where to start?

[luke11cnc]

if your using 25 mm supported rails you will need 60mm to mount them on don't buy the bearings for this size as I will give YES give you 4 as I have extra

James

[luke11cnc]

would he be able to use a chain in stead of a belt jazz

James

[Jonathan]

would he be able to use a chain in stead of a belt jazz

That's possible yes... but I believe it's more difficult to eliminate the backlash inherent in a chain/sprocket.

[JAZZCNC]

would he be able to use a chain in stead of a belt jazz

James

Yep every thing jonathan said, plus there's nothing to be gained over R&P in performance or cost, infact it would cost more and perform less. It can't even compete with Belts on any front.
To be off any use you need good quality chain and sprockets which arnt cheap. Cheap chain stretchs like crazy untill settled down, It needs dry lubing and crap gets into the links plus it's noisy as hell.! (Mind R&P aint exactly quite.!)

Basicly IMO it's not cost affective enough to give good performance without using expensive chain & sprockets so then whats the point.? . . . . . Unless your names Renthal and you own a chain factory. . . . there's far better options.

Suppose it's further up the horse scale than threaded bar thou.! . . . but not much. .:rofl:

Edit: That was a joke Chain users and send all complaint's to hell coz I don't give a stuff. .:twisted:

[Jonathan]

Suppose it's further up the horse scale than threaded bar thou.! . . . but not much. .:rofl:

and two below ACME screws....

[JAZZCNC]

and two below ACME screws....

Oh be carefull Jon your on sacred ground with the Acme brigade.! . . . They'll be after your Balls (screws).:naughty:

[trounce]

Sorry JAZZ mean't to post that that link to the belt driven machine and totally forgot..



I think I've made my mind up now to go with R&P instead of the belt. I need to start with something that seems a little more idiot proof and from what I've seen it seems the easiest for me to be able to achieve.

I bought myself the box section today because If I don't start spending I know I'll keep putting this build off and never get it started.
I bought 15m of 60 x 60 x 3 box and 12m of 60 x 30 x 3 for a total of £180 and had the shop cut it into smaller lengths to fit into my van.
This will just be for the bed section and not the legs etc as I'm aiming to put some more pennies away to be able afford alluminium profile for the bottom section or at least some other much lighter alternative that can be unbolted and taken apart.

I think I'm also gonna have to find a way to make the bed come apart aswell or at least some of the supports because If I ever have to move it all I'll need a crane :rofl:

I think with the bed I'm going to go with 9 x 5 to be on the safe side and as these linear bearings come in at 2750mm I may aswell stick to the same length.
http://www.ebay.co.uk/itm/2507409735...84.m1438.l2649

Again thanks so much for all the replys, I hate asking so many questions but this is so alien to me and quite bamboozling at times

[Jonathan]

Oh be carefull Jon your on sacred ground with the Acme brigade.! . . . They'll be after your Balls (screws).:naughty:

We'll see...

What about using 16mm ballscrews (RM1610) and rotating ballnuts. You save buying the end bearings, and the angular contact bearings aren't so expensive as they're not so big as with 25mm screws. Should get a very decent feedrate. Just a thought...

[luke11cnc]

all I'm going to say is hee hee hee

James

[trounce]

The space issue is really only a problem whilst its being built, I have a galvanised shed in the garden that's 10' x 12' so as long as it fits in there I'll be ok. My main concern was actually moving it because I'll be building it in a garage that I rent next to my house.
I've designed the bed so that a large chunk of the inner supports can be unbolted and removed to make it much lighter when moving it, though I'm not sure if all these supports are really needed.

The outer grey sections will be welded together and the inner sections will be bolted to the frame, though I may get rid of the centre bolts and just have a fully welded cross shape in each inner section.
Outer is 60 x 60 x 3 and the inner pieces are 60 x 30 x 3.
This is my first attempt using google sketch up and I'm pretty chuffed with the outcome :tup:

If you could let me know if it looks ok or if its overkill with all the inner sections?
Cheers
Neill