# Design review for a 4.5 kg VOXL 2 quad with M0138 on 12-inch props

Source: https://forum.modalai.com/topic/5538/design-review-for-a-4.5-kg-voxl-2-quad-with-m0138-on-12-inch-props
Category: Design Reviews and 3D Models (https://forum.modalai.com/category/39/design-reviews-and-3d-models)
Posted: 2026-11-03 02:15:31 UTC by jake_eizy
Replies: 0 · Views: 15

## jake_eizy · 2026-11-03 02:15:31 UTC

Hi ModalAI team,

**Hardware:** Pre-build design review, so no serial numbers yet. Planned stack:
- VOXL 2 (MDK-M0154-1-00)
- VOXL 4-in-1 ESC (MDK-M0138-11-01, 5.1 V kit with VOXL 2 cables)
- M0130-3 LTE and USB hub add-on on J5
- M0048-2 Microhard USB carrier with pMDDL2450, on an M0130 USB port with its own 5 V supply
- M0226 front end with two M0166 AR0144 tracking cameras (front and down)
- M0184 ELRS receiver and M0224 GNSS on J19
- 4x Unusual Machines UM3115 900 kV motors, APC 12x6E props, 6S Li-ion pack
- About 4.5 kg take-off weight

**Software version:** Not built yet. We plan to start on SDK 1.8.

**Configuration / services:** Not built yet. Planned: voxl-px4 with the M0138 in closed-loop RPM mode capped at 9,100 rpm, VIO on the two tracking cameras, Microhard for C2, and a small service that drives J10 GPIO_46 as a 3.3 V camera trigger.

**What I am trying to do:** Confirm the ESC, power and I/O choices before we build the first airframe. A motor model gives about 19 A per motor at hover (about 6,350 rpm) and about 37 A at the 9,100 rpm cap. Could you help with these?

M0138:
1. Is the 40 A rating phase current or bus current?
2. What airflow does the 40 A continuous rating assume?
3. The board senses total current only. How should each channel be protected at an rpm cap?
4. You describe it for 5 to 10 inch airframes. Is a 12-inch prop acceptable, and what ESC tuning does it need?

VOXL 2 and accessories:
5. Is the M0224 supported as the PX4 navigation receiver on SDK 1.8?
6. On J10: what is the drive strength of GPIO_46 for a 3-way star at 3.3 V, which J10 mode does a shipped M0154 boot in, and what state are GPIO_46 and the J10 level shifter in from power-on until our trigger service takes the pin?
7. How much current may the M0130's J5 3.3 V pin supply? We need up to about 0.16 A.
8. Is about 3.3 A steady through VOXL 2 J4's single 5 V Mini-SPOX contact acceptable?
9. How long are the M0138 kit's VOXL 2 power and UART cables? Our runs are about 150 mm.
10. Is a STEP file available for the M0226?

Handset:
11. What does the Zorro Blue (MRC-Z0001-1) cost on its own, and is it sold separately?
12. What are the form factor and price of the M0193 transmitter, and does it fit a standard controller module bay?

**What actually happens:** Nothing yet. This is a design review before build.

**Steps to reproduce:** N/A

**Logs / pictures:** None yet. Happy to share a block diagram if useful.