A massage gun is sold for self-care, but one sealed battery ends it in one to two years.
Theragun Core keeps the body and lets the battery and motor come out.
YEAR
2026
TIMEFRAME
Summer 2026 · 14 weeks
COURSE
Design for Sustainability, Lab 2 · ArtCenter
CATEGORY
Industrial design · Product-service system
TOOLS
Sketching · SolidWorks · Gravity Sketch · KeyShot · 3D printing
ROLE
Solo · personal project
01
The problem.
The product works against what it’s sold for.
A small upgrade means a whole new gun.
Eight models, $159.99–$649.99 · only the $529.99 PRO takes a spare battery
Mine
+$100 · heat
Spare battery
therabody.com · US prices · 28 Sep 2026
18 months from box to bin.
A 0.075 kg glued-in cell ends a 0.445 kg device
The battery goes first, and the warranty excludes it.
Battery 4
Durability 3
Reach, feel 3
10 public owner reviews · Therabody warranty, exclusion (viii)
Hard to hold for long, harder on someone else’s back.
“I was worried about not being able to reach with the Theragun Prime on my own without someone else to help me.” — Brit + Co
Under construction
Holding video
On someone else’s back, then a long session.
02
The market.
No battery gun today is both precise and long-lived.
Core keeps the precision and moves up the chart: the parts that fail can be swapped.
Four guns from the week-2 scan · the dots on the chart
Hypervolt Go 2
Compact, lower power
Ekrin B37
Good value, battery complaints
Theragun Prime
High-function entry, $300
TOLOCO
Cheap, weak build
All four share the two problems: reach and a battery that wears out.
Qualitative · week-2 desk research and owner reviews
03
What’s inside.
Six parts came off by hand. The battery and motor took tools and force.
My Relief, taken apart · 14 parts · 0.637 kg with packaging (estimated)
Electronics are 6% of the mass but 30% of the footprint.
Area = mass · kg CO₂e from public proxy factors
Half the footprint sits in parts an owner could replace.
Cradle-to-gate · public proxy factors, not Okala yet · 8.196 kg total
More analysis · the full research
↓
04
The system.
Sell the recovery, not the device.
Keep the gun, swap the module.
Product as a service
Ongoing relationship
Modularity closes the loop
System-level savings not yet quantified
A lifecycle with a way back.
Battery and motor: modules, swapped, recovered
Other parts and steps
Process tree · redrawn from my Lab 2 system map · click any chart to enlarge
05
The design.
From research to design
So the new body had to do three things.
How I got there · 14 weeks
The final design · week 14 · rendered in KeyShot
Test render · side
Rear view
Under construction
Product film
A slow turn around the body, then the base and the motor coming out.
01 · Sketch
Sketching every way to take the triangle apart.
Replaceable motor · turnable head · charging stand
Packaging · folding · swing arm · compact head · head set · turnable · sliding motor · bio-inspired grips
02 · Model
From a box head to two legs.
01
First render · box head
02
Two legs or compact
03
Line studies · head, handle
04
Eight heads, marked up
05
New model · CAD
06
New model beside the first
03 · Refine
Refining the legs into modules.
07
Handle studies · V legs
08
CAD · refining the joint
09
CAD · front, marked up
10
Colour-coding the leg modules
11
CMF · black + blue
12
CMF · white + yellow
04 · Print and hold
Drawn, printed, held.
Modelled in CAD, drawn in four views, then printed and held. The printer failed more than once along the way.
CAD · surface model
CAD · wireframe
Drawing · four views
Grip test · printed handle
Print failed
Print · earlier form
Grip test · final form
The final design, side and back.
Details follow: grip · texture · base · motor · kit
Two legs, longer reach.
The handle closes into a triangle: two legs and a base. Either leg is a grip, and the second one reaches the neck and mid-back without help.
Printed prototype · both legs in hand
Under construction
Mid-back reach
A short clip reaching the mid-back alone.
The legs are where the hand sits, so that is where the texture has to work.
01
Fine matte
An even grain all over. The hero and rear renders use it.
02
Hex dimples
Raised dots on every surface, for a damp or tired hand.
03
Diamond cross-hatch
Cross-hatch on the leg you hold, dots on the rest.
The battery lives in the base.
The cells sit in the base, not in a sealed core. A quick-release latch lets the base come off in the owner’s hands.
1 step · quick-release latch · no tool
The base slides out · four frames
3 steps · hex driver
The motor lifts out · three frames
Six steps, one tool.
Battery module
Head adapter
Attachment heads
Motor module
Control board
Total · 6 steps · 1 tool, a hex driver
Modular architecture from my Lab 2 deck · week 14 exploded render
Week 14 · carbon texture
Week 14 · side
Week 13
Week 12 · colour study
Week 12 · colour study
06
The result.
A dead battery now costs 1.88 kg, not 8.20.
50.2%
Of the footprint
owner-replaceable
Battery, motor, assembly, heads and adapter: everything the owner can replace.
When the battery fails · kg CO₂e, cradle-to-gate
Buy a new device
8.20
Swap the battery module
1.88
−77%
From my Okala-matched line items · public proxy factors
Next
What I would test next.
01
Wide PCB range.
My largest line item carries the widest published range, 50 to 150. At the low end, the battery leads instead.
02
No baseline.
There is no bill of materials for the current Relief, so there is no honest before-and-after, only a map of what the redesign can reach.
03
Proxy factors.
The Okala columns are still empty. Every number here is directional and will move when the official factors go in.
Theragun Core · Adam Zhou · 2026
A1 · Week 2 desk research
Owners complain about two things: reach and the battery.
Reach
Battery
Battery
Durability
Battery
Feel
Grip
Durability
Battery
What the reviews add up to
01
Reach is still the main problem when you use it on your own back and shoulders.
02
Battery wear is the most common reason owners stop using the gun or replace it.
03
Durability and repair are weak. Most owners treat it as a short-term product.
04
The triangle grip helps the wrist, but not reach or long sessions.
Battery 4 · durability 3 · reach and feel 3, out of 10 logged. One repeat is left out above.
The gap
Everything on the market gives up either power and precision, or convenience and lifespan. There is room for a gun you can use on your own and keep for years.
Battery guns today
Gun
Good at
Falls short
Hypervolt Go 2
Compact, travel friendly
Lower power, still limited back reach
Ekrin B37
Good value and power
Mixed long-term durability, battery complaints
Theragun Prime
High-function entry point, warming
Expensive at $300
TOLOCO
Very low price, good head selection
Weak build and motor
Next to the gun
Alternative
Trade-off
Foam rollers
Cheap, but manual and less precise
Clinic devices
Powerful, not for daily home use
Heat and infrared tools
Heat first, weak mechanical effect
App-connected recovery kits
More expensive and more complex
Sources: Brit + Co, PopSugar, Trustpilot, Reddit r/TheraBody and r/MassageGuns, YouTube reviews · collected in week 2
A2 · Weeks 2–3
Three directions, each from a strategy card.
01
Swap the battery and motor
User-replaceable battery and motor modules, compatible across models.
02
A handle that grips
An improved ergonomic handle with a better grip.
03
A head that reaches
An adjustable percussive head for better reach.
Why it matters
For the owner
Recovery that lasts longer, works better and costs less over the years.
For the planet
Less e-waste, fewer new materials.
For the brand
From one-time sales to a long relationship with the owner.
A3 · Cradle-to-gate · public proxy factors
Where the 8.20 kg comes from.
Subassembly
Materials
Manufacture
Distribution
Use
End of life
Total
Power & drive
2.97
0.56
—
—
—
3.53
Electronics
2.48
—
—
—
—
2.48
Structure & interface
1.42
0.56
—
—
—
1.97
Packaging & accessory
0.22
—
—
—
—
0.22
Total
7.09
1.11
—
—
—
8.20
— means no activity data yet, not zero. Distribution, use and end of life are the next columns to fill.
Five of eight steps change.
Material production, component manufacturing and assembly stay as they are. The redesign is architectural, so the factory does not have to be rebuilt to make it.
Step
Today
Modular
Packaging
PET blister, LDPE film, PP/ABS trays, foam
A moulded pulp tray the owner keeps
Distribution
Truck and air freight
Ocean, then road
Use
The battery cannot be replaced
The battery is a module, swapped in one step
Repair
Very difficult today
A repair step that exists at all
End of life
Glued and potted cell, mixed plastics
Modules come apart and go to certified routes
A4 · Error bars
The biggest line item is the board I keep sealed.
Board impact scales with area and chip count; battery impact scales with kWh, not kg. The two ranges overlap, so on this data I cannot say which is larger.
Published factor ranges · PCB 50–150 · battery 15–30 kg CO₂e/kg
Back to the story
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