measuring and correcting nonsquare frog?

Do you have a dial indicator?

Scott Burr in Ben Lomond CA

>If so you can jig it up to do some measuring of the base and the frog to see what's out where.

Also molding clay (silly putty work well) sandwiched between the two could possibly show what's out and where.

Interesting post a ways down about using valve lapping compound to correct the variants between the two.

Good luck! I for one am interested in hearing how it turns out.

Re: measuring and correcting nonsquare frog?

Jim in Burlington Ontario

>There's a great article in the last FWW on how to get a frog to seat properly by David Charlesworth.

2 other reasons/fixes for your problem

WoodburnBob

>I have no Records but more than once I've had the same problem with Bailey's. It's more often caused by either:

1) Take a look at the detachable little piece of metal at the back bottom of the frog which fits into the slotted screw which you turn to advance and retract the frog to open or close the mouth. That piece of metal can bind in the slot of the srcrew and prevent lining up the frog before you screw it down tight. For the early Baileys without frog advance-retraction tabs/screws there is never difficulty solving the blade problem you are having; you just line things up before you cinch down the frog. If they drilled and tapped the hole for the frog advance screw anything off perpendicular to the mouth AND the metal tab/slot fit is tight or finds, then there is no wiggle to align the front of the frog left and right.

More then once I've taken the metal tab and flattened it some with a file (creating room for a little wiggle to make up for shoddy drilling/tapping of the screw hole) and solved the problem you are having.

2) More than once I've hand the problem you describe at least in part be caused by a cap iron/chipbreaker problem. If the threated hole in the chipbreaker is not in the center line (or the square slot in the chipbreaker is off) this can translate into goofy blade edge-mouth alignment.

Re: thanks...

paul womack

>for the tips, guys. I'll investigate over the weekend, and report back.

BugBear

Re: results

paul womack

>OK. I now know what the problem is.

I removed the lever cap and blade, and scribled on the frog with magic marker - I don't have "real" layout fluid.

I then set the plane (wiped) on my surface plate, and used a surface gauge to scribe a line across the frog. This line is (obviously?) horizontal, and thus parallel to the plane's sole.

I then removed the frog and checked the scribed line against a small square held on the side of the frog. Oops. The line is at an angle, around 2.25mm out over the width of the frog.

But I guess I knew that from the behaviour of the blade ;-(

I then remove the frog, and used the surface gauge to check the heights of the 2 rear frog support points, and the front frog (lower) support surface.

Uh-oh.

The left support point is around 1mm lower than the right. There is a similar, but smaller error on the front surface.

Given that all these surfaces show clear spot milling marks, I'm assuming there was a piece of swarf (or similar) under the plane casting then Record milled the seats.

I could hand file the rear/upper supports (regularly cross checking using the surface plate and gauge), but I see no way to work the front/lower support with hand tools.

I'm off to find a friend with a small milling machine, unless someone can suggest a handtool alternative.

BugBear (who presumes Todd thinks I'm mad putting this much effort into a 12 GPB plane)