[nambass]

Guys, I need advise/Help

my CNC is all Aluminium design and on my Z-Axis i have
4 x 15mm Linear Block
0.68 x 15mm Linear Bearing Guide
0.34 meter 12x4 Ball Screw
1 x 12x4 Ball Nut
1 x NEMA 23 motor connected to Gecko G203V Stepper drive unit.

But I just upgrade my normal bosh router to a proper cnc spindle 3.5KW with weight of 8kg. I am afraid my current Z-axis design is too flimsy especially the ball screw design.

I was thinking of getting a proper design what I can even later vit a 9KW spindle with a weight of 33kg on it or just add a belt drive system to the new Z-Axis to increase the torgue, but keep the rest of the Axis as is. So the design I am thinking about should be solid, and capable of handling the increased weight without any problem.

My second question is will the new 8 wire NEMA 34 stepper motors still work with my stepper drive?

Would love to get feedback, advise and maybe if anyone know where I can get the z-Axis Actuator.

[hub]

Maybe add a counter weight or gas- or normal springs to help with the weight if it's a problem.

- Yes it (NEMA34) will work, but without more specs I can't tell how well it will work.

Hub

[nambass]

Thanks Hub

But do you have more information on the counter weight, gas or springs idea?

[ger21]

Do you have any drawings?
I'd recommend a 1605 ballscrew instead of the 12mm.
It's hard to know without seeing what you have, but if I had to guess, I would say that there's no way your machine can take advantage of a 9Kw spindle. I don't you could get anywhere near the limits of a 3.5Kw spindle.

[G59]

Do you have any drawings?
I'd recommend a 1605 ballscrew instead of the 12mm.
It's hard to know without seeing what you have, but if I had to guess, I would say that there's no way your machine can take advantage of a 9Kw spindle. I don't you could get anywhere near the limits of a 3.5Kw spindle.

My thoughts exactly. The linear rails are ok, but the ballscrew should be a minimum of 15mm.
The nema 34 will be fine with a 1605 ballscrew.
I too, doubt you'll make full use of the 3.5kw motor's capabilities as the rest of your machine most likely won't be rigid enough.

[nambass]

Well I tried to draw my current design, bit the linear blocks is not 100% on the same measurements I have, but is giving the idea. This gives an idea of how my Z-Axis is constructed and function. I will later try to complete the drawing to show the full table, but for now, hopefully this gives an idea.

So what you recon, is this rigid enough for the 3.5KW spindle?

[G59]

You realize 3.5kw is almost 5 HP?
5 hp can make a mess of those aluminum extrusions.
If I was on my computer I'd link an existing design that you can look at and make sense of.
Why reinvent the wheel?
This design of yours is weak in many spots.

[hub]

Thanks Hub

But do you have more information on the counter weight, gas or springs idea?

I did design for a gas spring, but didn't install it yet anyway... The idea is that the spring pushes up the Z-Axis against gravity. You need to calculate how powerful gas spring(s) you need to push/pull up the total weight.
Basically, the spring is the taking care of lifting the mass, and the stepper/servo moves the mass up or down, with almost same torque for up & down.

Hub

[nambass]

Oh you killing me!! LOL

SO you recon I myst have a proper welded machine and rather get way from aluminium extruder. Ish, that will mean a new machine, or at lease a new frame and then reuse the current lineers etc.

If so, then do you know of a solid - proper design out there that will get the job done.
What about this one on gabcad.com (https://grabcad.com/library/cnc-router-4)

[nambass]

Thanks Hub

Did you designed a complete machine? Would love to see some designs. Frankly I am now at a dead-end. Seems I need to re-design my machine to be a proper welded machine. Drawing most of the parts in Solidworks is not the biggest problem, and getting them cut on Laser cutter is also not a problem. But getting all this done too perfection taking into account all these smaller issues, I am totally out of my depth.

[hub]

Thanks Hub

Did you designed a complete machine? Would love to see some designs. Frankly I am now at a dead-end. Seems I need to re-design my machine to be a proper welded machine. Drawing most of the parts in Solidworks is not the biggest problem, and getting them cut on Laser cutter is also not a problem. But getting all this done too perfection taking into account all these smaller issues, I am totally out of my depth.

Yes I did, this is my second (current on-going build):
http://www.cnczone.com/forums/diy-cn...nm13-quot.html

Just a few photos so far and basic info, but I'll add more as I go along.

Hub