Sorry this thread and my posts are running on the long side.  But I am hoping to provide enough detail that someone running into similar problems could figure out how to do it themselves. 

People are asking all the time about inexpensive violins.  These problems are very possible on any inexpensive violin/fiddle, and definitely affect how playable the instrument is, as well as how good it can sound.  For some it could mean getting discouraged and giving up.  For others it could mean paying a shop or luthier possibly as much or more than the instrument cost in the first place to have it fixed.  Or it means asking some questions and getting going with some ingenuity and elbow grease and learning how to do it yourself.

But at the least, anyone thinking about the more inexpensive violins who looks through this thread will have a better idea what they may be letting themselves in for.  I happen to enjoy such work.  But I think that most folks would probably rather spend a bit more and maybe not run into such problems. 

On the bright side though, as cdennyb said it would, just fixing the bridge positioning and doing a better job than the factory did of trimming and notching the bridge has made quite an improvement.  This violin is at least 100% more comfortable to play than it was when it first came out of the box.

FM: Thanks.  I had seen a diagram of how to make a bridge jack on the net somewhere in the past couple of months.  Of course I couldn't find it again when I decided to make my own, but it was simple enough to figure out.

I haven't ever seen even a close-up pic of a bridge that was really well done by a pro.  I'm kind of figuring it out as I go along by what I can find on the topic here and there.  And especially by cdennyb's thread on how to make a back-up bridge, obviously. 

I would agree that the wood might not stand too much thinning.  I would assume that good luthiers use a very specific cut of maple and choose their blanks carefully.  This was a freebie that was most likely just a bit of unsorted scrap in the factory in China.  It is about 4mm thick at the base, and then I tapered the side towards the fingerboard starting at the top of the kidneys to as close as I could get to 1.3 mm at the top. 

Not perfect I am sure, but better than what it came with, and I'll call it good for my second ever go at trimming a bridge for a violin.  LOL

Mad_Wed: I will definitely be putting up more recordings.  But when I trimmed the bridge for my electric, it sounded ok right after it was done, but definitely even better after it had sat overnight.  from that one experience, I am guessing bridges like to settle a bit after they are trimmed.

springer:For both you and Mad_Wed (and anyone else who might think of making such a tool) here is another pic of the bridge jack taken into it's 2 main pieces so it is easy to see how it was put together.  I made it from just a little scrap wood I whittled with a paring knife and smoothed a little with sandpaper and a couple nails and a screw and a scrap of leather.  You could do it.  It isn't hard at all.

WTG springer!   These little things make getting the bridge in and out a lot easier.  When you go to use it, sort of lie it down with the top toward the fingerboard and slide it under the strings and stand it up.  If you are going to want to put the bridge back in the same exact spot, slide it right up against the bridge and then tighten the screw until the strings lift enough that you can slide the bridge's feet back towards the tailpiece and get it out.

When you are done working on the bridge, slide it back up against the jack and let the jack down so the strings are back on the bridge and you can put the jack all the way down and slide it out.  It makes it much easier than trying to do it without the jack. 

Walnut should work great.. I used pieces cut from "Square Hardwood Dowels" that I bought a bag of at a craft store a while ago.   What kind of hardwood?  Well, it don't say.  

LOL

Test recording of the MV300 after this initial trim and adjustment of the bridge.  Tuning pegs still slipping a bit, especially the D.  I strongly suspect the "ebony" paint over the rosewood pegs for the slippage.

I figure they have to be damping the sound at least somewhat, springer.   I'm not sure why6 there is one on the A, actually.  It is even w wound string, and so far as I know they don't usually cut as bad as the plain E.  But it is how they came.

It is getting better.  That blonde wood on the fingerboard when I stripped it was a surprise.  But not necessarily a bad one.  It is some sort of very hard wood, and it looks kinda cool.  I can work with it.  And it will still almost certainly sound better with that crappy paint gone.

On the other hand, the nut appears to actually be ebony, which is a nice surprise!

Ok, and the work I originally set out to do today before getting distracted by the fingerboard and neck..LOL

The nut has been cleaned up and trimmed down.  If you look back to the first pics, you can see how much it has been carved down and shaped. Tonight I will probably cut the slots and then take it down the last little bit it needs to go and then this part will be done. 

If I get that done, I will perhaps tung oil the fingerboard and neck.  Two coats should be enough, since I want to keep it close to the "bare wood" feel. 

So maybe sometime tomorrow night it will be ready to be restrung and etc, and it should play well.  I may need to trim the bridge a tiny bit lower as well, but I won't know that for sure until she's been strung and tuned for a few days. 

Once the action and tuning are good, then I can work more on fine points as cdennyb has suggested to get the sound a bit better at a time.  But the instrument has to have good action and stay in tune first.

It is going good.  Some interesting surprises along the way, but she should turn out pretty cool.  She should be back up and playing, at least by some time this weekend.

Sources vary on that a bit, springer.

The source I am mostly following is the manual the Stew-Mac company puts out for their violin-in-the-white.  It says the bottom of each string slot should be 1/64th of an inch (approx .03mm) above the fingerboard, and that the slots themselves should be about 1/3 of the diameter of the string for depth. It describes the height of the bottom of the string from the fingerboard as being about the thickness of a business card.

As someone more used to carving guitar nuts, that sounds certifiably insane to me.  But a guitar string has to clear the frets, and a guitar is played percussively in that the strings are routinely struck with a pick (not always gently).  So I am shooting for it ending up somewhere close to that 0.3 mm between the bottom of the string and the fingerboard.  Well, probably a teeny bit higher than that, more like 0.5 mm maybe.  I don't trust my craftsmanship to get it down to 0.3 without messing it up and my measuring instrument for this project is just a ruler.

My electric has a very comfortable play feel for me.  The bottom of the strings are about 1 mm up off the fingerboard.  I wanted this fiddle to end up playing about that easy or better if I can manage it.  So I'm trying taking it closer to "by the book" than my electric goes.  Kind of an experiment, since the electric has a very easy play feel to it, enough so that it almost feels like "cheating" compared to playing a guitar.

On the other hand, when I first got this acoustic violin and tuned it up, the original action was abut 3 mm on the outside strings and maybe 2 mm on the inside ones.  And it felt a bit like trying to play a cheese slicer.  The work done on the bridge helped, but it still felt a bit stiff near the nut.  Also the nut as it came stock just felt too square and blocky for my liking.

That's how this great adventure began.  LOL