OT - CNC Router
Turbo Mini Forums

I just like to share my current project with you and on the advice of Custard to explain the background behind the project here goes.

Essentially I wish to start making Aero components for cars, full on design using computers to aid along the way.

So. In essence this video explains what id like to achieve with this machine.

http://www.youtube.com/watch?v=TNZK8-z0ndk

Those lattice parts. I can create the full form on a computer then slice it at two inch increments chop these out of MDF put foam in between when built then skim over the top and pull a mold.

I also want this machine to be fairly versatile.

I want the machine to be able to mill other materials such as the machine does in this video:

http://www.youtube.com/watch?v=k6vctryRfHU

That machine is removing material at around 20 cubic centimeters a minute. I'm looking to be removing 125cc per minute on roughing passes in 6 series t6 aluminum.

24,000 rpm spindle speed. 1.25mm depth passes at 10 meters per minute. Using a 3 flute 10 carbide ALCrN coated slot drill.

To put that into perspective. The BMW conversion plates you get. The one on the head could have the holes and outside profiles machined in under two minutes with one minute being just the finishing cuts. How this will all work out im not sure after resonance and strength of the machine is taken into account.

However its not a production machine, its for me to make nifty things in my garage. So speed, not critical. But it is a project and I do fancy going a bit mad on it and over building it.

I also wish for it to be able to do this:

http://www.youtube.com/watch?v=2mDOlrpaXv8

Edited by Sam on 8th Jun, 2014.

Impressive stuff Sam

That mostly went over my head and I expect that's the case for a few other people on here.

It looks really interesting though so if you could perhaps explain in slightly simpler terms what exactly your doing/goal is I'm sure you'd get more interest!

What do you do for a living?

Dave the Cake

I work for a company which does the cable tracking you see down the axis of this kind of machine. If you need some let me know, i'll see if i can swing you a "sample"

Nice project, i'd like to see updates!

My build thread: http://www.turbominis.co.uk/forums/index.php?p=vt&tid=454802

Flickr: http://www.flickr.com/photos/85313398@N02/

So first bit of progress!

Also first bits of material turned up.

This is what 70 quid will buy you....OUCH!

That all sounds really interesting Sam, nice vids. Can't believe how quick that chomps through the alu!

Do you have any aero parts for minis in mind?

Dave the Cake

For the uneducated amongst us, what's the difference between a router and a milling machine, is it just a case that in a router the cutting head moves and in a mill the work piece moves?

More the spindle motor to be honest and really a case of strength as a result.

You can get CNC machining centers that will run at 30,000 rpm. But they are also 15+ HP.

This will be a 3HP motor running at 24,000 rpm.

Today's progress. Modeled the ball screws profile rails and blocks from pdf drawings and chucked them into the assembly document.



That will be the rough position of the z axis screw. It will be held rigidly to the Z axis and the nut will turn rather than the screw.

Makes it easier to load a couple of nuts against each other on springs down the axis of the ball screw. Also stops the screw whipping about at high speeds.

so basically to make body kits? couldnt you just use a CNC router to cut the wooden forms and then place the foams in between and then use a hot wire to run down each pair of wooden forms and hot wire the foams to match? seems simpler

That's exactly the plan for those parts. But i need this to be quite a multi purpose machine. So mostly working on sheet materials. But with the odd occasion where I can pop a 4th axis down the length of it and machine up table legs or something.

I also plan to have a removable panel that removes part of the main bed of the machine to reveal a lower bed. Here will take the 5 axis fixture for things like cylinder heads and a rotary forth axis for things like table legs with a live center on the opposing end.

Sorry custard I completely ignored your question about my job. I'm a mechanical engineering apprentice, currently in my second year out of four total. But I've never been trained on how to use any CAD software. Ive learnt by picking it up and having a go pretty much.

Would anyone be interested in me producing a step by step guide with how to get yourself off the ground with solid works?

Well, a little more progress.



But didn't like how overly complicated it was. That's only so i can load the ball screws against each other. Plus the drive is off axis. Causing a torque triangle through the whole thing. Less than ideal.



So this is my new idea.



This should support the bottom of the screw from whipping about and ill drive the screw directly with the servo motor.

So the ball screw sits in the bearing, then the bearing sits in that sleeve and its all held in from the bottom with an Allen cap head into the bottom of the screw. A couple of orings on the outside to keep it concentric within the tube.

Edited by Sam on 12th Jun, 2014.

It times out if you take too long writing a post, bollocks!

Ill get on that when Ive finished this little design project. Couple of months till I'm free as I'm doing a big turbo conversion on my daily.

So take two!

I thought that its best to drive everything centrally within the rails too. So i positioned the spindle centrally. I offset it because I wanted to ensure the same amount of material was on both sides of the cut. But it doesn't really make any difference as most of the area clamping is on the other side and the pins take the rest and transmit it up through the other plates. Means I can drive it centrally through the rails too.



But then I realised with this the tube pokes out the top and it means ill loose strength on the motor mount above by making it so tall. So I offset it. I wanted to drive the Z axis inline. But I couldn't so I offset it and make the tube the full length of the z axis. Means it allowed for location in the z axis so i can just glue the tube in place.



I put the hole pattern on top to bolt the ball screw down to and the holes for the vacuum line and coolant feed.





Added back in the pins and made the diameter smaller as was having clearance issues. Will probably chance the PCD they sit on and make them bigger.



Added in some dummy tubes for weight simulation purposes then buttoned it up.

3 little jobs to finish then this section is finished. Little finishing plate for the bottom to stop crap getting through the slot. A hood for the vacuum. and the coolant nozzles.

Just priced up the rails for the machine.

£930 delivered for all the rails and slider blocks. Golden!

Ive not been sitting idle on this. Ive had a few weeks off to get on with other things. But I'm back into it.

Its an idea I've had in my head for years.




I knocked this design up a fair few years ago.

I'm incorporating this as a design project for my HNC

As a result of that Iv'e knocked together. The crap thing is Ive needed to reference everything to something. So as a result ive spent a lot of time searching round for equations that i know from reading in text books years ago and finding a link on the internet.

But anyway, what I've been up to.

http://samueallewalters.blogspot.co.uk/

Getting there slowly but surely.

Andy, when this is designed I'm taking a break from it and getting stuck into that CAD guide for you lot after.

I'm thinking just enough to get you lot into it and get you comfortable making basic parts. From there you'll have the confidence to start exploring the program a little.

I'm thinking:

2.5D So plates, profiles and holes (Counter bores and things like that)

Bit of an effort of Simple round items (You'll pick up a lot of the know how on this from the 2.5D bit)

Assembly including fastenings.

Ill pop in a few tips and tricks all the way along and a few different methods to give you some versatility

The two most complex bits of it almost done. Ill put in screw locations and counter sinks tomorrow night

So sick of looking at a computer screen now.

Omg nice work there

I run a supercharger and I don't care the TB is on the wrong side.
VEMS + 12 PSI + Liquid Intercooler = Small Bore FUN!

Incredible!

Dave the Cake

Cheers fellas. But honestly its not all too hard. Just a lot of work thus a lot of repetition.

1600 parts all up. Screws and jazz like that.

130 or so parts that I've designed.

Once I've written up this guide to get you lot on your way with it, it will become apparent just what I'm talking about.

Work wise on it, I've just been kicking out drawings and adding in the holding devices for the drag chains down the side. One is going to be used to run power, the other is going to be used to run signal and fluids. Keeping the power and signal separate is always a safe bet.

Got to stress test it soon. I think my machine will probably be on that flat out for a couple of days. Ill set it going then get off to work.

Edited by Sam on 10th Aug, 2014.

Alright, jobs done. Render time.



Ill get back to you lot in 4-6 hours.

Did the trick