[WOTDesigns]

I have some programming I cant figure out how to get it "right".

Parts are simple letter stamps for hand held stamping and programming them is simple BUT the customer does not like the way they are coming out. The letters are 2mm tall, and I am using 30* 0.003" tip 1/8" single point engravers to machine, but I can not get a clean mesh with the flat. I have to cut off part of the angle or leave things sticking up which the customer is not happy with... either option.

The engraving good job of creating the top shape required (as long as I stay very shallow on the interior work) but how can I get it to mesh better with the flat around it?

First picture is a sample provided (different font).
Second picture is the best I can get from mastercam


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[Tony T]

It would help to post a file, so someone could see all the cut details. Maybe be able to fine tune or give suggestions on a different type of cut that would work for you.

[victorofga]

im not using mastercam..

but... with solidmodeling as mastercam works, break down letters to strokes..

like the sample on the picture, make the ""o""shape and make the little swash ... even I think o shape could be break down to another 2 shape...


extrude it downward using negative vale for extrusion angle..

then you can merge (unify) shapes and again unify with a base..

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I made for a logo, for signwork, and I used the surface edges to derivating toolpath.. it was two feet letters and 3d toolpath was too timeconsuming..

[Superman]

Your 2nd pic of the Verify session is a bit "grainy"... is this what is coming from actual machining ?
- you can tighten up the verify pic by making the tool cut accuracy smaller.... this will make verify go slower
- you may also get "cuspy" paths if splines are used, and your toolpath filter is set too large. Splines tend to give point-to-point moves ( with very few arcs ). Make the filter smaller to get a more accurate path if you do have splines.

( I'm describing it for others to understand, so forgive if it seems basic )
This operation ( the letter ) needs to be drawn as having a face "Land" , not as a single O and a tail.
This is so Mastercam can understand that it has some sort of surface area

[WOTDesigns]

The letter is an actual font "Chiller" but is not the font that the customer requested. She wanted to see if I could make it look similar to the sample which I have not been able too. Using "Engrave" the cutter moved up and down in Z to compensate for the smaller radii on the surface, but leaves a mess at the bottom edge requiring I machine it all off lower than the desired flat.

.ZIP Attached... couldn't remember how to upload without zip-ing

I wasn't concerned with the quality of the verify or cut as they are inconsequential if I can not get the part to do what the customer is asking for, but I will definitely fine tune if I can get this figured out and get the job.

The part was not solid modeled as the engraving option uses single line to engrave just as easily and I could not get Solidworks to extrude this with draft correctly anyways. I just sketched text, drew a circle and a square. I did extrude the square for stock verification, but otherwise I do not need these solid modeled and as there are 52 letters + 10 numbers (upper and lower) I am hoping to be able to copy the program, change the text, refresh... rinse repeat.

[victorofga]

wotdesign..

i believe modeling each letter will takes a lot work.. thinking on at least 25 letter..
the 2 mm height might require 0.05 mm flat end..
and that need rpm.. some spindle can spinning 50-80 K and i think those really need for this work


you might try to offset the letter as sideangle need and create surface between the two vector.. see sample i made..

you might also can try to using mastercam engraving capability, and toolpath can be reversed to derivating the bottom contur, or outline..


on other side, with a pantograph you can make without any modeling those letters..
on ebay you can get a very good pantograph mill for 3000...

before cnc those mills were used to making letterstamps..
first they milled around with a bit, with larger flat end.. and changing bit for smaller and smaller they achieved the desired result..

square bars were tapered in lathe and pantoghrap mill were used to mill those tiny letters.. with your cnc you can make the 5-10 times larger master pieces, that used for pattern..

[WOTDesigns]

The modeling side I'm not concerned with really. With mastercam I just load the font, type the letter, engrave around it using the built in TOP engraving option and get the shape. I can draw what I want, but to get the detail at the top it moves the z up to a smaller part of the engraver which leaves the bottom all different heights. Note int he verify from MC where the tail of the Q and the body meet the cut depth is significantly lower than the rest. Definitely not planning on making these full time, but the customer has several fonts and is considering making 10+ of each set = (26 upper) + (26 lower) x (10) x (several sets) is still only a few $K... not worth buying a machine for. I just want to machine the detailed ones like your CAD and the example actually look.

[victorofga]

well

I should read better you before I posted..
I came from ol world and we made very cool things with conventional machines..

while cnc very great on complicated outlines, 3d surfaces...

letterstamps, unless you make a lot same letter, cnc not really affordable for.. but who knows, customer willing to pay for..

however you might try to """roughing"" as on manual -conventional mill were made.. simply profiling around very close with same angle but larger tip ,

then using the tiny engraving bit..

im curious for the result, and if you don't mind I like to see what comes out.. the 2 mm just way too little..

imagine the tip only 0.05 or less of the bit and generally a mill steps by 0.01 mm ... so it will be very challenging..

[Darth Yoda]

Could you use a "big" ball mill to rough it to an oversized (over thick?) letter then use the taper of the engraver to get the draft angle?

I am about to try this same thing so I am very interested in you results.