Richard asks: I know you have one of the Expensive Frame Jigs, did you get a chance to try any of the others before buying it and which one is it.
I'm guessing you are referring to the Hobby Holidays chassis jig. It's a wonderful tool but, as you say, not the cheapest in the world. Whether you consider £200 a worthwhile investment depends on how many locos you intend to build.
Operation is simple, set the axles to match the crank pin holes in your connecting rods and then build the chassis on them. You'll be confident that wheel and rod centres are identical and that all the axles will end up parallel. I've built several chassis on it and every one has run straight away.
And no I didn't buy it myself, I inherited it from a late friend who would be delighted that it was still in use.
Before this, I used a jig from the other end of the price scale. London Road Models aluminium jig axles.
Now stainless steel, they are only 4 quid a set. With these you build the chassis but don't solder in the bearings. Put the axles through the bearings as though you were putting in the wheels and poke the points through the holes in the con rods. Then solder the bearings.
Again, the wheel centre to rod centres will be spot on removing a major cause of poor running. Making a square chassis is down to you but not too difficult to do as if it's too far out, you'll never get the jig axles in place.
These are the only jigs I've used and I'm happy to say that both are excellent. The axles are so cheap it's daft not to buy a set. The bigger jig, well it makes the part of loco building I hate, reasonably pleasant. I own a few expensive tools and had I not inherited mine, could well have been persuaded to part with the cash for this one.
My feeling is that if the tool helps you finish a kit loco then it's probably worth it. A half finished loco kit languishing in a drawer is expensive no matter how little you spent on it. A completed one you enjoy isn't, no matter how much money it cost to get there.