How-To: Install New Belts on the Bernina 730 Record

Today I replaced the upper and lower drive belts on a Bernina 730 Record.  I took some pictures along the way so you could see the process.
Start by unplugging the power supply. Take off the side panel under the hand wheel.  There are two screws, one on each side of the panel.

Screws for end panel

The panel then slides out an down to get from under the hand wheel.
Take the screw out of the hand wheel and remove the end cap and the washer.
Turn the machine on its side and remove the two screws holding the motor cover panel.  The panel with then slide/lift off, just be careful to navigate around the motor switch panel.

Screws for motor cover panel located underneath the machine

Now you should have a clear view of the belts and access to the end of the machine and the motor pulley.

End panel and motor cover panel removed

The screw to release the tension on the belt wheels is below the bottom wheel and you will need an allen wrench to loosen it up.  You don't need to take the screw out, just back it out a quarter turn or so until pulley behind the wheel is loose.  This will give the wheel some play horizontally and vertically.

Loosen screw below the wheel, do not take screw out

Remove the lower belt from the motor and wheel first and then slide the wheel up slightly to remove the upper belt.

Lower belt comes off first

The upper belt is nestled behind the lower wheel and stretches up over the hand wheel. Slide the hand wheel off and the belt should come with it.

Both belts and the hand wheel have been removed

Now start putting the new belts back into the machine.  Start with the upper belt and remember it tucks in behind the lower wheel.  You can slide belt over the hand wheel and put it back on the shaft.

Upper belt goes behind wheel and up over hand wheel

Hand wheel back in place and upper belt tucked in behind it

The bottom belt goes over the wheel and connects to the motor pulley.

New lower belt in place

You will need to adjust wheel position so that the belts are not too tight and putting strain on the motor or too loose and not engaging the wheel or hand wheel.  When you think you have the correct tension, tighten the screw back up with the allen wrench.  At this point you can plug in the power supply and try running the machine with the foot controller.  Make sure the belts turn smoothly and make adjustments if necessary.  Remember, the adjustment screw only needs a small turn to loosen or tighten.  Here is a quick video of the machine running with new belts.

Once you are confident with the placement of the belts, you can unplug the power supply and reassemble the machine.  Put the washer back on the hand wheel with the little raised tabs pointing out away from the machine.

Tabs stick out away from machine

Put the cap back on the hand wheel and replace the screw.

Hand wheel reassembled

Slide the motor cover panel back into place and put the screws back into the bottom of the machine. Reposition the side panel and tighten screws.You are now ready to plug the power supply back in and begin sewing.

This is my first how-to segment and I welcome any feedback you have that would help improve future segments. Thank you.