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A useful tip...roll dimensions, checking angles

Roll dimensions. People call it different things, but it's a way of checking angles on a sine plate for location.

(DESCRIPTION) The way of checking a part by putting a pin of known diameter (gage, dowel, core, drill rod, an endmill, whatever...) in the corner of a sine plate against the back rail. Get a zero number over the pin. Now remove the pin and replace it with your part, raise up the "over roll you got from your computer or from an easy formula", that's your location. (THAT WAS FOR THOSE WHO DONT DO ACCURATE ANGLES)

Ok...I say forget the dowel pin, or gage pin, whatever. It's not needed. The sine plate already has a roll, the roll it rotates on.

If you add (1) the thickness of the bottom plate of your sine plate,(2) the distance from the top of the roll it rotates on to the floor of the sine plate where the part sits on, (3) and the distance from the back rail to the top of the roll with the sine plate standing on end. Add those three things to your cad gimmic, or your simple roll dimension program, or your xcell roll program and you will make your life a lot easier.

Now...you will be checking from the surface plate to the angle face(simple). No pin needed. No need to see where the pin is, than add the formula number to it, blah, blah, blah. My way you zero your drop indicator on the surface plate (use gage blocks to stay in drop indicator length range), touch off on the angle, and read the number on the indicator. Cut and dry. More accurate, a hell of a lot simpler, and a lot faster, and less prone to mistake

As a programmer I'd like to provide that number, plus a number identifying the sine plate that number is for.

If you do angles a lot, it will make your job easier. If you don't you just wasted a minute of your life.

lol

Reply to
vinny
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Good info, moldmakers are "angle heads" I'm sure you have the dowel pin screwed/brazed to flat plate- shop made checker? FYI(non-moldmakers)most all mold cavities/cores don't have a freekn straight surface!, for part release/ shutt-off ect.

1/2,1,1.5,2,3,5,7,10 deg are common taper mills- DONT USE 3.5deg for example - if possible. On complex / big - tools I use a precession 1/2"tooling ball. It looks like a tonka trailer hitch ball By pre deturmining a location before hand on the CAD,& installing a .2500 hole off in some obscure location, ANYTHING can be accutrately checked - on the angle- direct reading. Very handy on the CNC when finishing S.O.'s on a sine plate. We had a big one for the mill(shop made) It would hold 2 Kurts. Well worth having in the mold shop, for those big ass slides ect.

Another trick I have been shown, when fitting tapered S.O.'s on a sine plate. Usually in a sqr. block with tapered fingers/ect sticking out the front. Telescoping Shut-offs. This works for a blocks with a flat face somwhere on the PL. On the sine plate: put one block ,of the cav/core set, on with the back of the block against the rail, get a reading on the taper surface, get gauge blocks (2 sets)to make up the diff to the PL, slide its mate against the jo-blocks, get a reading, now on the underside. Anyone else ever do this?

Reply to
cncmillgil

Good info, moldmakers are "angle heads" I'm sure you have the dowel pin screwed/brazed to flat plate- shop made checker? FYI(non-moldmakers)most all mold cavities/cores don't have a freekn straight surface!, for part release/ shutt-off ect.

1/2,1,1.5,2,3,5,7,10 deg are common taper mills- DONT USE 3.5deg for example - if possible. On complex / big - tools I use a precession 1/2"tooling ball. It looks like a tonka trailer hitch ball By pre deturmining a location before hand on the CAD,& installing a .2500 hole off in some obscure location, ANYTHING can be accutrately checked - on the angle- direct reading. Very handy on the CNC when finishing S.O.'s on a sine plate. We had a big one for the mill(shop made) It would hold 2 Kurts. Well worth having in the mold shop, for those big ass slides ect.

Another trick I have been shown, when fitting tapered S.O.'s on a sine plate. Usually in a sqr. block with tapered fingers/ect sticking out the front. Telescoping Shut-offs. This works for a blocks with a flat face somwhere on the PL. On the sine plate: put one block ,of the cav/core set, on with the back of the block against the rail, get a reading on the taper surface, get gauge blocks (2 sets)to make up the diff to the PL, slide its mate against the jo-blocks, get a reading, now on the underside. Anyone else ever do this?

********** Pretty common a few years ago, transferring shutoffs. Now everyone makes everything to print. It's our downfall in my opinion, a product of iso. Interchangability is nice and all, but it costs money. And making everything like that, no matter if there's only one or 100 is insane.
Reply to
vinny

Real fun is accurately measuring an inside corner where say three free form shaped surfaces intersect. Or even something simple like the intersection of two straight walls each with a different draft taper and a floor on an angle and for the heck of it throw in a small fillet blend around the three.

You do keep a set of ball bearings just for such tasks in your tool box, don't you? I do, but I've gotten lazy over the years and take such stuff to Metrology to be checked with the CNC CMM. :)

Reply to
Black Dragon

I thought is was a slick trick? for the pain in the ass lots-o-little blade S.O.'s? Beats the shit outa any other way to final fit? Where they are they are! Fit'em Dano +-.0000! There S.O's! The mean nothing to the part. As long as they dont flash / break(from improper fit) ect.

ISO is.... well another discussion. But interchangablity on mold entire cavity/core or inserts , thats what I'm talk'in about. Again FYI for non-moldmakers: Alot of low volume parts that have different features are usually interchangable. Swap out the inserts & the mold makes a diff. version. These HAVE to be right. ISO or no ISO. Because the interchangeable inserts mate with the same master.

I built bakery pallet molds for many years. The outer cav/core inserts were swaped out for different size pallets, the only common piece was the center area. Some of my favorites I did: the 2 level Dolly Maddison cake basket (usually blue & some big brown ones) The Mickey D's big brown bun pallets (mine had the "D" shaped handle sidways) Those SOB's have to re-stack empty in the truck +-1/16 in 8feet? Wonder who does that work nowdays? Freekin China? Ah yes bakery pallets, 16 & 24qt milk cases, the good ol days.........

Reply to
cncmillgil

Fuck! I left my ball bearing down inside the cavity one time, man did the endmill have fun with that!

Reply to
cncmillgil

I call utter nonsense on that, man. "Machining to the numbers" in mold making saves an extraordinary amount of time.

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That's my work. When those mold half's were closed and the stack up checked it was .003-.004" proud without any handwork or fitting. After just an hour of hitting some high spots on the partings (mainly lines from CAM system occasionally skipping passes) they closed up to within less than .001". That's plenty good enough for the girls we go with.

"Transferring" shut offs on stuff like like that is immensely time consuming. I've seen it in the past. Tools like that would take *days* to close up and if you were lucky they wouldn't flash.

Making shit "to the numbers" is the only way to fly.

Reply to
Black Dragon

Did you know that Fadal machines don't warn you the spindle isn't turning after pressing cycle start after stopping the machine to change carbide inserts in a roughing tool?

Oh silly me, they do give warnings. Audible ones, the sound of the new inserts shattering.

Reply to
Black Dragon

Screw that. I could always find a lazy cheater way to measure compund angles vs 3d rolls. Maybe i'm lazy? lol

Reply to
vinny

Never heard of it referred to as 3D rolls.

Just touch off and machine to the numbers. Fuck measurements.

Reply to
Black Dragon

Exactly. But seriously, most of the time you can cheat and get real close. Maybe measure an edge of a face. Get that .015 indicator ball on the centerline of the edge. If it's good and your comps are at zero or close...whahooooooooooooooo!!! lol

Reply to
vinny

BD & Vinny:

Well here's a possible compromise between measuring compound angles with balls, pins, etc. and moving the mold to the CMM department.

In the October Online issue of Moldmaking Technology;

"3-D Laser Scanning Opens the Door to Inspection And Reverse Engineering for Moldmakers". Some excerpts from the article follow.

==============================================================

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3-D Scanning:

Using 3-D scanning technologies?such as a laser scanner mounted on a portable measuring arm?can significantly improve the efficiency of a moldmaking operation. The articulated arm moves similarly to a human arm, with ergonomic Zero-G counterbalance for one-handed operation from any position in the arm?s reach, above and below the midline. The scanner is used by moving it over, but not touching, various angles of a mold or part. Thousands of surface points are gathered in just seconds. The points, in the form of a 3-D point cloud, appear on the computer screen as you scan, and the software allows you to see the areas where you have and have not scanned.

This type of non-contact scanning system enables a very detailed examination of both geometric and surface features for any inspection or measurement task you can imagine. The arm-scanner configuration also allows for point data capture with contact probes when needed. Portability around the shop floor is a major benefit, and the scanning arm is available in measuring volumes ranging from 8 to 12 feet. ==============================================================

From the picture at the site, the laser scanner looks small enough to clamp to a mill for use without removing the mold. That alone seems like it would be a significant time saver.

Reply to
BottleBob

You are exactly right, cut-it to the numbers. 99% of the time its climb cut on CNC's, with cutter deflection it leaves stock. How much? well thats where all the variables come in. In good conditions, its just as BD said, a few thou & yer down.

Ah, drop fitting PL's.....BOOM! hehehe wakes everybody up in the whole plant, shit I think the next door neighbors felt it too, on some of the bigger molds, 6k+ Reminds me of the a guy I worked with, we called him "chopper" Man could that guy make noise. weather it be milling, grinding or fitting. chop chop chop. Till one day he forgot his vernier in the PL. opps!

Reply to
cncmillgil

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