If you follow me on Facebook or Discord, you have probably seen a call for donations. This one allowed me to collect about 80€. So for the sake of transparency, I thought I should show you how much it costs me to develop the P1. It will also be an opportunity for me to get an idea, because I must confess I have only a very vague idea. In general, I buy everything I need, until my account is empty (I’m calling for donations then^^). Let’s try to do the accounts!
To put it in context: I’m currently working on the P1 gas pedal and clutch pedals (not on the brake).
The first version of the P1 brake was released in December 2019. The gas pedal was never made (the GT version was there to make up for this lack), mainly because I was missing some technical solutions. I thought many times about this project. I sometimes printed parts, or ordered sensors, but nothing very conclusive.
Until I restarted the project in December 2021, thanks to some new ideas, and also to the help of Industry&CNC which once again offers us custom parts.
So here we go with the list of expenses. We’ll break this down into two parts.
Translated with www.DeepL.com/Translator (free version)
First part: the costs before December 2021.
Well, we are not going to count (boring), it is just to give an idea:
So..no potentiometer mount… I don’t know how old it is. I know I had printed the lever too, and that I had done a lot of tests on the axles for the springs.
Anyway, that was just to show you that I never really gave up on the project. But the GT pedal did the trick, and I had a gearbox to develop ;-).
To your calculators!
Let’s jump to December 2022. Just so we understand each other: the pedal is based on a principle similar to the Heusinkveld pedals: we have an axle on which there is a spring, and there is a secondary spring, much weaker, which presses on a load cell (pressure sensor) which is our position sensor.
The first order is 28,59€ of springs (85 springs in all) of different sizes.
Then we got 12,59€ of these nice little hand nuts. Well it was not an absolute necessity, but it’s so classy…
Then comes 43,2€ from Industry&CNC, for the custom axes, and these…I don’t know the name actually.
I then recommended two Arduino (one to mount on the simulator, and one on the pc side, to develop the code). 27,93€
The pressure sensors (obviously…), 5 pieces, with the HX711 amplification circuits: 10,83€.
As for the springs, we place a second order (I did not find my happiness in the 9 references received): 13,54€.
Then one week later I realize that I still needed other springs: 10,65€.
Then there is a moment we want that it advances, so we order on Amazon other springs: 9€.
GX12 connectors to make a junction box: 22,18€.
After a few tortured HX711 amplification circuits, I realize that it won’t do the job, I need another type of PCB. I then took out what I found from the INA129 and INA122 that I had tortured in the past (I found 46€ worth of bills in my history).
But, the INA, it’s because of them that I had given up the load cell for a hydraulic pressure sensor: I can never make them work… So I looked elsewhere, and I found this amplifier circuit on Amazon. 17,39€ for the three of them, not expensive, right? Except that I understood at the delivery that it was 17,39€ the amplifier + the dupont connector + the cable… So it’s expensive. I told the seller that it was a scam, he didn’t answer.
Mais bon, les INA, c’est à cause d’eux que j’avais laissé tombé les load cell pour un capteur de pression hydraulique : je n’arrive jamais à les faire fonctionner… Du coup j’ai cherché ailleurs, et j’ai trouvé ce circuit d’amplification sur Amazon. 17,39€ les trois, pas cher non ? Sauf que j’ai compris à la livraison que c’était 17,39€ l’ampli + le connecteur dupont + le câble… Du coup ça fait cher. J’ai dit au vendeur que c’était de l’arnaque, il n’a pas répondu.
So then I ordered two other AD620 on Aliexpress. 11,24€.
At that time, I ran out of the small male metal parts for the Dupont connectors, so I recommended a box, 13€.
Well, there are other parts I needed and had for a while: the KP08, the two bearings, and the ball joint. Well lazy, let’s say it cost 5€.
On the other hand, I had some play on the ball joint, I incriminated the M8 screw, and I ordered some roller pins. 3.08€ on Ali, and it’s red, so cool ! But it will only arrive in a long time, so 15€ on Amazon. At the delivery I realize that I still have the play, so I send it back (but the 3€ from Ali are lost).
After that, I order on 123roulement : 36,83€…
On the electronic side, I ordered the ADS1115 16 bits converters that I talk about here, 20€. But they are not very fast (one reading every 4ms …). So I ordered this special arduino, 12,44€.
There are two expenses left:
PLA: in 3 months I consumed 9kg of PLA. Not only for the pedals, that’s for sure. But we can count that since December, 3kg have been used (easy…), so we count 60€.
Then the maintenance of the printers: my two ender 3 turn a lot, so I have to change the heating element and other parts frequently. I’ll only count here this heating element, ordered at the end of november, and that I screwed up last week by running the printer without the fan that I had removed for cleaning… 27€.
Well, and we won’t count the screws, the tin, the electricity…
Total : 430,49€, and I still have to print everything all over again
Well, it was tiring…but enriching (yes, the term is wrong…).
It also gives a small idea of what the development of the gearbox could cost…
So I’d like to thank all the people who donated this week-end, it allowed me to place the last orders, and I hope that the final P1 will be in test this week.
I’ll put back a link to my Paypal in case your accounting is in a better state than mine 😉