Need 6' x 4' bed, 4 axis router design.. Help..!

[fasteddy]

Hi all..

Well. finally got fed up of mdf, angle iron and skate bearings..! But did manage to make a bit of money with it, problem is, I am now being asked to do some serious (for me) 3d stuff and my home-brew heath robinson setup will just not cut it (literally).. Just not accurate enough plus I want a fourth rotary axis to engrave pool cues..

Starting to get dizzy looking at the enormous amount of designs out there so thought I would ask you guys what you would recommend.. Needs to have a 6' x 4' bed which I would like to be T-track ally, which could be removable to have an open bed..

Also would like to mount a chuck at one end of the x-axis and a sliding tail stock at the other so I can do columns and pool cues...

Will make the base welded steel and was thinking of ally for the gantry and open bed cross members..

My current 5' x 3' cnc can machine ally (carefully!) so I could make parts for the new one as needed..

Anyone point me in the right direction?

Many thanks..
Steve..

[routercnc]

Hi Steve,

Joe's 4x4 is not quite 6x4 but gets alot of good reviews, and could possibly be scaled up. Still uses MDF, but also uses HDPE and bolted together 80x20 ali - might be worth a look to get some ideas:
http://www.joescnc.com/kitsplans.php

Or there's the Mechmate with the double gantry which has a good following. Mostly welded steel.
http://www.mechmate.com/

[fasteddy]

Hi..

Thanks for the pointers.. Joe's cnc is what I am trying to get away from, really dont like mdf and I am being asked to do some very robust stuff now which might be a bit too much for an mdf machine..

Mechmate.. Wow.. That is some machine, but also some level of manufacture.. Would love to do that but it involves a lot of bending metal and laser cut parts which has got to jack the price way up, especially in this country.. Doing it in the states where costs are much lower no doubt makes it more affordable.. Might try this if I cant find a simpler way to go...

Still trolling though many of the designs on this forum, man there is some nice machines here.. Just toying with the idea of making a hybrid of some of the designs I have seen, although the mechmate way of using a spring loaded rack and pinion motor mount looks a real winner...

Steve..

[Wobblybootie]

Steve ... the Mechmate was born in South Africa,but I gather the 'owner' (Gerald) handed it off when he could no longer afford the time to devote to the User Forum. There are a couple of companies here in the UK who can cut and bend the parts needed for a pretty good price ... the thing that puts many off is the cutting and profiling of the rails ... so a lot of folks fit THK style. The forum is a HUGE goldmine of info and the users are very helpful. If I had the space I would build one ... (over time)

Have a look at http://www.data-cut.com/ it can be modded to fit the size you want ...

[routercnc]

Hi Steve,

Here's a sketch I was working on a while ago. Double X axis motors, all ballscrews, profile rail Y and Z, supported rail X. Gantry sides are RHS with spacer block connection to gantry. Y axis ballscrew is underneath to give a low bending moment on the gantry sides. Disadvantage is risk of collision damage and swarf ingress (needs shield).
Maybe some ideas in there.

[fasteddy]

Hi All..

Mechmate is a very attractive option, I am currently going through the huge amount of data on their site to see if I can do the mods I had in mind.. As this will be my 3rd machine, I have learned some (sometimes painful) lessons that I want to correct for this build.. I have been a cabinet maker but now have a back injury that can often make this type of business difficult.. The idea of a cnc was to allow me to basically sit on my ass most of the time, either drawing on the computer, or being hypnotized by the cnc strutting its stuff..

Things I really want on this build are;

Open bed (with a T-track bed that is removable)
Rack and pinion drive (dual for 2 motor x-axis)
Supported rails for x and y axis
Vacuum bed (using T-track?)
Tool changer

If I can get some of the Mechmate parts done at a reasonable price, and can incorporate these mods, I will almost certainly go that route..

Routercnc..

I agree with your design comments.. My first cnc was an endless battle with dust on exposed lead screws and bearings, really have to have a very efficient dust extraction system, or even better, tuck all the exposed stuff out of the way..

Steve..

[fasteddy]

Hi Wobblybootie (nice handle)..

Have looked at that site, but those cnc'c seem to be the type with the gantry going under the bed.. That would not allow me the open bed style machine I want so cant go down that route.. Am going to post a thread or two at mechmate and see if anyone has tried a flavour of the design in the style I want, if yes then I may get some pointers that way..

Steve..

[routercnc]

Florins machine had some nice features:
http://www.mycncuk.com/forums/showth...ght=#post13864

[fasteddy]

Hi routercnc...

Thats it!!!! That is exactly what I am looking for... Thank you sooooooooo much!!! Will jump on him and pick his brains to bits... Yipppeeee!!!


Steve... :-)

[fasteddy]

Hi Chip...

I have found a few people on the mechmate forum from the UK who have built them, including a guy that made one in his garden in the open air..! I agree that the mechmate is an awesome machine, but also quite costly although having all those people on that forum for support will almost certainly save a few quid and loads of head-scratching..

But florins machine is, at first glance, exactly what I want so I will try and contact him and see what is involved in making that.. Only thing that makes me hesitate is he has used lead screws on his x-axis and I had always thought that was a no no with that sort of length.. Remember reading many posts about 'whip' but florin must have found a way round it..

Steve