Q: What is this? What does it do?

A: The RPA is an add-on for the MLAstro One harmonic mount that motorizes the altitude and azimuth adjustment knobs. It allows you to adjust polar alignment remotely, or let the integrated Polar Alignment routine automatically correct the polar alignment error on your MLAstro One without needing to be physically next to the mount.

The MLAstro One with RPA has an adjustment range of +/-10 degrees in altitude and +/-8 degrees in azimuth. This means you still need to roughly polar align the mount first, then the RPA can take care of the fine adjustment.

Q: Does this work with MLAstro SAL-33?

A: No, this kit is designed to work with MLAstro One only. It is not compatible with MLAstro SAL-33 or any other mount for that matter. We’ll add another RPA kit for the existing MLAstro SAL-33 later in 2026.

Q: Do you have plan for an Universal RPA base for other mount as well?

A: Yes, we have plan to add an affordable universal RPA base that you can use with practically every mount out there. We are estimating we will introduce the kit in mid 2027.

Q: How can I control it?

A: There are 3 ways to control the RPA:

1. Via the web interface. The RPA creates its own Wi-Fi hotspot. You can connect to it, open the integrated web server through a browser, and control the RPA directly. You can also connect the RPA to your home Wi-Fi network and access the web interface from your local network.
2. Via the mobile app. We will add RPA support to MLAstro Hub, which supports Android, iOS, Windows, and macOS.
3. Via native support in observatory control software. NINA TPPA and the KStars/INDI polar alignment routine are supported, with SharpCap support coming next.

Q: What’s in the box and how do you install it?

A: The kit includes 2 stepper motors with high-quality, low-backlash gearboxes, belts, motor covers, screws, couplings, and everything else needed to install the RPA onto your MLAstro One.

Installation is straightforward and similar to installing an electronic focuser on a telescope. The kit is designed to be customer-retrofittable. That said, if you know you want RPA, we recommend ordering it together with your mount so our experienced technicians can install it and make sure everything is set up correctly before shipping.

Q: Is there a weight limit for the RPA?

The RPA is designed to handle a fully loaded MLAstro One, up to 40 kg payload with a 5 kg counterweight.

Q: Is the mechanism backdrivable?

A: No. If power is lost, the RPA will hold the polar alignment position without needing any power. After polar alignment is complete, you can turn off the RPA to save power.

Q: I want to go back to manual polar alignment with my fingers. Is that possible?

A: Yes. You can remove the RPA mechanism and reinstall the manual adjustment knobs.

Q: Does the RPA motor interfere with how the mount works in any way?

A: In most cases, no. However, with the RPA motors installed, certain telescope setups and orientations may cause the telescope dovetail to touch the RPA motors. In that case, a saddle riser kit may be needed to provide enough clearance.

This is mainly relevant for users at very high latitudes, especially above 65 degrees. If you are located above 65 degrees latitude, please contact us by email so we can check whether you need a saddle riser kit.

Q: If I order the RPA with the mount, when will it be shipped?

A: It will be shipped together with your MLAstro One.