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View Full Version : Lego CNC update (the real thing)



jwstolk
09-10-2006, 06:42 AM
This project has been going on for a long time, but I just dismantled the Lego prototype a few month ago, since I finally have started on building the real thing (tm).
It will be about 5 times bigger than the Lego prototype. about 1200x810x610 mm working range (note the very high vertical clearance) total estimated weight: +/- 450..500 kg, mostly build from 50x50x5 angle-bar. It will be a moving table design, so it's about 2x1200 mm long. the rail is 30 mm steel rod (drawn KV45, H9), supported (and adjustable) every 180 mm, both vertical and horizontal. I drilled and threaded the rod and glued in 52 pieces of M8 thread.

The steel base frame is almost completed and i will be starting on the (moving) table soon.
I just welded the supports for the wheels. my website ( http://jwstolk.xs4all.nl/mill.htm ) could do with an update, but here you have two new images:

http://jwstolk.xs4all.nl/i/cnc_2006_9_10b.jpg
http://jwstolk.xs4all.nl/i/cnc_2006_9_10a.jpg

current weight is about 180 kg. current dimensions: 2260x920x600 mm.

jaap.

ZipSnipe
09-10-2006, 10:12 AM
Wheres the Lego pics? Looks like it will be plenty rigid, will you be using it to cut steel?

Kipper
09-10-2006, 10:49 AM
Wheres the Lego pics? Looks like it will be plenty rigid, will you be using it to cut steel? They be here (http://jwstolk.xs4all.nl/millp.htm) Cant wait to see the results!

jwstolk
09-10-2006, 05:20 PM
Wheres the Lego pics? Looks like it will be plenty rigid, will you be using it to cut steel?
as pointed out before: http://jwstolk.xs4all.nl/millp.htm

The original idea was to cut hard modeling foam, but it's slowly shifting to include MDF and aluminium as well :-). I don't think the machine will be stiff enough to use very large tool sizes in aluminium, so 3D milling very large aluminium parts will not be practical, but i do intend to make small aluminium parts and for drilling and engraving aluminum sheet, as well as milling the end shapes of pieces of aluminium angle-bar and drilling aluminium angle bar.
The large working range is mostly for 3D milling of large models from blocks of foam (scaled ship models as well as real-size polyester molds) and for doing 3D measurements.

The frame is very stiff, especially agents torsion. if one wheel is off the ground because of an uneven floor, it has no effect on the frame.

Combining a large working range (for foam milling) with a good stiffness (for aluminium milling) is difficult, especially if the machine size and weight (and cost) need to remain practical, but I'm fairly sure it's all going to work.

The frame and basic design will be as strong as possible, but i will start with low-power drive spindles (T12 thread) and some motors i have laying around (possibly with some gear or belt reduction) and update the drive spindles, motors and router later, depending on what turns out to be required for the material and the needed milling speed. I'm sure the initial setup will cut foam to a high accuracy, but I think i will need some bigger motors to cut aluminium. I measured that the T12 threads start bending at a load of about 50 kg (500N), so i think they will be ok for cutting aluminium with small tool sizes.

I also designed the machine to be fully dust-proof. The spindles are enclosed in thin flexible AC-ducting pipe, and the long linear rail is outside the working area. The bearings for swing arm with the router will be sealed as well. I also designed the machine for use with liquid cooling, so all liquids sprayed around drip into the bottom tray, while keeping the rail and spindles dry.