Miguel, thanks I'll give it a try.

After some more adjustments I am creating a prototype mold for a machine I am making.. Let me know what you guys think. I will post more video of the final piece and some pictures


http://www.youtube.com/watch?v=62LO67lnXLc

http://www.youtube.com/watch?v=Cg5fPDltW0Q

http://www.youtube.com/watch?v=Rd4407Di7yE

http://www.youtube.com/watch?v=U3QwM79loK0

I see you are experimenting with collecting the foam - wise move.:)

Ross

Mold Finished
 

@Ross: Foam can get very messy as I quickly found out :). This week I am getting the acrylic so I can finish the dust shoot.

I am attaching a couple picture of the first try at making the mold for my first prototype. Although it came out fairly nice I think there may be a few things that are setup wrong with the machine. The edges of the mold are far from perfect, I am guessing it either has to do with the bit choice, speed or something not leveled with the machine, Does anybody have any idea as to where I can start looking? One thing that I noticed is that after about 5" or so a pattern would occur at the edge of the mold. I have to look more into this..

This is what I used for my Mach settings

Rough cut
1/4" Flat / Double fluted end mill
200 IPM Feed Rate
40% Step over

Rough cut
1/4" Flat / Double fluted end mill
100 IPM Feed Rate
25% Step over

The material is Insulation Foam..

Lastly, here is another quick video of the finishing pass.
http://www.youtube.com/watch?v=fPWqA2xm1Jc

Is this prototype going to be used for the "car wash, Lube, or Parking"?

Looks good so far :)

James.. Two out of the three :). Thanks..

Hi Miguel

As a challenge try slightly redesigning the door so it is suitable to cut in 2.5D.
I can see the bevel on the "screen" would change but virtually nothing else, then it could be cut far more quickly and accurately with an ordinary flat mill.
The bevel could be also cut if you purchased a 90 degree V bit. With 2.5 D you can also cut your part out of the parent block to finish up.

For an improvement in 3D finishing turn the finish tool path 90 degrees to the roughing tool path.
Also nothing says you can't run several finishing paths using different tools until you end up with what you want

PM me if you are unsure what I'm on about here.

Ross

Step over down to 7~10% & maybe you should look at bullnose bits instead of end mills.

I have to agree with Ross. A 2.5 would have turned out much better results and probably a little quicker with the machine time.

Is the edge pattern happening along the whole X axis that it is cutting at the time of the pattern or just along the outside edge?

If it is happening along the whole X axis of the cut you will want to check the Y Cars wheels for anything that might be on them. Each revolution of the wheel is around 5 3/4 of an inch along the rails. Something wedged in the wheel will lift the Y car and could produce the results there. The deeper the Z axis the more of the angle will be compounded.

Thank you guys for your feedback. I just received the new spindle from China and will be installing it tomorrow. I found out the project for my burned spindle was that one of the wires inside the spindle connector came lose and shorted the ground wire. Something told me to double check the connections before connecting the new spindle.

I must have a problem somewhere in my configuration. I was cutting some circles over the weekend 1/2", 1/4", 1", etc.. and they all cut smaller than should. My 1/2" circle is actually 0.44", my 1" circle is about 0.92" when measured with a caliper. My configuration is as follows:

--KL34H280-45-8A Motors wired Parallel Bi-Polar
--Boston Gear YA30 (30 Tooth, 20 Pitch)
--3.33:1 Reduction Gears (from Mike)

Based on the spreadsheet from the forums my Steps/Per should be 1414.69 But that's when my measurements get screwed up. I been playing with some numbers and the number that gets it close with some initial testing is 1475 steps/per. I don't really want to keep on guessing number since I am sure there is either a problem somewhere or I am missing something. Does anybody else have this setup?

Why not use the Mach3 CALIBRATION to get it spot on.

@Kobus, I just learned about that 10 minutes ago :). I will check it first thing tomorrow morning. Thank you.

Cold Air Gun Success
 

Today I finally had a chance to hook up the Cool Air Gun I bought a while back. I have to say I am pleasantly surprise, more like blown away, how well it works. Although the manual says that it likes to work at 100PSI @ 15 SCFM I was able to run it without a problem at 85 PSI @ 5 SCFM and it cooled perfectly in my opinion. I started by cutting 1/4" acrylic with a 1/8" bit @ 18K RPM without the plastic even melting. The different with and without the cool gun was very noticeable. As as second test I cut 1/8" thick Aluminum with a 1/4" carbide bit and again the bit didn't even begin to get hot. I didn't have the right hose or fittings or filter connected to the system which I will connect tomorrow so I think it can only get better from here. I will also measure how cold the air comes out of the gun but it felt as cold as air coming out of window air conditioner.

Bellow is a quick picture of the air gun, I will take some better shots when the hose is connected properly.

Lastly, the problem with my circles not looking like circles was a combination of "loose" parts:

1) One of the Z-Rail Rollers was not making good contact with the Z-Slide. Barely noticeable but was causing problem.
2) One of the rollers in the Y Axis was dirty with what looked like a piece of dried paint from the rails. It was a nice chunk so I know it was also affecting it.
3) The little lock screw on the Y Axis stepper was a little too long and was touching part of the laser put part(wall) once per revolution.

Thank you to everybody that pointed me to the Mach3 Axis Tunning function. I think this is the best thing since sliced bread :).. After about 15 minutes I had the machine 100% tuned.

OK Miguel

A success. You get the first cold air gun on a Mechmate award (that I know of anyway).
At 18k acrylic is generally melting big time unless the feed rate is really quick.
I do like 12k max for acrylic, polycarbonate and alloy using cheap carbide 2 flute cutters.

Very interested in any information you can pass on about RPM, feed rate and depth of pass with your cold gun and aluminium.

Regards
Ross

Another good day. For some reason I had my Y motor fail on me today but since I had a spare one I was up and running within 30 minutes.

I finally been able to get all the fittings correctly for the Cold Gun and I have to say that it works great. Even with my 5HP compressor it works great. The little smoke you see in the video is from the spill board. Every 5 to 6 minutes there is a little rock of ice that comes out of the gun, it just shows how cold it gets. I will post some pictures of the final cut piece later today.

I had to turn off the video to pause the cut job and remove the middle piece before it could break the bit.

https://www.youtube.com/watch?v=2s0wB9r8O1Q

Some Pictures
 

Here are some pictures of the final plate and installation.

That looks very very good actually..

What was the plate for???

Kim; Thanks. The plate is to mount a Pneumatic cylinder to a Vacuum Forming machine I am building.

Cool.

How long was the actual cutting time for the entire plate?

21 Minutes. The plate is 10x10 with 12 3/8" Holes, 2.75" Middle Square and outer Edges.

That's not bad at all... a bit slower than lasercutting, but still, for DIY then it's actually rather fast when milling...

whats you spindle power? its the first time i see mm cutting iron. iam not crazy thats iron right?

so now get a bending machine and MM can replicate itself.

@Fernando. Yes, it is iron/steel (Hierro). I have a 3HP air cooled chinese spindle.

Miguel,

What size and kind of bit did you use?

Now this is very interesting. :)

wow.. iam amazed.. i was looking the idea of a 1hp spindle.. not any more.
soft materials.. aluminum and not ferrous, now steel. the working posibilities are too wide.
please give us more specs about the cutting.
speed mm/min , spindle speed, i see you using reductions.
bit specs.
you cooling using cool air. liquid can be use but you need a container to not ruin the spoiler mdf base.

Gracias Miguel

@Nils; For that video I was using a Onsrud 57-281. It's 1/4" Double Fluted Carbide Bit. Picked it up on ebay for $7

Cutting Edge Diameter: .250"
Cutting Edge Length: .875"
Shank Diameter: .250"
Overall Tool Length: 2.500"
Tool Material: Solid Carbide
Number of Cutting Edges: 2
Helix: Downcut Righthand Rotation

@Fernando;

When cutting the steel here were my settings

Spindle Speed: 9000rpm (200Hz on the VFD)
Belt Reduction: 3.33:1
Speed: 10% of my 'Normal Speed(450ipm)' or 45ipm for this cut(I incorrectly stated this yesterday)
Acceleration: 25in/sec
Downward Rate: 0.05
Cool Air Gun: Exair Cold Gun 5215

Iincredible that you can use the onsrud 57-281 for steel.

It's normally for wood...

Was it dull after the completion of one plate??

@Kim; I know it's probably crazy but I didn't even pay attention to the "Wood" specification part of it. The bit is carbide so I figured it should work. I have read in the forums that when asking for a bit most distributors/resellers wont know the material type so I figured it was worth a shot. The bit is not dull at all. I checked the machine first thing this morning after cutting that plate and the bit still as sharp as when I first bought it. It still razor sharp!.. Which I was impressed..