Sleeper80's Butterfied Butterfly Mods, and more

Hey Everybody,

Since the new generation of Duncan Butterfly yoyos were released I have been a little obsessed. Such a humble but iconic toy that was never particularly special, but still was always available to be played to its limits and sparked interest for generations. This was what 5 to 10 year old me knew was a good yoyo and imperials and butterfly’s have always been there since the beginning.

I like to tinker and I was never a modder in the late 90’s to mid 2000’s when i was really into learning tricks and discovering amazing new yoyo designs, but this new model Butterfly is really well made and super affordable so breaking them down and experimenting with mods is fairly easy and fun to do. Can i make it spin longer? Respond better? Do I like heavier or lighter?
So I wanted to document my Latest mod attempts for anyone out there that is a Butterfly Hype Beast and wants to see if they can make their own better Butterfly.

Here’s a list stuff you will need to follow my methods at home but you can make up your own processes and ways to make little parts as you see fit, I don’t have a workshop, just a few basic tools in my home office, nothing fancy.

  1. A multitool with a blade and a saw. Mine is a Leatherman Wave+ but any kind will do as long as you are comfortable the blades are sharp and can do the job. Or whatever you got to cut little plastic parts and wood axles.
  2. A metal punch, less than 1/4 inch diameter. you could probably just use a wood dowel too if its strong wood. or a plastic chopstick might work too…i use this to push caps out of bodys and some small parts work.
  3. A small bench vise. it doesn’t have to be big, I have a cheap $35 small vice with a tiny anvil that clamps to the edge of my desk. its from one of those cloud vendors that sells everything. like my punch.
  4. Sandpaper. I have some 180 and 220 and 320 grit patches from a sample pack at the moment, but may get some finer stuff at some point… you can use whatever grit works for you, if you want to remove material faster and work down to finer grits etc, all up to you.
  5. About 2 feet of paracord. I use this and the bench vice for separating new yoyo halfs from the stock axle.
  6. Superglue. you can use epoxy or other kinds of glue if you like, i just use simple gel control Loctite super glue with a tiny applicator needle and use it sparingly.
  7. Extra Duncan yoyo halves. its worth buying a few extras to destroy because it makes things easier for modding later. If you can find them for $3, buy a whole bunch instead of that one $100 yoyo you are scared to ding playing with it. these are gonna get dinged. I use these to help with making some small parts and for disassembling caps from the yoyo halves. On that note you should try to use the same generation/mold parts as what you are modding ( unless you are modding old and new parts together or other funky stuff) but its handy for modern cap removal to have a half from an older 80’s or 90’s model. the modern cap fits more loosely in those. you can find used ones on the interwebs auctions, or an old toybox in grandmas basement to take apart. Also, if you are looking for mod parts in the hardware store , it helps to carry around a disassembled half and cap to test fit stuff. in addition, if you find a batch of butterflies circa 2015, they are probably terrible, and crack with the slightest impact. I cracked one once taking it out of the package and have seen them cracked in the package. use these for making parts and not new yoyos.
  8. A little scale. if you really wanna get picky you can try to make the halves balance as much as possible. Usually parts from the yoyo are within 2/10ths of a gram of each other when I weigh them, but since its being modded you have opportunities to try to get them to the same weight, within a 10th of a gram in this case.
  9. a marker or way to mark your axle or parts as needed.

Build materials for the build below:

  1. Some new duncan butterfly yoyos. I have a pink and blue here and some white caps from a new psychedelic model leftover from another build. i like half swaps alot and i’ll l have some parts left over for another custom.
  2. 1/4 inch wood dowels for axles. Can find in local hardware stores and or the cloud. i recommend stuff like hard maple, walnut, oak, or other hard woods you find suitable/avaialble. In this mod I make a walnut axle, but I have made a few with oak dowels as well. I am going to try some other types of wood at some point too, they have diferent grain structures and hardness, etc so they all have a litle nuance in play. The length of the axle will dictacte final string gap.
  3. Plastic tube. specifically with an outer diameter of 3/16 inch and inner diameter of 1/4 inch. this is used to make a spacer to fill the gap between the new axle and the starburst that is made for the stock axle. got it from the cloud pretty cheap and have enough for the rest of my life. It comes in diferent colors too if you care that much about aesthetics.
  4. Weights. You do not have to add weights if you do not want to. I will note changing the steel stock axle to a wood axle does reduce weight a bit at the center. you can add o rings around the platic hubs inside the body, or glue in washers or other types of flat bushings of whatever material you can find. in this case I have some aluminum machine bushings from one of those builders stores. Finding parts in the store is easier if you bring a disassembled yoyo with you to test fit.
17 Likes

First step is to disassemble the yoyos to get a blue half and a pink half . this begins with unpackaging, removing the string, and then wrapping your paracord around the gap about 2-3 times.

pull the paracord at both ends away from each other, you are trying to force the cord in to the gap. this will help push the halves apart as it bunches up around the axle…

wrap a couple more times…

pull again till it pops…

9 Likes

Ok so now you have these parts. note the axle is gonna stick to one side, sometimes the graphic half, sometimes the blank half.

To remove the axle, put the axle in your vice. In this case i have a micofiber rag draped in the slot to lessen the markings from the vice on the axle and i also put the axle through this bumper washer as a surface for the paracord to press against… it will work without the washer too but its easier this way.

clamp in the yoyo axle tight…

Now the paracord…

note there are pretty strong forces going on here, the half will pop off and fly away sometimes

7 Likes

OK now both yoyos are de-axled, time to separate the caps…
First get your old capless half from another project, ideally this will be a 90’s half like I have here to make it easier to get the cap removed easily. we’re gonna use it as a backstop for the cap being removed since it will hold the edge of the body while the cap is pushed out and the older mold is not as tight around the cap as the new mold is.

Stack your new half face down on the old half I put some paper towels pieces in the hole so that the punch doesn’ t scratch the plastic behind the face of the cap. this is really for clear caps, opaque ones you can’t see any marks. Get your punch and another used up half to help push the punch…

push straight down. it takes a little force but it will go as long as the halves are lined up well. the cap will go face down into the bottom half…

Take out the paper towel, and use it to push the cap out of the old half with the punch without scratching the graphic and save it for later…


At this point i weight the parts to find a matched set. i want the halves to weight the same within a 10th of a gram on my scale. i re-weight as i add parts to the half so i can try to keep them in check. Other parts might have slightly higher or lower weights to compensate for differences on the other half so sometimes switching weight rings to the other half can help adjust…


7 Likes

Now axle spacers need to be made.This is the most critical part besides the axle itself and getting weight balanced and centered. Without the spacers, string will slide down the axle and deep under the starburst and snag alot more often than you want. I learned this using a prototype I made without the spacers during Fixed Axle Feb 2023. First, I cut the plastic tube with my multitool knife to make these plastic spacers that will fit on the axle where the normal metal axle has shoulders… i cut them a little long so i have material to work with to sand them down to the right size and make the ends flat as possible.

next, put the spacer into an old yoyo half to sand the end flat. I want to get both ends flat so flip it around to make sure both are flat before they are fully sanded to final depth. you want to sand it down past the starbursts so that it fits right below them in the new yoyo you are modding. note this old half is a junky 2015 model with easily cracked plastic.



i push the spacer out of the backside of the half usng my punch…

8 Likes

ok, so now i have a pink body, blue body and white caps, weight rings and axle spacers. I also have sanded the weight rings and the inside surface of the caps a little to make better surface area for the superglue to hold/bite. once this thing is glued together, if a weight ring comes off from a hard hit or something, that might be the end of the yoyo unless you like it to play horribly.

In addition, i sanded the rim around the cap edge a little because i have found that it can cause stress cracks in the clear plastic body when you push it flush as its slightly too much diameter (which i cannot explain.) i put the metal axle in my drill chuck, pop the cap on the end and run it with the edge down on sandpaper on my desk. its a bit wobbly and imperfect but it takes just enough off to not cause stress cracks in the body when i assemble it.

Now the Axle. the thing holding all this together. the better this turns out, the better it should play. first i cut a piece of dowel with my multitool saw. i measure a bit longer than the stock axle so i can sand it down to length.

Sand the ends as flat as you can and don’t go too short or you will have too narrow a gap. . i like the finished axle to be just a pinch longer than the stock one, like .5 to 1 mm longer. the wood is more responsive than steel and this allows me to have a little wider gap.

next i sand the surface of the axle to get it smooth and to get it to just fit tightly in the plastic spacers for fitment. it should all fit tightly but still allow the axle to insert all the way through the halves. they seat in the caps. I put it in my drill, sand a little with 320 grit, flip, sand the other side, test fit, and repeat as needed a little at a time.

9 Likes

Heres all the parts ready for assembly, the halfs, caps, weight rings, spacers and axle.

First, glue the weight rings to the caps. i have also done some on the inside of the body as well, just depends where you want the weight. this is my first attempt on the cap side.

I just eyballed these, but if i can find a better ring that matches the exact inside diameter of the cap i’ll use those next time. also glued in the spacers to the body with a few tiny drops in the seat of the body gap.

next once the glue is dried put the caps in the halves… I just fit them together, no glue, the axle will have glue and will seat in the caps to hold it all together.

now, glue in the axle in one half, i put a few drops of superglue around the edge of where the cap meets the body in the axle hole. and push the axle in till its flush to the bottom of the cap. Put a little glue in the second half and push it down on the axle, i also align the graphics on the caps so they are as symmetric as possible.

This one is 57 grams on the scale when completed…

11 Likes

below are a couple more recent experiments:

this one has walnut axle and some orings stacked on the hub to get it up to 50 grams. there are 3 #11 o rings and then a #16 o ring mounted in the valley between the 2 inside most #11 o rings.


This one has aluminum machine bushings on the inside of the body instead of the cap, and a little o ring stretched over the hub to center it. Oak axle. 55.7 grams.


25 Likes

Boy, do you love Butterflies. Who can be bothered with all this? :sweat_smile:

4 Likes

Awesome work. I grew up on a Duncan Butterfly. To make it even better is definitely applauded.

4 Likes

Idle hands… gotta keep them busy, so I don’t go crazy. At least I keep telling myself that…consider this my manifesto, lol.

6 Likes

I think it’s brilliant! Maybe we’ll find the perfect setup and it becomes an all time legend!

I wish there was more modding going on today. It sounds like it was a big deal back in the day. Maybe @yoyodoc can share some stories and or give some tips for this particular setup.

Mod on!

4 Likes

Awesome work dude! Now I need to stock on those.

3 Likes

Messing around with dye and glitter…


24 Likes

What do you think the safest way to pop the caps off is? The glitter looks amazing and my girlfriend has tons of the stuff.

1 Like

Its explained in the dissasembly process posted above. Safest way i can do it.

1 Like

Tweaking my dye recipe/techniques, getting some good results on these

16 Likes

Trying to get a lttle more intricate/cleaner pattern.

23 Likes

Man o man. That is some gorgeous work right there!!!

1 Like


First attempt at modding a FHOne. bearing spacers, permatex ultra grey silicone for unresponsive play, Dyejob, caps modded from a psychedelic butterfy. 73.9 grams.

11 Likes