Mount with +-0.3 arc sec periodic error

Geoff45 (Geoff) · #1 07-07-2010, 04:22 PM

That's what they claim here . Nice if it turns out to be true.

wasyoungonce (Brendan) · #2 07-07-2010, 05:41 PM

I think everyone is waiting for some else to buy one & test it!

multiweb (Marc) · #3 07-07-2010, 05:43 PM

Get an EQ6 + AO and you'll have $5k left to buy a really nice scope to go on top.

terrynz (Terence) · #4 08-07-2010, 07:05 AM

I'd like to see a real test of this, as i'd be really suprised if it can do +/- 0.3 pec out of the box. As we all know, theres some pretty bold claims when it comes to mounts.

If spending this sort of money, I'd be sticking to whats been proven. The Vixens, takahashi's Paramounts and AP's.

rat156 · #5 08-07-2010, 07:22 AM

There's also the ASA ddm60, which has similar claims for 5750 Euro...

Terry B · #6 08-07-2010, 07:38 AM

Quote:

Originally Posted by multiweb

Get an EQ6 + AO and you'll have $5k left to buy a really nice scope to go on top.

The mount the OP pointed to isn't really comparable to an EQ6. It states 75lb load (34kg) load limit. This is much more than any EQ6 can handle.
The comparable mount is the iEQ45 at the list price on the website of US$1599.
Still dearer than an EQ6 but not as much.

AdrianF (Adrian) · #7 08-07-2010, 07:45 AM

Nice and does that look like an ED127 on top?

Adrian

Zaps · #8 08-07-2010, 09:05 AM

So is this thing direct drive, or does it still have gears?

If no gears then it's certainly another interesting alternative, but if it's geared then IMHO it's better to look at the various direct drive mounts now available.

Edit: OK, I just looked at the specs and it's geared, so that means PE (even if small PE). For the price or less you can get better direct drive mounts.

garymck (Gary) · #9 08-07-2010, 09:39 AM

One could always use:

http://www.sitechservo.info/

and add a hi res encoder to the ra axis for PE correction in real time. people are getting better tha 1 arc sec pe total when correctly set up. Could be retrofitted to almost any mount.

cheers
Gary

wasyoungonce (Brendan) · #10 08-07-2010, 10:44 AM

Quote:

Originally Posted by AdrianF

Nice and does that look like an ED127 on top?

Adrian

Ha!...good pick-up. Yes it is.

Hioptic & NorthGroup have a relationship & Hioptic are involved with Ioptron (NJIdea or Bostonati (Boston Applied technologies)).

Indeed my Northgroup 127 had Hioptic email address on the invoice!

terrynz (Terence) · #11 12-07-2010, 01:55 PM

I upgrading recently and looked into the ASA Chonusmount's and other variants. Personally, I think until these new variants will have a hard time catching up to the AP's, tak's and Paramounts; al least for the little while. Like all things, their time will come.

In the meantime I wouldn't buy a mount like the one refered to in this forum. Probably not yet. My experience (until now) with mounts has been all bad. Basically, over sold and under delivered.

cheers
Terry

Disclaimer: As of Jan 2010, I'm Paramount ME convert hence now incredibly biased and broke!

Moon (James) · #12 12-07-2010, 03:24 PM

1+ what Terence said.

There gets a point where periodic error is a non issue with many mounts already on the market today. IMHO the ability of the ChronosMount to track through the Meridian - that's interesting. No looking for a new guide star in the wee hours, no 180 degree rotation of your images, no more cropping due to misaligned subs..... Sweet.

James

TrevorW · #13 12-07-2010, 04:24 PM

Why such a huge price variance between both mounts the 45 and 75

????

Kal (Andrew) · #14 12-07-2010, 11:29 PM

Quote:

Originally Posted by TrevorW

Why such a huge price variance between both mounts the 45 and 75

????

The high resolution encoders use to correct for the gearing errors (why it has such low claimed PE) are expensive.

gregbradley · #15 13-07-2010, 12:37 AM

It seems the mount world is moving forward and a lot of new competitors in the market. This is good for us.

The trend seems to be towards hi-res encoders which are the basis for these direct drive mounts anyway.

Like the trend in scopes is towards 2 mirrored scopes of various configurations with a built in corrector.

Its good for the hobby to have this innovation.

Greg.

terrynz (Terence) · #16 13-07-2010, 07:50 AM

Yip, in the end it is all good for us. The questions about this mount and others is, should be...

Does it met my current and future needs?

How long will it last?

How well supported is it?

Can it track at true lunar, solar, minor planet or comet, NEO or LEO satellite rates, or at almost any user-defined rate?

Will it track past the Meridian? If not, can I automate this and maintain my exact FOV for imaging?

Can I afford it?

Can I trust those reports on the internet?

I like where it is all heading, but don't expect the price to come down as technology improves, quality will still set you back.

gregbradley · #17 13-07-2010, 09:26 AM

Quote:

Originally Posted by Kal

The high resolution encoders use to correct for the gearing errors (why it has such low claimed PE) are expensive.

So the high precision encoders do a constant PEC type of thing?

Clever.

Greg.

Kal (Andrew) · #18 13-07-2010, 11:55 AM

Quote:

Originally Posted by gregbradley

So the high precision encoders do a constant PEC type of thing?

Clever.

Greg.

Yep, on the product page they mention the brand too - Renishaw high resolution encoder-enabled double closed-loop

My google skills fail when it comes to seeing how expensive they are, but you can read more about the encoders at the Renishaw website.

AndrewJ · #19 13-07-2010, 01:04 PM

Gday Greg

Quote:

So the high precision encoders do a constant PEC type of thing?

They dont "do PEC" per se, they simply allow you to bypass it
( and backlash on reversing, and geartooth spacing errors)
They cant help with mechanical misalignments or flexure etc.

In std setups, the encoders are on the motor and hence the vagaries of the geartrain have to be "guessed", so that the motor control loops can provide an "estimated" constant speed "at the final axis"
With a high precision encoder, it is normally fitted directly to the RA or DEC axle itself, hence ( by using a high speed close coupled feedback loop ), the motor simply drives to give the required theoretical encoder rate, and this is guaranteed to be the axis rate, as the encoder is on the axis.
Thus, any PE etc in the geartrain is irrelevant as the system no longer needs to know about it.

Andrew

Kal (Andrew) · #20 13-07-2010, 01:09 PM

Quote:

Originally Posted by AndrewJ

They dont "do PEC" per se, they simply allow you to bypass it

I guess you could call it 'real time error correction' instead of periodic. Maybe RTEC is a suitable acronym?