So last night I was listing the motors needed and all the stepper drivers needed. I came to 16, with 2 using a Y adapter and 6 needing to be connected to relays to switch with 6 other motors. I'm assuming that 1 line of each coil needs to switch, meaning that I'd need a 12 channel relay. They only seem to come in powers of 2 and 16 is cheaper than 8 + 4.

They seem pretty sizable though.

BTT EXP MOT

Anyway the slippery slope started when I remembered that the "scraper" axes can't be shared as the PET film will move the unpowered one when the "tension" motors tensioned it. Now thinking about it, the scraper roller would've just moved to its axis limit and all would've been fine again, but last night it meant bringing in the BTT EX MOT.

There's 2 main reason's I dislike the motor extension board. The first one is that it comes with some unreasonably short joiner cables and it's only after seeing user posted images that I understood why. The second thing is that BTT has their EXP1 and 2 inverted, compared to the FysetC Spider and MKS Monster8 that have the ports in a similar location. I could buy (or probably ask for) longer cable but that's more expense on a £6.50 board, more wires and more PCB footprint. 

Anyway, now only 3 motor pairs used relays, and that 8 channel board is still pretty sizable, and I was like "Man, I don't really want to be cutting and trimming and risking a timing error, causing fried stepper drivers just for 3 motors. Add another BTT MOT.". 

FysetC F6 v1.4

Since I'm using Klipper and the Manta M8P comes with 2 USB ports instead of the 1 I thought it had (I had to look closely at one of the listing images that wasn't a birds-eye view), I was thinking that I could replace the 2 MOTs for a £19 F6. I'd spend a couple quid on what is looking to be a £1-1.2K printer just for quality of life. 

I was thinking that I could save a stepper motor by having the fibre extruder be a racheting system, but then I remembered I needed a pump for the (clear) UV resin that the fibre would be placed on.

I was wondering if I should just go for 2 Monster8's instead of a Manta8+Monster8+F6 merger but all was well...

...Until the string stepper attacked.

I totally forgot about that.

Motherboard8

The next maybe hour or so was me deciding if I should go with the Monster8 V2 for £31 or the rediscovered Monster8 V1 for £27. AliExpress search isn't the best, so I all the Monster8 V1's I found were around £30 and I didn't even know that there was a V2 and that I was looking at it until I saw this image:

I will be honest. If price was equal and I had the choice between the Spider V1.X and Monster8 V1, I'd go spider just because it looks so much nicer and has a more compact footprint. However, the Spider from any non-shady seeming seller was £40, even more than the BTT Oct. Speaking of which, I didn't choose the Oct because it required a second input for motor power and I didn't want to pay more for a board and then have to strip and crimp more wire.

The Monster8 V2 is certainly more apealing to my eyes.

As you can see, all the capacitors are aligned and all the headers are neatly on the bottom of the board, as well as the USBC port on the same side as the M8P's USB ports. For the aesthetic, I plan to place the boards in the following orientation:

Having the ports in the V2 location helps with wire management. The MonstV2 also has easily ressetable fuses, unlike the V1 and M8P, so I could put the UV lamp on one of them if needed.

Especially since the board is designed by FysetC, I never understood why it didn't come with the classic blue heatsink in the first place. The potentiometer is covered when used with the long silver heatsink. 

Conclusion

I'm currently at 23 motors if I can get away without a stepper motor for dispensing the fibre. If I can't that'll be motor 24. I do wonder if there would be some mysterious motor 25 down the line, but I don't think s--

remembers that the PnP also needs a solderpaste dispenser

oh. Yeah I should see to it that I avoid the need for a fibre dispensing stepper then.