Sturdy and Fast all Steel CNC , my first build

[Boyan Silyavski]

80V Digital drives and recommend Leadshine AM882

I see that these get more popular here than the geckos. I read some threads here on the forum. I will go with them

3Nm nema 23 motors like these SY60STH88-3008BF

I had my eye on these as a substitute for the ones that i had to buy from abroad and pay duty. I will look deeper in the specs, but most probably will order them through Zappautomation.

70Vdc PSU preferably unregulated toroidal with correct amperage for all motors.

No idea for this one. I should educate my self how to calculate this amperage and from where to get the transformer.

BOB recommendation is difficult because the one I'd recommend and think is by far the best is PMDX 126 but it's expensive. PMDX.COM - Products for CNC and motion control applications

I was looking into this one. For sure i need a board with 2 LPT connections as i need more ports for communicating with the VFD, turning on mist and vaccum and
On my actual small machine i have trip signals from the VFD and power detection which are very handy in real life. And a second BOb af course. So that BOB wins. Actually its not so expensive for what it offers. I spend more money on my 2 boards.

Ball-screws would be 10mm pitch and 16mm Dia for X & Y axis with 5m pitch 16mm dia. Motors would connect to them using 15mm HTD timing belts and pulleys with 1:1 ratio. This lessens resonance which helps on a steel framed machine and it's much more flexible if you ever want better resolution or higher speed has it's easy to apply a ratio with simple pulley change.
20mm Dia 10mm pitch could be used but really not required at this length and would be over kill, would also restrict performance not increase due to extra inertia of larger screw and ballnut.

All the above I've used on several steel framed machines with gantry's approaching 80Kg so know they work.!!

Sorry, i dont understand you

1. 1610 for long axis that moves gantry and 1605 for the gantry / that moves Z/ and 1605 for the z, correct?

2. I buy belts from Belting online. Should i use the minimum sized belt pulley or go a bit bigger for the size of belt i mean? What is the typical size? I cant seem to find the sheet i used for calculating belts. I remember the AT was stronger but a kind of harder. Obviously either way it should be pitch 5, otherwise i have to go with bigger pulleys

[JAZZCNC]

No idea for this one. I should educate my self how to calculate this amperage and from where to get the transformer.

Will PM you about this has it's easy misunderstood and don't want others reading and not understanding properly so getting into trouble blowing stuff up and electrocuting them selfs.!!!!!

Sorry, i dont understand you

1. 1610 for long axis that moves gantry and 1605 for the gantry / that moves Z/ and 1605 for the z, correct?

No 1610 for Long X Axis and Gantry Y Axis (moves Z).
Then 1605 for Z axis (UP/DOWN)

2. I buy belts from Belting online. Should i use the minimum sized belt pulley or go a bit bigger for the size of belt i mean? What is the typical size? I cant seem to find the sheet i used for calculating belts. I remember the AT was stronger but a kind of harder. Obviously either way it should be pitch 5, otherwise i have to go with bigger pulleys

Don't go less than 18 teeth and I always use 20 teeth has the belt engages pulley better giving better wear.
Don't use less than 15mm wide belts and I find 15mm is perfect size. 20 or 25mm is overkill and wasted money.
HTD is the preferred belt type for it's profile but don't think it would make a big difference here anyway has the belts are only short and not under much stress or heavy loads.

Yes 5mm pitch.

[Boyan Silyavski]

After some fast brainstorm i decided on the CNC4PC breakoutboard 23 coupled with solid state relay board. This board seems more perfect for me:

1.I have my spindle control board from him and the support was great
2. All IC are mounted for easy removal without soldering / this is a big deal, i have repaired breakout boards in the past /
3. All necessary functions and really no extra ones that i dont need and would pay for choosing other boards
4. Better priced than the PMDX 126. When i started adding the spindle control/ not integrated/ ,relays, inputs, outputs, cables and so, the price jumped a lot
5. Some extra jumpers and functions i like
6. Straight out from the box 2 ports BOB with most possible inputs and outputs

Soon will start showing you packets

Thanks again to Dean/ JazzCNC/, now i know quite more than yesterday

Tomorrow will redraw the design for the ball screws.

[JAZZCNC]

Erm.!!! . . . Arturo's stuff is ok but it's no where near has good or well built has PMDX boards.!

[Boyan Silyavski]

Erm.!!! . . . Arturo's stuff is ok but it's no where near has good or well built has PMDX boards.!

He he he, maybe not but i have been with faulty breakout board and had to wait a month for an exchange. The easily removable IC is a feature that living here in Spain is a must.
the local electronic genius has work for 3 months ahead. And i am not into electronics repair really. Sometimes simpler is better.

[Boyan Silyavski]

Today after whole day drawing, considering, redrawing, considering... designed the ball screw assembly on Y/ the long axis that moves the gantry/.

I wanted it sturdy, compact, at the right place and most of all easy to rectify and assemble. Following step by step. Still have not figured the belt length, so a minor correction maybe tomorrow. Other challenge was how to keep the working distance at maximum and at the same time ball screw length minimal.

Designed the hard stops with threaded holes for proximity sensors. A bit overbuild but for sure there will be crashes as the guy is a new to CNC.

Some pictures. Have to finish the design this weekend in order to buy the rails, ball screws and order the laser cut pieces.

[Robin Hewitt]

I don't really understand why the spindle motor is sitting so far below the gantry?

The maximum depth of cut is usually the longest tool that you can fit.

If this to engrave the top of a large object, to clear hold down fixings or what?

[masinecc]

Hi dear friends, do u thing its good ide to use ballscrews RM2505-L=2600mm on both sides of my y-axis. Could it be too long and cause vibrations ? Or should i use R and G instead?

[Clive S]

Hi dear friends, do u thing its good ide to use ballscrews RM2505-L=2600mm on both sides of my y-axis. Could it be too long and cause vibrations ? Or should i use R and G instead?

Welcome to the forum. It would be better if you started a new thread with this.

You could use rotating ball nuts so that the screws remained static. ..Clive

[masinecc]

Thanks for ur reply, would u like to post a picture from that rotating ball nut? Just to see how does it look like. Thanks !