Micro Motor Community

NotFastEnuf "Brushless Boss Series" - 3D printable frames


I was concerned about that. Should I increase them from 2 walls to three? It certainly would make them a bit stronger if I do… however with a filament like NylonX I am positive it would be sufficiently strong as is. In fact I’m surprised petg broke easily there - it’s layer adhesion is usually quite good. These are typical design problems and why a target printing material has to be chosen and designed around. I suppose I should increase thickness since not everyone has access to NylonX.

That was also a point of concern and hard for me to guess without owning any 0705 motors for reference. Could you take a close up picture?

Thanks again for valuable feedback! Also is that a brushed fc that you are going to convert to brushless?


Just downloaded Fusion 360. Looks good and easy to pick up after dealing with Solidworks.

@NotFastEnuf Nice frame. How thick is the base plate on that thing and does it flex at all?


The frame is hollow like bird bones - the outer surfaces are 1.2mm thick. They converge at the motor mounting pad to be 2.4mm thick. Flex is minimal - not unlike a carbon frame of similar weight.


The Lack of strength of the top of the guards was likely due to the PETG sagging a little? More heat+fan my have given a better result? The added weight of 3 lines would be well worth any extra weight in my opinion and there is plenty of clearance to the motor to go inward with the 3rd line. PETG does generally have very good layer adhesion and the rest of the print seems good. I have resisted purchasing any Nylon for now as we are coming into the wet season, the Humidity is very high and I’m working ‘outdoors’ (open carport).But I think to design around PETG does give more of us the ability to reproduce your efforts.
A rough measurement shows approx 1mm between arm struts to the rear and 1.5mm to the front, A Generous 2mm would allow the wires to sit neatly with 2 below and 1 above.
The board in the picture is one of Charlie’s F4 Alienwhoop DIY boards. When I do get around to ordering the parts and attempting assembly I will certainly consider converting one to brushless and dedicating it to one of your frames.

Regarding Flex, While I would not quite put the frame in the same stiffness category as CF, my PETG frame feels as though the thrust of 0703 motors on 1S would not cause mach concern.
The motor mounting plates appear to be 2mm? This I think could be reduced by 0.5m or so to give better grab to the stock screws, or perhaps a motor screw recess could be incorporated into the first layers? As could a bearing recess be incorporated into the upper couple of Layers ( easy enough to do later with a drill bit).


Ignore my suggestion regarding the motor screws, upon closer inspection, I am happy with the ‘grab’ of the longer screws (possibly 1103 screws). The front screw is probably from an 0705 and the back screw more likely an 1103.


Changing the gap between the rear arms would change the geometry of the entire boss series in 100mm size. That would be a major rework - we’re probably stuck with it as is. I will add another line inward at the motor mounts. I’m surprised to see such a large gap there. Motor spec is 10mm diameter? ID of my mount area should be about 12.5mm - so 1.25mm gap? Looks bigger than that.
Finally, I made the thickness of the motor pad based on info from @yets… are your screws not going all the way in to your motors? Edit - good picture. Thanks! OK on screws then. Can you get me a diameter of your motor can and let me know how close you’d like to see the wall to it?


As can be seen above the motor screws are sufficient. An option of soft mounted motors may be worth considering however as solid mounting the FC does greatly increase the torsional stiffness of the frame, and, these motors aren’t well known for their smoothness.
I had guessed the gap for motor wires may be hard to change, a little trimming will suffice.


I may be able to work that divot I made a little bit. I just don’t want to compromise strength too much at a point where the motor pad ties into the arms. I’ll take a look tonight. Try to open it to 2mm if I can. I’ll add another line along the ID of the motor mount area also. Agreed on the fc being structural - that’s was part of the intention of the design. Make any weight we have to haul earn it’s keep. I also have a few bare alien whoop boards - one will be dedicated brushless for sure!


The motor is 10mm the inside of the motor protector is 12mm, There is currently a generous 1mm clearance, with a 0.8mm wall thickness. So, I’m guessing what we would be left with uld be 0.6mm motor clearance, which sounds tight and could give way to collection of foreign matter and be more difficult to clear, as well as limiting proper air flow through the motor?


On second inspection, the motor protector inner dia is a tight 12.5mm as you stated.


I am currently working on an F3 Alienflight Whoop, and, do have enough brushed whoops, It would appear the 16x16mm ESC does fit nicely on an inverted board…


@Theon Is that a tiny pepper ESC and a 20x20 FC?


It’s a Racerstar Tiny Pepper Clone, and an Alienflight F3 Whoop board, which have a standard Inductrix (24mm) srew pattern.


I have been printing a couple of your brushed designs, and, I know you already have your hands full, and have your priorities, however I thought I might chime in on my findings and thoughts.
The 90mm frame of the Boss XL 7 would appear to give perfect lend to a Boss Whoop style prop guard at the scale (approx 150%) to accommodate a 2" prop and would appear sufficiently stiff and strong enough to mount a brushless motor (or an 8x16 brushed).

Here I have a Boss XL 7 and a Boss Whoop Scaled to 135%, The combination of these two, with an Approx150% Guard could, in my opinion result in a nice sturdy design.


Late to the party… Looks like you have it sorted now. Great feedback Theon.


It is a little selfish of me but whooped frames are at the back of my line. I’m not opposed to making them eventually but I won’t be flying one. I love the feel of the drag from the ducts on an actual whoop - and that’s the only place it belongs in my fleet. I do respect that we all have our own preferences though so I will get around to it. I do still brainstorm it and honestly am thinking of abandoning the boss subframe for anything ducted - and may focus my efforts on a nylon specific ducted design possibly from trimmer line ( :smile:) … but more on that later. Thanks again for all your feedback. I’ll let you all know when the next revision is ready.


I do understand totally, I am very impressed with how my Boss 7 performs compared to a 7mm whoop running same motors. My main concern however is in the durability of the 070’ series motors without prop guards. The 1103,s and 2S or even 3S for the 6500’s will probably be my personal choice for the 100mm frame.


Agreed. I probably won’t even buy any. I’m excited about the 90 mm frame on 1102 2s myself… and maybe an 80mm or even smaller for high kv 1102 with 1.5" props.


Finished the 100mm frames for 1102 and the old school racerstar 1103 in both the E011 mount pattern and the INDY mount pattern. That leaves only the 16x16 mount pattern and 100mm series will be complete for what I am going to do. It’s 2AM so updated STL’s for all the changes that were made today will have to be posted later.

Next up will be 90mm frames with all the same options as the 100mm…then something light duty (like the boss 6 brushed) in the 70 to 80mm range with prop guards for 0703. I just may cap off the series with a 70mm heavy duty frame for high KV 1102 on 2s. That could be a rather interesting option.

Once all this is done its on to building some out. I plan to build a 1102 11500kv 90mm for 2.25in props on a 16x16 stack, 1103 racerstar 8000kv 100mm for 2.5 in props on an e011 converted to brushless, and maybe just maybe 1102 15000kv 70mm for 1.5in props on an alien whoop board converted to brushless.


Oh man, I can’t wait to see your next creation. :slight_smile: