Re: Are the new mounts really less rugged than the very old ones way back when?

Mike Shade

I have been an astrophotographer for over 30 years and have used a number of cameras, mounts and OTAs. I have found AP mounts to be a very good investment-and I have used other brands through the years. I have a first generation 1600 permanently mounted in an observatory holding a CDK 17 and this system runs about every night most of the year (we shutdown during summer monsoon). It has been doing this flawlessly for years. I have to remesh the gears twice a year and grease the gears, typical maintenance. Prior to the 1600, there was a 1200GTO-it is still in use but is for the occasional visual work and the more frequent planetary work. There have been problems and in every instance it was user/software error, not a failure of the equipment. A quick call to AP and there was a friendly helpful person on the phone to assist.

I have found through the years that there are a number of amateur astronomers ( I might offer over 50%) who are experts on equipment that they don't use or own, or are experts on the equipment that you own. They will tell you all about the flaws inherent in the equipment, without having any real firsthand knowledge or experience. With the advent of Internet discussion groups, everyone is now an expert, often on some obscure and generally irrelevant point but they have to prove that they are experts on the topic. There are also those who do own the equipment in question but are so tightly wound that they are unable to use it because they are obsessing about every possible detail, every potential pitfall and disaster. I have seen discussions on this list go on for days about which grease to use and people being almost hysterical because they don't have the "right" grease. They seem perhaps more concerned with this than actually getting out and using their equipment.

The point is that AP makes a fine product, have been doing so for years. They continually work on improving their products and designing new ones, and have a very good customer service reputation. The proof of this would be perhaps what has been called in the political world the "silent majority" those like myself who use their equipment regularly and push it to the limits. And it works well as it was designed to do, every clear night. Period. The proof is in the results that myself, and quite a few others are getting. This is a better testament to the quality of AP mounts than the experts on an Internet discussion group.

Mike J. Shade:

Mike J. Shade Photography:

In War: Resolution

In Defeat: Defiance

In Victory: Magnanimity

In Peace: Goodwill

Sir Winston Churchill

Already, in the gathering dusk, a few of the stars are turning on their lights.

Vega, the brightest one, is now dropping towards the west. Can it be half

a year since I watched her April rising in the east? Low in the southwest

Antares blinks a sad farwell to fall...

Leslie Peltier, Starlight Nights

International Dark Sky Association: <>

From: []
Sent: Wednesday, June 05, 2019 8:10 PM
Subject: [ap-gto] Are the new mounts really less rugged than the very old ones way back when?

Hi Astronuts,

Recently on CN there has been a discussion about our Mach1 guiding issue that was brought up by one of our customers. Thankfully the mount did not have a problem since we tested it here and found no tracking anomalies on the RA gear. The issue was most likely a setting in PHD which caused the Dec axis to not get any correction signals in one direction. And thus the mount drifted in Dec. This is not a trackign issue because only RA tracks at the sidereal rate, Dec does not ordinarily move unless commanded to do so.

In any case, the whole thing has been blown out of proportion again, as usual on CN, but I should be used to that by now. So of course this has caused some consternation among readers who are now getting gun-shy about mounts in general. No, our mounts are not fragile, and yes, if treated with care they will last a lifetime. So now one Mr. Kennedy has posted this, and I wish i could answer him, but not being on CN, I cannot.

"I am in a real quandry, my wife has ordered me to sell my Pentax MS-5 GEM since they are apparently very highly sought after in Japan and would command a high price. I do not want to sell it but since she was born in Japan and speaks fluent Japanese, she really would not need my help or cooperation in finding a Japanese buyer. My Vixen Super Polaris is obsolete. Both the Pentax MS-5 and the Vixen Super Polaris have worked flawlessly without ever once having even the slightest malfunction over the 31 years since I purchased them while stationed in Japan but it appears that both will need replacing in the not too distant future.

I read all the horror stories in this forum about new mounts, even premium ones like AP, 10 Micron and SB ones having problems that I would not be prepared to deal with and feel despair, I need mounts that I can absolutely count on to work perfectly right out of the box for years, very low PE and substantial capacity like the Pentax MS-5. However, as the OP in this thread's problem indicates, you can not expect that even from so-called premium mounts any more due to either a faulty design or sub-standard materials. I understand that AP is planning to replace the Mach 1 with a Mach 2 sometime later this year but there is no guarantee that it will not have the same kind of problems as the OP's Mach 1. I also believe Vixen will be coming out with a new premium mount that at least uses brass and steel rather than aluminum for its gears but I think it is likely to be extremely expensive."

Ok, so here is what i would say to him: First, the old Pentax is a nice rugged mount, but that has nothing to do with the worm materials used. The Pentax does not have high speed slewing capability and so it was never slewed around. As such the worms have never seen any kind of wear because the amount of rubbing action of the worm teeth is about 1% of what happens in a modern GoTo mount that is slewed all over the sky every night. Since the Dec axis does not normally even track, I'm betting that the worm is still within one or two teeth of where it was originally set. On these old mounts only the RA tracks slowly at the rate of one worm tooth about every 5 minutes. Dec doesn't track at all and is only used to center an object, which maybe uses one tenth of a worm tooth motion.

Contrast that with a modern GoTo mount where both axes have to move at some 1000 times the sidereal rate many times per night when used visually or when used in survey work. A mount that only has to track at 1 revolution per 23hrs 56minutes the worms can last 100 years. When you multiply that rate by 1000x the worms wear at 1000x that rate and can wear out in a lot less years. Worms are not the greatest for low wear and have very poor efficiency. The reason we use worms is because they have extremely precise motion, and with a bit of PE correction our 1100 / 1600 mounts can track for hours at 1 arc sec or less per worm cycle. While the Mach1 can't haul as much gear as these two, it still has the same rugged construction, in fact the gearbox of the Mach1 is the same as the 1100 mount. Just the gearwheel is somewhat smaller, but same material and same machining.

We have two 1600 mounts right now at our remote site at Las Campanas in Chile that are still imaging each night and tracking at precisely the proper rate for the last 5 years. Nothing mechanical has ever been done to those mounts. On our last trip 4 years ago we also were fortunate to visit Cerra Tololo where there are half a dozen Software Bisque mounts running continuously each night and have been doing so for at least 10 years now. These mounts all have the same brass and aluminum worms gears as we use in our own mounts. None of these mounts, as well as ours, are getting much of any attention from the staff there, not even occasional lubrication. In fact I'm probably going to visit our remote observatory in the next year just to do some routine measurements and maintenance and I expect them to outlast me.


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