[krsykes]

There are a few things I need help with, but I thought I'd submit some basic details and a picture of my recently completed machine.

It's a 3 axis CNC for my hobby of 1:24 finescale Truck Modelling.
Working area - 455mm x 245mm x 30mm. 500w mains spindle with 1/4 collect.

Mechanics are completely designed by myself and it uses Vexta 266, 125oz steppers, individual drive boards, custom made PSU and control cabinet and machine enclosure.

The axis slides are actually, high quality drawer slides, while the leadscrews are plain and simple M10 threaded rod (allthread) .

I have been totally surprised by the accuracy and performance.

I am now in the process of setting it up to machine some work and need some help. I'll post these shortly !

[krsykes]

Sorry, forgot the picture...!

[Chagrin]

Can you give us the lowdown on those drawer slides? Manufacturer/part number/price?

[InventIt]

Nice enclosure.

[krsykes]

The slides are made by Hafele Limited and I obtained them in the UK, although they are made (I believe) in Germany. I'll post the part numbers later, but I'm amaized at the results. I know they are not something you'd use for a commercial machine, but for a hobby system, they are perfect.

Although the picture doesn't show it, they have a decent sized mounting plate which can attach to the carriage. The longest size available however, is only 600mm, so they will only suit small machines. One advantage is the cost...the largest ones are less than £20(GBP) and that's for a pair.

Another drawback however, is that they may be susceptable to swarf. I'm trying to make some rubber bellows to cover the Y and Z axis. Although I only cut light plastic, so I can blow off with compressed air!

Hope this helps but I'll post the contact details and part nos. when I can get to the catalogue!

[Ferenczyg]

Nice all

krsykes, have you got any detail photo of all the axis? I am interested in take a close look because I can't understand how you have designed your machine to provide the space for displacement of the drawer slides. The ones I know must hang at some point and can't figure your Y and Z, because the enclosure must interfere. I almost can understand X, but from the picture it seems that the moving table cannot displace the full length because the enclosure too.

Not criticism, I really like how the machine looks. I am planning to use drawer slides for my first machine, but footprint and overhang of the drawer slides intrigues makes me doubting. As your machine looks very nice It have raised a lot of interest to me.

thanks in advance

[Ferenczyg]

Ok ok, your drawer slides looks more adequate to make a machine than the ones I can afford at my usual hardware store.

But if you can post more pictures It will be very useful.

Fer

[Chagrin]

Thanks for the followup. I was just about to purchase a pair for my own CNC and was looking for a little more detail on what you had used. No part numbers necessary. The pictures tend to clarify things

[ger21]

The slides look like either an Accuride 3832 or KV 8400. A lot of the stuff Hafele sells is manufactured by other companies.

[krsykes]

Ferenczyg,

Easy design but difficult to describe! However, I've used two pairs of 600mm slides for X (inverted to keep dust out). These pairs are staggered to give a wider span on the X carriage.
Y has one pair of 400mm slides while Z has one pair of 250mm slides. I could have done a better design on the Z, as I've lost some height, but I'm only machining thin sheets so it's not important

[krsykes]

ger21,

Well spotted, I hadn't realised they were Accurides, but yes they are! I was amaized at the quality for the low cost. Seeing as I used the aluminium extrusion system, I could always change to proper slideways later on. By the way, the extrusions are from Item, through MB Systems in the UK. Not cheap, but superb results.

[bennylaird]

You just saved me asking if anyone had used these drawslides. I saw them in the local hardware store last week and thought they would be fine for the y and z axis on my machine, they seem to have very lttle play in them?

[ger21]

Just my personal preference, But I think the KV 8400 or 8405 is a little bit better slide. I buy mine here:
http://www.wwhardware.com/catalog.cf...%23%20Class%20

[bennylaird]

Are these the ones Gerry?

http://www.hafele.com.au/isapi/online/tchff/tchff.asp

[pminmo]

krsykes,
The drawer slides are interesting, how accurate do you think you can cut?

Phil

[Mr.Chips]

Krsykes
Nice looking machine, how about posting some examples of your work.
Regards
Hager

[Hobbiest]

It looks as if you modified the slides so that the moving carriage is shorter than stock. I have been thinking of same thing, but can't figure out how to do this and still get the travel without the carriages rolling off of the bearings. If this is what you did, can you explain how?

[marvinstov]

I used the same type of drawer slides on my home built machine. Modified the slides to accommodate the same travel in both directions. Then was able to cut off a lot of material (length) which wasn't needed. The machine geometry keeps things from sliding off the track and losing all the little ball bearings but you have to keep this in mind when assembling or disassembling things. As for accuracy, it is almost as good as my factory built "Cheap CNC 24-12". It is pretty good when things are in the center of the slide but get somewhat shaky at the ends.

Pic at http://www.cnczone.com/gallery/showp...cat/500/page/1


Marv

[krsykes]

Mr.Chips,

I'll post some pics of some machined work when I have completed the setup. I've just finished adapting the post processor for Mastercam v7, and to my surprise... it works!

I've just got to add a clear lexan door to the front of the enclosure and a dust extractor nozzle, close to the cutter.

I'll keep everyone informed...!

[Ferenczyg]

I always thought that drawer slides, at least the ones I know, will limit the workable area, or if we want to take profit of all the displacement, will increase the footprint of the machine. If you permit some bad ascii art to explain myself, one rolled slide is like this:

=============
############
=============
<------- L ------>

an 'unrolled' or 'unfolded' drawer slide is like this (ignore the · characters plz):

==============
················############
························· ·····==============
<-------- D---------><-------L-------->

I got some questions about that:

1) The overhang D will protrude from the sides of the machine increasing footprint artificially from L to 2D+L being D always unsupported.

2) If we limit the overhang from D to the expected footprint, we are loosing working area

Do you know some tactic to avoid these issues? I am not saying that drawer slides are a bad idea, in fact i think is the paradigm of KISS, but do you think there is a solution for the problem or is something we must 'live with it'?

I just have post this in other thread, I beg your pardon for the crossposting, but now I think this one is more adequate, so if someone can answer I will be grateful.

Fer