Giant hot wire cutter

[charlieuk]

So after my giant router build the next thing on the list to think about is a way to chop the large blocks of eps up into usably pices which is normally just smaller blocks so a horizontal and vertical cut however it would allso be nice to have two and Possably four axis cnc posabilities in the future.

the blocks I cut range from 8'x4'x4' to 16'x4'x4' but normally 16x4x2 and weight about 70-80kg

the he machine is going to have to go in the shed were I store the blocks at the moment so restricted a bit by size

I'm not after super accuracy just a nice straight line that can be set up in minimal time and keeping costs as low as posable. I'm wondering if to start with rather than having it cnc I can just have it motorised and controlled by a simple switch or something to give a constant feed rate.

The first thing I have been trying to deside on is what liniar motion components to use. For this as nice as it would be to use Hiwin rails I'm hoping I can come up with a suitable and cheaper method with the 6meter long axis at least possibly something along the lines of the cnc router parts method of using barring and flat steal plate ( I will put a link to when I'm on a pc)

I have seen a few similar machines which has given me a few ideas some quite minimal and some a bit more substantial but yet to deside on how to do it myself.

[GEOFFREY]

would it not be possible just to have a floor roller/conveyor system (powered or manual) and a goalpost arrangement with the a hot wire height adjustable spanning between the posts? G.

[charlieuk]

With the goal posts fixed? Not unless I had nearly 40' of shed. I think it's going to have to be a moving gantry design of sorts. The one bellow is one I have seen on Google that looks rather nice but possibly a bitt by be over the budget to build the same.

[charlieuk]

this was the other which is perhaps the opposite it terms of build strength but certainly simple ish

[charlieuk]

and this is what I am wondering about for rails

http://www.cncrouterparts.com/linear...ent-p-100.html

however I cant help but think if I use extrusion there must be a way I could use the aluminum as the rail and have some sort of rubber wheel as the forces are going to be so low along with the weight of the gantry being pretty small all so. I am aware of the v rail aluminium but I don't think it comes in 6m lengths.

then there are the wheels you can get from kjn but not sure if they would be up for the job and there are quite pricey considering you would need probably 6 or 8 per rail.
http://www.aluminium-profile.co.uk/a...40.html#SID=71

[mekanik]

Hi Charlie
With the limitation on working area, best option would be to knock up a trolly with integral adjustable hot wire cutter and run it along the top of your block.
No need for anything complicated.
Regards
Mike