Your friend is mistaken about how the current works in a **universal motor**, like the one in your Makita HR2610. The **current does not double** when you double the voltage because the **stator and rotor (armature) are in series**.

### **Why the Rotor Won't Burn Out at 220V**
1. **Series Circuit Behavior**
   - In a **universal motor**, the **stator and rotor share the same current** because they are wired in series.
   - When you install a 220V stator, its windings have **more turns of thinner wire**, which reduces the current to match the higher voltage.
   - Since **current stays the same through both components**, the rotor **won't draw double amperage**.

2. **Same Power Output**
   - The **watts stay the same** (800W in both 110V and 220V versions).
   - Power = Voltage × Current → If voltage increases, the **current decreases** proportionally.

3. **Makita Uses the Same Armature for Both Versions**
   - Many Makita tools use the **same rotor for 110V and 220V versions**, only changing the stator.
   - If the rotor couldn't handle 220V, Makita would use different part numbers, but they don’t.

### **What Would Actually Cook the Rotor?**
- **Installing a 110V Stator on 220V** – This would **double the current** and burn everything.
- **Overloading the Drill** – Running it under heavy load for too long could cause overheating, but that's the same for both voltage versions.

### **Final Answer:**
Your rotor **won't burn out** if you swap in a proper 220V stator. Your friend’s logic only applies if the components were in **parallel, not series**. You’re good to go with just the stator replacement!