Hello everyone. I was wondering if anyone has this or a similar machine and could help me. I have a janome mc3000. It was a gift but out of time/etc. I got the timing working from watching videos but i have a feed dog problem. When i got the machine there was a loose screw (maybe called a set screw) without a head, just one size from top to bottom kind of like what you have to loosen to fix the timing on either the shuttle or needle bar but this one i think had a flat head screw slot instead of a metric Allen wrench type. I dont think that matters but just encase someone is looking at their machine.
I lost it before i could figure out where it went and have not played w/ the machine until recently.

So i think that screw should have gone in a hole that is all the way through the shaft in the bottom that turns when the machine rotates/sews. There is a plastic piece that is on the shaft and has a spring behind it and the plastic piece looks like it would slide over the screw bc there is an indention in the plastic where the screw would be raised out of the shaft. The plastic piece looks like it guides the feed dogs into a position that is raised a bit and my guess is if that screw was there, it would hold the plastic piece in one spot and therefore hold the feed dogs in a position. The feed dogs are not working properly. They do not rise, go backwards, and then fall to push the fabric.

when i press the plastic against the spring and hold it just where the screw would keep it, and rotate the machine, the feed dogs work properly. So all those things make me assume that screw went there.
Now I dont really have a clear memory of the screw but i dont think it would have been long enough to come out the other side of the shaft. (shaft has a hole all the way through but the plastic part only has one indention.

Could someone look at their machine and see if i have the right idea please? I see that the hardware shop has a few screws that look like the right size so i may be able to just pick one up.
I emailed janome and they told me to go to a repair person. That is not an option for me right now so its either I figure it out or the machine goes back in storage.Thanks for any help that can be offered.
Ive enjoyed checking out the different threads here and hope to be able to contribute in some way in the future. Have a great day!