The reason may have to do with the height of the ruler foot and clearance for the needle bar and the needle clamp. I applaud Bernina for wanting to protect the machines of their customers.
The height of the ruler foot---any ruler foot---is for the most part too high for proper clearance of the needle bar and needle clamp. I show this issue and talk about how to avoid this issue in one of my videos about ruler work. Check it out for a good explanation.
|With the ruler foot up, the needle on my Janome can't go all the way to the down position.|
Simply stated, don't lower the needle unless the presser foot lever is in the lowered position which drops the foot into the position for sewing.
Yes, if you lower the needle with the foot in the up position, the needle clamp will hit the top of the ruler foot. Yes, that can harm your machine.
Am I advocating the use of a dangerous technique? No. Should you try ruler work with a regular free motion quilting foot to avoid this issue? In my opinion, no. I think that's more likely to cause a problem by accidentally running the ruler over or under the foot and under the needle.
Bottom line, I think this issue is about as hazardous as having a straight stitch plate on a machine and then trying to stitch a zigzag and forgetting to change the stitch plate. If the ruler foot is on the machine, don't lower the needle (sew) with the foot in the up position.
It's been a pretty easy switch for me to stop dropping my needle down before lowering the foot when bringing the bobbin thread up. This is aided, I admit, by using the knee lift that raises and lowers my presser foot with my knee. Yes, I forgot a couple of times in the beginning and no, it didn't damage my machine. The clunk when it happened though was enough to teach me to lower the foot before lowering the needle.
Since I understand that Bernina's feet are sometimes coded with a chip, maybe they can make a ruler foot that won't allow the needle to lower when the foot is raised. I know many Janomes will beep at you if you try to sew with the foot up.
But it is a common thing for free motion quilters to drop the needle down to bring up the bobbin thread with the foot up. So this could be a problem.
The talented Terri Lucas mentions the ruler foot for Bernina machines and this issue on her blog post here, along with some insight on why Bernina is waiting before releasing a foot they recommend for their domestic machines. I've had a few other quilters tell me they've heard the same thing. I've also had one Bernina user tell me she has used the #96 foot (the ruler foot for the Bernina long arm) and it worked like a charm.
Ruler work on a domestic machine is still an out of the box technique. Only you can decide if you are comfortable with stretching your quilting skill set in this way. For me, the design possibilities are certainly worth it. I know that it's a great, new, technique and I've met so many quilters that are enjoying the heck out of it.
So if you are a Bernina user, you may want to wait for them to create a ruler foot that solves this issue. Or you may decide to use the Janome foot with a shank adapter on your Bernina. Or you may decide to buy a foot from Westalee/Sew Steady or even Parrs Reel Ruler. I hear from many quilters who have done both successfully.
For the record, I haven't heard from anyone who was complaining of hitting their needle clamp/needle bar on the ruler foot.
Again, when using any ruler foot, lower the foot before lowering the needle.
Now, I'd like to say a very heartfelt thank you to those of you who have left a comment about my upcoming Craftsy class on ruler work. You are so encouraging and some of you might be as excited to take the class as I am to teach it. Thank you again.