Re: Reducing DEC Backlash with Titan 50
? Thanks Michael for the comments. Fortunately at this time I only have one issue. That is when I am starting out in the lower east imaging, I have nice round stars with 10 min subs. But as the Counter weight Shaft and weights begin to pass the 45 degree angle, I begin to have more flattened stars. As it gets closer to the Meriden I get round stars again. I think I might have too much east bias on the weights. I am getting about 1+/- Arcseconds PEC when guiding. But I have to use the onboard PEC function. I have noticed that if you want good results with the G2 PEC you pretty much have to run it on each target as you begin each DSO. If you do it that way it will work on both sides of the Meriden. I use Maxim DL 6. for guiding and an SX Superstar. My Telescope is the AT 10¡± RC with CF Arms and shroud and 60 mm guide scope so I am caring about 50 LBS load with my heavy camera. ? Aubrey ? ? Sent from for Windows 10 ?
toggle quoted message
Show quoted text
From: Michael HermanSent: Saturday, May 8, 2021 4:08 PM To: [email protected]Subject: Re: [Losmandy_users_io] Reducing DEC Backlash with Titan 50 ? Aubrey, It's the RA that this matters most on a Titan RA drive.? Variable friction causes the drive speed to slow then speed up...it's either periodic or non periodic error.? Either way you want it to be near zero friction.? That's what the bearings are for.? But the worm has the ring gear and no bearings at that interface...just friction.? So that needs the best lube and that's the question.?? You also want near zero backlash else you get autoguiding time lags and hysteresis that PHD2 does not like.? So that's the other end of the coin....no friction but no autoguiding!?? Between those two extremes is the optimization point.? Springs can help if they keep the surfaces in contact but not too tightly.? Lubes are essential to minimize friction. Aligning bearings to keep balls from pinching (the Titan has these bearings in a massive cylindrical sleeve...they can't go off axis...the OVision worm did this for the G11 and they used a Belleville R4 spring washer for the end bearing). Have fun,...get some nice images! ? Thank you. I have always just tightened my endcap down and did not notice it. I will check it out when it gets it¡¯s annual oil change. ? Thanks ? Aubrey ? Sent from for Windows 10 ? ? it¡¯s a spring washer rather than a spring, and is housed inside the worm block assembly.
Regards,
? -Paul
On Sat, May 8, 2021 at 12:47 PM, Aubrey Brickhouse wrote:
Can I ask a question on this subject. I have a fairly new Titan and I have never seen a spring in the assembly. I have relubed it several times but have never taken out the worm and so I can not say if mine has one or not. ? Thanks ? Aubrey Brickhouse ? Sent from for Windows 10 ? ? Dan, yes, indeed. I have a Titan50 and a G11 :)
The spring loaded adjustment I'm talking about is not for the whole worm block -- it's at the end of the worm block, on the opposite side of the gearbox. It pushes a spring-loaded bearing into the worm block, preventing it from moving horizontally, side-to-side. It may look like this, below, or have a single slot that you can use a screw-driver or a quarter to turn. If it's not pushed in far enough, the worm will float left to right:
Regards,
? ?-Paul
On Sat, May 8, 2021 at 10:27 AM, <dkfcpalfd@...> wrote: Paul:
Thanks for responding.? Do you have a Titan?? Losmandy has been telling me that they came out with spring-loaded worms for the G11, but not the Titan.? When I first heard about the spring-loaded worms for the G11, I initially was told that feature was in development for the Titan.? Then, several months later, that went away, and I have been hearing from them that spring-loaded worms may never happen for Titan.
Right now, I'm going to try adjusting up the TVC on the HC.... the Gemini-2 website says that is a built-in DEC backlash compensation adjustment that is available.
|
Re: Reducing DEC Backlash with Titan 50
This might help. The vid was made in 2017 by Scott himself. He is adjusting a G11 but the principles are the same for the Titan.
On Sunday, May 9, 2021, 5:08:18 AM GMT+8, Michael Herman <mherman346@...> wrote:
Aubrey,
It's the RA that this matters most on a Titan RA drive.? Variable friction causes the drive speed to slow then speed up...it's either periodic or non periodic error.? Either way you want it to be near zero friction.? That's what the bearings are for.? But the worm has the ring gear and no bearings at that interface...just friction.? So that needs the best lube and that's the question.??
You also want near zero backlash else you get autoguiding time lags and hysteresis that PHD2 does not like.? So that's the other end of the coin....no friction but no autoguiding!??
Between those two extremes is the optimization point.? Springs can help if they keep the surfaces in contact but not too tightly.? Lubes are essential to minimize friction. Aligning bearings to keep balls from pinching (the Titan has these bearings in a massive cylindrical sleeve...they can't go off axis...the OVision worm did this for the G11 and they used a Belleville R4 spring washer for the end bearing).
Have fun,...get some nice images!
Michael
Thank you. I have always just tightened my endcap down and did not notice it. I will check it out when it gets it¡¯s annual oil change. ? Thanks ? Aubrey ? Sent from for Windows 10 ? ? it¡¯s a spring washer rather than a spring, and is housed inside the worm block assembly.
Regards,
? -Paul
On Sat, May 8, 2021 at 12:47 PM, Aubrey Brickhouse wrote:
Can I ask a question on this subject. I have a fairly new Titan and I have never seen a spring in the assembly. I have relubed it several times but have never taken out the worm and so I can not say if mine has one or not. ? Thanks ? Aubrey Brickhouse ? Sent from for Windows 10 ? ? Dan, yes, indeed. I have a Titan50 and a G11 :)
The spring loaded adjustment I'm talking about is not for the whole worm block -- it's at the end of the worm block, on the opposite side of the gearbox. It pushes a spring-loaded bearing into the worm block, preventing it from moving horizontally, side-to-side. It may look like this, below, or have a single slot that you can use a screw-driver or a quarter to turn. If it's not pushed in far enough, the worm will float left to right:
![]()
Regards,
? ?-Paul
On Sat, May 8, 2021 at 10:27 AM, <dkfcpalfd@...> wrote: Paul:
Thanks for responding.? Do you have a Titan?? Losmandy has been telling me that they came out with spring-loaded worms for the G11, but not the Titan.? When I first heard about the spring-loaded worms for the G11, I initially was told that feature was in development for the Titan.? Then, several months later, that went away, and I have been hearing from them that spring-loaded worms may never happen for Titan.
Right now, I'm going to try adjusting up the TVC on the HC.... the Gemini-2 website says that is a built-in DEC backlash compensation adjustment that is available.
|
Re: Reducing DEC Backlash with Titan 50
Aubrey,
It's the RA that this matters most on a Titan RA drive.? Variable friction causes the drive speed to slow then speed up...it's either periodic or non periodic error.? Either way you want it to be near zero friction.? That's what the bearings are for.? But the worm has the ring gear and no bearings at that interface...just friction.? So that needs the best lube and that's the question.??
You also want near zero backlash else you get autoguiding time lags and hysteresis that PHD2 does not like.? So that's the other end of the coin....no friction but no autoguiding!??
Between those two extremes is the optimization point.? Springs can help if they keep the surfaces in contact but not too tightly.? Lubes are essential to minimize friction. Aligning bearings to keep balls from pinching (the Titan has these bearings in a massive cylindrical sleeve...they can't go off axis...the OVision worm did this for the G11 and they used a Belleville R4 spring washer for the end bearing).
Have fun,...get some nice images!
Michael
Thank you. I have always just tightened my endcap down and did not notice it. I will check it out when it gets it¡¯s annual oil change. ? Thanks ? Aubrey ? Sent from for Windows 10 ? ? it¡¯s a spring washer rather than a spring, and is housed inside the worm block assembly.
Regards,
? -Paul
On Sat, May 8, 2021 at 12:47 PM, Aubrey Brickhouse wrote:
Can I ask a question on this subject. I have a fairly new Titan and I have never seen a spring in the assembly. I have relubed it several times but have never taken out the worm and so I can not say if mine has one or not. ? Thanks ? Aubrey Brickhouse ? Sent from for Windows 10 ? ? Dan, yes, indeed. I have a Titan50 and a G11 :)
The spring loaded adjustment I'm talking about is not for the whole worm block -- it's at the end of the worm block, on the opposite side of the gearbox. It pushes a spring-loaded bearing into the worm block, preventing it from moving horizontally, side-to-side. It may look like this, below, or have a single slot that you can use a screw-driver or a quarter to turn. If it's not pushed in far enough, the worm will float left to right:
![]()
Regards,
? ?-Paul
On Sat, May 8, 2021 at 10:27 AM, <dkfcpalfd@...> wrote: Paul:
Thanks for responding.? Do you have a Titan?? Losmandy has been telling me that they came out with spring-loaded worms for the G11, but not the Titan.? When I first heard about the spring-loaded worms for the G11, I initially was told that feature was in development for the Titan.? Then, several months later, that went away, and I have been hearing from them that spring-loaded worms may never happen for Titan.
Right now, I'm going to try adjusting up the TVC on the HC.... the Gemini-2 website says that is a built-in DEC backlash compensation adjustment that is available.
|
Re: Reducing DEC Backlash with Titan 50
Thank you. I have always just tightened my endcap down and did not notice it. I will check it out when it gets it¡¯s annual oil change. ? Thanks ? Aubrey ? Sent from for Windows 10 ?
toggle quoted message
Show quoted text
From: Paul KanevskySent: Saturday, May 8, 2021 12:57 PM To: [email protected]Subject: Re: [Losmandy_users_io] Reducing DEC Backlash with Titan 50 ? it¡¯s a spring washer rather than a spring, and is housed inside the worm block assembly.
Regards,
? -Paul
On Sat, May 8, 2021 at 12:47 PM, Aubrey Brickhouse wrote:
Can I ask a question on this subject. I have a fairly new Titan and I have never seen a spring in the assembly. I have relubed it several times but have never taken out the worm and so I can not say if mine has one or not. ? Thanks ? Aubrey Brickhouse ? Sent from for Windows 10 ? ? Dan, yes, indeed. I have a Titan50 and a G11 :)
The spring loaded adjustment I'm talking about is not for the whole worm block -- it's at the end of the worm block, on the opposite side of the gearbox. It pushes a spring-loaded bearing into the worm block, preventing it from moving horizontally, side-to-side. It may look like this, below, or have a single slot that you can use a screw-driver or a quarter to turn. If it's not pushed in far enough, the worm will float left to right:
Regards,
? ?-Paul
On Sat, May 8, 2021 at 10:27 AM, <dkfcpalfd@...> wrote: Paul:
Thanks for responding.? Do you have a Titan?? Losmandy has been telling me that they came out with spring-loaded worms for the G11, but not the Titan.? When I first heard about the spring-loaded worms for the G11, I initially was told that feature was in development for the Titan.? Then, several months later, that went away, and I have been hearing from them that spring-loaded worms may never happen for Titan.
Right now, I'm going to try adjusting up the TVC on the HC.... the Gemini-2 website says that is a built-in DEC backlash compensation adjustment that is available.
|
Re: Reducing DEC Backlash with Titan 50
WOW.... I need to consult with you guys when I'm ready to try tackling lubricating inside the worm blocks.
I said previously that I cranked the TVC (DEC Backlash Comp) from 0 up to 5 on the Gemini 2 HC.? However, it dawned on me the reason why it was set to 0.? I now remember having read some PHD2 documentation stating that if you want to use PHD2 for DEC Backlash Compensation, you need to turn that feature off on your mount, because the two can conflict and work against each other.? So, for now, I cranked it back to 0, and will try running GA again tonight with only having torqued the block end plug.? If I still have poor test results with the GA test, I'll try cranking TVC back to 5.
We will see.
Dan
|
Re: Reducing DEC Backlash with Titan 50
Nice conversation! We normally don't hear about Titan drives as they are rarer than the G11 or GM8 or GM811.
I got a Titan RA drive on my G11T.? I asked Mr Losmandy at his shop how much torque should be on the 4-hole end retainer threaded (~30 mm OD ) plug.? He said "Just touching."
That did not work well for me, as over temperature changes, the pressure from the end cap on the worm bearings could get too tight or too loose.? So I added 2 Belleville spring washers for that sized bearing (30 mm OD 10 mm ID) cup to cup so the outer edges of the spring pair touch the worm bearing and at the end of the 30mm plug.? This gives about 1mm of extra plug compression room for temperature expansion.? If there is no compression... just touching...there is zero force on the worm bearings.? But you can get as much force as you like by torquing the threaded plug in with the spanner wrench.? So I compressed it about 1/8 yo 1/4 turn to give a light, and adjustable force.? This force will not change much as the temperature changes because the springs will just expdmd or compress very slightly.??
Paul's note suggests he or maybe the Losmandy originally put in a Belleville spring in at an earlier time.? My G11T had no spring in the Titan drive to start with.??
Here are some photos of the drive and showing the Belleville springs I used.? I have some left so if you need a few contact me.? My "spanner wrench" (USA usage...I think in UK it can mean something else) is an inexpensive tool I got off eBay long ago.? There are many types on the market, and are used extensively for automotive C clips.?
I also tried to measure the worm thread center to ring gear center. That is supposed to be as close to the same level as possible for worm drives...a critical adjustment.? It was almost dead center, but my measurements showed also the need for a tiny maybe 0.02 inch shim under the worm block.? I used some thin brass shim stock for that (also off eBay).? Here are some pictures of that.??
The worm to ring gear should be as low friction as possible. Otherwise you can experience "chatter" as the ring gear is vibrated like a violin string by the movement of the worm gear acting like the "bow".? I tried Superlube ("Cincolon" Teflon only) there but it did not suffice...still chattered.? I tried a product called CRC Brake and Caliper Grease (MolyD, Graphite, and Teflon in an anticorrosion grease) and this eliminated the ring gear chatter.? I thought that ring gear chatter issue from worm friction would not be a problem for DEC only RA, but recent discussion of a DEC glitch also causing an RA glitch makes me wonder!
That's not all... my G11T drive story is not finished yet.? I'm still comparing the 3 gear tucked motor drive to a belt drive to see what's lowest for PE.? ?I have switched already to a McLennan 25:1 gearbox.? My PE with the belt drive is running 1.77 arcsec RMS and no trouble in autoguiding to round stars in 500 sec exposures.??
Have fun, Michael ??
On Sat, May 8, 2021, 11:57 AM Paul Kanevsky < yh@...> wrote: it¡¯s a spring washer rather than a spring, and is housed inside the worm block assembly.
Regards,
? -Paul
On Sat, May 8, 2021 at 12:47 PM, Aubrey Brickhouse wrote:
Can I ask a question on this subject. I have a fairly new Titan and I have never seen a spring in the assembly. I have relubed it several times but have never taken out the worm and so I can not say if mine has one or not.
?
Thanks
?
Aubrey Brickhouse
?
Sent from for Windows 10
?
?
Dan, yes, indeed. I have a Titan50 and a G11 :)
The spring loaded adjustment I'm talking about is not for the whole worm block -- it's at the end of the worm block, on the opposite side of the gearbox. It pushes a spring-loaded bearing into the worm block, preventing it from moving horizontally, side-to-side. It may look like this, below, or have a single slot that you can use a screw-driver or a quarter to turn. If it's not pushed in far enough, the worm will float left to right:
![]()
Regards,
? ?-Paul
On Sat, May 8, 2021 at 10:27 AM, <dkfcpalfd@...> wrote:
Paul:
Thanks for responding.? Do you have a Titan?? Losmandy has been telling me that they came out with spring-loaded worms for the G11, but not the Titan.? When I first heard about the spring-loaded worms for the G11, I initially was told that feature was in development for the Titan.? Then, several months later, that went away, and I have been hearing from them that spring-loaded worms may never happen for Titan.
Right now, I'm going to try adjusting up the TVC on the HC.... the Gemini-2 website says that is a built-in DEC backlash compensation adjustment that is available.
|
Re: Counterbalance weight calculation for rig
Sry I was a bit fast in answering and didn't read properly.
Perhaps you can use some water bottles to test how it balances, here in Europe we have 6 packs of 1.5l that'0s a pretty good match.
Place your 11 lbs approx 2.75" away from the clutch knob and your water pack? in between (at 2.75" the 21 CW would be approx. 0.6" away from the knob...
|
Re: Counterbalance weight calculation for rig
The idea being your counterweights should the closer to the? beginning of the counterweight rod.
(Same torque, but not the same moment of inertia)
|
Re: Counterbalance weight calculation for rig
Depending on your maximum, and your gear, I would go for
- 21 + 11 lbs counterweights if your gear weight is close enough o the saddle plate or over 33 lbs
- 21 + 7 lbs?counterweights otherwise
- 21 + 21 + 7 (or 11) lbs if you plan to add heavier gear in the future
Personally my gear is 53 lbs (SW Esprit 150 + accessories), and I have two 21 lbs that are at the beginning of the counterweight bar and one 11 lbs at the end.
|
Counterbalance weight calculation for rig
I need to add weights to my G811G for a minimum 30lb imaging rig and thought I'd ask this group for advice on how much additional counterweight would be needed beyond the provided 11lbs that came with the mount. Would the 21lb weight be excessive? Any response is appreciated.
|
Re: Reducing DEC Backlash with Titan 50
it¡¯s a spring washer rather than a spring, and is housed inside the worm block assembly.
Regards,
? -Paul
On Sat, May 8, 2021 at 12:47 PM, Aubrey Brickhouse wrote:
Can I ask a question on this subject. I have a fairly new Titan and I have never seen a spring in the assembly. I have relubed it several times but have never taken out the worm and so I can not say if mine has one or not.
?
Thanks
?
Aubrey Brickhouse
?
Sent from for Windows 10
?
?
Dan, yes, indeed. I have a Titan50 and a G11 :)
The spring loaded adjustment I'm talking about is not for the whole worm block -- it's at the end of the worm block, on the opposite side of the gearbox. It pushes a spring-loaded bearing into the worm block, preventing it from moving horizontally, side-to-side. It may look like this, below, or have a single slot that you can use a screw-driver or a quarter to turn. If it's not pushed in far enough, the worm will float left to right:
Regards,
? ?-Paul
On Sat, May 8, 2021 at 10:27 AM, <dkfcpalfd@...> wrote:
Paul:
Thanks for responding.? Do you have a Titan?? Losmandy has been telling me that they came out with spring-loaded worms for the G11, but not the Titan.? When I first heard about the spring-loaded worms for the G11, I initially was told that feature was in development for the Titan.? Then, several months later, that went away, and I have been hearing from them that spring-loaded worms may never happen for Titan.
Right now, I'm going to try adjusting up the TVC on the HC.... the Gemini-2 website says that is a built-in DEC backlash compensation adjustment that is available.
|
Re: Reducing DEC Backlash with Titan 50
Excellent.... you're the man.? I tried unscrewing it, and it is indeed frozen.??
But wait.... I kept scratching my head.... I knew I had an adjustable pin spanning tool somewhere.... but couldn't remember.? All of a sudden it dawned on me.... for changing wheels on a hand grinder.
Attached is the perfect tool.? I checked the torque on both plugs.... RA and DEC.? I would say it could have been construed as loose..... no torque on it.? I loosened both plugs, and torqued them.... did not put all my weight into it, but much more torque than I had.
I slewed all around with no stalls and no strange sounds with either axis.
I will try this out tonight.? Thanks!!!
|
Re: Reducing DEC Backlash with Titan 50
Can I ask a question on this subject. I have a fairly new Titan and I have never seen a spring in the assembly. I have relubed it several times but have never taken out the worm and so I can not say if mine has one or not. ? Thanks ? Aubrey Brickhouse ? Sent from for Windows 10 ?
toggle quoted message
Show quoted text
From: Paul KanevskySent: Saturday, May 8, 2021 9:36 AM To: [email protected]Subject: Re: [Losmandy_users_io] Reducing DEC Backlash with Titan 50 ? Dan, yes, indeed. I have a Titan50 and a G11 :)
The spring loaded adjustment I'm talking about is not for the whole worm block -- it's at the end of the worm block, on the opposite side of the gearbox. It pushes a spring-loaded bearing into the worm block, preventing it from moving horizontally, side-to-side. It may look like this, below, or have a single slot that you can use a screw-driver or a quarter to turn. If it's not pushed in far enough, the worm will float left to right:
Regards,
? ?-Paul
On Sat, May 8, 2021 at 10:27 AM, <dkfcpalfd@...> wrote: Paul:
Thanks for responding.? Do you have a Titan?? Losmandy has been telling me that they came out with spring-loaded worms for the G11, but not the Titan.? When I first heard about the spring-loaded worms for the G11, I initially was told that feature was in development for the Titan.? Then, several months later, that went away, and I have been hearing from them that spring-loaded worms may never happen for Titan.
Right now, I'm going to try adjusting up the TVC on the HC.... the Gemini-2 website says that is a built-in DEC backlash compensation adjustment that is available.
|
Re: Reducing DEC Backlash with Titan 50
The tool to adjust it is called a pin spanner wrench, but yes, you can fashion something that would work from screws or even a long nail or two. It may be that that part has seized up and can't move, I'd try to unscrew it slightly and then screw it back in.
On a Titan, there should be no reason for large backlash, since you can move the worm block as close as you want to the worm-wheel. On the non-spring loaded G11, the issue was that the motor/gearbox axes were fixed to the mount and couldn't be moved. As the result, any adjustment to the worm to push it closer to the wheel could result in an offset or even an angle between the worm and the gearbox axes. On a Titan, the worm block contains and moves with the motor, so with careful adjustment you should always be able to find a distance where the worm/wheel don't lock up and yet produce very little backlash.
Regards,
? ? -Paul
toggle quoted message
Show quoted text
On Sat, May 8, 2021 at 11:19 AM, <dkfcpalfd@...> wrote:
WOW.... thanks for that, Paul.? I talked to Scott about this recently, and he brought up about the plug with the 4 holes on the end of the block.? What he said was that it needs to be tight, or a bearing will float around in there.? I checked it, and it is tight.? Are you saying I need to put more torque on it, with some special tool?? All I know now is that it is tight.
Maybe it would be useful to loosen it and re-tighten it?
Right now, whether it will make a difference is yet to be seen, but I checked the TVC value on G2 in the HC.? The Gemini-2 website shows an example of that value being set to 5.? It was 0 when I just checked my HC.? I set it to 5, and parked/turned off the mount.? I went back into TVC.... still showing 5, so it was saved.... we'll try that.
Let me know if I need to do something different on the 4 hole plug.... and whether there is a special tool for it.
Edit:? OK... I see you mentioned quarter or screwdriver to turn the plug.? Scott mentioned anything could be used.... even a screw.
Thanks so much.
Dan
|
Re: Reducing DEC Backlash with Titan 50
WOW.... thanks for that, Paul.? I talked to Scott about this recently, and he brought up about the plug with the 4 holes on the end of the block.? What he said was that it needs to be tight, or a bearing will float around in there.? I checked it, and it is tight.? Are you saying I need to put more torque on it, with some special tool?? All I know now is that it is tight.
Maybe it would be useful to loosen it and re-tighten it?
Right now, whether it will make a difference is yet to be seen, but I checked the TVC value on G2 in the HC.? The Gemini-2 website shows an example of that value being set to 5.? It was 0 when I just checked my HC.? I set it to 5, and parked/turned off the mount.? I went back into TVC.... still showing 5, so it was saved.... we'll try that.
Let me know if I need to do something different on the 4 hole plug.... and whether there is a special tool for it.
Edit:? OK... I see you mentioned quarter or screwdriver to turn the plug.? Scott mentioned anything could be used.... even a screw.
Thanks so much.
Dan
|
Re: Reducing DEC Backlash with Titan 50
Dan, yes, indeed. I have a Titan50 and a G11 :)
The spring loaded adjustment I'm talking about is not for the whole worm block -- it's at the end of the worm block, on the opposite side of the gearbox. It pushes a spring-loaded bearing into the worm, preventing the worm from moving horizontally, side-to-side. It may look like this, below, or have a single slot that you can use a screw-driver or a quarter to turn. If it's not pushed in far enough, the worm will float left to right:
Regards,
? ?-Paul
toggle quoted message
Show quoted text
On Sat, May 8, 2021 at 10:27 AM, <dkfcpalfd@...> wrote:
Paul:
Thanks for responding.? Do you have a Titan?? Losmandy has been telling me that they came out with spring-loaded worms for the G11, but not the Titan.? When I first heard about the spring-loaded worms for the G11, I initially was told that feature was in development for the Titan.? Then, several months later, that went away, and I have been hearing from them that spring-loaded worms may never happen for Titan.
Right now, I'm going to try adjusting up the TVC on the HC.... the Gemini-2 website says that is a built-in DEC backlash compensation adjustment that is available.
|
Re: Thanks for he tips Brian V!
Thanks, Anthony.? I'll just consider those good magic numbers for PPEC from Brian as his magic trick....his research and your confirmation.
I have not yet tried that new PPEC tool.? My skies are probably (light polluted) worse than clear (turbulent) Flagstaff!? I have not tried the PHD2 multi star tracking either.? More to learn.? That group has continued to add good inventions.?
Thank you and Brian for showing the benefits possible from this new PPEC tool in the latest versions of PHD2.??
_____FWIW, _____
Other good experience is also being reported:
Marc Aragnou says he is getting better gear performance from using a MolyD lube.? ? Jet-Lube Moly paste MP-50 on the spur gears exclusively
He uses super lube on other parts. I thought Marc was speaking about the worm to ring gear, but he says spur gears.? He has an older G11.??
Marc has an OPW that he modded to put a kind of short-force spring loading to his drive.? He replaced the small back off bolt with a threaded rod in the mounting plate.? Then a small nut with a rubber o-ring provides the spring loading.? Very clever approach using an OPW.??
Marc reports benefits with his 50:1 McLennan gearbox to replace his 25:1 stock gearbox.? He uses old motors as their 2mm diameter shaft exactly matches the 2mm bore of the McLennan 50:1 gearbox.? ?That gearbox will not fit the new high torque motor as the 3.2mm shaft is a little too large for the small 50:1 pinion gear.? ?However, another owner says he prefers to use the motor to spin and cut down the shaft to fit the small pinion.? So there are many ideas floating on his to perfect the drive.??
Another nice report came from Hugo Garnica near Tehachapi. Hugo said he used high end ceramic worm bearings with excellent improvement in his drive smoothness.? He is writing up his experience on that approach.??
Always room for?improvement...more to learn from our group.??
Michael
On Fri, May 7, 2021 at 08:48 PM, Michael Herman wrote:
Can you say what magic numbers you used to improve your autoguiding (or PPEC etc)?
Brian suggested Predictive and Reactive @70, turn off Auto and enter worm cycle of 239.34 seconds.
?
?
How did you find the magic numbers?
Brian told them to me.
?
Is there some calculation you can share?
You¡¯d have to ask Brian. I had been running with stock numbers of 50/60 and Auto.
I will say that I also had some exceptional seeing conditions last night, especially for here in normally turbulent Flagstaff.
?
|
Re: Reducing DEC Backlash with Titan 50
Paul:
Thanks for responding.? Do you have a Titan?? Losmandy has been telling me that they came out with spring-loaded worms for the G11, but not the Titan.? When I first heard about the spring-loaded worms for the G11, I initially was told that feature was in development for the Titan.? Then, several months later, that went away, and I have been hearing from them that spring-loaded worms may never happen for Titan.
Right now, I'm going to try adjusting up the TVC on the HC.... the Gemini-2 website says that is a built-in DEC backlash compensation adjustment that is available.
|
Re: Reducing DEC Backlash with Titan 50
Hi Dan,
Did you try adjusting the spring-loaded end-screw on the outside end of the worm-block? If that's not tight, you may have the worm floating horizontally in the worm-block, and this can produce a large backlash.
Regards,
? ?-Paul
toggle quoted message
Show quoted text
On Sat, May 8, 2021 at 10:06 AM, <dkfcpalfd@...> wrote:
I have recently had some noticeable DEC backlash issues with my Titan 50 mount.? Specifically, detected play when I physically rock the scope back and forth in DEC (windage test), and either terrible results or test not able to complete, when running the Guiding Assistant in PHD2.? The DEC backlash test there, when you click on "Show Graph," shows actual backlash in south movement going way off to the right.... off the graph.
So, I started playing with the wing nut and allen head bolts on the DEC block.? I reviewed the article from the Gemini-2.com website, entitled "Titan Tips by Bob Allevo."? After reviewing that, I put plastic shims under the DEC block..... that seemed to help eliminate a strange noise when slewing in DEC.? This noise appeared only after I had made significant adjustment to the DEC block bolts.... it is gone now after making additional adjustment to the block bolts, and adding the shims.? I used a feeler gauge behind the block, and get about .030" for a gap.
Where I am at now with this process is this:? No play with the windage test, slewing is smooth.... no stalls, and no strange noises, even when spinning the scope around in all positions of DEC.? But..... I still have the DEC backlash test in PHD2 reporting crap for results, or not completing the test, and PHD2 telling me I've got too much backlash to complete the test.? I seem to be able to guide fine.... the guiding graph shows DEC pretty close to 0 on the guiding graph.? ? ?
Last night, I tried making micro adjustments to the wing bolts on the DEC block, and re-running Guiding Assistant to see if I could adjust out the backlash.? That ain't going to work.? Too much torque on those wing bolts, and slewing gets strained.? I put some more torque on the wing bolts, and I could not detect improvement in the GA backlash test results.
I don't really know if there's something else I should be doing to reduce the DEC backlash, or if I should chalk it up to that I have to live with it, and maybe the GA backlash test is not a reliable measurement.? I have no reason to believe it's not.
I would rather not hear as a solution, "Let PHD2 use a huge backlash compensation factor," or "You may have to guide in only one direction."? That would only be slapping on a band-aid.?
Need some help from someone who's been down this same path.
Thanks a lot.
Dan
|
Reducing DEC Backlash with Titan 50
I have recently had some noticeable DEC backlash issues with my Titan 50 mount.? Specifically, detected play when I physically rock the scope back and forth in DEC (windage test), and either terrible results or test not able to complete, when running the Guiding Assistant in PHD2.? The DEC backlash test there, when you click on "Show Graph," shows actual backlash in south movement going way off to the right.... off the graph.
So, I started playing with the wing nut and allen head bolts on the DEC block.? I reviewed the article from the Gemini-2.com website, entitled "Titan Tips by Bob Allevo."? After reviewing that, I put plastic shims under the DEC block..... that seemed to help eliminate a strange noise when slewing in DEC.? This noise appeared only after I had made significant adjustment to the DEC block bolts.... it is gone now after making additional adjustment to the block bolts, and adding the shims.? I used a feeler gauge behind the block, and get about .030" for a gap.
Where I am at now with this process is this:? No play with the windage test, slewing is smooth.... no stalls, and no strange noises, even when spinning the scope around in all positions of DEC.? But..... I still have the DEC backlash test in PHD2 reporting crap for results, or not completing the test, and PHD2 telling me I've got too much backlash to complete the test.? I seem to be able to guide fine.... the guiding graph shows DEC pretty close to 0 on the guiding graph.? ? ?
Last night, I tried making micro adjustments to the wing bolts on the DEC block, and re-running Guiding Assistant to see if I could adjust out the backlash.? That ain't going to work.? Too much torque on those wing bolts, and slewing gets strained.? I put some more torque on the wing bolts, and I could not detect improvement in the GA backlash test results.
I don't really know if there's something else I should be doing to reduce the DEC backlash, or if I should chalk it up to that I have to live with it, and maybe the GA backlash test is not a reliable measurement.? I have no reason to believe it's not.
I would rather not hear as a solution, "Let PHD2 use a huge backlash compensation factor," or "You may have to guide in only one direction."? That would only be slapping on a band-aid.?
Need some help from someone who's been down this same path.
Thanks a lot.
Dan
|
Michael Herman
Paul Kanevsky