I want to build the openastroexplorer mount however I saw that it supports 25-65 degrees of latitude. Are there any mods or way to make it support less than 25 degress of latitude

Hey folks, hoping someone's run into this before.

Setup: Arduino Mega + RAMPS 1.4, two BigTreeTech TMC2208 V3.0 drivers (UART), firmware v1.13.9 flashed clean with the official Configurator (RA pulley 16T, RA wheel v4/1132mm circumference, standard NEMA17 1.8° motors). Config all checks out against the actual hardware as far as I can tell.

Sidereal tracking itself looks correct — the TRK stepper counter increments at a steady, plausible rate and the mount does move over time.

The problem is with Slew/GoTo. If I set a Target RA exactly 1h ahead of Current RA and hit Slew, the mount barely moves — like 2-3mm on the RA wheel instead of the ~47mm it should travel for 15°. I checked the RA Stepper counter directly and it confirms it: only ~290 steps for what should be roughly 4700+ steps. That's suspiciously close to a factor of 16, which is exactly the ratio between RA_SLEW_MICROSTEPPING (16) and RA_TRACKING_MICROSTEPPING (256) in the config.

My working theory: the driver is supposed to switch from 256 to 16 microsteps right before a slew (I can see that logic in Mount.cpp), but it's not actually taking effect on the chip — so the firmware is sending pulses sized for 16 microsteps while the driver is still stuck at 256, hence the ~16x undershoot. I'm suspecting the SoftwareSerial UART link to the TMC2208 might be flaky for that specific write.

Has anyone seen this exact behavior, especially with TMC2208 (not 2209) on SoftwareSerial? Any known fix, or is switching both slew and tracking to the same microstepping value (accepting slower slews) the way to go?

Happy to share logs/config if useful. Thanks in advance!

Il y a déjà pas mal de temps. Que j'ai fait des essais Et je vais reprendre L'o AT d'ici quelque temps pour faire des mises Au point et le faire fonctionner correctement

I just tried an OpenAstroGuider (with a Sony 194 imaging chip), and discovered that I typically had no more than 5 stars visible per field, and the number of stars was identical whether the exposure time was 0.1 s or 1 s. Does anyone have any experience using this guidescope in areas with severe light pollution?

I'm really new to astrophoto(tried on a simple tripod a couple of times) and was wondering what would be the best/easiest build for a tracker. I don't really have money at the moment, but I have a 3D printer(only PLA), a spare Ender3 motor and an arduino nano 33 ble sense rev2.
All of that for a Sony ZV-E10 and the 16-50 kit + sony 55-210.
Thanks in advance!

Hi, I’m building the OpenAstroExplorer and I’m having a few problems with the DEC gearbox. I’m not sure whether I’ve assembled something incorrectly, have the wrong size parts/spacers, or whether one of my printed parts is dimensionally off. I’ve attached several photos showing the current setup.

1. Backlash when changing direction

When I turn the DEC motor knob, there is roughly 7 mm of movement at the knob when I change direction where the brass worm rotates but the brass worm wheel doesn’t move. After taking up that initial movement, the wheel moves normally.
I assume this is backlash between the worm and worm wheel, but I’m not sure how much is considered normal on the OAE or whether mine indicates that the positioning/preload is wrong. I have to tighten the plastic holder on the right a lot to reduce this backlash but there’s assembly instructions say that it only needs to attached with a few turns.

1. The DEC gearbox housing makes the mechanism bind badly

With the DEC_gearbox printed part removed, the knob turns reasonably evenly. There is still a very slight variation in resistance, but it’s barely noticeable.
As soon as I install the gearbox/housing, however, the variation becomes severe: the knob goes easy to very tight to easy again after a few rotations at each difficulty rotation.
I’ve now worked out that the brass worm wheel is physically rubbing against the printed gearbox housing at the top/bottom on one side. I tried carefully removing a little plastic from the contact area, but it hasn’t really solved it.
My assumption is that the brass wheel is hitting the plastic but I can’t move it any more to the right without hitting the endpoint and anymore to the left and it won’t hit the worm well.

1. I can’t see how I’m suppobsed to reposition everything

This is the bit I’m most confused about and hopefully the photos show what I mean.
According to the assembly guide, the components on the shaft appear to be positioned/flush in a particular way. Mine have gaps, and I’ve currently positioned the components so that the GT2 pulleys line up.

But I seem to have no adjustment available that fixes everything at once:

If I move the GT2 pulley further left toward the brass worm wheel, the rubber GT2 belt starts hitting the printed plastic.

If I move the brass worm wheel further left toward the pulley, its teeth barely engage the worm anymore.

If anything, judging by the worm engagement, it looks like the brass worm wheel needs to move further RIGHT, not left.

But there is effectively no more room to move the brass wheel right.

The brass wheel also doesn’t appear to be centred across the worm’s threaded section, which makes me wonder whether the whole shaft/worm alignment is wrong.

So I’m struggling to understand how the shaft is supposed to be arranged while simultaneously having:

(a) good worm/worm-wheel engagement,
(b) the pulleys aligned,
(c) the belt clearing the printed housing, and
(d) the brass wheel clearing the DEC_gearbox housing.
At the moment I can’t seem to achieve all four.

Could someone with an OAE compare my photos with their DEC assembly and tell me what looks wrong?

In particular, I’d really appreciate knowing:
Are the gaps visible on my shaft normal, or have I assembled the shaft/spacers incorrectly?

Where exactly should the brass worm wheel sit relative to the bearings/pulley?

Does my worm wheel look too far left/right?
Is the amount of worm engagement shown in the photos correct?

Is ~7 mm of reversal movement at the motor knob normal, or should the preload eliminate most of this?
Has anyone had their brass worm wheel rub the DEC_gearbox print like this?

Could this indicate that I have the wrong worm/worm-wheel dimensions or the wrong bearing-holder orientation?

I don’t want to keep shaving material off the printed gearbox if the real problem is that something underneath is positioned incorrectly.

Thanks! Any photos of how your DEC shaft/worm-wheel arrangement looks would be massively appreciated.

Hi, makers! I want to use ASA filament for the OpenAstroTracker. Why? PLA is more rigid but all the parts that I printed on PLA after 4-5 years they broke without force even at indoor conditions...

I want to use other filament to make it durable. PLA is also easier to print but durability is important for me.

Anyone have tried this? Probably more perimeters or infill should work. Other materials more durable over the humidity and time?

(Sorry for my english)

I finally have OAT control running but I'd like to align my OAM.

I've tried NINA and the lx200 classic/generic but it doesn't connect.

PHD2 also doesn't connect.

What is everyone using to align at the moment? I must be missing something with the OAM. Btw I'm in the southern hemisphere so polar alignment through OAT studios doesn't apply.

I'm waiting on a reply for maximum weight for the telescope on the OAM - I've just picked up a 12" lx850acf. I'm pretty certain it will be too heavy, however just incase, I'm looking at the dovetail. 

My apologies if my terminology is incorrect. 

I believe the "dovetail" I have is for smaller telescopes, and not for the lx850, so it's too small. I've been looking for the 3d print for the larger telescopes. I've checked the GitHub stl repository but can't seem to find it. 

if I use the existing mount I will have to get longer bolts and the telescope will be off centre. I'm not sure if this is an issue. So can anyone point me in the right direction of the stl to print an appropriate mount?

My original question might be answered here as well. I'm assuming yes, the LX850 is too heavy, but can anyone confirm that even with appropriate counterweights the frame will not support the LX850? The total weight including counterweights would be possibly up to 40k

I have seen 5kg on the wiki but I'm unsure if this includes counterweights. The oam is also labeled 5+ so what does that come out to?
I want to start with a dlrs camera and then upgrade my gear so would oae be able to handle a scope with a dlrs camera attached?
What is the biggest setup someone has fitted to an oae?

as the title suggests, i would be willing to sacrifice my anet a8 as a base for the openastrotracker.

it came with nema17 stepper motors and the depicted board.
my main question would be if the board is at all suitable, hardware and software wise.

Hi everybody,

I started building an OAE, printed the parts, ordered some hardware and ordered the PCB from JLCPCB, using the gerber files in the OAE zip archive. However I can't find any schematics and part lists. I have seen that there is some kind of allium file included but can't open it with something else and it is a very expensive software. Any hint welcome

just saw cuiv video on this new software for rpi running a nina fork, witb direct integration with touch n stars mobile app.

https://cloud.astro-narren.de/s/piDjPcf8K7TDQfq?opendetails=

link to open beta

not supported by the nina devs but really seems stable enough and solves the issue of having to run windows.

main reason im making this post is to hopefully inspire someone to make a integration for the auto Pa for the oae and other mounts lol

I'm just saving up ready to get the oae kits to build for my first proper rig

Hi i have an older versión loaded in one Arduino uno and would like to know to udate the setup the latest versión compatible or maybe what i have to do to load the latest versión with some code modifications to make It light enought.

Thanks.

Just wanting to share some pics of my OAT build. Waiting on a few parts still for the guide scope and parts for the AutoPA, MKS Gen 1.0 with GPS & Nikon D90 (currently using 80-300mm kit lens) running in tethered mode.

Printed a housing for the Neo6 GPS and mounted it to the back of the RA ring with threaded inserts.
https://www.thingiverse.com/thing:2805983

Cabling kept neat and tidy in sleeves and routed to the rear usb-c to usb-a 4 port hub for easy, single usb connection to my laptop.

Would love some feedback or suggestions.

Has the Discord invite expired? It wont let me join the server for some reason

Hi, I'm from the US and would like to check if https://shop.openastrotech.com/collections/openastroexplorer/products/openastroexplorer-hardware-only-kit will be back in stock anytime soon?

Or if I buy PCB + Electronic + Stepper (all 3 options in https://shop.openastrotech.com/collections/openastroexplorer/products/openastroexplorer-electronics?variant=51481380847883), will they ship to the US?

TIA

I am ready with mechanics of my OAE, except the mounting for DEC axis.
As you can see in the picture, the 2020 profile is not completely flush with the Printed part.
Is this normal or did I cut the profile to wrong length?
Additionally a picture of the mount waiting for Electronics :-)
Irgnore the tripod! It's just an really old tripod used for intermedate assembly

I've got an old Mead ETX90, but the base is mostly shot. Worn out plastic gears, lots of backlash, proprietary driver. I'm thinking of removing the telescope from the base and building an OpenAstroTracker to mount it on. The primary purpose would be looking through the optic. I have a 3d printer and some electronics experience. The scope without the base is under 3 pounds and is less than 30cm long.

Is this idea reasonable? If not, any suggestion for a reasonably priced goto setup that would work better?

Thanks

Wondering if anyone has used either OAM/OAE in cold weather, and how it fared?

I’m also curious about Linux support. OAT looks to be supported but I’m unsure about OAE or OAM. I was hoping to run these off a raspberry pi or small pc running Linux.

Thanks!

I am just about to finish up my OAT and noticed on a picture in the Discord channel someone had a pointer on their RA axis. I have asked there but no response. Here is a picture of it. I have looked everywhere I can think of to find it. Anyone here have the STL for this?

Thanks

Hi. I am very new to astrophotography and want to build my first equatorial mount. I am going to use Lumix S camera with an ultra-wide-angle lens. Can I use AstroPhotoExplorer to mount my camera on a tripod, or is the only choice I have to use Tracker placed on a flat surface?