Seats

Task Description

We need seats for 4 Barbies in our cabin, past seats can be found in PDM in WARG_CAD\COMP2023\Competition Drone\Cabin\Seats. These were good but we would like something that fits the Barbies a little nicer this year.

Constraints

Assignees

Task Progression/Updates

Author: @Alison Thompson Date: 2023/10/04

INITIAL IDEAS

These should be made of lightweight PLA and potentially some soft foam padding of some kind. Whoever is assigned to this should talk to @Evan Janakievski about the cabin dimensions and layout.

Initial Design Ideas (10/18) @Jason Li

Open

Open

Design Features:

• Designed to mimic appearance of helicopter seats

• Following BIFMA guidelines for seat dimensioning and general anthropometric/ergonomic design principles

• Seat parts (legs, seat+back, headrest) will be created separately and connected together

• Current manufacturing plan will have frame of chair printed out of PLA, shape foam to pad the seats and headrest, then cover with a fabric (Open to suggestions)

• Seatbelt will have release buckle and be similar to car seatbelts

• Dimensions are around 85x40x230mm (Subject to change)

Design Update (11/8) @Jason Li

• Dimensions are ~50x70x240mm

• Curves are hard

• What screws to use for mounting to cabin and parts to each other?

• Things to consider:

  • M3 screws to screw into cabin

  • Avoid using screws to connect parts, consider glue or other ways to connect pieces

  • Legs need to be thicker and keep weight in consideration

  • Cabin has more size but check with the CAD

Seatbelts

Design Update 11/29 @Jason Li

• Chair CAD done (I feel like something’s off)

• Need to review before printing @Alison Thompson

• Test to see if the clip will actually work (might be easier to just print one and see)

• Have mountings to cabin been decided yet? I checked the cabin but couldn’t see anything

Revised Chair Designs (1/21) @Jason Li

• Two chairs combined into one to reduce horizontal space taken up

• Seatbelt buckle abandoned, going for a shared place to hook onto in the middle of the two seats

• Bars and supports made thicker, bars/rods are 6mm in diameter and legs are 8mm wide, we could make the legs thicker and remove the middle one as well

• Made new folder in PDM Seats folder called “Edited Seats” with new model (Has (R) after the name)

Author: @Alison Thompson Date: 2024/01/22

CAD Review 1:

• I like the bench design

• Don’t think we need middle leg

• Mounting holes should be M3 (WARG standard is only M3 or M5 bolts for consistency)

• What is your plan for the attachment of the seatbelts? I’m unclear on how the loop you have works to hook them? This could be replaced with a more hook shaped thing to just hook the belt onto

• Headrest seems awkward to print

• I want @Evan Janakievski and @Sohee Yoon to review and give feedback based on how this fits in the cabin layout assembly.

• Happy to start with this as the current seat rev to work off of

Author: @Evan Janakievski Date: 2024/01/23

CAD Review Layout:

• Dimensions seem to work well for the cabin. Testing with real barbies will be nice once the seats are printed

• Agree with Alison that the hook for the seats does not seem too optimal. Maybe it needs to be a larger loop in between the two barbies?

• The front seat may overlap with the aeropanels in the front. This might cause an issue with how the legs connect. Would need to shave a portion of the bottom of the legs off so it overlaps well

  • Check layout assembly to see what I mean a bit more

Author: @Sohee Yoon Date: 2024/01/23

CAD Review:

• I agree with Alison and Evan’s points. Def would be a good idea to 3D print a prototype of the chair and test them with the barbies (maybe checking that they fit in the cabin when the cabin is built).

• I worked on the chair last year and I had a similar design in the beginning with the hooks on the side of the chair (I ended up moving the hooks to the back to make it easier to attach the seatbelt and it wasn’t sturdy enough with the hooks on the side ~ barbies moved around a bit when I shook the chair). I would just make sure that the seatbelt is strong enough and easy to attach the barbies too.

• Alison mentions adding a hooking method for the seatbelt. I found that you’ll have to test out the material the seatbelt is made out of. When I was using Thera-band I tried attaching ‘hooks’ (hook-shaped paper clips), and the Thera-band wasn’t strong enough to support the material so often times it would break/rip apart. Therefore, I ended up creating a knot with the Thera-band ('claw' part of the seat was a bit large to accomodate for Thera-band thickness). If you have any questions about seatbelts, you can def ask me as I might’ve tried it out last year!

• Overall, the design looks pretty good so far!

Author: @Evan Janakievski Date: 2024/01/27

• Looking better with the bigger hook and a simpler design. Like Sohee asked in discord, what is the method for hooking the Thera-band currently?

• The photo I added shows that the seats overlap with the walls though.

• If you were wanting to keep the larger loop on the sides, maybe think about sliming the sides of the chairs down to accommodate this slightly.

  • It looks like it may be around the barbie’s neck level, not sure what your dimensions were but it could definitely be adjusted so it fits.

• Not sure how important the middle leg is on the bottom either, that could probably be removed.

• There is some interference with the aeropanel, so when the final arrangement is done, @Sohee Yoon and I will let you know how much to shave off, so it fits in perfectly.

Author: @Nathan Green Date: 2024/02/15

• Printed one of the seats out of PLA at 5% infill and it’s fairly heavy at ~127g. The print also uses a lot of support material (more material than the model itself). It would be nice to simplify this design to br printable with less support in lightweight PLA.

Author: @Sohee Yoon Date: 2024/03/09

• Working off of Jason's iteration of the chair, we would like it to be lighter. So decreasing the chair thickness would be a great change! (both on the back and bottom of the chair).

• We found that the 3D printer could have some issues (and a lot of time needed) to print very detailed parts, so making it a bit simpler would be nice (similar to the old chair in C:\WARG_CAD\COMP2023\Competition Drone\Cabin\Seats).

• The height of the chair could be slightly decreased as well since the barbies feet do not touch the floor (you can test this out in-person as one of the seats have already been printed).

• The top corners of the chair can also be removed or chamfered or designed to only cover the barbies head (from image below there's some space beside the barbies head that could be removed).

• We thought the bottom part of the chair (not the seat) could be redesigned to decrease the amount of support needed but should be easy to attach to the cabin.

• We still need an idea for the seatbelt of the chair.

• Something that would be beneficial in the design would be for it to not be as sharp changes. Our aim is to use lightweight PLA and that prints easier with smoother surfaces. The seats from last year demonstrate the simplicity, however we would like more detail than that or some adjustments from that type of design

Author: @Billy Karantzoulis Date: 2024/03/16

• I shortened the support of the chair by 7 mm, so that the barbies feet could touch the ground

• I reduced the thickness of the backrest to cut down on the weight

• With modern car seats narrowing at the top, I cut out the middle and corners of the seats, further reducing the weight

• The top of the chair was fillet as requested

• I still need to work on the seatbelt, but it shouldn’t add too much weight to the overall design

Author: @Evan Janakievski Date: 2024/03/17

Some notes about the changes:

This area can be filled in. I understand it helps with limiting mass, but for printing with lightweight PLA, leaving it in will be the best most likely. @Sohee Yoon may have other thoughts about this. Being able to have one continuous motion is very beneficial to printing with lightweight PLA as it bubbles up and creates a lot of surface blobs otherwise.

The legs can also be simplified into one extrusion. Last year's seats did this. Although if we were to print the legs separately, that could also help with weight saving. The image below is last year's seats and an example of the simplicity almost needed for lightweight PLA. Combining these two designs could help keep your design simple but practical. (the angle the seat is at for the current design is good)

Good progress and just ping us if you have any questions

Author: @Billy Karantzoulis Date: 2024/03/20

• I removed the middle cutout of the chair, as requested

• I added another boundary cut to the headrest area to reduce the weight of the overall chair

• I simplified the legs so that it is hopefully easier to print

• I added a rubber seatbelt that hooks onto the middle seatbelt holder

Author: @Sohee Yoon Date: 2024/03/25

It’s looking good! Some ideas/concerns:

• The curve of the ‘legs’ should be checked inside the cabin to make sure it will not interfere with the other barbies legs. I am unable to check them rn as someone has checked the assembly in PDM.

• Because of the way last years chair was designed, it was difficult to screw the chairs into the cabin. Unless we plan on using adhesives or screwing from the outside, I would advice we might want another approach or redesign it so that it’s easily attachable since the area between the seat and floor is ~7 cm. @Evan Janakievski what do you think?

• I feel like the seat design (top part) right now is good. We should prob move on from it and focus on improving the legs of the chair.

• I am concerned about the seatbelt, specifically the portion below that the seatbelt wraps around, because I’m afraid it might break off easily. Currently it has a diameter of 3.5 mm so maybe changing it to 5-10 mm would be better. I would def recommend when it gets printed to test it out. Last year, a lot of my time was allotted to seatbelt design and testing them out to find a secure and easy way to attach them. The seatbelt material we used last year was theraband, so working with that will be helpful.

• Maybe fillet the edges highlighted in red below (if you’re able too, I’m not sure if you can) to make it sturdier.

Author: @Evan Janakievski Date: 2024/03/25

• I think the area the seatbelt is attaching to would be quite weak and would snap off

• I also think printing this design would be difficult

• the legs should maybe be made separate from the chair as the chair can be printed on its back and the legs can be glued to attach them

I agree with @Sohee Yoon with finding a better method to attach the chair. We can maybe print two separate pairs of legs and then not have them be the entire width of the chair?

Keep the roundedness of the legs, but simplify them down. Should we have the latch for the seatbelt be similar to the previous design?

Author: @Alison Thompson Date: 2024/03/27

CAD REVIEW FROM CABIN V2:

• These look much simpler than the last revision

• If we keep the cutouts they should have filleted corners

• The cutouts may make printing in LW PLA not work super well, I think filling these in and printing in LW PLA will be lighter than keeping them and printing in regular PLA

• Similar feedback for the legs, I think switching to legs like this may print nicer in LW PLA even though its more material

• If we are using 3D printed hooks to attach the seatbelts I think the hole for them between the barbies needs to be bigger or the hooks will have to be tiny and likely snap

• I would also beef up the loops on the tops of the chairs so they don’t snap, LW PLA is pretty delicate

• Would be worth making sure there is more material around the holes for heatsets, the heatset will likely break the legs as they are