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Hi guys. I'm using a g11g, has anyone tried a simple belt drive with a spur gear for the timing pulley? Eliminates rattling of spur gears. Tajy

I plan to make a number Ra extension blocks. These will have a hole to allow cables to be fead through the mount. If anyone is interested in one of these extension blocks please contact me.

Hello, I am a visual observer and on my G11T when I select the centering speed and apply a value below 40 the image is shaky when I move the AR axis, the worm is smooth when moved with my fingers but it feels a little gritty in contact with the crown and I don't know how to solve it. greetings to all!

Originally, I posted this in the Losmandy group. Probably more relevant here.... I'm doing a maintenance overhaul (long overdue BTW) on my G11T. Looking for info on a tool I can use to push (and re-seat) the bearings (and worm gear) out of the RA one-piece block. Has anyone done this? Also looking to replace the worm bearings on the RA and eventually on the DEC. They are 5200 ZZ C3 on the RA, don't know if the DEC is the same as I'm starting on the RA first. I can get replacements from Losmandy but don't know the ABEC rating. I have knowledge with ball bearings as I installed an ERP system in a ball bearing factory about 20 years ago, very interesting business. Online searches only show ABEC-1 when listed, hoping for a higher rating. Appreciate any info in advance! - Jerry

Jerry, Very good... thank you for confirming the 5200 is the right model number for Titan RA worm bearings. ___ Bearing prices ____ The 5200 type Titan bearings seem to vary widely in price, even for the same nominal brand name. The Amazon Nachi link you sent was priced $50. Also on Amazon they list 5 of QHJ 5200 for only $30! Here is that link: [5-Pack] 5200-ZZ - Double Row Angular Contact Ball Bearing 0.393 in x 1.1811 in x 9/16 in (ID x OD x W) | 10 mm x 30 mm x 14.3 mm (ID x OD x W) with Double Metal Shield https://a.co/d/45SvbES I saw the single Nachi 5200 on eBay for ~$22 each. Maybe old stock on some factory shelf. These are stainless bearings I think. NTN and NSK also make them for about $20 on eBay. And QJZ 5200 for $18 each on eBay. I did not see any "ABEC" quality rating for any of these bearings. Many brands...many prices. I bought my G11T used and the original owner told me he replaced the Titan worm bearings with very expensive ones. I thought he said they were like $75 each at that time and he thought a higher quality than the stock bearings. (He never told me what problem he found about those original bearings; the ones I took out of my G11T RA, his replacements, ran very smoothly in my hand. ) The website BearingsDirect has a single steel ball version made in China for as low as $6.75. But: perhaps this is worth a try:BearingsDirect shows a 5200 with ceramic balls instead of steel balls, for $40 each: https://bearingsdirect.com/5200-2rsc-double-row-ceramic-ball-bearing-10x30x14-3/ Their blurb says ceramic balls give lower friction than the steel ball version. I doubt you'd find a periodic error in any of these 5200 bearings because they have double ball bearings inside. However, there is a factor called "rumble" in bearings which would show up as "noise" and would be indistinguishable from "seeing" noise. It's why bearings should be preloaded, which is the purpose of adding the #6200 Belleville spring washers under the Titan worm capscrew. ___ Gearbox deserves an examination if you do long exposure deep sky imaging or planetary ___ I'm sure that any noise from the double-wide 5200 Titan worm bearings will be far less than the PE possible from a bad plastic stock gearbox. That gearbox period will come at 42 sec interval on a Titan RA. The solution to that is to change the stock gearbox for a metal McLennan 25:1 gearbox. If you are purely a visual user, it's not worth your time but if doing long FL work like planetary imaging or deep sky using a big SCT, you'd want to change that RA gearbox. ___ Middle spur gear deserves an examination for wobble ___ There is another issue that can affect the G11T (G11T has "tucked motors", but not the Titan versions with straight motors). It's the stock 3 spur gear system that drives from the gearbox (one spur gear with 3/16 inch hub borehole) to the worm spur gear (10 mm hub borehole). See top photo attached of the stock 3 spur gears on the stock drive. The problem is that the 3rd spur gear, between the worm and gearbox, can wobble. See the attached center picture. It's an aluminum spur gear on a thin diameter steel pin hub. Because the materials are different, the hole in the aluminum is noticeably larger than the hub steel pin. A better idea, from fellow G11T owner Allen Ruckle, is to replace these 3 spur gears with just 2 pulleys and a belt. That works great and is quite silent in operation. Allen used 2 identical pulley diameters but I went with a 1:2 ratio to achieve the "Titan 50" gear ratio, that halves the strain on the gearbox (but would make the stock gearbox period only 21 seconds!!!). Photos and videos of that version, and the original 3 spur gear parts, are here: https://www.flickr.com/gp/25150413@N06/2SK35uxWo9 I have "HowTo" PDFs about the McLennan gearbox changeover, and the pulley installation on the G11T, if interested contact me. Have fun and of course clear skies! Michael

FYI - I am selling my G11G and moving to a Harmonic Drive mount. If you are interested see the link below. https://www.cloudynights.com/classifieds/item/345966-losmandy-g11g-mount-with-lightweight-tripod-and-extra%E2%80%99s/ ---------- Jim Waters Phoenix, AZ Equipment - Losmandy G11G, ASI2600MC Pro / ASI533MM and Sky-Watcher OTA Scopes Software - N.I.N.A. 2.1, PHD2 2.6.x, ASTAP, TheSkyX Pro and PixInsight

One of the nice things about having an observatory is that it is a much nicer place to play around with the mechanical settings than when sitting out in the open on the driveway. Not having to spend time on polar alignment each time frees up time to look at other things. The wind is much less of a factor, too. Two nights ago, I had good guiding of 0.5" RMS, something that rarely happens so I decided to finally sit down and check how to tune my stuff, way overdue. As part of the tuning, I spent a whole day figuring out my adapters that came from who knows where meant for who knows what. I made a table of possible configurations for running the Baader MPCC Mark III (55 mm backfocus), my ES field flattener (45 mm backfocus) or nothing (like my Mak-Newt that has a flat focal plane), in combination with the ASI2600MM, ASI2600MC, QHYOAG-M with ASI120MM mini autoguider and ZWO 7x36mm EFW. This was when I switched my configuration from 6" Mak-Newt to the 12" GSO astrograph. I now have better stars than ever before with my Newt, so the work paid off. I got better stars in my ASI120MM OAG as well. My setup is a DIY motor-integrated one-piece worm assembly (blocks bolted on an aluminum edge with pivot tightened from below by a pair of Belleville washers, outer block unconstrained) with Abec-9 bearings, no preloading, 17HM15-0904S direct drive on the pivot side, TCM2130 stepper drivers on 24V with SPI, bicycle tube rubber for SLW springs. 1) One thing I noticed is that the drive was wobbling tangentially because I had always been too careful with tightening the Belleville washers on the pivot. Tightening them up to the point where the friction becomes noticeable then backing off a little, leads to substantially straighter calibration curves. I also changed the calibration step sizes to be larger than the Ekos defaults. 2) My RA balance has apparently always been off. The RA balancing at 34 degrees always has a bit more friction than DEC balancing where you can put the DEC axis horizontal. As a result, I may have misjudged the balance and the worm apparently had a lot more (one-sided) friction. Tuning the balance such that the worm assembly pivots with minimal resistance, leads to a quite different balance that makes the drive work better. 3) My ZWO ASI120MM mini (on an OAG) is a bit noisy. Reducing the noise by 2x2 binning helps. I usually run at 2 seconds and noticed that my calibration curves have the dots in pairs - small jump, large jump and repeat. Going to 1 second leads to equidistantially spaced dots. Is this an ASI120 firmware issue? I may be looking for a better mini autoguider. Most of the other settings (autoguider gains, multi-star vs single star guiding, integrating control action, aggressiveness, SLW spring tightening) don't seem to matter a whole lot so long as the settings are reasonable. Curious to hear about similar experiences, suggestions are welcome. -- Mount: G11S mount with HD tripod. Worm assembly: DIY motor-integrated one-piece worm assembly (blocks bolted on an aluminum edge with pivot tightened from below by a pair of Belleville washers, outer block unconstrained). Bearings: Abec-9, no preloading. Motors: 17HM15-0904S (0.9 degree) direct drive on the pivot side, TCM2130 stepper drivers on 24V with SPI, tracking at 32 microsteps. SLW: bicycle tube rubber. Control: OnStep (Wemos/CNCv3), Ekos on a Pi4b (8GB) mounted on-scope. Scopes: 6" MN152 Mak-Newt, 12" GSO Newt astrograph, ES ED127CF, RC6, ES ED80, Redcat 51.

Hi there, I recently inherited a G11 that I believe was modified. I am curious if anyone here knows a way to power on a Los Mandy mount without the Gemini main control unit but still use the Motor Cables? I have located the hand control. I have gone through all of the equipment I now have and cannot find that main control unit anywhere but I know this mount was regularly used until I had inherited it. Any help here would be amazing, thank you!

A few days back John Kmetz pointed out how nice it would be to get rid of the needle-roller thrust bear that sits in-between the ring gear and the plate. Newer G-11 mounts have a 6010 deep groove bearing inbedded in the bottom of the ring gear. Might it then be possible to have the mount ride strictly on the inner race of this bearing? Robert Benward has drawn up what this would look like in the attached drawing. Currently, the roller-thrust bearing is held in position with a 2x3x0.159 aluminum washer. To correctly maintain the height of the ring gear one needs to add a shim washer that catches only the inner race and not the outer race of the 6010 bearing. It seems that this part from McMaster will do the job: https://www.mcmaster.com/97022A066/ But, the aluminum washer is often a loose fit to the and the thinness can vary from mount to mount. Instead for a more precise arrangement one might consider stacking washer. These parts look like they get you to the right height of 4.4mm: https://www.mcmaster.com/98089A622/ https://www.mcmaster.com/98089A484/ But is there an even better solution? Robert thinks there might be. Here has found 50mmx80mmx13mm Cross Roller Bearing BRG-I-457=P512. These are rather expensive but Ebay has a few available. This Bearing is 3mm narrower than the 6010 bearing, so these will be needed: https://www.mcmaster.com/98089A159/ Note the shim washers come in packs of 5. Check my math before ordering anything! So why do this? Well if you have ever removed the worm and tightened the clutch, you will notice just how hard it is to rotate the ring gear. I mean it is a lot of effort. It kind of grinds around. There may even to a tight spot. This grinding action often manifests itself by unevenly worn thrust washers. You know this can not be good right? Possible high frequency noise in your guide chart and a low frequency wobble maybe the result. It is not even certain, at least not to me, if the ring gear moves in a circle or an ellipse? I for one am going to try this and will report back to the group.

On a recent L. Users post a gentleman posted his guide data after LV6 upgrade. He was forced use PPEC because the PEC is not currently working under Lv 6. He was looking for validation on his guiding performance, not an unreasonable thing to seek. Believed he was at a new level! If he only new that 4x mode for Ra does nothing to improve guiding so he could use G2 PEC and not rely on PPEC. 4x mode only has benefit for Dec, but I digress. Image 1. is a side-by-side based on posted data from L. Users forum post (Left) of the uncorrected data, and my data from last nights (right). The charts are roughly to scale. Please note the large 240s PE error, the not insubstantial 76s bearing error and the signature 32s gearbox error in the poster's FFT data. Image 2. represents the corrected data as a result of guiding. So why do we bother with these mods? You must decide that for yourself! Incidentally, I'm carrying around 130 lbs total load on my G11, not to gloat.

Hi Hackers, I have been reading the topics on Dec tweaking to improve tracking and backlash. My G11G is < 2 years old so I am loathe to do any surgery on it apart from clean, grease and readjust. I am looking/hoping that you may be able to give some guidance on what baby steps this beginner could take to work on improving my situation. Below are some of the results I am getting from PHD2. Hey Michael Herman - we have connected at times and are not far away from each other - is this something you could help with. Private message me if it is and we can talk turkey. Thanks, Ken

OK, some results from my first run with the ball thrust bearing in DEC and no thrust bearing under the RA ring gear. See the analysis dated 2023-06-28. Note that these are PHD2 logs with guiding removed (ie., raw). Not conclusive, but..... Due to smoke and clouds, this was a very short run (about 15 minutes) but like Peter found, it looks like my raw PE is worse without the RA thrust bearing so I think I'll clean it, re-grease with 50/50 Mobilgrease and MP-50 and re-install. I'm hoping the MP-50 will help the rollers slide as they run around the race. I've included a couple other frequency analyses for comparison. Yes, my mount is messy.... I think most of it is the Oldham since it is predominantly harmonics of the worm? DEC seems like it is at least no worse and probably better with the ball thrust bearings. PHD2 backlash correction was at 90mS and TVC was at about 80 (4X worm resolution). With the ball thrust bearings at both ends of the DEC shaft, I can now easily observe and feel the right side worm bearing pistoning as I gently torque the DEC shaft. As soon as I release, it springs back to the rest position as expected. This was difficult to observe with the roller thrust bearings so for now I will keep the ball thrust bearings installed. However, I do not feel this is a viable solution for all mounts. To make it a drop in replacement for the roller thrust bearing, the balls are only 2mm in diameter (to attempt to match the rollers). Since the balls run on the same flat races as the roller thrust bearing, I am concerned that the very small contact area (infinitely small in a perfect world) is insufficient to carry the full rated load of the mount. Possibly OK for me since my load is maybe 25 pounds including the 11 pound counterweight. I will keep the ball thrust bearings for the short term and at some future date will disassemble and look for wear on the races. In the mean time, I tried printing a test piece with various hole sizes in the first and last layers. I think I have a combination that will (marginally) retain the 2mm balls but let them roll freely. The balls are not held as securely as I hoped but I am stretching the capabilities of my printer so it will have to do. I know someone with a liquid resin printer.... that might be the best way to print the ball thrust bearing guides. I note that with Peter's spring worm bearing preload mod, reducing DEC and RA friction is crucial. If the thrust bearing friction causes the worm to overcome the Belleville spring and move the worm bearing, this will cause tracking issues. Remember that on RA, normal tracking causes the worm to want to move to the right, against the preload spring. Lastly, if anyone wants the STL files for the DEC shaft ball thrust bearing guides, let me know and I'll send them to you. The 2mm balls are silicon nitride ceramic balls from Amazon. The overall stack is a couple thou thicker than the stock roller bearing. Paul G. -- Paul Goelz Rochester Hills, MI USA pgoelz@... www.pgoelz.com

A modification to make leg adjustment easier if you transport the tripod frequently. The photographs show the addition of a 3/8 Thrust Bearing on the Leg Extension Clamp Handle in place of the delrin like washer. These bearings increase the torque applied to the clamp by lowering the torque lost on the handle due to friction on the nut face (handle). Thus, they reduce the physical effort of the knob adjustment by quite a bit. Mine came from Amazon. They were less than $10 for the set of three. Doug

Thinking more about how difficult it is to knock out the needle bearings from the RA and Dec axis housings, I figured there must be a tool professional machinists or mechanics use to remove bearings like these. So in a quick Amazon search I found this tool: https://www.amazon.com/gp/product/B09LCJ45Q4/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1 This extractor uses expanding collets to reach inside and behind the inner race of the bearing from the front side, so you don't have to drive it out from the rear. Then you use either the slide hammer or threaded counterstay to apply force to pull the bearing from its countersunk seat. I am tempted to purchase one of these as insurance against damage of the aluminum finish where the bearing OD sits. Damage would be a more expensive option in replacing the whole anodized part from Losmandy vs. its price. I plan on changing more of these bearings in the near future, when I put my second G11 out in the shed. I'll take plenty of pics if I ever successfully get this type of tool to operate. John