The Boeing 737 Motorised Throttle Quadrant is underway!

Probably the most requested design of all time on this website! and already one of my favourite components to design on Fusion 360 to date. The hours on the CAD front have been immense, I often find myself working into the early hours not wanting to go to sleep. In my mind, I can already see how immensely cool this design could be! This design is ultimately for me and for use in my sim, so I am going for the ultimate pro version from the start! If I can make it adjustable, better, stronger or more reliable from the start. That's what I'm heading for. From adjustable gear meshing depth to bearing pressure. I want this unit customisable to the person building it.

Initially, due to the size of the unit I was going to create it on the CNC machine and use the metal forming machines at work as I did in the V1 motorised throttle unit. The CNC has been feeling very lonely and left out since the 3d printers arrived on the scene. Thanks to the Creatilty CR10 v3 with its 300 x 300mm print bed. This unit now fits on the print bed without any issue, including life-size trim wheels!

Boeing 737 CAD design starts here with basic life size shapes
The Boeing 737 basic design with correct dimensions. It all starts here

First up was a simple shape base design, this allows me to transfer the various shapes to the correct dimensions and I used different colours to represent the different parts. All the workings have to fit in this space. The thrust handles I thought, would need no adjustment. They were already perfect....So I thought!

Then I saw Flightdeck Solutions Instagram video of their new throttle, Beautiful! I need (but out of my price league). It was at this point the thrust handles would also get a major overhaul. More on that later.

Let's address the first elephant in the room to which there are already many from various social media posts.

"Karl, you told me to buy the Creality Ender 3 pro or V2! That's exactly what I did! Now I need a bigger more expensive printer for this design?"

Honestly, I will state now that when the design is finished, if I can split it to fit on the Ender 3 bed, it will happen. However, I already have my reservations as this is a very complex design with 3d printing in mind while keeping the actual build simple.

Boeing 737 Throttle CAD design LHS only
Boeing 737 Throttle CAD design LHS only. Motorised trim Wheels, Trim Indicator, Spd Brk, Parking Brake

The Ender 3 is an amazing printer for the price and allows you to do so much. I still whole heartily recommend it. It's in the correct bracket for most of not wanting to spend a fortune but allows you to create parts not only for your sim but also for other projects. Who doesn't like sitting back and watching a machine create the most perfect parts while you sit and watch on at home (after you realise 3d printing is very much a game of patience...Said the most impatient guy in the world).

I recently was able to acquire the CR10 and this has been another massive step forward for us in the sim world but comes at a much more costly price. It allows full-size parts to be created which have such a complex design that wouldn't be possible on my CNC. With this complexity of component design, it should allow for a simpler build process with fewer parts.

The video shows the first working prototype powered by Nema 17 stepper motors and an Arduino controlled by Mobiflight. I am super impressed with how this turned out. You can force the motor while it's powered and because it's a stepper motor without a gearbox, it just stalls without damage. The pot picks up the position of the lever regardless of the stepper position and creates a closed-loop feedback. The attached homing switch adjusts the throttle to the correct position on powerup. With power removed from the driver board to the stepper, the motor then acts as a friction device and the faster you move the throttle in manual the more friction you feel. A very happy unexpected side effect! I do admit, the stepper can be a little loud when it's holding a position, in what I would call a "stress position". The weight of the lever trying to fight against the stepper. That why I added the counterbalance spring at the bottom.

Now onto the design, starting with my throttle handles. They were already pretty perfect dimensionally, 2mm bigger in width I believe. The biggest change was to the thrust lever operation. I wanted to see the thrust bar to pop out forward as the thrust reverser handle rises. The pot in the handle has gone, moved down to the base. I want really strong detents, this mechanism has also moved to the base. I am now using a 9mm bearing and a rather large spring. I also want the lever to snap close and not wear over time.

Some of these parts are 3d printed which I will use a metal flat bar for, but for prototyping, it's easier to substitute them for PLA.

Here is a quick look at the rest of the design so far:

Now for the other elephant in the room...

"Karl, I have bought V3 throttle, this will be free, right?"

I can only imagine how many people this will upset. But no, I'm afraid this is version (v5) of the throttle quadrant and won't be free. This is not an upgrade in any way from the v3 throttle. V3 throttle came about by Patreon request for people that didn't have a Saitek unit.

Let me guess your next question, "How much?" (Comment below!)

I haven't thought about that, despite the many questions I get about it! This is only 5 days into a major project which I expect a couple of months to perfect. Im already encountering item collision between the plates and this requires major redesigns. This is why I like fusion so much! If it's possible in Fusion, then it's possible in real life! It Fusion says there's a problem, trust me, despite how much you think you can wing it, you really can't! Fusion 360 the like google of the CAD world, It knows all!

Take care All! I'm off to play with Fusion more!


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