ETX-90RA AND ETX-90EC USER FEEDBACK
This page is for user comments and information specific to the Meade ETX-90RA (originally known as the "ETX Astro") and the ETX-90EC. Comments on accessories and feedback items appropriate to other ETX and DS models are posted on other pages. If you have any comments, suggestions, questions or answers to questions posed here, e-mail them to me and I'll post them. Please use an appropriate Subject Line on your message. Thanks.
Subject: Another night with my beloved ETX 90EC Sent: Wednesday, March 7, 2001 19:50:04 From: firstname.lastname@example.org (Tim Sheets) Well, it's been many months since I have had the opportunity to use my ETX, but tonight, it wasn't too cold (42f) and the sky was beautiful. It's getting late so I don't go through the motions of aligning and such. Orion, glittering in the sky was beckoning. After 6 months with my new ETX, after having had a 8" Meade Starfinder EQ, I can honestly say, I would take the ETX anyday. Don't get me wrong, the 8" mini lightbucket produced some beautiful sites. But, even as a fairly seasoned star hopper, the mechanics of of the eq mount, with no electronic controls, made finding anything a challenge. With the ETX, all you need to know is approximately where something is, and the slewing controls make getting there an easy task. Of course, the Autostar makes finding things as easy as toasting bread. M42, the jewel of the winter sky. I only have 96x capability right now and it was still gorgeous, under moonlit skies. Of course, Jupiter's bands were bright and beautiful, and Saturn (with Titan), my favorites, were amazing. I know most of the conversation on Mike's great site here has been technical of late, but for those of you simply wanting to know how us ETX owners feel about our scopes. There is absolutely nothing in the price range that can compare. Tim
Subject: ETX90EC question... Sent: Wednesday, March 7, 2001 18:10:10 From: email@example.com (abcuellar) Hi,my name is Adrian,I'm eleven.I'm trying to buy an ETX90EC. The problem is that it's going to be hard to get $600,so I really want to be sure if it's worth the time and effort. The question is if I could ask you (or anyone who reads this message) COULD YOU BE SO KIND to take a picture with your ETX90 plain ? I mean with no addaptation (cept for the T-adapter), the way i'll recieve it from the store. I want to know if without any addaptation I can see Jupiter's clouds,Saturn rings etc.like it said in MEADE'S site. Please answer me ADRIAN CUELLARMike here: See this page from Meade's online product catalog: http://www.meade.com/catalog/meade_etx/index00.htm. It shows the standard ETX-90EC and ETX-125EC without any optional items. And yes, you can see a few cloud bands on Jupiter and the Saturn's Ring and a whole lot more with just the standard 26mm eyepiece. Of course, most people will quickly want to see more details so perhaps a 2X Barlow Lens would be a good first accessory for you to consider. One caution: don't expect to see objects with the same look and details as you see in the color photographs on the box and in the catalogs. Many of the photos on my ETX site are closer to what you might actually see.
Subject: ETX-90RA on a DS mount Sent: Wednesday, March 7, 2001 09:07:49 From: firstname.lastname@example.org (Brent Powell) First of all, thanks for having your site; I check it daily. It's clear you put a lot of work into it and there's lots of great information on it. I wish I had seen more of it before I bought a DS-70EC/AT for my son. I'd definitely have tried harder to find an ETX-90 in my price range! Thanks to the info on your site and on the Meade-DS Yahoo group, I've gotten the darned thing to work as it should! Now that we've been able to use it a few nights, I know that I should have forked over the extra money for a 90mm objective. I'm watching e-bay and Astromart for an ETX-90 to buy, EC or RA. Which brings me to my question. I saw (I think it was on your site) where someone had mounted their ETX-90RA on a DS-90 Mount so that he could use the Autostar with it. Now I can't find it on your site. Can you point me in the right direction? Thanks again for all your help. Brent PowellMike here: Check the "Telescope Tech Tips" page for the "ETX with DS mount" item.
Subject: ETX90: Problem with Electronics Controller Sent: Sunday, March 4, 2001 23:47:09 From: email@example.com (PAKDEE MAKEJUMROEN) Thanks for the excellent information of ETX on your website. I just buy new ETX-90EC a couple of days. Have the same problem as MrPhatOne@aol.com. My scope seem to randomly have the problem with the moving up & down with electronic controller. Sometime didn't even hear the motor moving sound. Once I try to recycle power sometime work sometime doesn't. I'm sure it not the DEC knob issue that you mention in your mail. I wonder if this problem is known problem as you post on your website "Random Slewing Problem with DS and ETX Drives" announcement from Meade. How I can solve this problem Thanks, PakdeeMike here: If you have just the standard controller then what you are experiencing is not the random slew that has been reported. That seemed to only happen with the Autostar handcontroller. For starters, if possible you should try exchanging the handcontroller at your dealer.
Subject: Re: Trunion Slop Adjustment Question Sent: Sunday, March 4, 2001 13:50:23 From: firstname.lastname@example.org (Clay Sherrod) To: Bill Yes! You've got the part identified that needs the Teflon tape; keep in mind that Teflon tape is very difficult to work with and does not want to stick. CLEAN the tapered trunion first with mineral spirits and rub vigorously to remove all grease; then very tightly wrap the tape.....it is the stretching of the tape as you wrap that results in a firm grip. A couple of wraps should do it. THEN, spread a generous amount of Lithium grease with your fingers over the tape and work it around (being careful to not dislodge the tape) evenly. When you replace the arms into the fork, you will note that they are very tight; this is okay. Just work them back and forth (rotate) as long as necessary; eventually the tape will "seat" and the OTA support arm will rotate very freely. Be sure when you reassemble and place the setting circles back on to LUBRICATE behind the setting circle where it rubs against the plastic (you will see a wear line of the inside of the setting circles). Otherwise, you will get bothersome binding when slewing. Good luck....let me know how it comes out! Clay Sherrod -----Original Message----- >I'd like to thank you for your ETX tune-up articles, they are very helpful. > >I have an ETX 90 - EC. > >Regarding adding the wraps of Teflon tape around the trunions, it looks like >I have to remove the OTA so that I can do this, right? > >Thanks again, > >Bill
Subject: Thanks! Re: ETX 90 loose gear assembly?? Sent: Thursday, March 1, 2001 22:22:45 From: Bryan To: email@example.com (Clay Sherrod) Thanks for the info! I appreciate it. I fixed most of what was happening. It was the plastic gear assembly that was messing up. The one with the plastic white gears and the drive motor. What I did was: Take the whole danmed thing apart. (I'm a regular mr. fixit hehe) Wash and degrease everything. Though they used so much grease on there I scraped a bunch off to re-use The pins in the gears did not sit tightly in the grooves, so I used some white paper and KwikBond glue to add some extra plastic to the grooves. (Similar to glassing a surfboard...thats where I got the idea) The pins were also not installed correctly from the factory. One side has a flat spot that fits into a matching flat groove. One of the pins was put in backwards. Put all of the gears back together and greased them liberally. Noticed the motor was not braced tightly at all, so I used some nylon washers as braces wedged along each side of the motor. All this (along with the cleaning/tightening described in your article; did notice my clutch plate/nut didn't have any metal nubs to grind off though) got rid of most of the delay in the RA drive system. The remaining delay can be taken up with the dec % thing in the new Autostar software. The lifting problem is still persisting though. I put everything down and went to the garage and installed an exhaust system on my Mustang to give me time to think about the problem... The large nut that holds the RA drive system to the rest of the telescope has a plastic washer that seems to wiggle a bit. If I tighten this nut too much the scope is difficult to move. If its too loose it seems to lift when the RA drive is activated. I thought about removing the plastic washer and just using a good amount of grease instead. What do you think? Thanks again for your help and great articles. -bryan ----- Original Message ----- From: "Clay Sherrod" (firstname.lastname@example.org) > Bryan - there are two (2) gear assemblies in the RA drive which you might be > talking about, both of which are causing both problems (the delayed star in > Azimuth (RA) and the upward motion in ALT (DEC)). You need to specify WHICH > gear assembly is moving: > > 1) in the very middle of the inside of the base is a larger, flat "drive > gear" which is engaged with a cylindrical "worm driver" gear. This assembly > has been known to come loose; > > 2) the second drive gear assembly is the series of very small white (nylon) > relay gears that transfer the motion (and reduce it) from the motor to #1) > above. > > I suspect that, from what you are describing, it is the main gear/clutch > assembly that is LOOSE from the turntable of the telescope. Go to Mike's > TECH TIPS and pull up the "ETX Tune UP" article and then to the "ETX-125EC > Right Ascension lock Fix." In the latter post, you will see a photo of the > drive gear and clutch plate removed from the large shaft that moves the > scope; it is connected with a 1-1/2" nut and steel shaft. It sounds like > that nut is loose on your ETX 90. Every time you apply torque (push the > buttons in RA), the turning worm driver "lifts" the drive gear in the > direction the gears are turning if this nut is loose. > > I doubt it is the numerous small gear assembly; but if it is, tell me > exactly how it moves relative to the large drive gear. > > My "Enhancement Guide", Part 1 under the Tech Tips tells about working on > the clutch plate and the main drive gear. Getting the clutch plate OFF is > tricky, but it is described; if the scope is still under warranty, I would > ask for a new one. The movement of the main gears can cause a lot of > unnecessary and premature wear on the entire gear train (not to mention your > nerves!) > > Tightening the three screws indicates that we are talking about the main > drive system as I suspected. Those three screws will not affect the > looseness, except to jam the worm driver too tight against the drive gear > (hence the grinding). > > The uplifting in declination is a "false" impression. What indeed is > happening is that the ENTIRE TELESCOPE turntable (which holds and rotates > the fork arms) is LIFTING as you torque the drive gear.....when the drive > gear activates and pushes against the drive shaft (that big steel shaft that > the 1-1/2" nut holds tight), it literally lifts the scope. What you see is > what appears to be DECLINATION movement, when in reality it is not.....your > declination is NOT moving. > > You CAN fix this yourself. But I would NOT use it until it is fixed. If > it is not under warranty, certainly try to use the helpful guides I have > mentioned in conjunction with my "Enhancement" Part 1. It should step you > through it completely. If you do NOT want to try yourself, and if the scope > is out of warranty, I would be happy to fix it for you but you would, of > course, have to ship the scope to me via UPS. > > Good luck....getting in there and working on it is not as hard as it might > appear; THE MAIN CAUTION that I always express to self-helpers on the ETX > is the WIRING and ELECTRONICS. They are VERY fragile. > > I hope this helps....I know it is not good news, but you have a loose drive > shaft and it most definitely needs immediate attention! > > Let me know if I can help further. > > Clay Sherrod > Arkansas Sky ObservatoryAnd a final note from Clay:
Bryan - it sounds like you licked the problem. Normally these things, as you have seen CAN be fixed if you are willing to get in there and do it; you methods sound good, particularly shimming the motor as well as the reversed pins. Glad it worked. Regarding the RA axis and the loose nylon nut. Leave the nut in, it smooths out the power transfer in the RA train, making tracking and GO TO smoother and more efficient. HOWEVER, the RA axis is SUPPOSED TO BE TIGHT. That is where the "lifting" is coming from; when you apply torque in RA (i.e., slew or move) the power is transfer through the path of least resistence, in this case a loose fitting to lift the scope's turntable. Snug down on the nut as I suggested until you have some tightness; most ETX scopes demonstrate significant resistence in RA when attempting to move when unclamped; this is pretty much what you WANT. However, again do not overtighten. My ETX 125 is very, very tight, as though my clutch is engaged all the time; having experience with other clutch mechanisms in more complex drives, this worried me at first, but now that I understand the very simple - and effective - clutch design for the ETX, mine is as tight as can be and works just great. So, tighten the RA (do this by trial and error...stop when it begins to tightly bind) until the nylon washer is snug and DOES NOT MOVE under the leverage of a screwdriver placed against it. I hope you did not remove "too" much of the play in the white nylon gear train; they are supposed to be a bit "relaxed" in their motion so as not to put accessive torque onto the small driving motor; backlash or looseness in that assembly usually cannot transfer past the main drive gear/clutch assembly. You're off to a good start...keep me posted! Clay Sherrod
Subject: ETX 90 Sent: Thursday, March 1, 2001 06:31:42 From: email@example.com (Barbara Warburton) Hi: I bought my husband an ETX 90 Meade Telescope for Christmas last year. We have never operated a telescope before and we are having a little difficulty with it. We are having problems using the manual that came with the book. We also have the tripod and the Autostar. We would like to be able to view things in more detail. I saw the tutorial on aligning the Autostar. Will this get us started. Are there any basic easy instructions for us to use so that we can fully learn and enjoy this telescope. I also bought a blue and yellow filter, a Barlow lens and also another lens recommended to my by the store where I purchased it. We have taken the telescope out during the summer months and viewed the moon. However we did not have the other lenses at that time. We would really like to view things like the moon, stars etc. in more detail. Can you give us some pointers on what to begin with first since we are novices at the telescope. Thank you, Barbara Warburton firstname.lastname@example.orgMike here: I'm a little unclear exactly what you are asking. If you are having problems locating objects and have the Autostar, then getting it properly aligned should help. If you don't have an Autostar then you'll need either some astronomy charting software or some books or one of the monthly magazines or you'll want to check various astronomy web sites. Some of all of these are mentioned either on the Astronomy Links page, the Book Reviews page, and/or the Software Reviews page on my ETX site. If you are having problems aligning the Autostar, see the alignment tips on the Autostar Information page on my site. Hope this helps.
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