7 Essential Mods for a 3D Printed Astromech
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- Опубликовано: 5 авг 2022
- If you plan on taking your 3D printed droid to events, driving him around outdoors, or basically doing anything beyond leaving him within the safe confines of your home, there are several modifications you should consider that will dramatically improve the durability of your droid.
Center Leg
1. Steel ankle joint - Use 5/16” threaded rod cut to about 2.25” or 60mm. Use a Dremel or rotary tool to carve slots in the end so you can insert/remove using a Philips head screwdriver.
2. Vex omniwheels - Newer design and detailed parts list is available on the Patreon file share. This is an expensive mod, but I feel it’s worth the investment.
Main Feet:
1. Steel ankle joint - Use a 110mm M12 socket cap, partially threaded bolt cut down to 80mm (www.mcmaster.com/screws/socke...)
2. Vex omniwheels for drives - I used the Hans Bekaert files available on the Baddeley file share within each Drive subfolder. Parts and instructions are available there.
3. Tim Hebel Metal flange motor gear - Uses these flanges: www.amazon.com/dp/B08335MYGW.
UPDATE: There is an additional upgrade option available for mounting the gear to the motor shaft - sonic hubs. This modification was also developed by Tim and is available in his mods folder in the Baddeley file share.
4. Tim Hebel Hollow center axle - Uses a 40mm M3 bolt. Details in the instructions in the file share.
5. Steel Main drive wheel axle - Uses an M8 steel rod (www.amazon.com/Linear-Motion-...) and lock collars (www.amazon.com/dp/B08SK2LNNV). Steel rod should be cut to about 105-110mm in length. Use these inserts to fill the gaps on the drive housing: www.printables.com/model/2511...
Thanks for sharing this video, very helpful. I used a 2.8mm drill bit to widen the hole of the middle-gear pin, so that the M3 bolt can get screwed in more easily.
Nice. Getting that screw all the way in can be very difficult. If you don’t have spare nuts or bearings to wrap around the outside to prevent splitting, then widening the hole is the best alternative. Thanks for the tip!
Thanks again Jason. His goal for a 100% printed mech is noble but some points I feel are a bit weak. Appreciate knowing about these parts before I get there.
Hey Jason, THANK YOU for explaining everything in great detail! You have saved me tons of headaches with your upgrades! I am very grateful for this video! Keep up the awesome work!
Thank you! I always appreciate hearing when I'm able to help out a fellow builder. Keep in mind that the metal flange upgrade to the drive gear that I mention has since been superceded by the sonic hub upgrade - also done by Tim Hebel. Be sure to check out his directory of updates in the Baddeley file share. Happy building!
Hi Jason, do you have the center foot printed parts and hardware specs as seen in this video?
The exact version of the center foot that I used can still be found in the Baddeley OneDrive: Print Files -> Astromech V2 -> R2D2ver2Feet -> Retired Legacy -> R2_JD_VEX_PRO_wheels. center_foot_main.stl, center_foot_side1.stl, and center_foot_side2.stl are three pieces that make up the frame. There is a center "bridge" piece on my frame that is not there, and I looked everywhere for that file but could not find it. The "end caps" on my axles are vex_hub_4inch_wheels.stl. The wheels, flanged bearings, and center locking "versahub" are the same as the newer version of the mod - you're better off using the updated BOM located here: Print Files -> Astromech MK3 -> MKIII Body -> Legs & Feet -> CenterLeg -> VexFrameRelease. I used (I think) 8mm steel rod and lock collars for my axles. If you're in the Baddeley Facebook group, you can do a search for my name and you should see a post or two from years ago where I detail the assembly. Good luck!
AWESOME! Thank you so much!
Jason. This is a fantastic video. One of the few that are out there that actually makes sense. Thank you for putting this together. Two questions for you..
1- what is the length of the sliver rod for the large wheel?
2- what is the length of the 1/2 inch Thunderbolt vex shaft for the smaller wheels?
Thanks for the kind words! Unfortunately, I don't have easy access to R2s drives to measure, but the exact length for the main drive wheel isn't too critical - it needs to protrude out both sides enough to slide a lock collar on each end. I would guess the total length to be about 6 or 7". There's space between the drive and the foot shells for them to stick out a bit. The hex shaft is definitely a lot shorter - in the neighborhood of 3-4" (or less) if memory serves. You'll want to be somewhat precise with the hex shaft - you want the ends to sit JUST proud of the bearings at each end. This is so that when you add the large washers on each end, the axle keeps them from pinching down on the bearings. If the hex sits too low, you'll impede the spinning of the wheels, and if it sits too proud, you might get some slop. A grinder or belt sander can help you dial it in. I'll try and check soon and get back to you if my memory was way off! Good luck.
Thanks for the Mods. I am starting my foot assembly now and these will be incorporated into mine. Appreciate your sharing.
Happy to have helped. Best of luck with your build!
I luckily stumbled across Tims mods and one of your vids too and did all these during my build and just yesterday my 110lb wife was standing on the back of the foot shells and R2 barely creaked and held up fine.
Excellent mods.
Excellent video. This will help me a lot 👍
Excellent run through! Great timing as I'm currently taking my drive units apart for painting. I was already planning on looking up all the individual mods but here you've got them all in one place with great video.
At this point, I've taken these drives apart and reassembled them so many times, I could do it blindfolded!
excited to get started on mine!
great vid thank you!
Good luck with your build! You have quite an adventure ahead of you!
@@jasonsR2D2 dude I bet, I'm already working on Mando cosplay, green ranger helm, and a proton pack, and a mk5 ironman helm. I need to finish these first. Not that great with electronics yet too the mk5 mask with nine servos was a little much to start with.
Aargh! I started assembling my drive units with the modifications only to find I don't have any M3 square nuts or M3 15mm screws and the icing on the cake is that the M12 socket caps I ordered last year were 100mm instead of 110! At least cutting the M8 linear rod's and the hollow center axle mods went smoothly. Sometimes you have to celebrate the small victories!
Thanks again for posting links to the M12 bolts. I found the nuts at my local Ace Hardware but I'm going to wait for the bolts to arrive to make sure I don't get the wrong thread pitch.
Oh, that is sooo frustrating! I've been there too many times myself - I feel your pain. On the motor gear mod, you may have a little flexibility on the length of the screws (15mm can be hard to find, but 14 and 16 are easier). When assembling, I drop the motor into place and let it fall all the way until the end of the shaft rests on the wall of the drive unit itself. When I do this, I find I need to shift the motor gear back a bit so it sits closer to the motor itself instead of leaving it flush with the end of the shaft (maybe 1/16 of an inch of shaft protrudes beyond the motor gear). This is needed to better mesh with the center/intermediate gear. As a result, there's a bit of extra room available so if your screws are a bit longer, you should still be OK. Can't be certain if this would be the case for you, but if you've got some hardware that's close, might be worth giving it a try. Good luck. You've only got about 25 more dissassemble/reassemble cycles on these drives left to go!
Great modifications! Will definitely implement these when I build my feet.
I feel like I'm missing something. For the center foot ankle joint, how are you screwing it in? When I look at the files, the hole is just straight through. Did you tap threads or is there a nut hidden somewhere?
The 5/16" threaded rod is slightly larger than the hole, so it cuts threads as it goes. There may be a metric equivalent that is closer to an exact match of the hole, so maybe a smooth rod could work, but I would rather it be slightly too large and cut threads than be slightly too small and leave any wiggle in the joint. Since we're dealing with plastic, any small wiggle is likely to become a big wiggle over time. Thanks for watching!
Are the vex wheels in the center leg the same model as the out legs?
No. The center leg uses a total of four of the 4" vex wheels, while each drive uses one 3.25" vex wheel.
Jason, do you use locktite on the large outer ankle M12 bolts/nuts? I'm just about to cut my bolts to size and realized that they might vibrate loose.
I have not. So far, there have been too many instances during the build and for maintenance when I've needed to remove the feet from the legs - I figured any locktite would just make that too difficult. Currenly, I only use it on the drive gear flange mods and on the lower nuts of the threaded rods that run through the body and shoulders.
I see you listed the 8mmx1.75 bolts. I assume 8mmx1.25mm won’t work? Looks like I bought the 1.25s.
No, you should be fine as long as you get thin nuts with the matching 1.75 thread pitch. Be sure to get thin nuts - regular nuts will sit way too proud of the drive frame and prevent the foot shell from fitting over it. Honestly, the bolts are the hard/impossible part to find locally. Once you have those, take one to your local hardware store and find the matching nut. Good luck!
Thanks, sorry I meant m12, not 8
What size is the Omni wheel, how many did you order
The center foot requires four 4" Vex omniwheels, and each drive requires a single 3.25" omniwheel. It's deceptive when looking at them, as each single omniwheel assembly consists of two "platters" of gray wheels.
What the other parts, I know I’m going to have trouble with the hex rod
What size are the one wheels?
Each drive requires one Vex 3.25" omniwheel, while the center foot requires four of the 4" Vex omniwheels. The large powered wheel on the drives are printed in TPU/Flex filament. There are some additional parts required - bearings, spacers, and for the drive omnis, hex shaft to use as the axle. The part availability has varied and some Baddeley builders have recently found some alternative sources for compatible parts. I would recommend joining the Baddley Facebook group and searching there for the most recent list of parts and sources.
Thanks
theres a much better mod for the center gear out now that someone designed
Interesting. Can you provide details?