Modular Dumbell 1 to 5 ish pounds cheap

In trying to figure out what was wrong with me my doctor send me to physical therapy and issued some water pills. I ended up not needing the PT it was just some retention once the water went away my flexibility returned.

While I was their I noticed people using simple dumbells for therapy. injured older etc.. also many times financially challenged. got me thinking can I do it cheaper? its $30 to $40 “each” for set of dumbells. in theory you can do it as low as $19 if you have a 5 below handy but out here that is $20 in gas and a nice drive to reach one of those.

I wondered if I could PRINT such a thing. here is the result. in theory you can print 2 of these with an $11 roll of PETG so around $6 each when you factor in the sand ($5 a bag at walmart and you can fill many of these for that.

One part that will need something not printed is you need to seal one end of the “tubes” so the sand does not come out when you unscrew the end. (can't seal both ends printing or you could not fill with sand though….. in theory you can include top layers and carefully pause when nearly done and CAREFULLY fill with sand then resume printing. that would work. otherwise stuff some TP or Tissue in the end and add some hot glue or epoxy to seal the end.

These are designed to be fat nozzle printed. 1mm nozzle. and in vase mode except the dog bones. 3mf files included.

In theory you can print these with a 0.4mm nozzle I am going to test that next. tell slicer to extrude 0.5mm and use 2 perimeters/walls and 0% infill for the tubes and 1mm thick bottom layers. I used first layer 0.6mm then 2 at 0.2mm to get my 1mm however you can also just do 5 at 0.2 as well to get 1mm

For the dog bone this really needs to be FAT for durability. use 5 or 6 walls (2mm or thicker walls) and print the infill “SLOW” and extrude it at 1mm thick  or adjust infill density till total mass is around 180g each. that should do the trick.

I originally made the rugged version first but its a PAIN to adjust the mass since you have to undo all 10 screw caps every single time. the other slim version is newer. made some changes to make it stronger since the outer tubes just “sit” in place and are compressed together by the central pylon with 2 screw caps. this means a lot more stress on the center pylon since impact is no longer spread across 10 caps but just 2 now.

the bones are also thicker so they can be REVERSED this way if the part experiences any “creep” over time and becomes loose you can just flip it over and reinstall which will tighten things back up again.

you can add as many weights as you need. each outer pylon should be roughly 1lb when fill with sand. using sand from your yard if you have any can work though this will be lighter (not as fine so lower effective density)

I wanted this to be something people can print to donate if they wish to needy therapy patients who might not be able to afford to buy such things. an $11 roll of PETG should let you print 2 full sets. I printed these using Atomic Filament Bubble Gum and Kandy Blast (amazing color) and Graphite Grey PETG colors. definitely not $11 a roll but super nice filament and colors.

I have made these pretty strong but if you drop a loaded set onto a hard surface there is a very non zero change it could break. it is plastic afterall. if you have the patience you can print it in TPU and well that should be pretty much indestructible :-)

the “rugged” version is a PAIN to adjust but also much stronger. the Slim version is much easier to adjust (remove a single end cap) and much nicer and more elegant and uses around 100g less plastic (2 screw caps instead of 10)

Let me know what you think. no support required for any parts.

I don't like telling people they can't sell what they print. So how about this. if you want to sell printed copies toss me a bone :-) www.nerys.com my digital store. that one includes rights to sell printed copies.