Ivo, thanks for the file, your design is just too sexy to pass... :D

Ken did you check to see if the WASHER fit when you open it on your programs ?

Kobus, They look fit well enough to me.

Thank's must be the conversion from DXF into my programs. But I fixed it manually already.

Tried lot different combinations of cutting aluminium atv skid plates. Seems that best is spindle 18000 rpm feedrate 1000mm/min and 2mm depht per pass. What do you think guys is it normal that tool lifetime is about 2-3 sheets cutting, then it brokes. ( its about 200-300 meters cutting lenght?)

Ivo,

Your spindle rpm seems a little high for you speeds and feed. For a 6mm endmill you will want a 4 mm cut at 1800mm per a minute. This calculation is for a 2 flute HSS endmill.

Router and High Speed spindle guys are always going to have a problem with heat due to rpms. I have a feeling your are cutting your chips as well. If your spindle can handle the side pressure you want your chips to look like small flakes. No dust looking chips.

Here is a free program that will take all your information and give you a speed and feed calculation for you cutters. It takes in deflection and chatter and a type of machine. It has a few other useful things in it. http://cnccookbook.com/CCGWizardv6.html

4mm seems a very deep cut at 1800mm/min
but I've yet cut any AL with my MM. Until I gain more info & confident. I'll be watchin such discussion with a keen eye.

Russel i have one flute endmill, that makes almost same chipload at 1000mm/min as you said 1800mm/min at two flutes. I have on that speed/feedrate no dust. And chips are "normal" and hot

Ivo, you are in the right area then. Are you doing anything for cooling? Is it cutting good one moment and then it turns bad and snap? Can you see if any aluminum is welded to the cutting edge?


Ken those speeds and feeds are what is recommended for getting the most out of the bit with the least amount of deflection. After that its a matter of what the machine can handle. To give you an Ideal of what it should look like in a almost perfect world check out this video http://www.glacern.com/index.php?pag...course_mill_08

I have no cooling. Aluminium is welded minimal. Looks like bits going to broke because its material tires, not because it wears down and dont cut anymore then starts jamming and brokes.

Sounds weird, but looks like i got bad set of bits. Yesterday arrived second shipment and i cutted with one bit 6 sheets of alu. That is 12 hours cutting.

And final truth of cutting alu 5754 sheets is totally different as discussed before... I moved from 4mm bits to 5mm bits because they are stronger and dont broke so easy and give better results.

Final cutting data:
5mm one flute endmill (20 degrees spiral angle)
Spindle 20000 rpm
Ramping plunge (10 deg ramp angle 10mm ramp lenght) feedrate 1500mm/min
Cutting feedrate 2000mm/min

I was cutting 4mm sheets and cutting depht inside contures 2mm per pass and outside contures 1,33 mm per pass. Outside i was cutting less with one pass because sheets arent always ideally straight and if cutter takes more than 2mm it goes to resonance and it may broke.

Some pictures too:

Expertly done.
Looks like racing car seat backs.....nice!

Nicely done. How many bits did you end up going through. Are they going to be bent. The reason I ask is the grain direction looks different across the different pieces.

They arent rally car seat backs. they are ATV skid plates. I make cutting job and then they gonna be bent and welded.

Some pictures of one job. Wind turbine blades, 2,8 meters long. Workpiece was 120*400*3000 mm. Cutting time for one blade about 16 hours.
Pictures:

exceptional use of the MM. Bravo.

Sweet !!! Have I mentioned how awesome MechMates and their owners are ?? !!! I am loving all these great projects I am seeing everyone working on.

???
Is that blade made from a single block of lumber or is it laminated.
You can't find lumber that is that nice for a good price here in the states.

Its laminated spruce. Price here is about 100€ per piece. Many are already asked for sharing blade file. I post it here. Profile is NACA 4419

Those blades look like they can be quite heavy?

No they arent so heavy. One blade weight is about 15-20 kg.

Havent posted here for long time. I decided to build second mechmate. This time all steel tubes. Work area same as first one 3400x2100
For now steel is here.
Attachment 15688
Attachment 15687

Good luck with the second build Ivo.

Do you have that turbine blade in STL format.
I tried some online conversions but I keep getting a empty file message.

I have .igs file. Stl seems to be already deleted. If that format is ok give me your e-mail address.

I downloaded the .igs file from your earlier post.
That is the one I tried to convert to .stl online.
Thank you for your reply.
Have a good weekend.

Here is stl file. Attachment 15701

Thank you very much.
It worked.
I will build one to scale some day:)

Its taking shape. Has someone good idea how should i turn this beast on feet? If i gonna weld base table all togehter i weights about 900kg.
Some pictures too:
Attachment 15735
Attachment 15736
Attachment 15737

Good luck with second build Ivo.

Its now on feet, with help of telescopic loader. For cross bearers i added one rectangular tube to support center. With 115kg load ( i standed on it) bends cross bearer 0,08mm. On my first mechmate i havent measured bending, but it is visible if i stand on table.
Attachment 15752

Nice and beefy ;-) good to see some activity here.
Why did you make your triangulation short as in with straight pieces in between ? You loose a little of the effect yoir are after that way.
Also since you are all welded, other way round would mean even more stiff tabletop.

Making triangulation is limited by bandsaw sawing edge. But i think its strong enough like this. Diagonals and lower cross braces are made from 80*60*4 rectangular tube, cross bearers 120*60*5 tube. By adding 5x more steel i think table is almost unbendable, but this is already story of third build.

More about rigidity. Main beams are 200*100*8 tube, end plates not welded yet. I fixed indicator on cross bearer and its needle to upper edge on main beam. Flex with twisting it with hands are 0,02mm. #38 main beams are made from 200*75 C channels and i can twist them about 1,5mm!!!!!!:eek:

To achieve better accuracy i gonna use hiwin HGR20 linear guideways. To get linear slides better fixed and keep them on their place i made from 12*80 steel bar linear slide bases. Of course i milled them out with mechmate.
Milling with endmill tip is good endmill killer.
Attachment 15757
For saving bits as cutting 2,5*20 stripe on steel bar i drilled some holes.
Attachment 15754
Steel bars were quite warped too, so lets cut them straight.
Attachment 15755
Attachment 15756

Milling steel bar

On video i am cutting steel bar straight with endmill side. Spindle 10000rpm, feedrate 480mm/min, stepover 0,6mm. Endmill is TaeguTec TSE 2060M UF10

That's cool ! Interested to see the linears, I have same laying around, but never mounted them yet still using MM v rails.

To make main beams straight i am levelling them with epoxy.

Dams made from melamine board and coated with mold release wax are in place:
Attachment 15777
To seal it correctly i poured first on corners one layer fast curing epoxy:
Attachment 15778

Meanwhile when epoxy is curing i have lots of holes to thread. For rails about 230 pieces.
Attachment 15779

Laying epoxy went out good. Nice and flat surface.
Attachment 15780
Attachment 15781

Here are some updates about buildlog over looong time.
Linear rail straightness is checked with steel wire. Hanging weight on one side is about 35kg
Attachment 16116
Attachment 16117
Attachment 16118
Linear rail block mounts milled
Attachment 16119
To make it more stiffer as original Mechmate, gantry tubes are 120*60*5
Attachment 16122
Attachment 16120
Attachment 16121