Question Things I wish I'd got correct first time

Hi all

I just wanted to write a quick piece to highlight a couple of points to take note of before you start your CNC journey!

1. Content item number 6, the orange X-Z connector position. Take note of the way you slide this piece into the X-Z axis linear tracks. The arms that sticks out must have the kink facing down towards the bed not up in the air.



2. Label the cables coming from each axis motor, when I threaded them through the flexible hose, I couldn't tell which one was which, a quick spray of grease down the line also helps with pushing it through.

3. My drive pulleys often come loose from the spindles for the Y axis (which leads to unplanned design modifications! ) put some NOT permanent thread-lock down there to keep them in, I also ordered some longer grubscrews to add to the friction. I will eventually get an engineers vice, use the Z axis to drill a hole into the spindle so the grub screw locks in tight and hold them together.

4. Extraction nozzle which goes on the underside of the tool holder will touch/cause problems the linear tracks on the Y axis if you get too close, I've raised my bed up using a thick piece of 20mm MDF (glued to the hardboard bed) which gives me that extra bit of room so I can get to the edges, not perfect but helps.

Kindest Regards,
Alex

heustec wrote: Hi all

I just wanted to write a quick piece to highlight a couple of points to take note of before you start your CNC journey!

1. Content item number 6, the orange X-Z connector position. Take note of the way you slide this piece into the X-Z axis linear tracks. The arms that sticks out must have the kink facing down towards the bed not up in the air.



2. Label the cables coming from each axis motor, when I threaded them through the flexible hose, I couldn't tell which one was which, a quick spray of grease down the line also helps with pushing it through.

3. My drive pulleys often come loose from the spindles for the Y axis (which leads to unplanned design modifications! ) put some NOT permanent thread-lock down there to keep them in, I also ordered some longer grubscrews to add to the friction. I will eventually get an engineers vice, use the Z axis to drill a hole into the spindle so the grub screw locks in tight and hold them together.

4. Extraction nozzle which goes on the underside of the tool holder will touch/cause problems the linear tracks on the Y axis if you get too close, I've raised my bed up using a thick piece of 20mm MDF (glued to the hardboard bed) which gives me that extra bit of room so I can get to the edges, not perfect but helps.

Kindest Regards,
Alex

Thanks Alex for your feedback - great stuff.

1) easy mistake to make

2) Using tape of different colours can help identify the axis wires. you can also figure it out from the length of the cables. They are all the same length so one will be longer / shorter than the other when they come out on the electronics side.

3) Make sure to tighten well first with the nut - as tight as possible before adding too much friction to the pulley rotation. Then tighten the grub screw. Make sure the grub screw is seated in the alignment hole (but don't tighten totally until the nut is tight).


4) Sometimes it can also be a good idea to then machine the top surface of the MDF that you glue down. That way the bed is super super accurate in the X Y plane. We do this for vacuum tables also - its great for engraving projects.

Got started on building my 420. Though I have never built anything like this before I have built any number of kits from Aifix Spitfire to complete Ikea kitchens, so I followed my usual process.
Everything out of the box, all parts identified, separated counted then placed in bags and labelled with their number. For a couple of parts I had received an extra one, this I wrote down beside the picture in the manual.
Boy, am I glad I did that. As I approached the end of the build I noticed that I had one of Part No. 48 (the brass spacer that sits between the bearings) left over. Immediate panic as I thought I had failed to insert it in one of the track roller assemblies- an easy thing to do. This would mean stripping the machine back down until I found the error. Before starting I checked the manual and sure enough this was one of the three parts where I had an extra. Sigh of relief