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Tom Suddard
Tom Suddard Director of Marketing & Digital Assets
12/19/20 5:32 p.m.

In reply to Mr_Asa :

To do that, I'd make a fixture to hold the stock at an angle so the tool path is flat, even on a real CNC mill. That would make getting good results waaaaaaay easier.

And that reminds me: Solving problems like this turns out to be a large part of machining, both regular and CNC. I'm no expert but I'd say it's 40% design, 20% equipment, and 40% setup and problem solving to create what you designed with said equipment in an efficient, repeatable way. 

Tom Suddard
Tom Suddard Director of Marketing & Digital Assets
12/19/20 5:42 p.m.

I'd established that the machine was working correctly, and I'd figured out how to turn CAD drawings into real parts. Time for the real test: Metal!

I wanted to start small, so I ordered some blank aluminum keychains on Amazon. I think a box of 50 was like $15, giving me plenty of chances to screw up. Plus, I need some keychains to keep track of all the different keys in my life.

First I modeled the keychain in Fusion, then I carved a fixture for it into a block of wood, then I screwed a blank down, pressed "Send" and waited to see what would happen. 

Success! Here's my very first keychain, engraved with the bit included with the machine. It's not perfect—you can see where I tightened the screws too tight to hold it down, and where I accidentally dragged the tool across the keychain while setting the origin, but I'm happy with it for a first attempt! 

SVreX (Forum Supporter)
SVreX (Forum Supporter) MegaDork
12/19/20 6:24 p.m.

Curse you, Suddard!

The least you could have done was made an ATTEMPT to organize the group buy!!

I just finished setting up my wood shop. Now I'm gonna have to move E36 M3 around!

Mr_Asa
Mr_Asa SuperDork
12/19/20 6:38 p.m.

I'd be tempted to try hot-gluing the keychain down

Tom Suddard
Tom Suddard Director of Marketing & Digital Assets
12/19/20 7:01 p.m.

In reply to Mr_Asa :

Oh don't worry. I'm working on an over-engineered solution for keychain engraving. Should be ready in a few hours....

 

triumph7
triumph7 Reader
12/19/20 9:40 p.m.

Oh great... now it will be GRM keychains!

Mr_Asa
Mr_Asa SuperDork
12/19/20 10:05 p.m.
Mr_Asa said:

I'd be tempted to try hot-gluing the keychain down

Actually, thinking about this and the possibility of it letting go, I have another reason you should go with a tupperware box around it.

Having the billet piece come loose isn't going to be as big a problem with that as with a full sized one, but it could still cause some serious damage.

chada75
chada75 HalfDork
12/20/20 10:42 p.m.

In reply to Tom Suddard :

Didn't need to read this ....

Driven5
Driven5 UltraDork
12/21/20 12:07 a.m.

I have officially fallen down the rabbit hole. As far as I can tell, the best use for a 3018 CNC is to make the parts to build this:

https://youtu.be/89bQLGi4qjs

Which can be used to make a number of self-upgrades to become this:

https://youtu.be/21zEnGqctUc

Now if only there was a cheap and easy way to skip the intermediate steps requiring the 3018...

Honsch
Honsch New Reader
12/21/20 2:14 a.m.

Just start binge watching  NYCCNC.

John Saunders has gone from "I want to learn how to CNC" to "I own an run a successful machining business"

Also you can watch  Grimso Knives.  They've done the same thing.

TIGMOTORSPORTS
TIGMOTORSPORTS Dork
12/21/20 5:06 a.m.

One never gets too old for new Christmas toys. Thanks for sharing this.

Tom Suddard
Tom Suddard Director of Marketing & Digital Assets
12/22/20 10:16 a.m.

So, in order to really ramp up keychain production (I do have something like 25 sets of keys to keep straight), I needed a way to quickly and repeatably hold the blanks down without marring the surface. There are a few ways to do this, but I wanted to learn a new skill so I decided to build my very first fixture! What's a fixture? I'm not an expert (though Wikipedia is), but basically it means anything that holds what you're making. Making fixtures is as much of an art as the machining itself, but I'm no artist. Oh well, to the CAD!

Tom Suddard
Tom Suddard Director of Marketing & Digital Assets
12/22/20 10:25 a.m.

 In order to cut all the way through things, the bit has to go, well, all the way through. It's not good to put cuts in your machine's bed, so I ordered a spoilboard on Amazon for $25. Normally I'd have gotten a big sheet of MDF from Lowe's for the same price, but I'm trying to avoid stores as much as possible due to Covid. On the bright side, this board came with holes spaced 50mm apart, which meant it would be easy to bolt my fixture down once it was finished. By designing the fixture to work with the spoilboard, I wouldn't need to reconfigure the machine to switch between keychains and other projects. 

Why the funny hole spacing in the CAD? That's the result of me only having a piece of aluminum stock that was 54mm long. Oh well—close enough. 
 

I also needed some real endmills in order to mill aluminum, so I just ordered the Genmitsu house brand from Amazon for $29.99.

Median
Median New Reader
12/22/20 11:34 a.m.

I did not need to see this!

I was contemplating a 3d printer, but this looks like a better option. Looking forward to see how it performs.

Keith Tanner
Keith Tanner MegaDork
12/22/20 12:32 p.m.

It's a different creature from a 3D printer. There are some shapes you just can't machine :) And there are some materials you can't print with a machine in the hobbyist price range. I'd call them complimentary tools.

californiamilleghia
californiamilleghia SuperDork
12/22/20 1:21 p.m.

just asking but can you put a 3D printer head on the  CNC router ?

or a laser head ?

all three machines are using X-Y-Z axis   and a type of Gcode

cyow5
cyow5 New Reader
12/22/20 1:29 p.m.
californiamilleghia said:

just asking but can you put a 3D printer head on the  CNC router ?

or a laser head ?

all three machines are using X-Y-Z axis   and a type of Gcode

Yes, all the hardware is is a gantry plus a specific head. Change the head, and it can do any of those tasks. Note, it is far better to start with a CNC-capable gantry though since it *should* be the stiffest. A 3D printing gantry might lack the stiffness to make a router. There are subtle details though like thermal stability and all that jazz, but the gist is doable. 

RevRico
RevRico UltimaDork
12/22/20 1:33 p.m.

In reply to californiamilleghia :

There is a tool out there that does just that. Snapmaker I believe. But they're challenge car money for now

Tom Suddard
Tom Suddard Director of Marketing & Digital Assets
12/22/20 8:53 p.m.

It was time to start machining, so I put a 4mm end mill in the machine and secured the stock to the spoil board. How'd I secure it? I don't have a low-profile vise and I wanted to make the entire fixture with one machining step, so I used what the internet claimed was magic double-sided tape that would hold anything down.



 

Bit installed, tape taped, file loaded... it was time to machine! I clicked send on the laptop, aiming to take a .5mm deep, 1mm wide cut at 100mm/min. BZZZZZZZ BANG!

At this point I figured my tape was the problem, not the machine, so I drilled a giant hole straight through the middle of the aluminum and bolted it down. Elegant? No. But still cleaner than some of the shortcuts Tesla has taken over the years. I'm basically Elon Musk!

I reset everything and made a new file with the feed speed cut in half.

BZZZZZZZZZ ZZZZ ZZZZ ZZZZ

Oh my gosh, this might actually be working!! 

BANG!

Whelp... This time the machine made it a few cm or so into the project before catching the stock weirdly and jumping around. Oops.

Hey, that's why I bought cheap end mills though! Trial and error is the best teacher as long as you don't die, so I kept at it. I lowered the feed speed again, this time to 20mm/minute, and reset for a third attempt.

BANG

Did you know it's possible to bend the spindle shaft on your 3018 in just three easy steps? Neither did I, but I was suddenly looking at a pretzel spindle after the bit chattered, then  caught the stock wrong and took itself for a walk around the workpiece. Oops.

At that point I called it a night. Maybe aluminum just wasn't in the cards. Or maybe 6061 isn't the most machinable type. Either way it was time for a break. I ordered a new spindle and went to bed. 

Mr_Asa
Mr_Asa SuperDork
12/22/20 8:57 p.m.

Could also be your program, and the feeds and speeds you're trying for.

Walk us through what the machine is doing.

Tom Suddard
Tom Suddard Director of Marketing & Digital Assets
12/22/20 8:59 p.m.

The next day, though, I found an actual use for the CNC: I need to mount some AEM Wideband gauges to the 350Z's roll bar, and making a plate to do that is a perfect job for the 3018. I grabbed the spindle and bent it back somewhat straight, then taped a piece of Kydex plastic to the bed and let it rip. I'd call this a 75% success: It made a perfect part except for when the tape failed and it threw the Kydex out of the machine with three minutes of time left on the program. Oh well; I finished the second hole with a die grinder and installed it in the car. Success! 

Tom Suddard
Tom Suddard Director of Marketing & Digital Assets
12/22/20 9:04 p.m.

In reply to Mr_Asa :

I tested feeds as slow as 20mm/min with a .1mm x1mm cut, and just couldn't make it happen. No matter what, the spindle didn't have the power to keep spinning when the flexible machine let it bite off just a tad more than it was planning to.

Fortunately I did find a solution; this thread is nearly caught up to real time and I'll post it soon. 

Mr_Asa
Mr_Asa SuperDork
12/22/20 9:05 p.m.

I wonder if an upcut bit would work.  Sounds like you might have downcut bits and they're digging in

Looking forward to the solution

Keith Tanner
Keith Tanner MegaDork
12/22/20 9:15 p.m.

Machining is harder than poking holes with laser beams, this has become clear. There's a whoooole new learning curve.

How long did that gauge mount take to cut?

Tom Suddard
Tom Suddard Director of Marketing & Digital Assets
12/22/20 9:18 p.m.

After a few days of waiting the new spindle arrived... and not just any new spindle. For the amazing sum of $29.99, I'd ordered an upgraded 20,000 rpm spindle and an extra collet.

The 3018 was getting a crate motor! This bolted right in, and then I turned it on.

WOW! Before the machine sounded like a bee. Now it was so loud I need earplugs when I'm around it. The OEM spindle supposedly runs at 10,000 rpm, but the internet says that's more like 9000 in practice. So this one is about twice as fast. It's also more powerful, as the instructions warned I might not be able to drive it from my factory 5 amp power supply.  

But could the fancy new spindle cut aluminum? Let's find out! I didn't want to kill two spindles in one week, so I set a super conservative cut (1mm wide by .1mm deep) and set the feed to 60mm/min. Then I hit send and waited for the carnage.

But there wasn't any! Instead, the 3018 spent the next few hours making my fixture. Success! 

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