home made epoxy granite cnc - part 10 - mist cooling
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- Опубліковано 11 січ 2020
- Nothing really new, but a short fun project.
To be honest I don't see any difference, but hopefully my tools will last longer ... (not that it's been a problem so far).
A little more details on this build in written form you'll find here: dangeroustools.com/category/cnc/
Part 1: • home made epoxy granit...
Part 2: • home made epoxy granit...
Part 3: • home made epoxy granit...
Part 4: • home made epoxy granit...
Part 5: • home made epoxy granit...
Part 6: • home made epoxy granit...
Part 7: • home made epoxy granit...
Part 8: • home made epoxy granit...
Part 9: • home made epoxy granit... - Наука та технологія
I am so grateful that you created and shared this project with us !! I have learned so much that will help me be able to realize my goals of being a maker and creating!! Danke!!!
Thanks for your words.
Filming and sharing it kept me motivated going on and finish this project one day. And comments like yours are the proof that it's worth every second!
Dude. Reversing the drill to the vise. Mind blown. I need to get out more.
Dang dude you’ve got some dope choice in music.
Agreed! One of the few times I don't mute or lower the volume.
Dude I like your music style man
Very nice piece of artwork.
Congratulations.
Do you intend to mill ferrous metals like iron and steel?
I tried with steel. It'll only work for smaller parts. Can't really use big endmills with that spindle. 4mm is the max I guess. Did some tests so far with a 3mm 2flute. It's a whole different story then aluminum ...
@@joergbeigang you mean only by the spindle or the structure stiffness? I intend to build one, still in project part, but the target is to mill iron/steel.
One more point. What do you say about epoxy granite? Here in Brazil there's no much information about. Does it bring stiffness to the structure as cast iron? I want stiffness to achieve centesimal tolerances.
It's both. The limit of the spindle is reached as bit earlier. Just doesn't have enough torque in lower rpm.
And in the structure the weak point is the z assembly made of aluminum, and the weak t-slot table. One day I'll change both ...
If I'd aim for milling steel I went for a big enough servo with a sk30 spindle. And everything should be a bit more solid then on my machine. My machine is all together about 100 to 125 kg. You should aim more for 250 to 400 kg.
About epoxy granite aren't many informations around. Only some advertisements of companies using it and a few diy solutions.
It's difficult for me to compare. I'm not having a cast iron one here next to the epoxy granite.
My guess is, that if you compare it to cast iron by weight, it's got very good properties.
By volume of course cast iron is by far better due to it's higher mass.
But this is just my feeling. Maybe I'm wrong here. Anyway, casting iron isn't really something easy to do in the garage.
I'd be more interested in the comparison of epoxy granite with concrete. Because concrete is an other interesting option
@@joergbeigang I truely like your videos, I figured you wouldn't be able to mill ferrous metals. I used to work in cultured marble and granit. I would suggest using just powders, no big materials. Inside I would reinforce with rebar like you would with composite concrete. Another thing that stands out, I don't think I seen you vibrate the filler. We used to mix 3 part systems, powder filler, resin for calculated 2 hrs. Then we added the catalyst, and laid the filler by hand. It should have a putty feel to it. Almost between slime and play dough. We spread it on glass tables smeared with petroleum jelly, and sprayed with a clear coat. At the end of the day, the regidity comes down to how you reinforce the composite itself.
@@chronicblazer84
Unfortunately you are quite wrong on most points, there are some very common misconceptions.
They often steem from the very natural approach to transfer knowledge from other applications. That often works but it leads you down all the wrong roads in this case.
First, you want as big material as your casting size allows and a graded selection like a Fuller grading curve. You want the highest density packing possible with as much large particles possible. That way you reach the highest possible elastic modulus wich is basically everything that counts. Stiffness ist the be all end all here.
Tensile strength etc. pp. is completely irrelevant.
Second, rebar or similar is nearly completely useless in this specific application. Rebar has it's strength in high stress situations or when the concrete already starts to develop failures on the tension side etc.
That's a point you'll never reach with a properly designed machine bed etc.
It increases tensile strength and such but doesn't do that much to improve the modulus. Except if you pre tension your parts which is a bit out of the scope of a homemade machine. And futile - just use sufficient dimensions instead.
An outer hull in Form of a weldment, now that's a completely different thing and works well. That's why it's common practice in the industry alongside non reinforced mineral casting structures.
But you can just as well pick your dimensions accordingly, mineral casting is rather light with ~2,2-2,4g/cm³ after all.
The third point, your application is/was like day and night to this specific application. Completely different requirements and completely different properties are important. But you're right, vibrating the mold in a manner that achieves a kind of liquefaction of the rather dry mix with as little epoxy as possible is indeed the gold standard. Every professional casting business does it on huge vibration tables.
And the last, mineral casting don't need reinforcement.
These are very well established things, you can see how it's done best if you take a look at those who manufacture high end high precision machine tools or other million dollar machine beds etc. They're well thought out, work excellent and avoid unnecessary complication.
But I understand the urge to stuff something in there to reinforce it all too well. It's kind of counter intuitive at first but becomes clearer the more you know.
Before cutting screws or threaded rods, put a nut on it, perform a cut, chamfer the end and unscrew the nut, it will reform the thread!
If you stroke the file in the right direction (away from the screw) while chamfering, there's no need for the nut. It just works out of the box. Very useful technique, especially if you're cutting long pieces of threads. Then you don't need to spin the nut all the way up to the end...
What is the brownish liquid you are spraying?
It's a cutting oil for mist cooling: www.mehring.ch/rixol-8000-kuehlmittel.html
@Ole have hou heard of phrasing? 😃
Do you prefer mist to flood?
Can't really tell. Got no experience with flood. I'm using mist because it's easier to realize. And I don't need to deal with disposing the coolant when it's getting old.
Greetings,
I was actually going to ask something similar, based on what you are milling (steel?), you would need coolant and mist would suffice.
I was going to ask how you collect/recycle your coolant.
With your enclosure, epoxy bedding, coolant instead of mist shouldn't be an issue, and with the rigidity you proved in your videos why not milling steel as well?
After 2 years using your cnc mill, you might have come to same conclusion if not I am curious why not 😉
I am looking forward to see a #12 to the serie with a receptacle for coolant under your cnc that filters, recycle and pump back the coolant.
Thanks for your videos!
Use for finish 3 flute mill cutter , best finishing .
They make roughing and finishing mills. They make special mills just for aluminum that have different spirals and cutting edge geometry. The only thing an extra flute does, is add how fast you can run your feed speeds. 4 flute being better, because finishing is a shallow cut of depth with a relatively high RPM and slower feed speeds. This means you can finish faster with more flutes.
@@chronicblazer84 for u 4 flute u need a low spindle , and that they make 4 or 5 or 6 or even more flute , to make chips small , and to engage all time in stock , but if u use a high rpm spindle , like all use , 24000 rpm , even single quality flute make nice finish , 2 flute i see doesn make better finish , 3 flute make best finish , 4 flute clogs all time , because at high rpm they can't evacuate chip so fast , and they gum the aluminum fast .
@@CeNuVezi lol, speed up your feed... Do you know how to calculate feed speeds?
@@CeNuVezi this is straight out of my machinist handbook, which is in metric. Non hardened aluminum composite is normally 200m/min assuming that you're using an 8mm carbide endmill you should have a max speed of 240m/min which equates to 9554 RPM.
n=240m/min*1000 ÷ 3.14*8mm
@@CeNuVezi
Vf= feed
n=spindel RPM
fz=speed per flute (a standard is given from the manufacture)
z=number of flutes
Vf=n*fz*z
9554 RPM*0.016mm*4=611.5mm/min feed.
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