Regular sewing thread?
 

I would like to use normal sewing thread to embroider a quilt sandwich together-both top thread and in the bobbin. Has this been done? Should I expect problems and do free motion quilting instead? I am not that good at FM.

i use all sorts of thread to machine embroider quilting.
test the thread you want to use on a sample sandwich. it will probably work.

Yes, I would practice on a sample piece using the type of material and batting you will be using. I would use a pretty open type of embroidery design. I made some redwork quilted panels for my sister and I just used Aurifil Thread but used a heavier weight than I usually use to piece to make the outline standout.

I have used machine quilting thread with my embroidery machine before. I have used it with quilting designs and to make freestanding lace.

It would probably depend on what your normal sewing thread was and what weight it was. As stated, make a sample and see how it works.

I don't see why it wouldn't work. Where you'd run into problems is if you did the reverse - use rayon embroidery thread to quilt it together. Embroidery thread tends to be on the fragile side.

My Viking is programmed for 40 weight thread - so as long as I use a 40 weight, all will be good. According to the manual for the machine I can change the tension for the different weight of thread, but my repairman said that works well with sewing but not the embroidery. He said I can do it, but don't be surprised if I don't like the results. So I haven't bothered to try using a different weight.

I don't know what brand machine you have but have you looked in the manual as to using embroidery to quilt. Now I am confused as to what you mean by embroidery. Are you talking about using decorative stitches or are you talking about using your embroidery arm to place portions of the quilt in the hoop and using a quilting design as embroidery? I have used different weights of thread to do embroidery in the hoop using my embroidery arm and have not changed tension.

Check out the utube videos on quilting with your machine. There are a few to watch. Also at one time nancy zimmerman
(Sewing with Nancy) had a lady guest that did two video presentations on quilting with embroidery designs. That would answer many of your questions. I am pretty sure her site is still up. Once there just look for the video link.

I have done quilting in the hoop on my Janome 12000 using 100% cotton thread Essentials by Connecting Threads, since I had several dozen colors of that already when I got the machine last year. It works great! I've also used (quilting in embroidery hoop) Signature cotton, Aurifil, and Coats cotton (quilting). I actually don't recall what weight is the Essentials but I think it is thinner than regular sewing thread. Always make a test sample with your intended needle & at least start your design with samples of your quilt batting, to see if you can manage hooping it (or modifying the hoop) before beginning the entire quilt.