2021 POTD Thread Archive

According to Starrett their edge finders are accurate to within .0002" and repeatable when used in a collet. It's hard to justify spending $500.00 for an instrument that is only accurate to .0004". In both cases I think it's overkill for anything but a jig bore machine or surface grinder. I doubt my Bridgeport or any other machine in the shop other than the surface grinder is capable of holding tolerances tighter than a $25.00 Starrett edge finder would show.

I always run mine at about 500 rpm and touch off at least twice to verify a true edge. If the edge is free of burrs and contaminants all attempts are within .0002" on the DRO.
 
I made a knurled handle for my grinder. I had to use a die for the threads because I didn't have enough shoulder room on the lathe. I thought if I slightly undersized the diameter, it would tap easier. I underestimated my cheap die set. I did finally get it to start but it's not 100% square.

This was my first try on my Leblond lathe. I probably should have tried to go a little deeper but it provides plenty of grip as is.

I mainly used the cheap set for cleaning threads. I think this is the first time I actually used it to make threads. It's hard for me to spend the money for a good set since I very rarely use them.
 

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I got my valve installed yesterday. It was warmish all day, then turned freezing cold when I got out of work. I put the lines on the new valve in the same physical position as they were on the old valve. Both valves are loader valves with float. It turns out that the new one is plummed opposite of the old one. Once again, a perfect example of what happens when you ass-u-me something.

The loader worked opposite, down was up with float back down, up was down, and bucket tilt was backwards too. The hoses only swivel on the piston end so everything had to come off again, but it gave me an opportunity to route the hoses better. Today went much better. I blame the weather.

Oh, and go Red Power!

The old.
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The new.
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I modeled the loader after the original International basic design. The bucket extension comes off for digging.
 
I think the main value in the Haimer is you don't have to do any math or remember to subtract the edge finder width. I have screwed up enough pieces this way to justify the expense (maybe...) . I am unclear as to why there would be a metric and imperial version? Don't you move the work until it reads zero anyway?
Robert
 
Nice job on the valve install. Most of the C's and CA's around here were used for cultivating. I forgot my cousin had a CA. I was on it plowing tobacco for him and went up a hill to turn out on the road. Cousin forgot to tell me the pin or bolt on the steering knuckle was missing and shaft slid off. By the time I got stopped, I was facing back down the hill and took forever to find the half moon key.
 
tjb said:
Bruce,

What's a 'passive probe'?
Click to expand...
I'll shoot a picture tomorrow, but it's essentially a switch that's triggered in X, Y and Z. It mounts in the spindle and has a probe tip like a Haimer 3d taster. Mine has a 1/8" ball on the end.

Tormach's PathPilot software has routines for the probe for finding an edge, corner, surface, center of a pocket and center of a boss that all automatically control machine movement. PP also has probing routines for the 4th axis like finding the center of a round.

It makes edge finding really simple. If I want to zero X and Y on the LH corner of a vise, I position the probe tip about 1/4" off the corner and hit the Find Corner button. PP moves the table in X at 25 ipm until the probe trips, backs off and repeats at I think 2 ipm, then zeros the X axis. Then repeats the process for the Y axis. Lots quicker than manually moving the table, watching for an edge finder to kick, then setting the axis to the radius of the edge finder.

For Z, just position the probe over the work and hit Set Z. The spindle moves down at 25(?) ipm until the probe trips, backs off, repeats at 2 ipm and zeros Z.

On Cnczone, someone posted that they had asked Tormach about the differences between their active and passive probes. The major difference was the >$1000 active probe has switch contacts in non-conductive oil that don't need to be cleaned. The passive probe works the same, but has switches in grease. They say the accuracy is the same between the two.

Bruce
 
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