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Re: Semi OT.. Needed - 12" Bahtinov Mask..
Good conversation. Epoxy a long 1/4 inch wooden dowel?on the edge of the Bahtinov mask as a handle. In this way you have a lightweight, long handle to put the Bahtinov mask at the corrector plate, even with a deep dew shield in place.?? You could drill and insert a small bolt, then screw on the dowel handle.? However the plastic of these Bahtinov masks are breakable. Epoxy also helps fix these broken masks too. There are waterproof epoxies too, and those filled with a metal filler.? I recommend using a waterproof epoxy to avoid moisture deteriorating the epoxy. Best?regards, Michael On Thu, Dec 9, 2021, 9:58 PM John Kmetz <jjkmetz54@...> wrote: There are Bahtinov masks that have a hole that fits over the secondary cover, but you need to remove the dew shield to use it. I have one for my C925 EdgeHD but haven't touched it ever since I went with an auto-focuser. Not remembering the brand now but here is an example: |
Re: Futura losmandy G11T
On Fri, Dec 10, 2021 at 06:25 AM, David C. Partridge wrote:
?Yo utilizo el traductor de google pare el ingles, que no se hablarlo. Se puede hacer lo mismo con el espa?ol.? Si te parece mal, mis disculpas |
Re: Futura losmandy G11T
开云体育For non-Spanish speakers, here’s a translation: ? “I just ordered the Losmandy G11T from the Valkanik supplier in Spain, hopefully in a few months I will be enjoying it ????, I am looking forward to having it !!” ? David ? From: [email protected] <[email protected]> On Behalf Of Davidspain via groups.io ? Acabo de pedir la losmandy G11T al proveedor Valkanik en espa?a, con suerte en unos meses la estare disfrutando ????, que ganas de tenerla!! |
Re: Semi OT.. Needed - 12" Bahtinov Mask..
There are Bahtinov masks that have a hole that fits over the secondary cover, but you need to remove the dew shield to use it. I have one for my C925 EdgeHD but haven't touched it ever since I went with an auto-focuser. Not remembering the brand now but here is an example:
Your dealer should be able to hook you up with one for your scope. John |
Semi OT.. Needed - 12" Bahtinov Mask..
开云体育So I can more effectively use my 12” SCT on my G11, does anyone know of a focusing mask that is easy to apply / remove from near the corrector of a 12” SCT with a homemade dew shield.. i.e. I can’t put one on the end of my poster board dew shield, it needs to go near the corrector.. ??? Or I need a completely different way to quickly focus.. TIA.. Derek |
Re: Worm centering - how close is good enough?
开云体育. How close you have to get is what I am questioning. *** My Answer?? Like everything else on these mounts, it depends on the effort / reward ratio.. If it’s easy – for you - to get it perfect, then that would be good enough! ;-)) Derek From: [email protected] [mailto:[email protected]] On Behalf Of John Kmetz
Sent: Thursday, December 09, 2021 7:23 PM To: [email protected] Subject: Re: [Losmandy_users_io] Worm centering - how close is good enough? ? Derek, |
Re: Worm centering - how close is good enough?
Derek,
The ring gear measurements were made with the clutches tight, so all the thrust bearings, washers, are surrounding contacts are all snugged down. I now use Michael Herman's high friction discs, so it is not necessary to overly tighten the clutch knobs to avoid slippage during mount operation. I have my original RA and Dec blocks plus 3 new pairs I bought from HGM at different times over the last few years. They all have the same holes and thread sizes, but are not precisely the same size, off by perhaps 0.01" or more in height, though I haven't logged all these dimensions. Thus the need for shimming if the blocks are too short for the ring gear involved. If the blocks are too tall you may have to perhaps sand down the bottoms, or shim under the bottom thrust washer, but I haven't seen that situation yet with my parts. How close you have to get is what I am questioning. John |
Re: Worm centering - how close is good enough?
开云体育OH! This is awesome.. Actual Numbers on something! 1).. What is the difference in measurements from “the clutches are loose” to “the clutches are freaking tight”.. 2).. If I buy new worm blocks, will they be drilled and tapped like the ones shown in your image?? Derek ? From: [email protected] [mailto:[email protected]] On Behalf Of John Kmetz
Sent: Thursday, December 09, 2021 6:01 PM To: [email protected] Subject: [Losmandy_users_io] Worm centering – how close is good enough? ? Recently did
another rebuild of my G11 (with non-spring-loaded worms) as I wanted to replace
the 3” ID thrust bearings and the 3” ID thrust bearing washers which were a bit
scored. Also, I had a stubborn 80 second error (1/3 worm period) which I could
not figure out, so I replaced the current RA worm with an old one I had good
results with previously. I replaced the thrust bearings with Koyo NTA-4860
bearings which were 5/64 or 0.078” thick. For some reason I was unable to find
the same 3” ID washers which Losmandy used which are 0.045” thick, so I used an
INA TWA-4860 with 0.030” thickness, and a Koyo TRB-4860 with 0.060” thickness,
which together total 0.090” thick, same as the two original washers. The RA worm blocks were changed out to another set
where the right block was honed out a bit to allow the right bearing to slide
back and forth as compressed by the Belville washer. As a new test, the
bearings were replaced with McMaster-Carr part 2342K163, which are permanently
lubricated, and have a black plastic seal over the ball bearings. A micrometer was used to measure the various parts positions to try and determine the exact center of the worm axis and center of the ring gear. This issue has probably been discussed before, but I was wondering how close is good enough for best RA periodic error behavior and proper function of both axes. All parts were at approximately 50F, the temperature in my unheated workshop. ? The following measurements and determinations were
made: Diameter of worm shaft inside of bearings: 0.400” Radius of worm shaft: 0.400”/2 = 0.200” Thickness of ring gear: 0.300” Midpoint of ring gear: 0.300”/2 = 0.150” Thickness of black anodized base plate: 0.329” ? With these values in place, the centers of the worm
and ring gear can be determined by measuring the distances from the bottom of
the base plate to the top of the worm shaft and top of the ring gear,
respectively (see pics). The calculations then are as follows: Top of worm – 0.200” = Worm center position Top of ring – 0.150” = Ring gear center position For the RA drive prior to disassembly: Top of worm: 0.856” – 0.200” = 0.656” at worm center Top of ring: 0.807 – 0.150” = 0.657” at ring center Centers difference = 0.001” The worm top surface measurement appeared consistent whether done on the left or right side of the brass worm teeth in the central area, thus no tilt. ? RA drive after reassembly: Top of worm: 0.846” – 0.200” = 0.646” at worm center Top of ring: 0.805” – 0.150” = 0.655” at ring center Centers difference = 0.009” Note the top of the worm measurement had dropped by
0.010”, which appeared to be too much. I also saw that my original blocks now
in use had a bare aluminum bottom, while the newer blocks I bought later were
anodized black on all surfaces. So, it would appear all worm blocks are not
identical. To remedy this centers discrepancy, I bought some 0.005” brass shim
stock which I trimmed to fit under the blocks and folded one time to get twice
the thickness. RA drive, second assembly after shimming: Top of worm: 0.856” – 0.200” = 0.656” at worm center Top of ring: 0.805” – 0.150” = 0.655” at ring center Centers difference = 0.001” This difference is now the same as originally, though the worm is 0.002” lower than before disassembly. ? Now for the Dec drive: Before Disassembly: Top of ring: 0.806” – 0.150” = 0.656” at ring center Centers difference = 0.000” After Dec Drive Reassembly: Top of worm: 0.850” – 0.200” = 0.650” at worm center Top of ring: 0.805” – 0.150” = 0.656” at ring center Centers difference = 0.006” Here I’m not sure of the reason for the worm drop,
since the same blocks were used. One layer of 0.005” shim stock was used under
the blocks and new measurements were performed. Dec drive, second assembly after shimming: Top of worm: 0.854” – 0.200” = 0.654” at worm center Top of ring: 0.805” – 0.150” = 0.656” at ring center Centers difference = 0.002” Again, the worm center is dropped by 0.002” from original position. ? So finally, the question is what difference between
worm and ring gear centers really plays a factor? I think 0.01” off seems
significant and needs to be adjusted. After shimming, the worm centers are very
close to the ring center but have dropped a tiny bit and are essentially on the
other side of ring dead center. During previous mount rebuilds, I had never
made these measurements, so I do not know what they were when the mount was
new. I would assume the scoring I saw on the thrust bearing washers would drop
the ring center a bit, but all seemed to return to the same position with the
new thrust bearings and washers. Any comments appreciated. ? ? ? ? ? |
Worm centering – how close is good enough?
Recently did another rebuild of my G11 (with non-spring-loaded worms) as I wanted to replace the 3” ID thrust bearings and the 3” ID thrust bearing washers which were a bit scored. Also, I had a stubborn 80 second error (1/3 worm period) which I could not figure out, so I replaced the current RA worm with an old one I had good results with previously. I replaced the thrust bearings with Koyo NTA-4860 bearings which were 5/64 or 0.078” thick. For some reason I was unable to find the same 3” ID washers which Losmandy used which are 0.045” thick, so I used an INA TWA-4860 with 0.030” thickness, and a Koyo TRB-4860 with 0.060” thickness, which together total 0.090” thick, same as the two original washers. The RA worm blocks were changed out to another set where the right block was honed out a bit to allow the right bearing to slide back and forth as compressed by the Belville washer. As a new test, the bearings were replaced with McMaster-Carr part 2342K163, which are permanently lubricated, and have a black plastic seal over the ball bearings. A micrometer was used to measure the various parts positions to try and determine the exact center of the worm axis and center of the ring gear. This issue has probably been discussed before, but I was wondering how close is good enough for best RA periodic error behavior and proper function of both axes. All parts were at approximately 50F, the temperature in my unheated workshop. ? The following measurements and determinations were made: Diameter of worm shaft inside of bearings: 0.400” Radius of worm shaft: 0.400”/2 = 0.200” Thickness of ring gear: 0.300” Midpoint of ring gear: 0.300”/2 = 0.150” Thickness of black anodized base plate: 0.329” ? With these values in place, the centers of the worm and ring gear can be determined by measuring the distances from the bottom of the base plate to the top of the worm shaft and top of the ring gear, respectively (see pics). The calculations then are as follows: Top of worm – 0.200” = Worm center position Top of ring – 0.150” = Ring gear center position For the RA drive prior to disassembly: Top of worm: 0.856” – 0.200” = 0.656” at worm center Top of ring: 0.807 – 0.150” = 0.657” at ring center Centers difference = 0.001” The worm top surface measurement appeared consistent whether done on the left or right side of the brass worm teeth in the central area, thus no tilt. RA drive after reassembly: Top of worm: 0.846” – 0.200” = 0.646” at worm center Top of ring: 0.805” – 0.150” = 0.655” at ring center Centers difference = 0.009” Note the top of the worm measurement had dropped by 0.010”, which appeared to be too much. I also saw that my original blocks now in use had a bare aluminum bottom, while the newer blocks I bought later were anodized black on all surfaces. So, it would appear all worm blocks are not identical. To remedy this centers discrepancy, I bought some 0.005” brass shim stock which I trimmed to fit under the blocks and folded one time to get twice the thickness. RA drive, second assembly after shimming: Top of worm: 0.856” – 0.200” = 0.656” at worm center Top of ring: 0.805” – 0.150” = 0.655” at ring center Centers difference = 0.001” This difference is now the same as originally, though the worm is 0.002” lower than before disassembly. ? Now for the Dec drive: Before Disassembly: Top of ring: 0.806” – 0.150” = 0.656” at ring center Centers difference = 0.000” After Dec Drive Reassembly: Top of worm: 0.850” – 0.200” = 0.650” at worm center Top of ring: 0.805” – 0.150” = 0.656” at ring center Centers difference = 0.006” Here I’m not sure of the reason for the worm drop, since the same blocks were used. One layer of 0.005” shim stock was used under the blocks and new measurements were performed. Dec drive, second assembly after shimming: Top of worm: 0.854” – 0.200” = 0.654” at worm center Top of ring: 0.805” – 0.150” = 0.656” at ring center Centers difference = 0.002” Again, the worm center is dropped by 0.002” from original position. ? So finally, the question is what difference between worm and ring gear centers really plays a factor? I think 0.01” off seems significant and needs to be adjusted. After shimming, the worm centers are very close to the ring center but have dropped a tiny bit and are essentially on the other side of ring dead center. During previous mount rebuilds, I had never made these measurements, so I do not know what they were when the mount was new. I would assume the scoring I saw on the thrust bearing washers would drop the ring center a bit, but all seemed to return to the same position with the new thrust bearings and washers. Any comments appreciated. ? ? ? ? ? |
Re: Any one using an ST-i for guider with Losmandy G2 conversation
Hi Doug,
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What are the symptoms? Does the mount not guide? Can you calibrate the autoguiding software? Are you plugging in ST-i guider cable into Gemini guider port, or are you using ASCOM pulse-guiding from PHD? That second one may be the way to avoid any compatibility issues between the guider output and G2 guider input. Regards, ? ? ?-Paul On Thu, Dec 9, 2021 at 09:50 AM, Doug Askew wrote: Morning all, |
Re: Any one using an ST-i for guider with Losmandy G2 conversation
Hi Doug, Not clear yet what's causing your issue.? You said "modified" but what exactly has been modified?? How does the mod affect auto guiding? You say you have a Gemini-2.? That has several ways to set up autoguiding.? It has a direct auto guide input port (ST4 port).? It also has a USB B port and internal USB controller that allows serial communication and so you can use, say, PHD2 for autoguiding.? It also has a CAT5 port that allows high speed communication with the PC and PHD2 with that.? I use the serial port on the H-2 like the serial port on the G-1, with PHD2 autoguiding.?? If none of those G-2 ports work perhaps your camera has a faulty output?? Try to use a different auto guide camera like a ZWO ASI (120 or other models all have an ST4 output port on them).? That way you can determine if the problem is with the Gemini-2, the G11 mount, or the camera you are using.?? Best of luck, Michael On Thu, Dec 9, 2021, 6:50 AM Doug Askew <doug@...> wrote: Morning all, |
Re: Any one using an ST-i for guider with Losmandy G2 conversation
开云体育10 years ago or so I used it with limited success using my 492 drive and CCDDops. The large pixels made it hard to get good guiding at longer f.l. ?I switched over to a asi 120 with PHD2 and never looked back.?Sent from my iDork On Dec 9, 2021, at 9:50 AM, Doug Askew <doug@...> wrote:
|
Any one using an ST-i for guider with Losmandy G2 conversation
Morning all,
I am having no success with using the ST-i guider for use my my G11/G2 modified. ?I have tried PHP, which does not work well once guide star is selected and even have gone back to SBIG's CCDOPS, which I used with my ST-5c pretty well successful in tracking and controlling the G11. ?I am not sure where/how this problem I have with the ST-i & G2 combination comes from or whether is is just plain incompatibility or most likely operator error. ? Also, ?if someone has a cheat sheet on their set & control. I would appreciate having a copy of it. Thanks for any assistance, Doug |
Re: ASI airpro printer cable
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On Dec 8, 2021, at 7:40 AM, Ian Taylor <robert.ian.taylor@...> wrote:
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Re: SharpCap vs Drift Alignment
Thanks for the update Jeff I'll respond more to your support ticket as well For those reading this, i just want to clarify Jeff has an older non-spring loaded worm mount, so the unbalancing is appropriate for him Brian On Mon, Dec 6, 2021 at 4:16 AM Jeff Rothstein <rothstein.j.s@...> wrote:
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Brian? Brian Valente portfolio |