Newbie looking at 6040 (China CNC) for polypropylene 15mm sheet

I bought one of those cheap misters off eBay for like £7. Not installed it yet as I need to tap a hole for it.
Not looked into what coolant to get for it yet though.

I see what you mean about the down cut now. Like on that wood I tested on, would have been better having a down cut as it does not pull the fibres up.


https://www.shop-apt.co.uk/economy-3...-diameter.html
Probably best bet in terms of roughing end mills to get delivered this week?

Yeah exactly, gives a very sharp clean top edge on plastics like acetal etc too. Just something else to consider playing with :)

Shop apt are very good, I've used them plenty in the past.

Can't for the life of me work out what this is called.

Fusion wants to helical down all the way through this 15mm and then circle around.
https://s15.postimg.cc/69lxy1wh7/Capture.jpg

Rather it go down 1-2mm to cut then step down.

If not, is this the correct way to do deep stuff?



Also, new bit arrived to day.
https://s30.postimg.cc/d4n7fy7bl/IM...503867_HDR.jpg
Not bad? Ignore the stuff to the left of it :p

Which bits are those?

Side finish is a bit poor, looks like a lot of chatter. Chips are also a bit small and fluffy suggesting too slow a feed rate. What bits and what feeds/speeds?

This is the sort of wall finish you should be able to get out of this machine with a bit of practise

http://i.imgur.com/XAAhxhX.jpg


You can set max depth under multiple passes in fusion, even on the adaptive stuff.

https://www.amazon.co.uk/gp/product/...?ie=UTF8&psc=1

Think your right about feed rate. Upped it to 0.01 per tooth.
Was on 0.004

Quote:

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Originally Posted by Zeeflyboy

You can set max depth under multiple passes in fusion, even on the adaptive stuff.

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That's it. Found it now.


[edit]
Still got chatter.

[edit2]
Upped my feed rate in Mach3 to 200%. Improved a bit.
Here are the F&S that I am going to try now.
https://s2.postimg.cc/9w70itue1/Capture.png
Previously it was 0.01 per tooth.

that's quite long for a 1/8 bit... you'll need to be fairly gentle with DoC to avoid bending the tool. Insert the tool so that you have minimum necessary exposed shank to help minimise flex.

Then try something more like 18k rpm, feed down to 600ish and I wouldn't go much beyond 0.5-1mm DoC at first with a tool that long/thin. You could try a bit deeper with adaptive type strategies (although perhaps limit the step over it allows to reduce loading on the tool.

Let it rip at full speed.
https://s2.postimg.cc/6qozkh0uh/IMG...703110_HDR.jpg

Had it weld towards the end causing a few problems. Air pressure was low because it has gone 9PM.
Doesn't look like it stuck to the bit that much. I was able to pick it off with my nail.



Ill try it now at 0.5mm DoC at those rates.
Was at 1mm (went off the rule of it being half the width?).

Looks a bit better, see my edit just above your last post for some further thoughts.

Saw it and will be testing it out tomorrow!


Also, just found a 2 flute 6mm...
Must have come with the machine xD

Might give that ago tomorrow too..


Mobile footage of the last cut.
https://youtu.be/P_gak9nr59A

looks pretty good in the video

I found the cutters that came with the machine fairly crap btw

Quote:

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Originally Posted by Zeeflyboy

looks pretty good in the video

I found the cutters that came with the machine fairly crap btw

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Thus why I did not bother with them :p
Ordering a few off shop-apt tonight. Hopefully they will come Wednesday.
Will still try the 6mm they gave us. Worth it.

The only problem with the video was the cooling, which I expected because the compressor was low.

This is the latest result.
Forgot to mention that I am not doing a finishing pass yet.


https://s15.postimg.cc/9qwor50ij/IM...302537_HDR.jpg

Cut my product's case rear end.

Not perfect. Some work to do on the CAM but in terms of output it is great.

https://s28.postimg.cc/urwqp7xpp/IM...314987_HDR.jpg

Really do need a chamfer bit...

So I started playing with the 6mm that was included. Worked well at first.
Was getting some nice test cuts with it so decided to give it ago milling out my case.

https://s2.postimg.cc/fhhof5htl/IMG_0871.jpg

Working well for a good 45 mins. I had the feed rate at 200% as my stock settings was making quite a fine chip.
Having it at 200% made a much nicer chip that flew straight off.

It got to about 2/3s the way down the 15mm bit of aluminium and the sound frequency changed.
Went to check it out and I went to pause it but suddenly the bit started to get hot so the chips welded onto the bit.

Doh

Obviously can't go that fast when the ali has warmed up and you are doing 2mm cuts.

Was only air cooling though. I found water kept clogging up the chips and well I don't have any proper coolant system or liquid...

https://s30.postimg.cc/nsdrrqb1t/Capture.jpg

WD40 is good, a squirt every now and then or buy a mist system on ebay (£10 ish) and you'll be good to go...

Sent from my HUAWEI VNS-L31 using Tapatalk

If you are getting fine chips or dust, rather than upping your feed consider dropping your rpm to keep the material removal rate at a reasonable level... it will help control the heat production and reduce issues with tool deflection/chatter when compared to ramping up the feed rate. You need quite a rigid machine to get away with the high feed rates associated with faster rpm.

Bear in mind of course that these spindles don't really like much below 12k rpm for sustained periods. Coolant allows you to sustain a higher removal rate than dry cutting of course, but it isn't absolutely vital for good results it just makes dialing in those feeds/speeds a bit more critical. Chips do look better in that pic above.

This is where single flute give an advantage as you are effectively running at half the rpm vs a comparable 2 flute bit.

Quote:

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Originally Posted by njhussey

WD40 is good, a squirt every now and then or buy a mist system on ebay (£10 ish) and you'll be good to go...

Sent from my HUAWEI VNS-L31 using Tapatalk

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I actually found some draper cutting oil the other day that works better than wd40 imo (doesn't smell as bad when it evaporates off a hot tool either!) https://www.amazon.co.uk/gp/product/...?ie=UTF8&psc=1

It's a good temporary solution to no coolant I reckon!

Mist system is the better long term solution though, you already have the compressor so it's not difficult to set one up from there.

I didn't think to turn the rpm down... Make sense :p

This is what i got in terms of mister.
https://s22.postimg.cc/dww2i39b5/IM...737640_HDR.jpg

Though it it either just air or a fire hose...


Got the three flute with the bobbled edges coming tomorrow.
So will get to try that out with the lower rpm on the two flute.
No single flutes for at least two weeks :/

Wonder if the Banggood ones are worth trying. Might have some in their EU warehouse.

A mister unit will usually have two feeds going into it, an air line and a coolant line, and will have needle valves on both to vary the mix. They are generally designed to work on venturi but you are better off providing a pressurised coolant flow to them - you'll get bigger droplets rather than a pervasive fog.

I see yours looks to have a hose in the back for coolant but I see no second valve for controlling the flow, only a single valve which I assume is controlling the air flow.

this is the type I'm using http://www.ebay.co.uk/itm/Mist-Coola...8AAOSwUuFWzUwK

This one had a shitty one on the air feed.
Took it off as i have variable regulator on the compressor.

Going to look on eBay for a water tank with pressure feed inlet.

Here is an overview of my fog-less system and in video description are mentioned all major details so you can DIY one. A properly made one, i mean. Hope that helps you.

https://www.youtube.com/watch?v=NVu4mCFCvmA

Any recommendations on bits for fillets?
Like a round over tool for routers.

Also looking for alternatives to something like the Haimer Universal 3D Sensor.

Was looking at Zeeflyboy's link to the TPA2 but need something soonish and cheaper :p

Does this look about right for this 3 flute roughing bit?
https://www.shop-apt.co.uk/economy-3...-diameter.html

https://s15.postimg.cc/9220ieq63/Capture.png

I have a feeling that 3000mm/s is too much. Gwizard is saying 1000mm/s.

1000/S ? Do you mean 1000mm/min

Doh

Of course :p


Also, not 100% on the 1mm and 2mm. Wanted the single flutes but having to wait. Might as well try these.

Really struggling with the feeds and speeds for this 3 flute roughing bit.

Works fine for a few seconds then starts to chatter.

Guessing it is also a cooling problem?
Got the mister blowing a lot of air on it, also tried with a bit of water but same problem.

I have gummed up the roughing bits on more than one occasion when milling ecocast plate... to the extent that I actually had to dissolve the aluminium to get it off the cutters. What feeds/speeds and DoC/step over have you been trying?

Like I said they are definitely far more sensitive to incorrect speeds and feeds than single or 2 flute, proper coolant/lubrication would widen your envelope significantly.

Quote:

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Originally Posted by Zeeflyboy

I have gummed up the roughing bits on more than one occasion when milling ecocast plate... to the extent that I actually had to dissolve the aluminium to get it off the cutters. What feeds/speeds and DoC/step over have you been trying?

Like I said they are definitely far more sensitive to incorrect speeds and feeds than single or 2 flute, proper coolant/lubrication would widen your envelope significantly.

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Tried 500 and 1000 mm/m at their recommendation of 13000 RPM.
Only tried 2mm DoC.
Not sure what to try next.

removed......

So it looks like heavy mist/flood works really well.

The finish quality is really good too.


Having some odd problem where the Gcode is saying helical down, but Mach3 isn't doing it. It is still running the rest of the code as it should be but ignores Z.

It's only just started doing it?

Does the axis travel in mach (i.e. is the Z travelling in the mach "DRO" for the Z axis?). Sure you haven't accidentally picked the wrong post processor?

Does the simulation in fusion work as expected? Quite possible you accidentally set the depth to a top contour if not.

It worked fine when I did the simple 2D plate of 5mm.
So physically I know the spindle can go down further.

Quote:

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Does the axis travel in mach (i.e. is the Z travelling in the mach "DRO" for the Z axis?).

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No idea what that is. Will look into it.

Using the stock Mach3 from Fusion.
https://s30.postimg.cc/ebhwfzs0x/Capture.jpg

Simulator works fine. Even goes down the -2mm I set off the bottom of the stock.
https://s8.postimg.cc/sshby9h2t/Capture.jpg

The Gcode says the Z to go further,
https://www.youtube.com/watch?v=QeVdz5GYEEU&feature=youtu.be

you need more like 22000rpm and 3000mm/min with 3 flute roughing bit at 3mm depth of cut. heavily cooled by air at least. But that are speeds and feeds for very rigid machine or a mill

0.07mm feed per tooth on aluminum? i dont think so, especially on your machine. Lower the depth of cut and look to eliminate any chatter. Or lower feed per tooth to 0.3 lowering your feed speed half.

Just make a video to hear whats going on and we will tell you whats wrong...

Quote:

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Originally Posted by Boyan Silyavski

you need more like 22000rpm and 3000mm/min with 3 flute roughing bit at 3mm depth of cut. heavily cooled by air at least. But that are speeds and feeds for very rigid machine or a mill

0.07mm feed per tooth on aluminum? i dont think so, especially on your machine. Lower the depth of cut and look to eliminate any chatter. Or lower feed per tooth to 0.3 lowering your feed speed half.

Just make a video to hear whats going on and we will tell you whats wrong...

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This is what I am currently using under heavy mist and it works quite well.
2mm DoC

https://s27.postimg.cc/dbm9df4zn/Capture.jpg


This is the surface finish.

https://s16.postimg.cc/vfjt4uk11/IM...125061_HDR.jpg

Seems you have it under control now. Thats the surface finish after the roughing, right?

Quote:

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Originally Posted by Boyan Silyavski

Seems you have it under control now. Thats the surface finish after the roughing, right?

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Still having the Z axis problem.

Yes that is surface finish, you can feel those horizontal lines rubbing up and down with your finger.
Will be fine for external finish once I sand it down with a fine grit.

For me Mach3 when bugged always had only one cure possible. Reinstall all clean and start from there. You will not believe the number of times that Mach3 bugged during the last 4 years and cure was the same. Thanks god now i dont have to use it.

Quote:

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Originally Posted by Boyan Silyavski

For me Mach3 when bugged always had only one cure possible. Reinstall all clean and start from there. You will not believe the number of times that Mach3 bugged during the last 4 years and cure was the same. Thanks god now i dont have to use it.

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If I do that I lose my XY position though :p
It is only a test bit but rather not start again.

What are you using now?

DDCSV1. It started as a joke, i just had returned the Pokeys57cnc and was wondering what better controller to buy. I have written a lot in the forum about said controller use search function in forum. So at the end it worked so well i did not feel the need to buy the more expensive offline controller i had in mind.
But back to Mach3? God No. Only for special purpose machine where/if i can not avoid it in any other way.

I have basically 0 min downtime last half year in workshop and thousands of things done. I had at least 1 week downtime /if not more/ the previous half year . And the last 5 years if we put together the time i have lost installing windows, Mach3, reconfiguring, boards, plugins, figuring how to make things work...I have lost a couple of months with Mach3, plugins and boards.

https://img.memesuper.com/4f9cf15fc8...e_788-500.jpeg

So because I lowered my stickout with the new roughing bit and pretty much all the others, I forgot to lower my spindel to compensate.

Which meant it was hitting the Z limit thus not going lower than 10mm.