Wow! I can't believe you got everything together and working in less than 3 weeks! Btw, nice looking gantry plates there

 

They
do look good, don't they!
Thanks again for making them for me and the excellent "customer service". Next time I will post pictures with the plates in focus

Frederic

 

To everyone who have completed their OX, what did you cut with it and at what feedrates (XY and Z)?

 

A while back someone asked how I was doing my max Z endstop, so I figured I would post it. Note: The camera lens makes it looks tilted, but everything is straight in reality.

 

Hi BC,

I have read that lots of noise can be picked up by the wires between switches and controller causing spurious alarms. http://wot.lv/combating-endstop-noise-on-a-reprap.html
What controller do you use (grbl ?) and did you add some additional filters to combat any noise?

Thanks,
Frederic

 

For the Z-axis, I glued my switches to the gantry plates. I used CA glue but the bond seems very brittle, I will need to try something else...

 

On my OX build Frederic, I used sheilded wire, and ran it thru this - (http://www.mcmaster.com/#standard-cable-sleeving/=tciu7i) no noise issues here

 

I tried to cut 1/2" acrylic yesterday and I noticed some twisting in my X 20x60s when the spindle forces down on the material... is there any known way to reinforce the X beam? I also noticed that in SketchUcam, the multipass depth can't be under 1mm, is anyone aware of this problem? How can I fix it?

 

from this useful link http://www.shapeoko.com/wiki/index.php/Materials

Code:

 Acrylic

Notes from IC for cutting his dust shoe:

    Bit: double flute 3.175mm (1/8") end mill
    Feed: 400mm/min
    Speed: 20,000 RPM
    Cut Depth: 2mm (0.08")
    Stepover: n/a (through cut)
    Plunge Rate: 75mm/min.

O-flute bits are recommended.[27]

Makita RT0701 16in/min feed, 0.08" step down[28] at speed 2 (~12,280 r.p.m.)[29]
10mm cast Acrylic using 6mm Single Flute bit 2mm depth 400mm/min Feed speed.[30]
Fabrication Notes
Extruded acrylic tends to "store" energy and may randomly crack if one presses in a part as a friction fit. This happened when I.C. tried pressing in the magnets on his DWP611 shoe and broke a couple.[31]
The edges may be polished after cutting by rapidly passing an open flame over them and quickly allowing the material to melt and cool.
You may wish to consider misting the material w/ water[32] and/or dishwashing liquid[33] as a coolant or applied to the bit as a lubricant[34] 

 

Well... I was WAY too fast... I think I went 1000mm/min and 700mm/min... with 1/4" edmill... will try again tonight

 

The parts lists shows 7 feet of GT3 Timing Belt. Perhaps my math is off, but isn't there two 1500mm Y-axis steppers and one 500mm X-axis stepper for a total of 11.5ft plus slack (say 6" per run) for a minimum order of 13 feet?

 

John, I see the BOM showing 1ea 20x80 v-slot for the y axis (sides) cut in half (750mm for each side). With this, you only need about 7 feet for both the x and y axis

If, however, you decide to build a larger OX with a 1500mm y-axis for example, then you would need an additional 5 feet (approx.) of GT3

 

Ah, so my math was fine, but my inputs (assumptions) were wrong Thanks for the quick correction.

 

Speaking of a larger OX, I decided to build a 750x1500 OX. I have finished the table, got my computer, monitor and keyboard/mouse setup, started putting the frame together, and test fitted the gantry. It's coming along but I am waiting on some screws to finish the x/z plates, then I'll move on to the electronics. I was going to post the build, but I got so engulfed, I already had the table built before I got off any pics. Maybe I will try to start a build thread tomorrow...


BTW, Chris, the aluminum parts are all phenomenal. Thanks

 

I uninstalled SketchUp annd reinstalled it, all is OK now. If you have to use the comma for the measurements, and want to use the point, you have to change your regional settings in Windows.

 

To convert decimals it's a bit harder... 1/4" is 6.35mm 1/8" is 3.175mm etc... but metric decimals are a lot easier!

 

If I remember correctly, 25.4mm is the key to conversion

So 12 inches = 12 x 25.4 = 304.8mm
1/4 inch (.25) = .25 x 25.4 = 6.35mm

 

You are right

 

My father told me about Inches

Tweakie.

 

Anyone measured the backlash with gt2 3mm belt?

 

Hey all, I was wondering if there would be too significant of deflection if I used the OX design and extended the X axis using the same 60x20 v slot to allow for a 4x4 foot cutting area. Thoughts?

 

Working area (size) and the type of machine design depends to a large extent on the loading you are intending to apply to the tool being used.
Just for example; "V-Carving" imposes significant tool loading whereas "laser engraving" imposes none.

What is your intended usage for your machine ??

Tweakie.

 

Hello Friends.

I was looking to build a cnc but all i saw was wood builds with very little reliability. And then i found this forum and i have to say that is amazing. Congratulations to all you guys that make it possible.

I have two questions.

1 - I found in my country (Portugal) a company that can cut the ox plates but with 5mm aluminium and not 6, is this a problem?

2 - Is it possible that someone can tell me the measurement of the ox gantry plates? (width, heigth) I will print the plates in pdf with measures on paper and take to the shop to compare the final result with the prints.

Thanks,

 

yes i saw it but i'm new to cnc and here in Portugal people tend to not follow very well indications provided. What i want to know is if i give the dxf file to a company is it possible that they cut the all thing wrong?

And they only cut 5mm aluminium. I saw that everyone is doing with 6mm.

 

Tweakie,

I am definitely planning more on the V-cutting and 3d routing type of use. If this is the case will I need to use 8020 rather than the 6020 vslot? I am not too familiar with deflection calculations, I am more of an electronics guy at heart.