Im new, am a 3D designer. Need a New cnc machine and need advice and guidance

[njhussey]

>Cool guys, How deep are those channels?

They don't need to be as deep as I've illustrated 'em - I think 2mm would be under-doing it a bit - mix too little (or if the frame's level is slightly off) and you're maybe gonna end up with bald-spots... I'd calculate for a 5mm thickness of epoxy and don't forget to make the channel wide enough so that the resulting strip of epoxy supports the full width of the rail.

That's about the extent of my knowledge regarding this technique - someone will be along soon to better advise!

Wal.

If you look through the build logs for mine, EddyCurrents and others you'll see that we calculated how much epoxy we'd need. Eddy and I went for approx 5mm.

The width needs to be about 38 mm to give enough either side for the miniscus not to come into play. Also important is to make the bridge wide enough so the epoxy flows ok.

Sent from my Galaxy S5

[FlyHighRC]

Ideal, Yeah allot of measurements, just googled it to get the dimesnions f 20mm rail and the carriage to pu into CAD. once i made up the rails etc i can start the design....

Any design aspects i should need to know that people often do? Save me going back and forth as much :)

[JAZZCNC]

Ideal, Yeah allot of measurements, just googled it to get the dimesnions f 20mm rail and the carriage to pu into CAD. once i made up the rails etc i can start the design....

Any design aspects i should need to know that people often do? Save me going back and forth as much :)

Been busy today but I'll email the SW models in next 10 mins.

[FlyHighRC]

Thanks man, What do you think of the rails and Carriage I posted on the previous page?

[JAZZCNC]

Thanks man, What do you think of the rails and Carriage I posted on the previous page?

Yes these are the type of thing you need and Hi-win are good quality linear rails just expensive. I've sent email and put a little about rails in it.

[FlyHighRC]

Yes these are the type of thing you need and Hi-win are good quality linear rails just expensive. I've sent email and put a little about rails in it.

Hey, thanks, I have seen the email...allot of time saved with using these files! much appreciated..

When you sau adjust to suite do you mean extend the rails or shorten the rails in SW, per manufactured one...no point me making one 846mm right.

Ill get to work on a design now then, Any prefernace on something i have seen dont but to me there is no added benefit... Is it better to put the rails on the side of the machine or on top? The one benefit i see is that if its on top you get much more freedom in terms of fine tuning the machine.

[JAZZCNC]

Hey, thanks, I have seen the email...allot of time saved with using these files! much appreciated..

When you sau adjust to suite do you mean extend the rails or shorten the rails in SW, per manufactured one...no point me making one 846mm right.

Yes just lengthen or shorten to suit your needs. That particular rail is just one I grabbed from a machine design and each machine design will have it's own length version. The Bearing is standard across all machines so only need one instance which you don't change.

[FlyHighRC]

Ideal, Spent most of last night getting the basic design on paper then spent a couple hours on SW going through a few differnt configurations with this one being the easiest and simplest to make :)

What do you think? There is a piece connecting the rail section underneath going across the X axis. Oh and the board would be MDF...SW doesnt seem to have that

[njhussey]

That baseboard will bounce and sound like a drum!! That is unless there are lorts of supports underneath it, but I can't see any bolt holes apart from the ones down the outside? Why have you put the rails below the base, all the swarf will drop onto them! How are you going to mount the ballscrews and stepper motors? You're not doing a simgle ballscrew for the X axis are you? What is the gantry going to look like?

Have you looked at the build threads? Most (I do realise that you don't have to go along the same lines as most other people...however there is normally a reason why most of the builds look pretty much the same!!) look like mine below...

[FlyHighRC]

there is one support under the table though I could easily add another :) The table is above the rails to give more rigidity which ill show from the underneath. The, so bare in mind that its not at all done..still fiddling with the design. I see your point about crap going onto the rails but that would happen in most machines...yours even...rather than have the stuff been blown onto them after running alone your board mine will do the same but the machines rubbish will blow off the board and possibly land on the rails...but either way..Im going to add 3mm poly between the gap of the table and the rail carrages...so efficiently having a box where the machined rubbish(Any jargon here) will stay and be easily cleaned up afterwards :)

Ahh, I was planning on ussing a single ballscrew down the middle? Is that a big no no?

Also, the rails that the gantry run on...is there a good distance to keep them from eachother? Assuming that the closer they are the more slop you could possibly get?

My gantrry is 1 vertical piece with a large 40x40x4, 45deg support