Eyeball Engineering

[Duuuuuuuude]

Originally Posted by Robbob

You should Mother's it down

It's already too shiny as it is.

Originally Posted by eric113

Was wondering when you going to post up something.

Between my day jobs and DCW, I've been working 6-7 days a week for almost a year. I decided I'd better take some time off before I burn out.

[C*H*U*D]

Originally Posted by Duuuuuuuude

...I ordered up a 12x24x3/8" sheet of 6061...

This made me chuckle since I have a stack of exactly the same thing waiting for me when lunch is over

[Duuuuuuuude]

I'm now day 4 into my shop reorganizing project.

A few years ago it just used to be a hobby bench, the mill, and a storage cabinet/table on the north side of the garage. Then another storage cabinet/table when those got full. When the lathe came along, a 7'x36" bench in the middle of the garage. When the cnc router happened, I built another 8'x"36" bench and put it on the south side of the garage.

Wall space was always an issue on the north wall, due to a door, window, and breaker panel eating up quite a bit of footage. Wall space on the south wall was better, but occupied by some large shelves that served to store what was basically crap.

It was at the point where doing any machine work resulted in a garage wide mess, and there was lots of walking back and forth and around from one machine to the other. My rc car/parts collection was spread out almost equally as wide, and I was unsure about what parts I actually had any more. The cnc really needed it's own dedicated power circuit since 90% of the outlets in the garage were all tied together. It also needed to have air run to it. Both the power and the air were on the other side of the garage.

The plan: move all the machinery and required benches/storage to the north side to take advantage of power and air and to keep the mess contained to a smaller area, move all the rc related items to the south side, and (hopefully) leave one small bench in the middle for the bandsaw, drill press, belt sander, and vice, with some storage underneath.

No before shots, so here's the current state. All the benches, cabinets, and the mill got shuffled around on day 1. The past three days have been moving shelves and sorting through the nitty gritty. Lots got filed in the round bin. I also have a closet and a whole other set of shelves to go through. I was hoping to be back up and running by this coming weekend, but it's looking like maybe not.

[Duuuuuuuude]

lil' update. After scouring ebay for some cheap lighting, I ended up with these. 7" long led strips meant to be day time running lights. Two stuck to the top of the cnc box, two stuck onto removable plates on each side of the gantry. Still need to tidy up the wiring. Decent output and cheap.



Dustproof pc box. A single 4" biscuit fan on top forces air in, which flows through and exits out the cable routing hole in the top and another on the side. Added a light just because.



I spent the last couple of weekends wrapping up all of my remaining pre-paid orders. I won't be doing any more for a while...

[Duuuuuuuude]

11 months since my last update. Boy how time flies.

This summer I sold DCW. Too much to do, too little time to do it in, and I was just burnt out. It's hard to work full time and be in a manic rush during your off hours. The shop has been largely untouched since March, and still doesn't look a whole lot different from the pic I posted above. Up until recently my machines had just been sitting and collecting dust and rust. I did a little project for work, and dabbled very briefly in carving out mandalas via the cnc, but that was it.

But now winter is here, and I'm itching to get going again. Eyeball engineering will live again!

Minor updates and changes:

Sometime this summer I spied a larger drop in spindle and snapped it up. Nearly twice the torque and thought it would solve my stalling problem. It didn't. It's better, but it's not the cure. Good thing it was relatively cheap.



I've become a bit less anal about fixtures. I slapped this plank of wood on when I was experimenting with mandalas, and haven't yet taken it off. It's got a pilot hole punched every inch so I can anchor aluminum plate. It's not totally flat or even, but it's fairly close and it still gets the job done. Quick and easy.




A new build has just begun (first in a few years!), and there will be plenty 'o parts to be made. Super happy to be back in the saddle.

[C*H*U*D]

Woo-Hoo for winter builds!

[Duuuuuuuude]

Originally Posted by C*H*U*D

Woo-Hoo for winter builds!

And for not having to buy a bunch of shit!

[Duuuuuuuude]

Last minute Christmas gifts for the famn damily.





I'm starting to favor 1/16" endmills in this little cnc. 35ipm @ .005doc and it'll whip right along. No fuss no muss as long as it gets a shot of lube when it starts chattering.

[snapon boy]

Sweet

149 r/c worx's Team Driver

[JohnRobHolmes]

Nice! What's the radius of the tool edge?

[Duuuuuuuude]

As far as I know they're just square tipped endmills.

[Robbob]

Looks like fun little run making those, little emery cloth and some mothers and those will shine


Cut some 7075 sheets for an oval car last week on mine. Used a .125 3f bit, got some recommendations to try and set her up at .003doc @ 80ipm. It was really fun cutting something new.

Cleaning the mess up afterwards and changing back over for my normal stuff sucked though

[C*H*U*D]

Originally Posted by Duuuuuuuude

... .005doc

Originally Posted by Robbob

... .003doc

What WOC are you guys running with such shallow depths, and what's the total depth you're cutting?

[Robbob]

Originally Posted by C*H*U*D

What WOC are you guys running with such shallow depths, and what's the total depth you're cutting?

I used Robs site to figure mine out and it comes up with .013 .... dont know how to do the real math to be honest.

FSWizard - Advanced Online CNC Speed and Feed Calculator

Actually by the site my speed was high, says I should have been around 60ipm. Could explain the little bit of gummy edge on the cut out but my milling inside was spotless.

Spread some A9 on the material and used air to clear it and the chips away but was only cutting .090 thick material. Also my spindle speed was full at 24000 rpm.

I started with recommended depth from another person with similar cutting table and had no problems. 3 Oval chassis's with out any problem.

[Duuuuuuuude]

Jeep grill for my sis-in-law, the "K" is a logo for one of the rv brands we carry at work. I might see how many logos I can do, put them in the store, and see if I can't sell a few.

Originally Posted by Robbob

Looks like fun little run making those, little emery cloth and some mothers and those will shine


Cut some 7075 sheets for an oval car last week on mine. Used a .125 3f bit, got some recommendations to try and set her up at .003doc @ 80ipm. It was really fun cutting something new.

Cleaning the mess up afterwards and changing back over for my normal stuff sucked though

I've been hitting them with some 220, then various grades of scotchbrite. I don't want them super shiny, just clean.

Funny story: Had to upload the updated version of Cut2d this summer when I got a new laptop, and didn't get all of my settings right. I went to cut some scrap plate (which turned out to be of the 7075 variety) and the program was running crazy fast. My initial reaction was to shut it down, but it seemed to be doing fine so I left it. The program was trying to push 100+ ipm, but I've got mach set to 60 ipm max. Turns out my mistake was leaving the gcode at mm/sec instead of ipm.

Originally Posted by C*H*U*D

What WOC are you guys running with such shallow depths, and what's the total depth you're cutting?

Full bit width since I'm usually working straight through the material. Total depth is whatever. Sheet or plate is typically .125 or .090. I think my spindle maxes out @ 8000rpm. Using a feed/speed calculator is absolutely worthless for my machine. I just have to fiddle until I find the happy place between breaking or burning bits, and stalling the spindle.

[XSRCdesign]

I really want a CNC router.. and then I read the stuff you just posted and realize I have a lot to learn first.

[Duuuuuuuude]

Originally Posted by XSRCdesign

I really want a CNC router.. and then I read the stuff you just posted and realize I have a lot to learn first.

If a hack like me can do it, so can you. I learned it as I went.

[XSRCdesign]

Originally Posted by Duuuuuuuude

If a hack like me can do it, so can you. I learned it as I went.

That's kinda what I usually do..

[Duuuuuuuude]

A couple more for tonight. Hearts for my wife, and a Liberty grill for my service writer. I decided I'm going to make some for everyone at work, though the Ford and Dodge guys won't get any until I get some smaller endmills.

[monkeyracer]

Nice work on the emblems! Those will be nice gifts.

Feeds and speeds are somewhat of an inexact science. You can use calculators, but those really just give you a starting point to listen and watch what the cutter is doing. Also, with and without lubricant or coolant, spindle torque, etc changes those numbers as well.

For example, one of my recent projects at work was to machine some human bone into bone grafts that I designed. There's no easy number for feeds and speeds for bone.
It supposedly cuts like wood (because they are both natural, fibrous materials) but our process was to cut the bone that was submerged in a sterile water bath for cooling and material clearance. That isn't something you would want to do with wood.
Also, the special cutters that I designed weren't a normal milling machine cutter end mill or drill bit, etc. One is a dowel cutter and the other has a tapered internal dowel cut.
We had a rough starting point for feeds and speeds, but especially with the tapered cut (the beginning of the cut is the larger radius, and the end of the cut is a smaller radius - think of it like a pencil sharpener making a tapered point), there was nothing really to go off other than listening to the cutter interacting with the material while it cut, and checking for burning or other signs of excessive heat after it finished cutting.

We were able to figure out a good recipe for these cutters, but changing the diameter, or the taper, or even the difference between strong and weak bone will totally change the cut. One tool needed 8000 RPM Spindle, and 12 mm/sec (about 30 ipm), and the other tool liked 2500 RPM, with around 150 mm/sec (about 350 ipm).

Depth of cut, chip load, etc, are also things that a pro machinist will have rules of thumb for, and they are good starting points as well, but imprecise equipment will change that (like with a CNC router kit). It's best to start conservatively, and ramp up after you get more comfortable with the cuts.

One thing that is tough with the "DIY" or "Kit" CNC machines is that the spindle is usually not very well controlled, so your spindle speed can vary a lot. A good closed loop feedback controlled spindle will keep that in check, but most CNC Router setups don't have that. (A lot I have seen don't even have a variable speed control, they rely on the potentiometer based controllers).

I'm looking to get a mini mill and convert it to CNC soon. I'm set on the mill (LittleMachineShop High Torque 3990), and likely the CNC Fusion ballscrews and stepper mount Kit, but haven't decided on the electronics yet to control everything. I also need to find a CAM package that integrates with Solidworks, and has the option for 3D HSM without needing a recurring license. I've been using HSMexpress for 2.5D stuff, and when I was in school, I used MasterCAM for 3D HSM stuff. I don't mind paying for a CAM license, but would like it to be perpetual if possible.

I looked at CNC routers as well, but I figured for about the price of the CNC router, I can do the mini mill conversion, and hopefully have something more capable (other than cutting bed size). That will end up in its own thread of course.