MLAstro SAL-33 (Pre-Order) Batch 1
The Ultimate Harmonic Mount
$1099.00$999.00
MLAstro SAL-33
Not Just Another Harmonic Mount
The wait is finally over. After a year of design, testing, and refinement, the MLAstro SAL-33 is ready for preorder. This isn’t another no-name, corner-cutting, Chinese-made mount where you’re left on your own after checkout.
The SAL-33 was built by astronomers, for astronomers. We started by addressing the pain points that frustrate users most — flimsy Alt-Az bases, telescopes drooping the moment power is cut, overheated anodizing fading in the Sun, inferior Harmonic drive with huge PE...
Instead, we engineered a mount that cuts no corners: precision CNC machining, hand-selected harmonic drives, solar-ready coatings, and user-serviceable electronics. And we’ve priced it to stay accessible, without stripping away the quality you depend on.
The result? A mount that doesn’t just meet expectations — it redefines them.
Innovative PA Design
Experience it once, and every other mount feels outdated.
Polar alignment has been neglected for too long. Many mounts simply slap on a sloppy Alt-Az base as an afterthought. The SAL-33 is different. We built the MLAstro Zero-Shift Alt-Az base using micron-level CNC machining to eliminate flex, creep, and play. Alignment becomes smooth, precise, and rock-solid — and once you’ve tried it, every other PA mechanism feels primitive.
Customized Harmonic Gearbox
Handpicked low-PE gearboxes for sub-arcsecond guided performance.
Not all harmonic drives are created equal. Budget mounts use cheap gearboxes with massive periodic error, masked by heavy guiding. That trick works for nighttime imaging — but for high-precision solar scanning with the MLAstro SHG 700, the huge periodic error of inferior harmonic gearboxes is brutally obvious, stretching and compressing scans due to the uneven slew speed.
So cutting corner was not an option for MLAstro. The SAL-33 uses only Customized low-PE 17:100 gearboxes, hand-selected to deliver tracking accuracy that rivals mounts twice the cost. Yes, it eats into our margin — but it means you get true sub-arcsecond guided performance that no shortcut can fake.
Micron-Level Precision CNC Machining
We use only the finest materials, paired with state-of-the-art CNC machining that meets — and often exceeds — industrial standards.
Astronomical equipment demands uncompromising precision. A mount requires even more. To make the Zero-Shift mechanism work flawlessly, without play or backlash, we machine certain parts to tolerances an order of magnitude tighter than the industry norm. That’s the level of detail needed, and that’s the level MLAstro delivers.
Behind every mount is one of the most experienced CNC operators and industrial designers in the field, ensuring rigorous quality control and minimal unit-to-unit variation.
Simply put: no other mount on the market matches the level of finish and precision that we achieve. Period.
Pointing remember and fail-safe brakes.
FRAM memory and a physical RA brake keep your gear safe and convenience.
Ever had your setup sag helplessly when the power dies? With the SAL-33, that nightmare ends. A physical RA brake locks your payload in place, while back-EMF braking on DEC ensures safety across both axes.
Meanwhile, FRAM memory stores pointing data even after shutdown. Power cycle? Your mount wakes up exactly where it left off. For remote users, this means no re-homing, no annoying re-platesolving — just continuity.
Solar-Minded Design
Engineered for the Sun
Most mounts weren’t designed to sit under the midday Sun. Dark anodizing overheats, coatings fade, and electronics cook. The SAL-33 was built with solar imagers in mind. Its reflective silver finish shrugs off solar radiation, keeps the mount cooler to the touch, and never fades.
For the first time, you have a harmonic mount designed not only for deep-sky nights but also for spectroheliography and solar imaging during the day.
MLAstro-Level Customer Service
You'll never find a comparable service elsewhere
When you buy an SAL-33, you get more than hardware — you get us. Direct, responsive support from the same team that designed and built your mount.
And unlike sealed-box mounts, the SAL-33 is user-serviceable. Burn out a stepper driver? Swap in an off-the-shelf replacement. Motor failure? Unbolt and replace in minutes. For the rare issues you can’t solve yourself, we have forwarding warehouses in the US, UK, EU, and Australia, so you only ever ship locally for service.
Try getting that from a sub 2000$ Chinese mount.
Official OnStepX Hardware
The only production harmonic mount officially backed by OnStepX.
The SAL-33 isn’t locked down. It runs on official OnStepX firmware, giving you full access to open-source flexibility and fine-tuning. Need more motor current for a heavy setup? Adjust driver settings on the fly. Want to counteract a slight RA drift? Nudge the track rate.
And for tinkerers, we’ve gone a step further: our firmware and pinmap are public on GitHub, so you can dig under the hood, customize, and future-proof your system.
This is not just compatibility — it’s full endorsement. The SAL-33 is the only harmonic mount in production that is officially backed by the OnStepX project.
Category | Specification |
|---|---|
Mount Type | Harmonic drive equatorial/alt-az dual-mode |
Load Capacity | Visual: Up to 15 kg without CW, Up to 20 kg with 5 kg CW Imaging: ~⅔ of visual load |
Slew Speed | Adjustable, up to 5°/s |
Drive System | High-quality low-PE 17:100 harmonic drives for both RA and DEC |
Brakes | Physical brake on RA, back-EMF engine brake on DEC |
Retains Pointing | Yes, pointing retained after power cycle |
Firmware | Official OnStepX hardware with full support |
Open Source | Firmware and pinmap fully open-source |
Build | 100% precision CNC-machined metal |
Alt-Az Base | MLAstro Zero-Shift Alt-Az design for highly stable polar alignment |
Connectivity | USB Type-B, WiFi (AP and Hotspot modes) |
Mount Head Weight | 5.6 kg |
In the Box | Mount head only (PSU not included) |
Operating temperature | -20 to 50*C ambient temperature |
Warranty | 1-year limited warranty |
Q: When will the first batch ship, and how long will delivery take?
A: We plan to ship the first production run of 50 units before Christmas 2025 (December 24, 2025). That said, this is a startup-scale project, and delays can happen as we transition from prototypes to full production. I’ve already built in buffer time, but if unforeseen issues extend the timeline, I’ll keep all customers updated with progress reports and notify you of any delays. I take deadlines seriously, and my track record shows I usually meet or even beat them. Shipping time is typically 2–3 weeks worldwide.
Q: Can I cancel my order and get a refund?
A: Yes. As long as your order hasn’t shipped, you’re entitled to a full refund, no questions asked. Just email me at trong.minh@mlastro.com, and I’ll process it immediately.
Q: How does the warranty and servicing work?
A: The SAL-33 includes a 1-year limited warranty covering manufacturing faults. The mount is designed to be user-serviceable — if an electronic fails, it can be swapped easily with off-the-shelf parts. For repairs beyond user scope, we maintain forwarding warehouses in the US, UK, EU, and Australia, so you only need to ship domestically for service.
Q: Why is the recommended imaging capacity lower than the visual capacity?
A: For visual use, the SAL-33 supports 15 kg without counterweight, or 20 kg with 5 kg CW. For imaging, we recommend ~70% of that (~10.5–14 kg).
Some manufacturers downplay this rule, but it applies to all harmonic mounts. Torque ratings only tell you how much the motors can move, not how well they can track. Near the load limit, steppers are prone to vibration, resonance, and missed steps — all of which degrade guiding.
That’s why we set conservative imaging limits: to guarantee smooth tracking. You can push beyond our recommendation, and it may still work “good enough,” but we only guarantee performance within the stated range.
Q: I’m having trouble using the SAL-33. How do I get help?
A: Start with our Quick Start Guide. If that doesn’t solve it, join our user group where our support team is active. For one-on-one help, email me directly, and I can arrange a video call with remote desktop support.
Q: What tripod connections does the SAL-33 use?
A: The SAL-33 uses a 3/8" thread plus 3 × M6 holes — the same as the ZWO AM5. Any tripod that works with the AM5 will work with the SAL-33. For best results, we highly recommend the MLAstro P-200 Pier Extension, which prevents your camera from colliding with the tripod and adapts common tripods like iOptron 1.75"/2" and SkyWatcher HEQ5/EQ6.
Q: Why is shipping to the US more expensive?
A: The US recently imposed a 20% blanket tariff on shipments from Vietnam. To avoid this, we use a specialized courier that guarantees tax-free delivery but charges a 5–7% service fee. This is why US shipping is about $190 vs. ~$140 for other regions. The upside: your package arrives at your door without extra paperwork, hidden charges, or surprise taxes, all tariff/tax is included.
Q: Can you reduce import or VAT tax for my order?
A: In many cases, yes. If you’d like us to assist, simply note it in the order comments or email me directly to discuss options.
Q: Is there an iPolar or PoleMaster adapter?
A: Yes. We have a working 3D-printed adapter model. Email me, and I’ll send you the STL file so you can print it locally.
Q: Do you provide a counterweight for this mount?
A: Shipping heavy counterweights isn’t cost-effective, so we don’t have them. The counterweight bar (20 mm diameter) is optional, and you can use any counterweight with a 20 mm bore.
Q: Does the SAL-33 have cable passthrough, a 12V port, or a USB hub on the saddle?
A: No. Adding integrated passthroughs and hubs would drive up both mechanical and electronic complexity — and cost — beyond our target. At this price point, we focused on core performance.
The good news: with harmonic mounts, precise balance isn’t critical. That means you can mount a small power box or USB hub where it suits your rig and still maintain clean, reliable cable management without compromising performance.