<p>I have ordered a dual hotend Chimera and it came with 2x 12&nbsp;V heater elements (in my rush I forgot to order the one with 2x 24V).</p>

<p><a href="https://i.stack.imgur.com/xhQNem.png" rel="nofollow noreferrer" title="Chimera dual filament hotend"><img src="https://i.stack.imgur.com/xhQNem.png" alt="Chimera dual filament hotend" title="Chimera dual filament hotend"></a></p>

<p>Is it possible to run these 12&nbsp;V heater elements in series? </p>

<p><em>I am planning on running this with an SRK 1.3 board.</em></p>

You should be able to offset this with a
```
G54 Z-1.3
```
-
if your setup accepts these gcodes
.
If you do this, always add a
```
G53
```
to the very start and just before the
```
M30
```
to clear all offsets after job finish (or in the event of a cancel, at the start of the next job).
I'm not experienced with a wide variety of printers or firmware, but our repetier-based printers (and we use the same controls for our refurbished Fadal CNC machines) use G53-G59:
As explained in this tutorial from cnccookbook.com
:
Basic work offsets are very simple to specify: simply enter one of G54, G55, G56, G57, G58, or G59. [...] When you execute the work offset g-code, the XYZ offset will be added to all of your coordinates from that point forward.
As detailed on Wikipedia
:
G54-59
: Have largely replaced position register (G50 and G92). Each tuple of axis offsets relates program zero directly to machine zero. Standard is 6 tuples (G54 to G59), with optional extensibility to 48 more via G54.1 P1 to P48.
And on the gcode dictionary provided by Hyrel 3D
:
G54 through G59 - Set Offsets
G54, G55, G56, G57, G58, and G59 will each store and invoke offsets in the X, Y, and/or Z axes for all subsequent moves. Any values not invoked will remain with their previous value (0 unless earlier specified otherwise).
X is the offset in mm in the X axis.
Y is the offset in mm in the Y axis.
Z is the offset in mm in the Z axis.
Here is an example:
```
G54 X100 Y-50
```
This command is decoded and executed by the printer as follows:
G54 (set offsets)
- X100 (+100mm to all X coordinates)
- Y-50 (-50mm to all Y coordinates)
Note that this differs from an M6, where the offsets are only applied to a SINGLE tool position.
Disclaimer: I work for Hyrel 3D.