Catalyst Machineworks SlamNasty HD

By Jayembee67 on Oct 14, 2019

22  1,025  32

This is all @M490fpv 's fault. So I decided to see whether I too could get a DJI FPV System Air Unit into the SlamNasty 5" frame. And, after a good deal of time in TinkerCAD, and printing a not insignificant number of versions of things, I have indeed got a hovering, HD-transmitting quad squeezed into the SlamNasty. I'll have to wait until next weekend to see if it really flies though, but early signs are positive.

It was an interesting challenge that seems to have worked out quite well. It's a compact little ball of potential energy, and definitely a good looking frame, even though it is now oddly bloated with HD kit. I have hopes...

UPDATE 2019-10-17
I got to sneak out first thing before work and put a couple of packs through this build. And apparently it flies fairly well, although I was still tired, and this is an unfamiliar machine, so I wasn't trying too hard. But all the same, I am pretty sure this is working out just fine.



Sign in to comment

bugsysiegals   Jun 25, 2020  

How are you recording audio?

Show 1 more comment
bugsysiegals   Jun 26, 2020 

I see ... it seems you cannot stream the audio during flight but can record and playback after. ;( ... maybe they're will be an update for this in the future ...

Jayembee67   Jun 26, 2020 

Yes, this is already a fairly loud request from the community, I believe. Personally I have no interest in hearing the shriek of my machine in one ear, but some folks do like it as you can tell if your motors are fluttering or whatever. But you can tell that from the ground too. Still, I'm sure it will come in a f/w release at some stage.

bugsysiegals   Jun 27, 2020 

For me it would be handy if I was to fly in the winter while inside my house ... not sure how well crossfire and the DJI video transmit through a house but if they do then the audio could help if you hit something to know if anything is damaged??

bugsysiegals   Jun 26, 2020  

I'm almost done with my SlamNasty build and wonder about the top plate. The stock screws are 8mm, the top plate is 2.5mm thick, and the stock 19mm standoffs are recessed 2.45mm down from the top of the 3D printed parts ... did you use longer standoffs or upgrade to longer screws?

Jayembee67   Jun 26, 2020 

I used longer standoffs; you want the solid connection between the top and bottom plates, so the standoffs need to touch both with the bolts cranked down. I used 25mm M3 straight standoffs, that will give you enough height for the TPU Air Unit caddy and leave some space from the top of the stack. You really don't want stuff pressing on the top of the flight controller as that will transmit more vibration and add gyro-noise making the flight less smooth. You can get these sorts of standoffs from Amazon, so it's not a big issue.

bugsysiegals   Jun 26, 2020 

I've 24.5mm between plates so the 25mm will be perfect, thanks!

bugsysiegals   Jun 23, 2020  

I see you use the JST connectors rather than soldering ... have you had any issues? I read some people do not like them and not sure if they come out when you hit things or people are overly paranoid?

Jayembee67   Jun 23, 2020 

Yes, ultimately I am lazy, and my hands aren't as steady as they were, so the JST connectors are absolutely great in that regard - so much less soldering. Plus it keeps things tidier in the stack, and reduces the likelihood of cables trailing across the top of the FC and touching the gyro and such. I am sure that they might be a point of weakness for racing rigs that are slamming into gates on a regular basis, but I'm just a genteel freestyle pilot doing slow, wobbly circles, and I have not had issues with my JST connections. :-)

MotoRotor   May 04, 2020  

Really nice work on the design and thanks for sharing. I'll now be building one myself, thanks to you. :)

Show 4 more comments
Jayembee67   May 31, 2020 

This is looking great, really nice! And very tidy too. Splendid. If flies anything like mine, it's an absolute blast! :-)

MotoRotor   May 31, 2020 

This thing rips! I think it is faster than my skill level LOL! It's nice to be able to see super clear :)
Full build specs and pics here.

Jayembee67   Jun 01, 2020 

Nah, you want machines that frighten you a bit; that's how you get better! ;-)

denbleyg   Jan 21, 2020  

I just build one. Thanks for the inspiration.

Jayembee67   Jan 21, 2020 

Oh! Most excellent! I am very flattered. :-D And this looks great, so clean. Please post more photos and the full Bill of Materials! So how do you like it? I absolutely love mine, it's my favourite acro build; I can really throw it around and it takes it all in its stride, and yet it's fast and stable in the straights. The frame geometry is great.

denbleyg   Jan 22, 2020 

i'll try to make time to make a build list on this site. It's good, my pid tunes need work, i still get a lot of prop wash on sharp turns but over all it's my fav. It was worth gutting the geprc 5" to build this one.

denbleyg   Nov 13, 2019  

Now that you've had it a good while. Any tweaks/changes you would make? I'm getting the same frame with dji and was going to run the brother hobby avenger 2806.5 1300kv

Jayembee67   Nov 13, 2019 

So no, not really, this is perhaps the best of the HD builds I have done, it flies really well and with an agressive precision. I did print new rear standoff covers that have little lugs that keep the Air Unit MMCX connectors pressed in (see the last photo), which was a good idea, but othere than that, this has worked out really well.

As for 2806 motors, I think those might be a little bit too much, although I have only recently graduated from 4S to 5S so maybe these would be OK with 6S? But usually motors that big are intended for 6" or 7" props on mid-to-long range machines, not 5" racers. Personally I would stick to 2306 or thereabouts, but as I say, I'm not a 6S flyer so I may not know what I am talking about here (which is very often the case).

And as for the various TPU bits and pieces, I posted them to Thingiverse, you can find them here:, If nothing else, you can use them as a basis for your own parts!

denbleyg   Jan 04, 2020 

Good point, i was thinking of a 7" build when i mentioned 2806 motors. I appreciate the feedback. What was the final weight with dji setup?

adroc   Oct 28, 2019  

I love this build. Great job!

Jayembee67   Oct 29, 2019 

Thank you! I cannot deny that it came out better than I had hoped. Flies like a demon too.

LampFPV   Oct 16, 2019  

this is awesome, great pics. thanks for sharing, ill be doing a similar build with a Floss 2.1

Jayembee67   Oct 17, 2019 

Thank you! And yes, do it! With a bit of effort you can get this DJI kit into a surprising range of frames.

Yinka_Brasil   Oct 16, 2019  

Looks sick!!! Good work!

Jayembee67   Oct 17, 2019 

Thank you!

M490fpv   Oct 15, 2019  

Very nice!!! 😃👍 I thought I was the only crazy around 😁

Jayembee67   Oct 15, 2019 

Ha! Yes, apparently your craziness is inspiring!

Guides & Reviews

Jun 21, 2021

AirbladeUAV has done it again and this time they've brought long range to the 5" class! Based on the popular Transformer Mini, the new Transformer 5" Ultralight adopts a lot of the same design philosophies with larger props and more payload capacity. It can fly upwards of 20 minutes on a 4 cell Li-Ion battery pack and in ideal conditions it's got a range of over 4 to 5 miles. In this guide I'll walk..

Read more
Mar 04, 2021

With the release of the DJI FPV Drone cinematic FPV has become a lot more accessible, but you certainly don't want to crash a $750 drone! The QAV-CINE Freybott is a compact, lightweight cinematic FPV drone that can take a hit and keep going. It's a lot safer to fly indoors and around people. With a naked GoPro or the SMO 4k you can capture some great stabilized footage. In this guide I'll show you..

Read more