HUGE mill for foam, mdf and other soft materials?

[xarvox]

Im getting into fibreglass soon (big projects) and im starting to realize how difficult task i have at hand (building my own amateur built car), concidering how hard it is to get a true symetrical and straight construction.

So im starting to look about for a HUGE mill to cut my models for me

Im fabricating the car in a single piece in full size to create a plug to mold the form to mold the car shell in.
The plug will be dense foam blocks sandwitched with sheets of mdf to add stability to the plug.

But as its tricky to get it exactly symetric and straight when building manually, it would seriously ease alot of work if i could "print" it in the garage.

Ive been looking at homemade cnc-machines before and even concidered building one, but seriously, there´s a heck-load of work to get it to function...
is there prehaps something similar on the market for a tad less than a heck-load of money?

what type of machine structure would i need to cut dense foam, mdf and some other soft-wood with good enough precision?(+- 0.05 to 0.5mm)

The cutting area would have to be around 3,5x2x2metres to cover the whole body (with clearance), but im thinking roof-mounted rails like the travers cranes we use at work (movable in a linear motion in 2 directions) with a Z axis.

That way i could easily "rebuild" the garage into a giant mill and it would take very limited space when not used (mill head in the homeposition in a corner, workspace free for work ).


what sort of power would i need to provide some decent cutting speed?
about 5 metres per minute in feed rate would be awesome..
but whats reasonable?


By the way, i have access to a bunch of cnc-machines, tigwelds and most other cool things and gadgets for the fabrication itself, but have no clue in terms of hardware, motor requirements, control structures and so on..
If anyone would like to educate me youre most welcome!

anyhoo, this should suffice for one post..
Check out my website/forum for more info about the car project itself

http://hordur.se and http://hordur.se/forum (forum link only from index site.. yes i know, i suck at html )

[cramccar]

I happen to have quite a bit of experience working on full-bodied car patterns. Of course the method of machining totally depends on your budget, but I used to work with a Haas VB-1 bridge mill (200”x84”x40”) that was awesome for cutting dense foam and renshape patterns. This machine was also robust enough to machine aluminum tools when required. Haas made very few of these machines, and there are still a few floating around on the open market. Depending on the scope of your project, it may be more cost effective to outsource your pattern making…just a thought.

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[xarvox]

I know im probably shooting at the moon on this one, but im trying to make this a commersial product.

A single body would probably be cheaper and faster to outsource, but i could be doing some pretty cool stuff with a glassfibre-shop and a huge 3d-printer..

but for the car concept concerns, as soon as the frame is road-aproved it would be so easy creating different model body-panels to bolt on the tube frame and -Bam, new model!


But is it at all feasible to build a mill to do stuff like this by myself?
The resolution (machined surface) doesnt have to be great, some bondo and sandpaper-job is mandatory for the paint finish anyway


Cramccar, experience means you know where i am (first build)
Any heads-ups?


Cheers!

[mcphill]

The machines are out there, but NO WAY will you find one that is "budget" priced. I have been thinking of doing the exact same thing you mention. The axes would need to be servo driven to get the torque needed for such a large machine, and I think a 4th or 5th axis would make it much more feasible to machine the lower parts of the car.

Another idea is to make the panels one-off instead of the whole car. That way it could be smaller, and you could get away with a 3-axis machine by rotating the part around to machine the different faces.

Here's an inspirational video for you ; )

http://www.hsm-modal.com/fileadmin/D...l_en_2_mov.wmv

And this guy did it all the "old fashioned" way:

http://englishrussia.com/?p=1949

[Piñon51]

Contact Dan Bolfing at Zystech. He makes exactly what you are looking for. You can see one of his machines being used in this blog (scroll down to the 01/03/09 entry): http://dpcars.net/dplite/da.htm

More info on that car, plus lots more pics of the buck on page 2: http://dpcars.net/dplite/index.htm

[Doctor Bombeii]

The 5 axis machine & software from Zystech.com is $48,980