There are many challenges to overcome when bending sides using a heating blanket.
One of them is how to control the temperature during the bend.
The silicone heating blanket was a huge advance in technology over using light bulbs as a heat source.
The problem though is just how to achieve and maintain a constant temperature
throughout the bend.
LMI has solved this problem with a temperature controller.
This is much more than just a rheostat.
This controller, with the use of a thermal couple,
allows you set a target temperature and maintain it within a degree or two
while bending your sides.
The advantage is you can dial in the exact temperature needed
for the species of wood you are trying to bend.
It also allows you to maintain a desired temperature
after the bend to reduce springback.
Here’s how it works.
When making your sandwich of metal slats and wood in the bender,
place the end of the thermal couple between the wood and the heating blanket.
You only need to insert it about ½ inch.
The other end of the thermal couple is plugged into the temperature control box.
The green switch turns on the power to the controller.
The red switch turns on the power to the heating blanket.
This switch is red for a reason.
You should never leave the set up unattended when that switch is on.
In my shop while bending I turn off the phone, radio
and any other distraction so that the process has my full attention.
As an extra precaution I even unplug the temperature controller when finished bending.
A few guys have had close calls or even burned down their shops
bending sides so make sure it doesn’t happen to you.
Use the up and down arrows to set the temperature you want to bend the wood at.
I am going to set mine at 300 degrees.
When I turn on the red switch, the red numbers,
which indicate the temperature of the heating blanket, begin to rise.
The controller checks the blanket temperature with the thermal couple every quarter second.
As the blanket reaches the target temperature,
the controller cycles the power to the blanket on and off
to first stabilize and then maintain the blanket temperature at the pre-set target.
You may notice that the temperature passes the pre-set temperature slightly.
This is normal and the controller will recognize this and stabilize it at the predetermined target.
When I bend my sides I start bending before I reach the target temperature
and I am usually done by the time the controller has stabilized the temperature
at my pre-determined setting.
The entire process takes me less than 5 minutes.
Speaking of time, as an extra security measure I use a timer to make extra sure
I maintain my focus on the task at hand.
This timer also works well for timing reheating cycles.
Once you are through bending you can turn off the red switch and monitor the cooling.
The temperature controller comes from LMI pre-set for using with the large side bending blankets.
It can also be used with smaller repair blankets
like the fretboard extension and bridge blankets.
However, it will need to be tuned to be used with these blankets.
The temperature controller has an auto tune function for doing this.
Set up the heating blanket you want to use with the thermal couple.
Set the target temperature and turn on the red switch.
Once the blanket is at the target temperature,
press and hold down the right arrow key
until the AT/M indicator light starts flashing.
The controller is now auto tuning.
When the flashing stops the controller is tuned for the new set up.
Bending sides can sometimes be an intimidating process,
especially when bending that expensive set of sides.
The LMI temperature controller allows me to remove some of the variables in the side bending process
and get consistent results every time.