So funny this thread came up as I am sitting with lower back pain right now. From all of the above I think I may investigate the duffle bag suggestion. I'm finding I love my portable machine carrying case with wheels, BUT it's the transfer from the car that's my killer. The other thing, at retreats I can not discipline myself to get up from my chair and walk around. Also, the tables make my machine higher than is really comfortable. So, that's my story and I'm sticking to it!!! Actually, it's hard to get older and not be able to do things that used to be so easy for me.

I love my Featherweight and I think you would too! But If I may, I would urge some caution when buying one. They are extremely popular little machines so they often have high price tags no matter what shape they're in. They are all vintage machines so might require a fair amount of refurbishing and maybe repair in addition to the price of the machine, especially if buying online. When the description says ´working´ that may just mean the wheel turns, not that it is ready to sew. This was my case. When I bought my Featherweight on ebay, it sewed 3 stitches then locked up totally. I was so upset! Luckily I was able to use the wonderful free videos on the Featherweight Shop website to diagnose and fix the problems. I recommend reading info on this site to learn what to look for before you buy. If you can try it out before you buy, that would be the best. The good news is that featherweights were designed to be maintained by the owner so they're not super complicated. Hope you find a good one - you'll love it!
(btw-smoke should not be coming out of the motor)

I would buy a FW sight unseen only at a reputable FW dealer. There are several online. They are guaranteed and work like new in excellent condition. Check out the Janome Jem. Less expensive and more features. Great choice for retreats and take along.

I hope you did not buy a featherweight with smoke coming out of anything. I know some have had the foot pedal short out. And replacing the pedal is or was around $50.00. It's been about 10 years when I had to replace mine. For a quick machine I would go with a light weight Brother, Janome, or Eversewn Sparrow. My daughter uses those fold up crates with wheels for her classroom materials she takes to and from school. Before I had my trolleys for my machines I used her crate. I fastened my little Europro in the front seat then got to where I needed to go and then set my machine on a pillow in the crate. It worked great but then Joann's had a clearance on all their trolleys and let me use a coupon too, so I had to buy it. And it's still going great all these years later. When I bought my Janome MC6600P I bought the Tutto trolley at the same time so I knew it would fit AND the dealer gave me a discount to go with it.

Estate sales are a excellent place to buy FW's. I bought a white one for $50 and a black one for $75 at estate sales. The Featherweight Shop has excellent videos on getting one working.

Janome has a machine weighs 12# I think. Called tdravelmate Gal at our PL group got one because of back issues. It's electronic with lots of bells and whistles but samaller throat space. May be worth the inestment if you take lots of classes. link...

https://vacauthority.com/product/janome-travel-mate-30/

https://vacauthority.com/product/janome-travel-mate-16/

I bought a Bernina red machine, but it still weighs 17.6 pounds. It does have a handle. Before that I had a Janome Jem Gold which I recall only weighed 13 pounds and had a Sachel to carry it in. I don't think neither of these are current models They were great for straight stitch and had zig-zag. I like the Bernina better. One thing I have done is to separate the cart and the machine. Yep, lift out the machine. Place the cart or case into the trunk, then lift the machine. Helped me. I have a Rav4 so the back was a great space to carry it in as there isn't a lip to get it over. I always take the least machine that will do for the class. My bigger machines stay home most of the time.

I like the idea of using a machine at the class. If you do need to take your own machine, here's some ideas. Keep your machine on a rolling dolly, like a luggage dolly, while in the car. Get a doggie ramp that you can set up to help you roll your machine out of the car. Better answer...get some help from one of the class members.

I have a Janome Gem that I take to classes. It's a good, reliable and lightweight machine. I did find that I had to make an adjustment when using the quarter inch foot, moving the needle position slightly. I couldn't figure out why my 1/4" seams were off, until I realized what the problem was. Otherwise, I am completely happy with it and use it when my Janome. Horizon is in the shop (just for servicing -- no problems with it).