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

[Chaz]

Hi Spluppit

Thanks for the reply and sorry for not replying to your quote. I thought I got back to everyone but must have missed out on a few.
To be honest it has been a bad couple weeks, I am a few months behind on this project, moving house next week and my dog has been ill. So this has all been stressing me out.

The bit is being pulled out. Resulting it it cutting too much on the Z axis. My 12mm depth is resulting in 12.6-13mm
Should I try and increase the ramp speed a bit and see if that improves things? I think I am taking everything too general which has resulted in poor performance. That being said, some of the parts I have had out of it have been great.

Predrilling a hole for each case is my best bet then for the rigidity problem?

Again sorry for not replying. Just not running on all cylinders the past couple weeks.

I picked the eco cast on recommendation of it being simple and easy to cut on the machine as well as having decent surfaces that I could use for product surface finish. I have not had a problem with the anodising. Other than my fuckup eary on the EcoCast has taken anodising well. What should I be using on this machine?

I understand a proper machine will joblot all 160 cases in a day or two but I didn't have the money for it.
I was quoted before I joined here around £60 per case. I felt that I could buy a machine and learn enough to make them. It is why I designed the case to be really simple though obviously it has not been as smooth and as fast as I would have liked.

Overall the parts I have had from the machine have been fine. It is just this last issue really that is holding us back.
https://s17.postimg.cc/4hp400lb3/IM...201123_HDR.jpg
https://s17.postimg.cc/f4ix5fe0v/IM...936926_HDR.jpg

I have been advised to lower my RPM and improve the coolant so tomorrow I will get a chance to try that out and see if that fixes the problem.
If not, idk.

Thanks for all the info, I understand it is hard to work out what is wrong when you are not in front of the machine and having some idiot on the other side trying to explain what is going on.

Jack,

Please also send me the fixed files (ie Step or Iges from Fusion or the raw F3D) so that I can look at how long it will take the machine these. Can give my 2p worth as well. Free to use / not use the info.

[JOGARA]

For coolant, unless you can get good flood coolant, the next best option is air with a bit lubricant.

The key thing with nearly all machining, is to get chips away from the cutter. Getting chips away is even more critical with aluminium, as it can be very prone to chips welding to the cutter, which is never good and often fatal for the part, cutter of both.

I managed for a good few months machining aluminium with just WD40 and compressed air. I'd set the machine running, spray a bit WD40 on, hit cycle start, then wander back every couple minutes and blow chips of the part, and a little bit extra WD40 if it looked like things were getting too dry. I only used enough WD40 to give a light coating on the part/cutter to help stop chips sticking. If I knew there was a critical cut coming up I.e. spiral in, or deep slot, I'd stay and hold the air on the cutter to ensure no chips built up, and add in a bit extra WD40.
The WD40 does make the chips clump together more and a bit harder to blow away, but the trade off was they were less likely to weld to things.

I eventually made a mister, which removed the need for as much babysitting, but it would still need a bit extra assistance in deeper parts.

My current system is one of those cheap bendy hoses with air and "mist".
I have pretty decent air going through it with a tiny amount of regular water and have not had any chip welds.

Probably could do with some sort of coolant fluid or additive in the water though to assist.

Please also send me the fixed files (ie Step or Iges from Fusion or the raw F3D) so that I can look at how long it will take the machine these. Can give my 2p worth as well. Free to use / not use the info.

Ill leave this public for now, will take down at a later date http://a360.co/2zPSUYP

Thanks

[m_c]

My current system is one of those cheap bendy hoses with air and "mist".
I have pretty decent air going through it with a tiny amount of regular water and have not had any chip welds.

Probably could do with some sort of coolant fluid or additive in the water though to assist.

Is the air flow enough to blow the chips well out the way?
Provided it's keeping chips well away from the cutter, then your setup should be fine. Even if you have to give an extra blast occasionally, it sounds like you've got a reasonable setup, and I wouldn't worry.

It might be worth trying some of the misting fluids though. This is what I used to use - http://www.johnnealeltd.co.uk/shopenvirocutse10.html

[JOGARA]

Is the air flow enough to blow the chips well out the way?
Provided it's keeping chips well away from the cutter, then your setup should be fine. Even if you have to give an extra blast occasionally, it sounds like you've got a reasonable setup, and I wouldn't worry.

It might be worth trying some of the misting fluids though. This is what I used to use - http://www.johnnealeltd.co.uk/shopenvirocutse10.html

Yea the chips fly miles. I found tiny amounts of water and decent air meant that 99% of the chips left my stock area.
The ones left tend to stick along the walls of my part. Not a massive problem as I then go around with my finishing path and I do that dry (only taking off 0.25mm) and that clears whatever is left from me brushing away the majority of leftovers.

That Envirocut SE10 looks good. I like that it is biodegradable. I am using a tiny amount of coolant as it is so 1L should do me for a while?

[JOGARA]

Just tested the machine with 1mm DOC at 6000 RPM and it was fine.
Pushed the machine with a face operation of 100% WOC and only when at 720mm feed it made a bit of noise.

So going to try it on part. Obviously not 100% width.

Will quickly try a couple helix with the new speed and faster plunge.