What kind of lifespan is everyone getting out of the MC Etcher bits? I only got about 5 hours of glass cutting out of my 90 degree bit. I used all the recommended specs. i did do about 3 hours on mirror backing, is it possible that the silver nitrate or whatever is used now was too hard?
I used a McEtcher that has seem it’s share of abuse and it cut ok. IDK about cutting through the backing material.
I run the default C3D setting and I use the set screw in the McEtcher as the adjustment.
I start at 3/4 to 1 turn in, then adjust from there (1/4 turn max per adjustment ).
I also found that sheet mirror has a noticeable thickness tolerance. I cut 6 mirror from one package and when I started the next package, the line work was much less. It turns out there was a 0.004" difference ( about 25% of the stepdown or 0.015 per C3D).
I have had one recent experience trying to etch glass ( I have done a lot of acrylic ).
I noticed there is two “etch” cut types. I used vegetable oil for lube.
The very thin wisp of a cut that makes almost no sound. I would use that next time in for hair, fur and for a “hint” of a feature.
And the glass crunching medium cuts. This scared me at first, but then I realized that is what is easy seem from a distance.
I did not do any area fills ( cross hatching ).
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It depends on how the diamond is bonded given the quality of alot of the parts we get being aliexpress alibaba/QC’d I’m going to assume it’s nickel bonded which is much cheaper and doesn’t last nearly as long as say diamond impregnated steel BUT should keep the quality technically better till failure albeit 1/10th the lifespan.
Edit: a further googling shows that this is a terrible tool for mirror backings When nickel comes into contact with a silver nitrate solution, a spontaneous reaction occurs where nickel oxidizes, and silver ions are reduced, resulting in the formation of silver metal and nickel nitrate
Your tip basically disintegrates and the diamonds have the choice to jump ship into your mirror surface or embed into the steel which is highly unlikely
Edit 2: “MC Etcher drags a diamond-coated” more than likely to be nickel electroplating, seems irresponsible to be resin given its a drag tool, unlikely to be sintered, braised or vitrified due to cost and ceramics,sintered powders and impacts dont mix. Where as nickel is more dummy proof which goes with the concept of the Shapeoko lineup
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i got a replacement bit and so far only using it on glass and the front of mirrors has shown much better results. in the future if i do and reverse side etching, ill go into it knowing the bit will be sacrificed. its unfortunate because it looks really cool. thanks fellas!
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Good to know it is nickel bonded. Will keep that in mind for future helping.
UPDATE: 2 hours of glass and i think i broke the tip again on the 90…
Wow !! Here is my check list.
Are you using the default CC settings for a McEtcher ? DOC and Feed rate ?
I assume you are using the Top of stock for Z 0 .
How many turns down is the set screw in the McEtcher ?
Is the glass crunching big time ? Did you use any lubricant ?
I use a lubricant, WD 40, 3 in 1. What ever I had available. I was pleased with the life of mine.
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i followed all of the recommendations from C3d, but i didn’t use any lubricant because they don’t mention anything about it on the page with the bit information or the “drag engrave everything” youtube video. i try to stick to what the manufacturer recommends… but at this point i’m 2 bits down, could it just be bad luck? poor diamond quality? maybe you guys are right with the lube.
not the quality of the diamonds its the bond type. The nickel bonding is the cheapest by far method of diamond bonding. The diamonds never embed into the substrate and exit stage left when pressure is applied in the wrong orientation.