New Machine Build- 8020 build 3x5

[sieg01]

Hello everyone,
I've been starting to gather components for my new machine.

• 8020 1530 pieces from 8020 surplus for most of the frame
• Cncrouterparts for the linear carriages, leadscrew bearings, and motor mounts.
• 5 start 1/2-10 acme rod for the leadscrews
• dumpstercnc couplers and AB nuts
• 3 425ozin keling stepper motors
• The new gecko g250 when it comes out
• more to be added later

Here is preliminary sketchup drawing.

Comments are appreciated!

[sieg01]

picture

[dcb007]

Hey,

I build one smaller but similar. Might give you some ideas. Visit http://www.neo7cnc.com

Look forward to updates on your progress.

Dave

[ahren]

Sieg,
I'll be watching to see how things go! Your parts should arrive towards the end of the week (once I get the radial bearings you requested). Cool that you're going with the G250 -- it will be interesting to see a machine using some of the latest and greatest components.

Ahren
www.cncrouterparts.com

[MakotoKamui]

Hey, great to see another 8020 build in the works. What kind of footprint are you thinking of?

Also, just curious, why did you go with the 5-start Acme screws?

Can't wait to see your progress!

[anne_mrudula]

Hey that looks good. I need a small help. am working on designing a CNC machine using solidworks for a course of mine. Am kinda strucka s I dont know where to start or what design to work with. Can you suggest em some ideas so that I can go ahead with my project.

[sieg01]

For my footprint I'm shooting for 3 by 5. I haven't gotten it completely designed up yet. It has to be at least 5 feet long... the y-axis I have some leeway. Not sure yet how much on the z-axis yet. Anyone have any thoughts on the height of the z-axis?

I went with the 5-start screw mostly for a decent speed. It seems they are better all ways in the 1 or 2 start ones except for cost. Also it seems that a lot of people who start on the 1 start end up switching to the 5-start.

[sieg01]

Hi anne,
I'm not sure if I can help you much... This is my first machine. What I did was look at lots of other people's machines to get some ideas. Such as, Joes 4x4, Hack's Machine, jgro, joes 2006.

[MakotoKamui]

That'll be an impressive beast when complete at that size - especially if you get some good speed with those 5-starts. Maybe I should switch to them as well, speed is one of my big concerns right now.

What are you going to be doing with the machine? That'll be the biggest decision maker for your Z axis. Seems like most of the setups around here have around 1-2" Z travel, but I built mine with 10". Biggest limitation there is actually the drill bit - I don't trust super-long bits, so I can't carve 10" straight down into a block of material.

[sieg01]

I'll mostly be trying to cut kiteboards... along with trying out skis and snowboard perhaps. So I wouldn't need that much z travel.

I have other ideas more artistic ideas... like a 3d relief of a map. That could use the slightly longer z travel. Although I probably could do something like that a few (vertical) inches at a time and glue it up.

[ahren]

5 start screws help for a few of reasons -- they're more efficient than single start, so for the same power in you get more speed/thrust out. They also require less rotational speed for the same linear speed, which has two benefits. First of all, it allows stepper motors to operate in a lower rotational speed range where they are more efficient. Secondly, the point at which longer screws start to whip is a function of rotational speed, so with multi-start screws, you can get more linear speed before screw whip cuts you off.

Ahren
www.cncrouterparts.com

[sieg01]

First Cuts.. More later