Fret Rockers

[rgand]

Trying to check the frets on two necks. I kept getting different readings so I checked my two fret rockers against each other. Neither one is true on all sides. One is German made and the other is just stamp cut, probably Chinese or Taiwanese. The German one seems to be machined with a crown in the middle of at least one side. The other one gives inconsistent readings, depending on where you place it on the frets. Crap.

It looks like I'm going to have to do some truing up on the faces of at least one so I'll probably do both. Boy quality control sure is piss poor these days. There was a time when you could buy fine US- or German-made tools. I think those days are buried in the pages of history.

 

[Cagey]

Well, that sucks. That's like buying a ruler where the inch markers are all spaced at 15/16", or a clock/watch that gains/loses time. What good are they?

 

[Fat Pete]

No good at all, yet depressingly common these days it seems. I have a fret rocker that's the same - at least one side is definitely not flat. I'd had it for ages without thinking to check it before it's first use, so too late to return, even if I could find/remember where it came from.

Bought a carpenter's square recently that wasn't square. About as much use as a chocolate teapot.

 

[rgand]

You know, I worked with a guy who couldn't build anything closer than to the nearest inch so his machinery was always screwy and needed additional effort to get it to work with any other machines. He was dynamite with a push broom, though. :laughing7:

Bummer about squares that aren't. I have 6 or 8 carpenter's squares and all of them are absolutely square. Of course I bought the newest one about 20 years ago. Several were my father's.

I consider those fret rockers are really just fret rocker kits. I'll get on them with a square diamond stone I bought for gunsmithing. It has 3 nice straight sides on it. One is a bit concaved from use. I figure I can use it with the same motion you use with a leveling block on frets. We'll see how that works.

 

[rgand]

I worked for an hour and a half to get a usable fret rocker. The 'made in wherever' one was a waste of time. Not only were three sides crowned and one dished, the stamping left really irregular edges. On top of that, the thing was not even flat so two of the measuring surfaces were curved. That one's landfill, not worth the effort to flatten it and then work out the goobers.

The German made one was salvageable. The edges had mill marks in them, like they used a dull bit and it chattered. In the end, I got it true. In the photo you can see the last bit of some mill marks before I got them completely out. I kept with it until the whole thing was straight on all four edges.

 

[Cagey]

I, for one, would like to know the sources of the rockers, and don't think it would be improper to name them. I understand a sample of 1 is hardly representative, but facts are facts, after all. If somebody it using a manufacturing process (such as stamping) that's inherently imprecise, a sample of 1 is plenty.

 

[TonyFlyingSquirrel]

Stamped makes no engineering sense at all when precision is the goal.

Machined is ideal, taking into consideration that the base platform that the workpiece is mounted to is machine leveled.

When Warmoth got some new CNC's back when I was there a decade ago, leveling the platform was the first priority of calibration.

 

[rgand]

I, for one, would like to know the sources of the rockers, and don't think it would be improper to name them. I understand a sample of 1 is hardly representative, but facts are facts, after all. If somebody it using a manufacturing process (such as stamping) that's inherently imprecise, a sample of 1 is plenty.

OK, the one I said was German made was actually from Portugal, the brand is Fratermusic. I found it on ebay. My mistake there. It was advertised as laser cut but I would think a laser cut would be more accurate than this was. Maybe laser cutting isn't accurate enough for this application. It was close enough that I could straighten it out with a little hand work.

Stamped makes no engineering sense at all when precision is the goal.

Machined is ideal, taking into consideration that the base platform that the workpiece is mounted to is machine leveled.

When Warmoth got some new CNC's back when I was there a decade ago, leveling the platform was the first priority of calibration.

Yes, machined is definitely the way to make these types of things. The stamped one was unbranded, from China, also found on ebay. I could find the seller if that matters but I think it's safe to not get any critical measuring tools unbranded from China. Had I known this would be made by stamping, I'd not have bought it in the first place.

 

[Cagey]

Well, I guess now I'm a little happier about spending what I did for the rocker I got from StewMac. They're $28 today, I don't remember what I paid, but I remember it felt usurious at the time. However, they come right out and say they're "Precision-machined for accuracy to .0015" per foot". I just checked mine against a straightedge that's supposed to be within .0005"/foot, and they lined right up.

 

[rgand]

You got your money's worth with StewMac. Look at what I had to do to make one work and if you include my time, mine is more expensive than $28. Maybe I can use the Chinese one for throwing. It does have one nice, sharp corner...

 

[Cagey]

I'm glad you took the time to check yours. It never occurred to me that one of those things could be off, and I'm surprised at how bad you found yours to be. I'm also surprised that anybody would sell something purported to be a measuring device that's so far off. Maybe I'm overthinking it, but it just seems to me that if you're of a mind to check things that closely, your tools shouldn't lie to you. Leave it to me to decide whether something is critical or not.

 

[rgand]

I got to checking mine because I couldn't get consistent indications. When you get something different each time you check the same fret, it doesn't take long to figure something isn't right. As long as I was at it, I checked both of them.

You're right, tools shouldn't lie to you. You can't do good work with bad tools. You can, however, do bad work with good tools.  :laughing7: