.? That would be the test for that effect.
If the latter is the problem, I'd ask Losmandy to replace the 1.25 inch shaft with a larger OD shaft.? That should eliminate the gap and the potential for tilt during clutch force changes.??
It is also a benefit to reduce clutch force as much as possible yet maintain the grip.? I recommend you try my high friction clutch disk to reduce clutch pressure, and reduce distortion of the mount materials.??
Anyway, I feel that somehow your undersized 1.25 inch shaft is the root cause of your worm to ring gear difficulties.? I think that can be addressed by the factory.? I know you are trying to solve this by needle bearings, but I think the alternative answer could be the shaft replacement.??
I think if you can get to the bottom of your puzzle it will help others know what issue to look for.??
All the best, Michael
I think I may have discovered something interesting regarding why it is so difficult to both reduce and get a consistent backlash value for Dec.
First, while out in the field disassembling my mount for the umpteen time, I had a very close call. Focused on the work at hand, I did not notice a thunderstorm moving in over head. Once I became aware of the suituation, I closed the observatory roof and started heading back to the house, when I felt a strange sensation, followed by a crackly noise, and I immediately hit the group. Almost instantaneously I heard and felt the crack of lightning. Several minutes later fire engines arrive at my neighbors house less than 800 feet from where I was standing. I never thought of this as a dangerous hobby?
After changing out the needle bearings, and adding a third, I noticed how stiff the worm gear was to turn after I had tightened the clutch. When I later measured my backlash I had actually gone from 2500ms to close to 4000ms, even though a visual inspection of the mesh seemed good. Actually, I set the mesh with the clutch undone, using finger feel to sense if the alignment was good (no high-low spots) and little to no blacklash. The loading placed on thrust bearings seem to be were the problem resides. I ordered new clutch plates and just received new thrust bearings from McMaster- Carr. I'm concerned by the stiffness and I think this means considerable pressure has to build up before there is any rotational movement in the worm. This pressure (force) has the created in the gearbox and coupler. This is both bad for the gearbox and means a large backlash.?
I will post my findings with the new parts next week.
Peter
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Re: Runaway slew while using PHD2
On Sat, Jul 17, 2021 at 12:49 AM, "Guilherme V¨ºnere wrote:
Alan
?
How do you have your mount limits configured? Did you use the default limit or MI-250 or did you customized them?
?
I had the same issue as yours and it fixed for me after I changed the mount limits from the default?
?
Guilherme?
Eastern position: 100 Western position:112 Western Goto Limit 2:18
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Re: Runaway slew while using PHD2
Alan,
This really sounds like the issue I has 3 years ago when the Beta ware was created. I had runaway slews when GoTo commands were sent from SGPro. At that time I recall sending my Gemini logs to Rene G. in Europe who interpreted and wrote the work around. This may be a communication issue between apps. Why the same fix does not work for you might involve some code analysis, which not in my skill set. You might see if you can get HGM to involve the appropriate parties and what they might need from you to proceed. Or if there is a second Windows machine you can use to operate the mount, you may want start fresh. I have had cameras that would not operate on my laptop, only to work fine from a new dedicated desktop. Each had the same software packages but only the latter would work. Hope you find a solution.
JK
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Re: Needle bearings and axial play, is this a significant performance problem and how difficult is it to fix?
I think I may have discovered something interesting regarding why it is so difficult to both reduce and get a consistent backlash value for Dec.
First, while out in the field disassembling my mount for the umpteen time, I had a very close call. Focused on the work at hand, I did not notice a thunderstorm moving in over head. Once I became aware of the suituation, I closed the observatory roof and started heading back to the house, when I felt a strange sensation, followed by a crackly noise, and I immediately hit the group. Almost instantaneously I heard and felt the crack of lightning. Several minutes later fire engines arrive at my neighbors house less than 800 feet from where I was standing. I never thought of this as a dangerous hobby?
After changing out the needle bearings, and adding a third, I noticed how stiff the worm gear was to turn after I had tightened the clutch. When I later measured my backlash I had actually gone from 2500ms to close to 4000ms, even though a visual inspection of the mesh seemed good. Actually, I set the mesh with the clutch undone, using finger feel to sense if the alignment was good (no high-low spots) and little to no blacklash. The loading placed on thrust bearings seem to be were the problem resides. I ordered new clutch plates and just received new thrust bearings from McMaster- Carr. I'm concerned by the stiffness and I think this means considerable pressure has to build up before there is any rotational movement in the worm. This pressure (force) has the created in the gearbox and coupler. This is both bad for the gearbox and means a large backlash.?
I will post my findings with the new parts next week.
Peter
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Edward Plumer
Michael Herman