Jump to content

Banner.jpg.b89429c566825f6ab32bcafbada449c9.jpg

Ioptron HEM27 owners thread.


knobby

Recommended Posts

Ioptron love to say 'backlash free' don't they 🙂

The Ra is locked, no way to balance It and apparently no need to (It chucks my C9.25 about with ease.

Dec is the same as any other Ioptron, can be adjusted to minimise backlash but all depends on your luck ... don't forget there is a belt in there that will give backlash if too loose.

And if by fluid you mean really smooth and free then yes, Ra is very free and 'spinny' 🙂

I've managed the 3rd axis balance by rotating the OTA as so the EFW and autofocuser become the offset weight.

 

PXL_20221018_094816431 (2).jpg

  • Like 1
Link to comment
Share on other sites

  • 2 weeks later...
  • 1 month later...
  • 1 month later...
  • 3 weeks later...

Hi, new HEM27 owner here. From reading around it appears that 3rd axis balancing is important for this and other iOptron mounts.

There is an M8 thread on the side of the saddle for a balancer accessory to be attached (amongst other uses), so after raiding my 'bits 'n' bobs' containers and digging out a short fully-threaded M8 bolt, nylon washer, 2 x M8 connectors, a load of penny/halfpenny metal washers, and a wing nut, I came up with this solution which works a treat. 

The connectors help it to clear the mount body and the wing nut allows easy addition/subtraction of washers until balance is achieved. 

There's no need to re-balance in Dec after each adjustment as the balancer is fitted at the balance point.

Hope this is useful. 

IMG-20230401-WA0004.jpg

  • Like 1
Link to comment
Share on other sites

Nice one 👍🏻

I've used wheel balance stick on weights because I like to look at my mount as it doesn't get out much due to the weather 😂

also hopefully has the advantage of staying balanced if I rotate the OTA.

IMG-20230114-WA0002.jpg

  • Like 1
Link to comment
Share on other sites

I've fashioned a vixen clamp which has counterweights screwed into it so I can clamp wherever at the front of the dovetail to balance my back heavy sct. Works to a fashion, the ioptrons are incredibly smooth and sensitive to balancing adjustments.

  • Like 2
Link to comment
Share on other sites

  • 2 months later...

So, thought I'd spend my Birthday money on a counterweight and shaft to steady things up when using the C9.25 ...

Not available in the UK 😞

At least not where I could find anyway.

So not to be deterred I bought a https://www.firstlightoptics.com/ioptron-mount-accessories/ioptron-45kg-counterweight-for-gem28-ieq30-mt-az-pro-zeq25-cem25-cem26-cem40.html

M16 - threaded rod / M16 couplers from Ebay.

Had to drill the hole out to fit (much fun and 3 25mm drill bits later).

I only drilled through enough to leave room to thread one of the couplers after the weight as a toe protector (if anyone finds an M16 -  thumbscrew let me know please.)

Just in case anyone else needs one.

Whats the bets that someone will post a link to the proper item being available now 😂

 

 

PXL_20230611_145004128_1.jpg

PXL_20230611_145255327_1.jpg

PXL_20230611_145351407_1.jpg

PXL_20230611_145429838_1.jpg

PXL_20230611_145451908_1.jpg

PXL_20230611_145531582_1.jpg

  • Like 1
Link to comment
Share on other sites

4 hours ago, knobby said:

Whats the bets that someone will post a link to the proper item being available now 

Not UK but Astroshop have got it. Alternatively a zwo am5 one has the right OD and you can use an M12 to M16 adaptor for the top screw thread.

Good round about work though.

  • Like 1
Link to comment
Share on other sites

Regarding thumbnut, you could use a standard M16 nut? It'd be a lot cheaper. Or get an M16 flanged nut, it has a bit more surface area, I use them with my DIY counterweights and bars.

 

 

  • Like 1
Link to comment
Share on other sites

  • 6 months later...

Waiting for my HEM27 to arrive that 10-15 days seems to have been there a long time FLO…

Any further set-up hints/tips guys while I wait for the postie…

Link to comment
Share on other sites

  • 3 weeks later...

My HEM27 has arrived. I’ve had some fun today making an adapter for the top of my tripod to take it. Weathers closed in so I’ve just been setting up my laptop and NINA with its drivers, my ASIAIR Plus’s too now recognises it. 
Bit of a fiddle changing the saddle over to take losmandy plates. It now doesn’t go back in it’s case without removing the saddle clamp screw.

Aim to get the rasa on it tomorrow and drive it around a little indoors.

HEM27+RASA.jpg

Edited by fwm891
image added
  • Like 1
Link to comment
Share on other sites

If it's not on a permanent pier be prudent and cautious to do a loaded east west balance test first and check if your tripod is unbalanced. If you weigh the tripod down that's good practice, but I find if you test it in its most basic tripod raw configuration you'll have more confidence in the setup being stable without a counterweight which was always a HD mounts design intent.

  • Thanks 1
Link to comment
Share on other sites

Tried the HEM27 out last night: Full Moon, no filters, IC434 (Horsie) not the best subject with no filters under a full moon! Mount control via ASIAIR Plus. RASA 8 mounted with an ASI 585MC camera fitted, guiding with a 9x 50 guide scope. PA taken into AIR+'s the smallest circle ? then straight to IC434 centred on the chip with minor framing alteration. Focus adjusted and 20x 30 second 'Live' frames stacked.

I moved on to M45, then M42 and a couple of other targets moving each side of the meridien framing on chip each time with minor adjustments.

Pleased with this first test of the mount under stars (shame about old blobby). Although it didn't actually perform a flip on the same target I did take it each side and it found what it was asked for.

As a precaution I kept the max slew rate down a notch at x512 as I 'm tripod mounted but it all handled well so next time out I'll change the settings and let it slew at max.

IC434 image attached. Colours are a bit washed out from the full moon. Processed in PI.

IC434_RASA_585_NF_BXT.pngM45_RASA_585_NF_BXT.png

Edited by fwm891
  • Like 1
Link to comment
Share on other sites

  • 1 month later...

Had a 'few' (sadly few being the operative word here) nights now with the HEM 27/RASA/ASIAIR+/ASI585MC combination. (no counterweight used). I run everything off two small Celestron LifePO4 Batteries.

I've used an 8x 50mm TS guide scope with an ASI120MM guide camera mounted on the RASA's top rail for all guiding and not had any problems with finding enough suitable guide stars. I've fitted the guide scope, ASIAIR+ onto a small losmandy saddle. This I can slide up/down the RASA's top rail to fine tune the dec balance when I swap between the 585MC and the 2600MC Duo though with the Duo I guide with it's second sensor.

Guide exposures: I'm finding as most seem to find that the shorter exposure times yeald the best guide graphs and ½ sec to 1 sec being best. That via the 8x 50 guide scope is quite easy and when using a UV/IR cut filter with the Duo. Guiding at <0.5" on a good night is achieveable, circa 0.6" on an average night and around 0.8" with pooer seeing or longer exposure lengths.

Narrowband filters with the Duo (6nm Askar Ha/OIII is my narrowest at present) require 1.5 - 2 sec guide exposures but the guiding doesn't seem to stray much beyond the 0.8-1.0" with total errors showing in the range of 1.25" - 1.46". There are night when things don't go quite so well and others where things are slightly tighter which as this is a grab-n-go kit rather than a permenent set-up.

It replaces the AZ-GTi (with EQ mod) I previously had as a grab-n-go so: a) the GTi would never have carried the RASA 8. b) guiding is better given that the focal lengths used are similar.

For me the pluses:

Carries more load (bigger instruments) Currently using either:  an Altair Ascent 80 f6 Triple with x1 or x0.8 reduce/flatteners or a Celestron 8 inch RASA future: Askar 120APO

Uses the same surveyors tripod so no additional expense on supporting the mount.

Easy to PA via the ASIAIR+

GoTo's are accurate and require little extra time centering

Minuses:

Black mount makes set-up more awkward in total darkness

Azimuth adjustment knobs are small (or my finger are too big) especially if cold.

Heavier than the AZ-GTi (I do keep it on the tripod so not a major negative)

WiFi connection via handset - doesn't really worry me as when in use the handset just lays on the tripods equipment tray.

Operation:

Setting up I've found that I don't fully tighten the altitude or azimuth locking bolts but leave them 'snug'. Tight enough to take out any wobble but loose enough that adjustments can be made to the alt/az axles when doing a PA. I've not found any slackening of the bolts/machine screws during an evening. In fact the last few sessions I've not even checked the 'snugness' of the locking bolts (until just now!) and they're fine.

I've not set the slew rate to 'max' keeping it one notch down. I've not had any problems with the slews from the Home position or when it does a flip. I'd just like to keep the RASA in one piece so a few extra seconds  is worth it.

Happy with my HEM 27.

 

  • Like 1
Link to comment
Share on other sites

Love mine too, 0.75 second guide exposure works well for me, usually sub 1 arc sec guiding.

Haven't touched mine for months as we're moving ... From bortle 7 to 8 to bortle 4 though, so looking forward to that !

  • Like 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.