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

Need to work on this 2mm bit.
I already use the rouging bit to hog out most of the material. Just need more square holes.

https://s3.postimg.cc/45z85unrn/IMG...438424_HDR.jpg


Here it is from the other side.

https://s3.postimg.cc/ym553z9ar/IMG...639280_HDR.jpg

Well you can't make a square hole with a round bit, so if you need it more square use a smaller bit.:encouragement:

Quote:

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Originally Posted by Clive S

Well you can't make a square hole with a round bit, so if you need it more square use a smaller bit.:encouragement:

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...or overcut into the corners and have a bezel to hide it!

Quote:

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Originally Posted by Clive S

Well you can't make a square hole with a round bit, so if you need it more square use a smaller bit.:encouragement:

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That is why I step down to a 2mm bit.
All the holes are different in that I tried different things with them.

The middle one worked the best as the buttons are not fully square themselves.

Maybe its wiser and easier to drill the corners first. Then pocket with the bigger bit.

Not perfect but I think I have got it down pretty well.

I don't have a 3D probe yet so whenever I reset the machine I am obvious out somewhat.
The last operation of cutting out the case was well out for some reason..

https://s14.postimg.cc/ba2tw7u5t/IM..._132245327.jpg
https://s14.postimg.cc/7rqtztt9t/IM...238414_HDR.jpg


I am working now on setting up a spoil board underneath the stock to then super glue my stock to.
This means I am not cutting out something floating in mid air.

Just another bit of aluminum stock will do that I can then glue my work stock onto with super glue?

Well superglue worked really well.
Surprised how quickly the two bits stuck together as soon as I got the air out of the gap.
Much better than cutting in the air.

https://s7.postimg.cc/afe5usri3/IMG..._195947468.jpg
https://s7.postimg.cc/z7ds218or/IMG..._201659530.jpg



Main problem atm is the water.
Thinking of building a dedicated table for the machine which is basically a drip tray that I can then have doors on each side and all the stuff bellow like the controller, spindle cooling res, cooling water etc.
Means I can flood cool too. Which will be quieter than using the air compressor.

Thoughts?

We are cutting steel on mills with mist so not to use coolant and you are going backwards. Cooling with liquid is nice for a production setup but for home? The less, the better. Mist is better for home. Do it properly as i have made it and there will be no problem. With one nozzle you can cool up to 25mm bits.

Thinking about it you are right.

Going to make a bed for the CNC that can hold the water that comes off the mist.
I actually had the bottle about a meter above the cnc the other day and just the water alone worked fine by the looks of it.
No air just gravity fed water.



Anyone tried these?
https://www.shop-apt.co.uk/corner-ro...ide-45hrc.html

There are 2 Flute ones but only in the US from the looks of it.
I need to put a nice round edge on my product housing and these look to be the only thing available.

Thinking about it you are right.

Going to make a bed for the CNC that can hold the water that comes off the mist.
I actually had the bottle about a meter above the cnc the other day and just the water alone worked fine by the looks of it.
No air just gravity fed water.



Anyone tried these?
https://www.shop-apt.co.uk/corner-ro...ide-45hrc.html

There are 2 Flute ones but only in the US from the looks of it.
I need to put a nice round edge on my product housing and these look to be the only thing available.

Quote:

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Originally Posted by JOGARA

Thinking about it you are right.

Going to make a bed for the CNC that can hold the water that comes off the mist.
I actually had the bottle about a meter above the cnc the other day and just the water alone worked fine by the looks of it.
No air just gravity fed water.



Anyone tried these?
https://www.shop-apt.co.uk/corner-ro...ide-45hrc.html

There are 2 Flute ones but only in the US from the looks of it.
I need to put a nice round edge on my product housing and these look to be the only thing available.

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I have never tried that ones but seem right. You could always use 90 degree V cutter, trim the corners and slightly sand then afterwards. Just pass them with fine sand paper.

Just order it with a ball nose too.
Might as well try it, might be perfect.


Still trying to work out how I am going to reduce my water problem.
Going to be moving house in about 5-6 months so I am thinking of making a dedicated table for the rig.

One which has some decent casters on it so I can wheel it around and then some retractable feet that had then go down to make it solid.


The main thing for me is adding a box around it with window so the noise is reduced and so is the mess.
I have aluminum everywhere in my workshop atm so building it into a box where all the mess drops into a pan under the cnc is sort of what I am thinking of doing.

Means I can also use as much mist coolant as I need and it will just drip into the pan and not onto my workdesk.



Over complicating things or pretty solid idea?
Main thing for me is reducing mess externally of the machine and not having water everywhere..

I have made a tray that sits on the bed and is water tight - works for trapping coolant (I put a drain port in the front too) and also for cutting composites underwater. It also traps I would say 70-80% of alu chips.

Maybe a similar thing might work for you.

http://i.imgur.com/XSJ4CPv.jpg

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

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

That looks perfect for what I need thanks.

I am guessing it is a bit of Acetal sheet for the base?

Acetal is a good choice, just want something with low water absorption and high dimensional stability.

When I make another for the new machine I intend to use SRBP.

I just used acrylic for the sides and then machined the bed area down, fixed the eco cast plate in place and then ran the drill cycle for the screws that hold it down and the hole pattern I required for work holding.

My only concern atm is that I use a vice to hold my work.
In my operation I need to flip the piece to run a 2nd op on the other side.

At the moment I don't have any way to calibrate the vice other than using the CNC's edge as a guide (which works really well at the size of stuff I am doing.


I am guessing my only option is to mill down to make it flat, but leave a lip to push my vice against to get it level?

Was going to get a Haimer Universal 3D Sensor at some stage but it is too long I think for this X6.

Can drill holes for DIN dowel pins for alignment. If your vice doesn't have any alignment holes then you can just put two in on one side and butt the vice up against it. Obviously it won't be perfect unless the vice has a milled edge but it's at least as accurate as your current method of aligning to the edge of the CNC

Quote:

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Originally Posted by Zeeflyboy

Can drill holes for DIN dowel pins for alignment. If your vice doesn't have any alignment holes then you can just put two in on one side and butt the vice up against it. Obviously it won't be perfect unless the vice has a milled edge but it's at least as accurate as your current method of aligning to the edge of the CNC

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It has space under it that will allow me to have the pins protrude to the vice's solid side and I can get it level that way.

Should only cost about £50 all in which sounds about right.

So it came to £60.

Not going the full 700mm, only 500mm so I have some room at the back to use for things not needing the water bed.
With 50-100mm hang over that means half of the table is water bed, half stock where I can put a wood spoil board.


Guessing that 2 Flute bit that came with the unit will be enough to cut the few guide pin holes and screw holes?

Desperately need a way to set offsets on X and Y.

Looked at the Haimer stuff again but even their smallest one is over 100mm long.
The X6 has 85mm of travel in Z so really pushing it I think if I was to get one of those.

Any other options out there?
That TPA2 is still not in stock.

if machining metals then all you really need is a rod of known diameter (e.g. 6mm), then you can use probing to find the edges just like the Z-height probe does.

The downside is that it only works with conductive materials, that's one area where a proper touch probe has an advantage.

I'll try that method and see how well it goes.
Ta

Any recommendations on what I can put in my water cooling to prevent rust?
Not been able to work for 2 weeks and the outlet pipe is going rusty gold.

you just got an open loop?

some antifreeze would probably do the job, and keep the tub covered and out of reach of any pets/children

Quote:

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Originally Posted by Zeeflyboy

you just got an open loop?

some antifreeze would probably do the job, and keep the tub covered and out of reach of any pets/children

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Yes open loop into a tub.
Does it have to be just antifreeze or is screenwash okay?

don't think screenwash has any anti-corrosion inhibitors which is really what you are after.

http://www.carparts4less.co.uk/cp4l/...FUg6GwodLDEB_A

something like that would do

Quote:

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Originally Posted by Zeeflyboy

don't think screenwash has any anti-corrosion inhibitors which is really what you are after.

http://www.carparts4less.co.uk/cp4l/...FUg6GwodLDEB_A

something like that would do

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Ahhh okay.
Ill go see what they have at Halfords.

Needs to have some colour in it as I did not realise a few weeks ago that my pump was off >.<
Got a bit hot...

Wondering if I could get some feedback on this cabinet design.

Would love to make it out of Aluminum profile but that is like £300-400 for a full cabinet.
So making it out of wood and painting it with water resistant something...
Main reason why I am going for a full tower is that I need the machine enclosed to lower the mess it creates.
That and it takes up a load of desk space that could be better used if the CNC was in a vertical form.

I have added a catch pan draw that will allow me to blow/brush off chips from the machine and parts and they can all land there to collect.
It will be water tight tough I might add a slop to it with a drain to allow the coolant to drain out as it builds up, allowing me to reuse some of it once filtered.

Windows/doors to the right are the main access to change things on the machine like stock, vice etc as they both open out.
The front window/door is to access the machine mostly while running. Which is why I am considering making it slide up so it is easy to get to the part being worked on.
The left doors are just for servicing.
The back is fully boarded with 12mm wood to add strength to the build.

Underneath is enough room for control box, PC tower, spindle cooling tank, fresh coolant and coolant collection.


The two beams going from left to right are for the CNC machine to sit on. They will allow for the waste and coolant to drip down below the machine into the catch pan.
It also pulls out to allow one to remove waste.



https://s15.postimg.cc/ar0l05opn/CN...using_v11a.png

https://s15.postimg.cc/hg74g6a1n/CN...using_v11b.png

https://s15.postimg.cc/lbaiiqt7f/CN...using_v11c.png

https://s15.postimg.cc/78ol3rntn/CN...sing_v11_1.png

Been a busy few months.

Ordering a lot of stock aluminum for the product housing.

https://s3.postimg.cc/nvx468m8v/IMG...414149_HDR.jpg


The unlevel bed started to show up in the finish if the housing so a bit of 8mm on the bed and faced it off about 1mm down. Oddly not that much difference in it so thinking the vice might be causing the unlevel finish. Might make some soft jaws that custom fit the housing anyway so that will make it level.

https://s3.postimg.cc/gwj26vman/IMG...024393_HDR.jpg


Also as I was ordering a load of circuit boards I whipped up this little ring light to fit the 80mm spindle.
These photos are just testing it but I am going to try and mount it using neodymium magnets.
I know the motor is using magnets so they might not work too well but there looks to be a decent amount of steel there so should be okay.
Take 12v at around 150mAh. Not the brightest in the world but I designed them to help improve lighting on the workpiece not light the whole thing.

https://s3.postimg.cc/4gmcd4syn/IMG...856181_HDR.jpg

https://s3.postimg.cc/u1ykczg67/IMG...907447_HDR.jpg

https://s3.postimg.cc/7yyc9itun/IMG...934673_HDR.jpg


I also made my cabinet.
Didn't make a whole stand like I designed a month ago. Don't really have the space for it so made a table top cabinet.

The base is actually from a Ikea bookcase. No idea where it came from. Think it was a shelf we ordered but was the wrong size, but it was perfect for this use...
The sides are just that regular chipboard? from B&Q. Everything painted with 3-4 coats of gloss. All joints filled with silicone.

The base is slanted to allow water (coolant) to run down into a small rain gutter.
2 doors on the front using 5mm acrylic.
No roof yet, will make one eventually as the noise comes from there and chips when blowing fly out of it xD


https://s1.postimg.cc/209hi9v9or/IM..._160041422.jpg

https://s1.postimg.cc/61y8au5vbf/IM..._160047321.jpg

https://s1.postimg.cc/20z0am8a8b/IM..._160114377.jpg

https://s28.postimg.cc/j7tbdghkd/IM...644893_HDR.jpg

Magnets look to work. IDK about vibrations but never really had any.

I have a few boards left over (12) if anyone wants some.
£1 plus postage I think is fair.

looking very nice.

I did a similar thing with a waterproof ring of LEDs I just bought off ebay, can't say I ever ended up using it much though.

So I attempted to make my own soft jaws. The CAD was not easy but managed in the end.
Wanted them so I could put my stock aluminum in and machine it all the way to finished product. This only required 2-3 setups.

Decided on machine half the stock off and that left me with 2 cases for my electronics, I can then shove that on the soft jaws to mill out.
Using a 6mm hole to get X and Y and eye balling Z (Z being really easy to do).
Either something is out in my measurements or the 6mm hole method just isn't accurate enough.
Obviously on this machine it is not that accurate but to be nearly 0.3-0.5mm out in X and Y it must be my error.
I am also just using a standard vise, might not help though it has been pretty solid so far. I can only guess my main issue here is going to be repeatability.

Really need a 3D probe I think to help here.


What I am going to do is go back to my old method of super gluing my stock on a bit of 5mm which then allows me to mill out everything.
I really want to be able to step this up to a production level though as I have quite a few to make, just being able to run step one 20 times and then step two 20 times would be great. No changing tools every 10-30 mins. Just swap out the part for the next operation.
That and the glue is a pain to clean up and sometimes does not stick fully resulting in the part flying.


https://s26.postimg.cc/wl7tr7ii1/IM...300972_HDR.jpg

https://s26.postimg.cc/4mi9e3695/IM...905966_HDR.jpg

https://s26.postimg.cc/6gv3vtt9l/IM...913160_HDR.jpg

https://s26.postimg.cc/40tahzb6x/IM..._194939442.jpg

https://s26.postimg.cc/wnwarsbjd/IM...415066_HDR.jpg

https://s26.postimg.cc/715jkrx49/IM..._163910005.jpg

https://s26.postimg.cc/mlcxbb78p/IM...746605_HDR.jpg

I think vacuum fixture is the answer...

Looking good there, a fascinating thread glad to see you're obviously getting on well with your machine ;)

Sorry to hear about your sizing issue but looking at it it seems your so very close, I would start to think about how you could make the piece without having to flip it if possible.

I'd have a word with Chaz about 3d probe's he knows his stuff but I wouldn't assume that having one is the answer to all your problems.

Can't see the all the way round the parts on the photos but is it wider the whole way round (ie suggesting G-code isn't setup up right with cutter size or stock to leave) or does it flip from overhang to underhang suggesting the zero has moved?

3D probe is great, but not cheap and isn't perfect - If I set mine up without dialing it in with an indicator every time then the runout can normally be expected to be around 0.03mm... can reliably dial it into around 0.005mm within a few minutes of tweaking but if you don't do that every time then you are already starting with a centre error of 0.03mm and I find the repeatability to be around 0.005-0.01mm so you're probably anything up to 0.04mm off centre.

If you spend the time to dial it in each time (which adds perhaps up to 10 minutes to each time you need to find centre or edge of something) then you could reasonably expect to be within 0.01mm or so.

It does come with constraints though - the probe body and length of the probe may preclude you from being able to probe stuff in a vice if it stands too tall... worth checking if that would be an issue with your intended probe. Some are massively long as they are really intended for mills.

They can also get unreliable over time due to oxidation of the contacts.

I do love my probe, but you can achieve a lot of what it does for much less with a short length of tool steel and an alligator clip when using conductive materials (or even just a conductive fence used for part location).

saw a very cool tip regarding super glue for holding down small parts the other day btw since you mention the faff:

lay down a strip of masking tape (I'd probably use decently wide stuff) on the bed and use a blade/whatever to squeegee it down flat. Do the same on the stock you want to fix down and leave a few cm sticking out beyond the sides so that it's easy to line up with the tape on the bed. Good idea to have some sort of fence you can line up with to ensure you're aligned to your X and Y if that's going to be critical for the amount of spare stock you have.

You then run a bead of superglue along the tape on the part, spray some activator on the tape on the bed and then press the part down firmly.

What you end up with is effectively double sided tape but with a firmer hold (carpet tape etc tends to have some elastic give in it) and the ease of removal of masking tape. Having used double sided tape in the past it can be a pig to pull up off the bed and can leave a lot of residue on the part, superglue on it's own is good but again can be a pain to clean up afterwards.

I think you are better off getting a jig sorted for this particular job, but something to try on low volume/one offs in the future. Given your semi-prodiuction like goals on this part it might be worth considering making an actual fixture plate to do several at a time rather than just soft jaws in a vice.

The Y was out about 0.5mm and the X was out about 0.2mm.
I think that is okay on the inside but on the outside obviously that is too much.

Thinking about probing off the stock instead and then I should be perfect when I flip and obviously proble off the same corner when flipped.
That should result in a perfect (excluding the machine's accuracy, which they say is "0.05mm").

I can't find any none hand made ones that would fit. Like you say they are for mills. Shame because the Haimer ones are good price and easily available here. If only there was another 3-4cm of Z travel and I could use it, though 20mm bore xD
Which one did you end up with Zeeflyboy? I remembered you linked one but it was out of stock for a long time.


I've seen a few people use tape. Sometimes using standard double sided 3M and having great results. I might go buy some tomorrow actually and try it.

Normal double sided carpet tape works but you can actually hear the difference compared to a proper clamped mounting in the amount of vibration it allows. You can also see chips "dancing" on the surface which shows the part is vibrating... I wouldn't recommend it for where tight tolerances or good finish is required - much better to get a good fixture plate sorted out.

I use the TPA-2 here (in stock now, though with a smaller stylus I think which may actually be better for our purposes) http://www.kurokesu.com/shop/TPA2

As mentioned though, in this particular scenario it won't do much you couldn't do with a tool steel rod and a micrometer. If you don't already own one you also need to feature in the cost of a decent dial indicator to allow you to get the ball centred.

For your particular scenario here I may even be tempted to machine a small vacuum fixture plate which will hold the parts in alignment and hold down the part whilst allowing you to machine the exterior in a single operation. I think you will never be happy with finish unless you allow it to machine the full exterior depth in a single op. Even a tiny misalignment will show in the finish.

Think I'll try that probe and soft jaws. Though I'll machine my stock on a sacrificial so my outer is perfect. I can then probe and machine my internals.

The problem with vac plate is that I mill through my part so will end up losing vacuum. Only way around that is 2nd op so might as well just mill out like I already am in 2 stages.

Quote:

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Originally Posted by JOGARA

Think I'll try that probe and soft jaws. Though I'll machine my stock on a sacrificial so my outer is perfect. I can then probe and machine my internals.

The problem with vac plate is that I mill through my part so will end up losing vacuum. Only way around that is 2nd op so might as well just mill out like I already am in 2 stages.

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Well with a custom vac fixture plate you could account for where the part will be cut through I'm sure.

Something I sometimes do for a tricky to hold down part is leave 0.3 - 0.4mm of stock at the bottom to help hold it in place (I guess like a tab, but all the way around), then just run a cut with a smaller bit that doesn't go too near the side wall to release the part, trim away the excess and then put a chamfer on the back side to clean it all up.

Vac table and jig is the way forward ;)

I'm doing a simple vac table with the idea that any repeated parts I'll jig up for to reduce the time it take to align parts. Seems to me 90% of the time you spend on cnc is aligning the part not the machining. Jig up correctly and you can reduce that alignment time the better the jig the less time you spend resetting the part. After all if you're repeating cuts you only need to generate the gcode once.

https://www.youtube.com/watch?v=UFmdSLs1EUw

Received my TPA2 yesterday. Looks really well made.
Sadly I am off all week so wont get to play till October :(