This project would have gone absolutely nowhere without the incredible knowledge and skill of Dave Rubenhagen, machinist extraordinaire, and his shop full of wonderful tools. Also to be thanked are Herm Veenendaal for use of his knowledge and wood shop, Doug Dieter for his electronic insight and support and Anand Rajiva for his motor control hardware.
If you have any questions about my modifications contact me at:
I was asked recently how I can tell everyone how great a mount the HEQ5 is; and then in the next breath tell them that I'm modifying mine. To start with, for visual observing the HEQ5 is a GREAT mount for the price. My requirements, though, called for a bit more than basic visual use. I considered the mount perfect as a 'blank slate' on which I could build to meet my needs. At project's end I want Losmandy GM-8 performance and features... for a lot less money.
It was time to retire my Celestar 8's Fork/Wedge mount. There was nothing 'wrong' with it. It still performed as per specification; but the 'specification' was circa 1998 and the design just wasn't 'there'. It wasn't a problem with the tripod/wedge combination as it sat on a beautiful tripod and wedge. My Criterion Golden Pyramid tripod and wedge had been modified and were absolutely stable and in all other aspects just perfect. The same unfortunately couldn't be said of the Celestron 9v spur-gear drive/fork. While very simple to use (aren't all forks?) it twitched like a kootchie dancer in any wind (tuning fork effect or just the abyssmally short polar axis?) and to see anything in about 1/4 of the sky I had to climb inside the forks and play 'circus contortionist'. This isn't a failure but is the nature of the beast. Therefore it was time for something new.
My Requirements
I had a list of requirements that my new mount has to live up to. These are (in order):
- It had to be a German Equatorial
- It had to be stable
- It had to be able to handle the load of a C8, camera and my gear
- The price had to not lead to divorce
- It had to have motors on both axes
- It had to power from 12v DC
- It had to be portable in a small car
- It had to be easy to setup/tear down in the dark
- It had to be able to handle guided imaging (manual and auto)
- If I decided I wanted it in the future, goto should be available
As you can see... I wasn't asking for too much. Any garden variety Losmandy. Tak or AP would, of course, do the trick but I wanted to try to get high-end performance for a lot less money. For this project I budgeted at total of $1500 (Canadian) which puts even used higher quality mounts outside the budget. As for turning a mid-range Chinese mount into a performer? From reports on the web; it could be done with a bit of planning, work and perseverance...
As for the last item on the list let me first say that I'm not a hard-core astrophotographer but I could probably be talked into it. Piggy-back and my digicam are the most important things for now, along with my visual addiction to DSOs.
The Contenders
To start with, the high-end mounts from AP, Tak, Paramount etc. were NOT even on my list. While they are the stuff that dreams are made from, I'm not Bill Gates. When I retire I'll build my 'retirement' scope and it will have the dreamy stuff. For now I wanted something that wouldn't send my banker (read 'wife') into fits.
Over the past months I had been pondering several different mounts and the short-list came down to these (not in any specific order)
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Celestron CG-5 ASGT
Synta EQ6/Orion Atlas
Synta HEQ5/Orion Sirius
Losmandy GM-8
Synta HEQ5 - The Winner!
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This one seems to be what I am looking for. The Celestron was too noisy, the EQ6 was too heavy and the Losmandy was too expensive to be the 'raw material' in a project. That leaves just one....
The HEQ5 mount, delivered and with taxes included is priced under $1000 dollars Canadian. It has the same costs as the EQ6 in the way of modifications for imaging and is a LOT more portable. I had read all the EQ6/HEQ5 short-comings and figured I could work around them. The HEQ5 is a close 'clone' of the Takahashi EM10 mount, a design that has been proven over many years. I coulnd't fault the design; the implimentation of the design was to be seen.
Arguments heard against buying a Synta mount
A Synta?? You bought a Synta? That was the response from the people on the astronomy IRC channel I hang out on. I have heard all of the complaints and I have dismissed them for the most part. The reviews I had read from actual users seemed positive but here is a synopsis of the complaints (just for posterity):
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It's Chinese
- So is a good portion of just about everything normal humans can afford to buy. It's why China
is eating everyone's lunch trade-wise. And they just bought Celestron. Note: All of the Celestron German
Equatorial mounts south of the CGE are made by Synta in China. I don't know about Meade's offerings... but I wouldn't be surprised.
- Oh well, I can spend 5 minutes.
- Yep, it's lousy but it can be replaced.
- In the nylon bushing days that was true, Synta has discovered ball-bearings.
- Yes, they vibrate. Steppers being what they are they 'hammer' at the mount to move it. This is a 'fixable' problem..
- As delivered, perhaps. But then, people have taken decent long-exposure pictures on mounts made from plumbing
pipe and bubble gum. Again, this can be fixed through judicious modification..
The HEQ5 mount is almost universally reported as being great for visual observing but not in the same league as the lower end Vixen or Losmandy offerings as an imager (I don't know why). The biggest problems with the HEQ5 seem to be it's drive electronics and gearing; both of which have viable replacements.
On to part 2 - The HEQ5 arrives
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