I would never personally put an end mill in a drill chuck, I generally don't count them to be any better than .003" TIR. There are a variety of other reasons not to use them, including the fact that collets provide far more contact with the tool itself, and resist cutting forces including pull out better. This may not be an issue with the smaller cutters, but the runout numbers sure will be. If I did it at work my boss would probably kill me as wellOriginally Posted by mr_westie
escott76, thanks for the tip.
What is the typical lower limit for a chuck?
You've more likely got other issues as well using a tool like that for a spindle, so this may not seem like a big deal. Just understand that it will limit the ability of the tool to do fine work accurately.
The other downside is more moving parts = more places to collect debris.
Harder to clean.
I should be happy with my 0.0012" then.
If I find I need more then I will look at upgrading.
Will keep those other points in mind when I start looking at milling other stuff.
You are right about the other issues.
Keeping the Depth Of Cut consistent is key after runout is below a certain point for these V cutters.
Yay! Got the CNC today. Looks in good condition except a connector on one of the steppers broke off. Shouldn't be to hard to fix. Sadly I have no time to play with it this weekend, I have a out of town wedding to go to. But I'm glad its finally here.
The chuck, using jaws and a scroll can wear unevenly, unlike a collet. TIR will most likely deteriorate over time, and can also vary dependent on jaw position. Most good quality chucks have rebuild kits available for just this reason.The other downside is more moving parts = more places to collect debris.
Harder to clean.
I should be happy with my 0.0012" then.
If I find I need more then I will look at upgrading.
Will keep those other points in mind when I start looking at milling other stuff.
You are right about the other issues.
Keeping the Depth Of Cut consistent is key after runout is below a certain point for these V cutters.
cpurious, shiny isn't it
escott76, I see. will keep the dial indicator handy then.
Very simple floating head design.
The hardest part was finding a suitable spring.
Wide and low tension.
Was looking at making my own after calling a few places and failing to find anything.
http://home.earthlink.net/~bazillion/springs.html
Got lucky with one place.
Had to cut to make it fit.
-
The system consists of
-2x circlips
-Low tension compression spring
-Head
Loosen the spindle mount just enough to let it slide up and down.
Cutting depth would be set when loading the bit into the chuck.
Good in theory.
It is hard to load the bit to 0.05mm accuracy by hand.
Sping tension may be a little high so will need to cut off some coils.
I did wonder if there was going to be too much play in the mounts when loosened.
Surprisingly there was not.
I can now mill the 0.3mm boards
Will make a new head with screw height adjustment.
Then I will tackle the 0.15mm board.
There a 3 versions of machine posted in ebay. the TI, TII and TIII. Any +ve feedback on the TII version?
They would be the small/med/large.
Have my eye on the large for the faster feed rate, not that I need it but just I'm a guy.
I think we have all bough the small in this thread,
No reason to think the bigger ones would be any less quality.
edit:
The ground mod fix my stuttering problem.
Last edited by mr_westie; 10-03-2009 at 03:54 PM.
Video
I searched youtube for this machine in action but not find any. Any link or source of it? Really appreciated if someone post the video for us at youtube.
thanks
I haven't gotten mine up and running yet, but I'll take some videos when I do.
Your floating head setup looks pretty awesome mr_westie.
Did you machine the headpiece?
How well does the vacuum tube in the headpiece work? I was thinking about something contained like that for clearing dust.
Floating head works good.
It has allowed me to use the 0.3mm PCBs
The headpiece was machined for me by a engineer friend.
Easy enough to do if you have a lathe or even using the machine itself as it's not that big.
This was made out of acrylic.
Gives me the option of polishing it clear/transparent so I can watch it work.
Not that exciting after the first few jobs.
Great to show off though.
Vacuum works as expected.
I am loosing a lot of suction due to loose fitting bits up to that point though.
Will fix that later.
Looking at it carefully, only the leftover copper have rough edges.
The track/pads have a good edge.
Will test feed rates to try and fix it.
Used a drewtronics 45 deg bit at 250mm/min, 20k rpm.
The other option is set the isolation gap high enough to mill it all out.
I did take a phone video but not a very good one.
I am ashamed to even upload it.
I have sold this machine and will be buying the medium sized one.
http://cgi.ebay.com/ws/eBayISAPI.dll...m=110424211181
Will be installing it tomorrow for the buyer so will take some nice videos tomorrow.
Note the ground mod did not fix my problem.
Slowing the feed rate down did, from 700 to 650mm/m on the y axis.
picked up a small (6Litre) toaster oven for my reflowing.
Since I am doing bottom up(skillet/hotplate) reflow I only needed the bottom element.
But the elements were wired in series so both needed to be connected or it would burn out the one left running.
Other options were,
skillet - no head protection/buffer, like one big soldering iron.
hotplate - as above
electric jug - limited size boards, no heat control if run dry.
I needed to move the element to the bottom.
Out with the rotary tool.
Works ok, now to try it with a real board.
Paid for new machine.
Unfortunately I forgot the chuck key when I dropped off old one to new owner so no drilling videos.
Another problem with the 0.3mm board, she bends a little on the hot plate.
Sorted. I will make something more elegant later.
It's all worth it for the thinner profile.
Another bonus.
The drewtronics bits were good after all.
Looks like they easily mill a 0.1mm wide cut now that I have sorted out the runout on the spindle.
Those cuts are 0.24mm apart. Cut is deeper than it needs to be.
A short clip.
Still waiting on my new machine.
My first mass(more than 1) run of reflowing.
The only parts reflowed on the left board was teh micro and ISP socket.
Note the colour change during baking.
Paste applied
Components placed
Doesn't smell quite as nice as my wife's baking.
This is the most I have reflowed at once, and smell is definitly noticable.
Moving this operation out to the garage.
Not as many bridges as you would think.
Some solder wick will fix that.
The pads were for bigger resistors.
I did not place some of the smaller ones on proplerly so they stood up.
Repaired, tested and ready to roll.
Mr. Westie,
What are you making?
Jeff...
Patience and perseverance have a magical effect before which difficulties disappear and obstacles vanish.
A wireless meshing rfid reader for outdoor activities
I will do a full write up once I finish it. Hopefully this weekend.
http://www.geekzone.co.nz/MrWestie
Onboard you have a
5v DC-DC
3.3v VReg
AVR Mega48
off board
RFID Reader
xBee moduel
2x AA battery holder
New machine arrived today.
Well collected from the courier depo as it was messed around in customs.
They forgot to send the control electronics
Hopefully here by next weekend.
Sadly I haven't have a lot of time to work on the CNC
I still need to get the vacuum system working before cutting up fiberglass PCB's, since I have no garage/shop at the moment to set up in.
I have gotten the most of it set up though. Here's a video of the machine drawing a circuit with a pen. It's a dev board with space for a AVR Mega48/88/168/328 and a USB to serial converter chip.
"http://www.youtube.com/watch?v=oMq6lMs8Srs"]YouTube- Test Circuit With Pen on CNC
Well done cpurious, you're almost there
Got my control box after a week in customs.
But NO settings.
Have emailed and hoping to get a reply soon.
Being a saturday morning I don;t expect much of a response till Monday afternoon local time.
I might just have to work it our myself.
Pics posted soon.
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