Purchasing new parts for new build.

[samsagaz]

Samgaz:

Channel isn't very stiff and certainly not flat. Welding in braces etc will cause heat and twist etc. So unless you intend machining the Gantry flat and true then I'd suggets you look at better materials that won't need stiffening by welding.

Your Z axis idea with Channel is disaster waiting to bite you. Like Clive mentions the practical side of bolting etc means it won't work but again Channel just isn't flat enough or good enough. Z axis IS THE MOST IMPORTANT part of the machine.

25mm ballscrews are too large for machine this size and will actually lower the performance and increase the costs in ways you haven't realised yet.
The extra interia of the Screw and Ballnut means you'll need motors with higher torque. This will mean using Nema 34 Motors.
Nema 34 motors spin much slower than smaller nema 23 motors for the same amount of voltage. So this means you need higher voltage to get the same or similar RPM.
In practise this means using drives which offer much higher voltage capabilty. While 60-70Vdc will be fine for nema 23 it will cripple performance of nema 34 and the Larger the motor size the worse it will get. So often larger Nema 34 Motors use drives that run at mains voltage levels.

If you try to run tham at same voltage would nema 23 then your RPM will be so slow the machine is crippled.

NorgMonster: This also applies to you and it's the only comment for you I'm making on this thread so start your own if haven't already.

It's common mistake that Bigger is better and offers upgradabilty. It DOESNT. What it does is Cost more and lowers performance.
Nema 23 motor matched with correct size and Pitch ballscrew run with correct voltage on decent quality drive will run rings around and cost much less than Nema 34 motor running on wrong voltage and connected to large ballscrew.

In your case Norgmonster with R&P then you'll probably need nema 34 motors because of the much lower efficiency of R&P. But again if you don't correctly size and match components then peformance will suffer and money will be wasted.
R&P machine requires careful thought towards pinion size and Reduction ratio used along with Motor/Drive/voltage selection.

Both of you are going about this all wrong and you will Both end up wasting money, time and probably resutling in less than great machine unless you STOP buying without knowing what's required and Design the machine before starting. Fag packet drawings while ok for some things just make this CNC building a disater waiting to happen unless you have plenty of experience which you two clearly don't.!!

Stop, take Step back look and learn then design. Then look again before buying any thing.!! . . . If in doubt ask.!!

Thanks for take time to write so much! Really appreciate your words/help.

I Already have nema 23 motors and drivers :/ im 99% sure that they support some high voltaje. I already made the mistake that purchase a lot of stuff a few years ago, will try to make it better now and follow your advices before waste more money :/

Maybe copy the design from other guys?

I really want to use some of the pieces that already have, but if not possible is OK, i want an stiff machine, dont want tooo much precision, but of course if more precise better.

[mekanik]

Samsagas
Do as instructed by jazz, take some time to read the build logs all the way through, then read them again. the forum contains priceless knowledge you just have ingest it.
Good luck
Mike

[samsagaz]

Samsagas
Do as instructed by jazz, take some time to read the build logs all the way through, then read them again. the forum contains priceless knowledge you just have ingest it.
Good luck
Mike

Ok, will try to find some good log that dont use welding :/

[samsagaz]

Guys, some log to recommend me?

As you see im looking for something useful, i was thinking abt use UPN because are not hard to find in Argentina at normal prices (i pay 18USD for 1 meter of used UPN 160mm yesterday).
Companies that cut aluminium and steel with water/plasma/laser are very expensive, but looks like i will need to pay for that service.

I get the idea of use UPN because its used in some of the vids that i post, but of course they guys have good welding equipment and mill the welded surfaces to fix deformations.

Im a little lost now... EPOXY very expensive, machining very expensive.....

[samsagaz]

Two months ago i asked for 1m2 of 10mm aluminium plate and cost 625USD i think thats its too much for my build. so searching alternatives.

Found the Drivers that i talked about a few post ago. Leadshine AM882 manual say that support 80V max, looks like its the only stuff that purchased that can use in the machine

[samsagaz]

Guys, what about IPN? not good to use it ? i can use the rails in top/bottom or at side. To level it i can use epoxy. I was checking IPN and looks like IPN280 have 10mm center wall thickness. I can bolt the IPN easy to side towers

Btw UPN and IPN are bad because the welding or exist other problem?

lx (7590cm4) of IPN280 are good, but ly (394cm4) dont looks very good

btw the UPN that i use to draw the first image was just lx (925 cm4) and ly(96cm4)

[lucan07]

UPN or IPN and angles are not recomended from what I gather because while they have good strength they have a tendancy to twist or deform more than closed box section. As in your video of the fixed gantry machine www.youtube.com/watch?v=K9UA9ZRFwWU UPN when used tends to be closed forming box section for strength.

[Clive S]

Found the Drivers that i talked about a few post ago. Leadshine AM882 manual say that support 80V max, looks like its the only stuff that purchased that can use in the machine

The Am882 are good drives but don't run them at the max voltage as Jazzcnc has said 70V is good.

In post #13 you said you have 1605 ball screws you can use those OK.

Start leaning some CAD Can you get Sketchup or Fusion360 and get a drawing made to start?

[samsagaz]

The Am882 are good drives but don't run them at the max voltage as Jazzcnc has said 70V is good.

In post #13 you said you have 1605 ball screws you can use those OK.

Start leaning some CAD Can you get Sketchup or Fusion360 and get a drawing made to start?

Clive, used sketchup to draw the images that i post. Still searching for complete design/log to get more ideas, at least now skip to use IPN/UPN

[JAZZCNC]

I Already have nema 23 motors and drivers :/ im 99% sure that they support some high voltaje. I already made the mistake that purchase a lot of stuff a few years ago, will try to make it better now and follow your advices before waste more money :/

I'd doubt they'll be more than 80Vdc drives. Which means Max voltage you'll be able to run motors is 70-75Vdc and that's not enough for large nema 34 motor. Your motors are nema 23 which for 25mm ballscrew are not strong enough. I'd also wager if bought from Ebay/china they are high inductance motors which lowers performance.

i want an stiff machine, dont want tooo much precision, but of course if more precise better.

Well if you want real stiffness and precision then dispite what's been said by Lucan07 then I suggest you forget using round rail and buy some profiled linear rails. It's ok for router but when comes to stiffness and precision it sucks compared to Profiled rails and don't let anyone tell you different.