The thing that comes to my mind is that it may stitch less than 800 stitches per minute. Where a longarm starts at about 1500 spm and goes up to 3200 spm. If you could find a domestic machine that stitches faster, that may help. There are semi-industrial machines that work great for that, like a Juki 98Q, 2000 or 2010.

Thanks Annette,
I'll look into that. :)

The vibration could be from your table. The white tables they sell now as work tables vibrate TERRIBLY. I like the old fake wood top tables. Those things were stable. Also I get that Kerchunk sound when I need a new needle. Free motion often takes a sturdier needle as you are putting stress on it that it does not get when you are sewing straight with feed dogs up. Just 2 things to consider. And remember! Everytime you tackle an issue with your freemotion quilting, you are learning to TROUBLESHOOT! (that little nugget gets me over ALOT Of issues!) Good luck!

I don't know for sure what you are experiencing, but I do know the weight of the quilt causes drag for me and I have to stop alot and reposition the quilt. The quilt gets hung up pulling and pushing - both ways. Mainly because I don't have a good set up. Some people hear have shown their set ups that are awesome. PVC pipes holding up the quilt. Some day I may get to try that. I have also found that I don't use the pedal any more. I could not stay consistent with my speed using my foot. I use the on off button - then the speed is consistent.

I just got a Ruby Deluxe and found the same problem...that oh so slight drag that makes all the difference. I felt like I was back to square one on free motion, I resolved the problem by reducing the presser foot pressure {now that is a mouthful } from six to five or ever lower if I have a really fat quilt sandwich. Look in the manual for what screen to go to...I find it is a bit of a poke here or there, I can never find it the same way twice it seems. It does really help with smoothing out the process. Also, I find the Viking screens are super sensitive and in the process of moving the quilt about if it touches the screen you can pop into another stitch just like that. Find the lock screen and do use it with every sewing session. Believe me this can stop an " oh $#!? what now " moment.
"

Can't you use Leah Day's floating foot tweak?
http://freemotionquilting.blogspot.c...tion-foot.html

You can find a cheap plastic foot to try.

I've used both. The tweak worked fairly well with a Brother PQ 1500, but the Juki 2010 prefers the hopping foot and is easier to sync hands and machine.