[joshendy]

Here are some pictures of my finished electronics cabinet. Looks much better than I thought it would. Real pain in the ass to get this thing done but I couldn't find a good sized one for cheap. It was a good exercise for the CNC though, getting to do some real cuts on it.

Just got to get everything fitted in the case and then I can start moving onto getting a dust shoe done. Should have done the dust shoe first really, my shed is covered in plastic swarf.

[louieatienza]

Nice machine, and case! great work,,,

[joshendy]

Cheers for the compliments Louie.

Thought I'd put up some photos of the finished electronics cabinet. Wiring is as neat as I could get it, or could be bothered getting it.

So in the case I've got two power supplies. Big 48VDC 7.3A for the G540 and a smaller 12VDC 1A for the cooling fan and hall effect sensors.

On the front door of the case I've got an ammeter up top which shows how many amps DC the G540 is pulling, which is quite cool to watch as a job runs on the machine. Theres a temperature sensor next to it, it ran on 1.5V battery cells so I threw together a voltage divider to get 12V down to 1.5V for it.

Its got two DB9's on the front panel. One is for the 4 inputs, 2 outputs, 12VDC and ground, and the other is for the VFD connections. I'm going to be making a SuperPID-like product for my Kress spindle. The electronics are quite simple really just a TRIAC and zero cross detection circuit and a ATMEGA8 microcontroller and I'll have some nice PID controlled action going on.

I've also got a small push button on the case, functioning as the G540's enable button. I'm going to have my bigger emergency stop button hooked right on to the AC line going into the case. If I'm hitting estop I want the whole machine cut off from power.

Anyways thats it, I'm off now to hunt down some flexible brush strips for my dust shoe.

Cheers,
Josh

[PaulRowntree]

Nice looking case! Depending on the size of the output caps in the 48V power supply, killing the AC in may not quickly kill the DC output. I am pretty sure that the G540's enable input would shut it down more quickly (ie in a single step). Plus, it informs the controlling program (Mach3 or EMC) that something is amiss.

[joshendy]

Thanks! Yea you're right and I did spend a bit of time thinking about it, but when I do pull the power with 4 stepper motors attached to the G540 idle or running, the power does drain very quickly.

I've also got the G540's charge pump activated so I can access the Gecko's enable via my Xbox 360 controller "pendant". So when it comes time to hit the emergency stop I might be closer to my controller than the AC cut off emergency stop.

[flippersplace]

Hi Josh,
I'm currently tracking down the cheapest T-slot extrude available in NZ through work, I'll let you know what I find.

James. I too am seriously interested to see what you find re above.

Cheers

Lindsay
Lower Hutt

[kiwichris]

James. I too am seriously interested to see what you find re above.

Cheers

Lindsay
Lower Hutt

If the t-slot is for a wood router it's relatively easy to DIY a T-slot setup from MDF that will be up to the task.

It can then be the sacrificial as well and the table itself can be of any design/layout you like.

Just throwing it out there. ;-)

[kiwichris]

Wood router as in for cutting wood, not made of wood that is... :-)

[flippersplace]

If the t-slot is for a wood router it's relatively easy to DIY a T-slot setup from MDF that will be up to the task.

It can then be the sacrificial as well and the table itself can be of any design/layout you like.

Just throwing it out there. ;-)

Thanks, but not for a router, I'm wanting the Tslot for both structure (like the 80/20 system) and for working base for my Mk2 version of this:

Home made pick place SMT machine

[kiwichris]

Arrr, ignore me then. :-)

[joshendy]

Got my new HDPE mount done for my Kress spindle. Came out quite well, much better than the temporary MDF mount I had on there.

I was a bit worried the self lubricating properties of the HDPE would end up not making a good clamp around the small shaft of the spindle but it holds it in there strong and I can't rotate it or pull it out.

The bearings in the steel shaft that the mount clamps on get quite hot when running so I'm going to get this mount replaced with an aluminium one. It'll be much stronger and act like a heatsink for the bearings.

While cutting the HDPE it threw a huge amount of plastic chips all over the machine, really nasty stuff. I put a picture of my dust bucket after I cleaned the chips all off my CNC. So I'm getting right on to the dust shoe. I've got it all done in CAM and ready to cut and I've got the magnets to join the shoe and dust skirts together.

I'm just trying to track down some flexible brush, which is proving to be a real pain. I'm going to try find some sort of clear vinyl to use for a dust skirt in the mean time, but even this seems hard to find.

If anyone knows where to find some flexible brush please post a link to the website, keeping in mind I have to worry about shipping to New Zealand.

Cheers,
Josh

[kiwichris]

Hi Josh...

For the brush, payless plastics have a range of different brushes, chop one up for the bristles and epoxy them into a slot in your shoe..

And you don't want the bristles to be too soft otherwise they'll get sucked into the vacuum and / or tangle in the tool.

Out of curiosity as well, what were the settings you were cutting the HDPE with? tool/speed/feed ?

Cheers, Me.

[JamesHussey]

Hi Josh,

Try these guys, from memory they have flexible brush. They have everything else too....

Comac

-James

[joshendy]

Chris,

For cutting the HDPE I used a feedrate of 800mm/min at 2mm depth increments and my Kress was running around 15,000RPM. I used a cheapy $8 carbide 8mm 2 flute endmill from Trademe, which seems to work really well. I haven't done any testing to see what produces the best result just yet but I know my RPM is probably too high. Perhaps bigger depths at a lower feedrate and lower RPM would work better.


James,

Thats exactly what I'm looking for, thanks for the link! I must of spent an hour on google looking around and didn't find this website. I can't tell from their website if you can buy the brush with a flexible rubber top but I'll send them an email and ask.


Cheers,
Josh

[joshendy]

Bit of an update. Ordered the flexible brush strip last week in the morning and it arrived in the evening, kinda. Seems the courier thought it would be funny to wait til I leave the house for five minutes then knock and leave his card. So I went and picked it up the next day and wow its exactly what I was after, big thanks again to James! Thought I'd have to search the earth to find some for a good price, only paid $35 including shipping.

I decided to get my dust shoe going so I got it all designed and on my first cut things didn't go too well. The bit I was using had a chipped tooth on the bottom, which I was unaware of until the lack of cutting power pushed the job out of its clamps. My newly made E-stop button on the wall had its first real use and I was glad it was there. Still took me a while to hit it, I was too busy yelling some choice words.

But everything was fine, the job was wasted but it was fine as I had realised I made some slight mistakes in the gcode. So I redid the gcode, clamped the material on there good and tight, adjusted my feeds and speeds and used a new bit and it went really well.

I now need to cut out some dust skirts to push the brush in. Its going to be a learning curve though as these jobs will require two sided machining but I've got a fair idea how I'll get it done.

Enjoy the photos!

Cheers,
Josh

[kiwichris]

Nice work...

Are you using anything to align the brushes other than the magnets?

Also, out of curiosity, What did Comac charge for freight? I've looked at their site a couple of times but didn't see any obvious info on courier charges.

And I love your WiFi high-gain antenna! :-)

[joshendy]

Cheers Chris. Yea theres going to be several skirts which attach to the dust shoe, each "skirt" will have a different length brush and one will have some clear vinyl type material. Much like the kentcnc design, if you haven't heard of his dust shoe here is a link to a video of it: [ame=http://www.youtube.com/watch?v=t8ehFKTjZN4]Dust Shoe Demo - YouTube[/ame]

Magnets are sunk down in the dust shoe and raised in the dust skirt so when they meet they should align. As for the brush strip, the top is 8mm wide and ~8.1 in some areas so I'm going to mill an 8mm slot and hopefully I can just press fit the brush in.

Comac charged me $8 for overnight shipping between Palmy North and Wellington, which is quite expensive for what is a fairly small item but maybe is $8 for anywhere in the north island.

Haha "high-gain" antenna, it looks hilarious I think. When people come to look at my CNC they first go whats that satellite thing?!

[kiwichris]

Arrrr, cool.

The machine I've got coming has a dust shoe that some folks have said is a pain when it comes to changing bits so I might have to make something similar.

I remember seeing that KentCNC video before but read on the forums here that he wont ship outside the US??

Although, I've got a pile of 10mm Acrylic here, and I know where to get the brushes now. :-).

Where did you get your magnets from?

Cheers, Me.

[joshendy]

Yea its a bit of a worry making sure you can still change out tools with a dust shoe connected. I'm hoping mine will work out, it looks like I should have enough room to get my hand under there.

Tried to do the two sided machining yesterday and screwed it up :violin: But what are you going to do, its a learning experience. My reference system for flipping the job over worked but my job hold-downs failed on me again and I lost my zero reference. I might try again today, if I screw up once more I'm all out of my 10mm acrylic supply. Knew I should have brought more in the likely event that I screw up a million times!

I got my magnets from ebay. I wont recommend my seller because he sent me the wrong ones first and pissed me around a bit. But if you just search in ebay "rare earth magnets" you'll find heaps of them. I've got some 5x3mm ones and wow they are strong little buggers, 6 of them on each shoe and I don't think it'll be going anywhere.

Cheers,
Josh

[joshendy]

Got the first dust skirt done today and no big screw ups finally! This was my first go at double sided machining and I ended up 0.5mm off on the X axis but the dust skirt still came out fine. One edge around the brush strip slot is 2mm and the other is 3mm, as opposed to 2.5mm either side.

But yea the flexible brush strip fit the 8mm slot perfectly, I had actually gotten something right for a change. Needless to say I was fist pumping the air :banana:

So I'm quite impressed with this dust shoe. Lot of planning and its come out wicked. Enjoy the pictures and quick video.

[ame=http://www.youtube.com/watch?v=l7M4uWDyjJM]CNC Dust Shoe - YouTube[/ame]