Building B-Carve

Tool: 1/4" 2 fulte
Slot: 10mm (*)
S: 23800rpm
DoC: 10mm (the plate’s thickness)
WoC: 0.2mm
F: chatter started around 1100mm/min, I dialed back to a safe 700mm/min

(*) therefore the tool diameter to slot width ratio was 63.5% . It would be even safer to start at 50% (i.e. 1/4" bit & 1/2" slot) to make the curves smoother and chip evacuation better. I just pushed it over a bit to save some time. It will still take hours to finish all (6) plates.

The chipload that your machine can take is a “personal” thing. Each machine will have its own limits before it starts flexing one way or another (and therefore chattering). Unless you have a Haas :slight_smile:

B-Carve’s rigidity (and therefore chipload capacity) is expected to go significantly higher once the alu plates are on. This is what I am trying to cut while using the plywood plates, so I am hitting a limit pretty fast.

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@EliasPolitis

Thank you! I understand that all machines are different and your setup provide me with atleast one data point :slight_smile:
No Haas in my shop, just a diy CNC-rig with MDF gantry & SBR16 rails.
In alu I currently run 1/8" bit @ 1400-1800mm/min and DOC 0.2mm with pretty ok result despite it not being truly solid/rigid.

CAD/CAM is Easel up untill now but I am slowly migrating more and more over to F360 hence my interest :smile:

Inkscape & jscut till I made the switch to F360 last fall.

I struggled initially with F360 and due to very limited time to play around it have taken me a while to feel proficient enough to make the leap :joy:

That was interesting… I got a couple of freezes mid-job. I checked out RPi’s dmesg and found a bunch of crazy USB error messages.

Up till recently, the physical layout was X-Carve, X-Controller, RPi. Now, in order to save same workbench area, it’s X-Controller, B-Carve, RPi, which means that that randomly picked USB cable was crossing behind the machine to reach the controller. It seems that we were hit by the EMI trolls! (Could it be the two Y motors? )

I found a proper cable with a ferrite on one end at work. That worked.

Production resumed.

2 down, 4 to go.

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Nope, the new USB cable was not enough. I had another disconnect. Bypassing the X-Controller’s USB pigtail did the trick. It seems I was not the only one.

I also took the opportunity to route the USB cable towards the back. All it took was filing a little notch on the top panel.

Rear Y plates.

2 more to go.

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It seems that the USB bulkhead connector has been giving several people issues lately.

I recently had to replace the cable and attached PCB (start/pause/cancel buttons)

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any updates?

First Easter break, then an incident (fortunately unsuccessful) at my wife’s school got us watching 13 Reasons Why at nights.

I’m planning to make some time for the X plates this week.

was your design based on a grabcad model? Bc I found one the other day that seemed to have some resemblances.

I did research several models as mentioned in the beginning of the thread here , but was not happy with everything they had to offer. So I kept some clues and came up with my own design.

Here was the main idea:

  • I settled with 15mm rails and 16mm ballscrews
  • simple setup for both X and Y, thus end plates everywhere (as opposed to boxes and braces)
  • therefore the ballnut mounts needed to be coplanar to the rail blocks
  • for the X everything is bundled into a custom C beam
  • for the Y after several iterations I came up with the solution of having both rails and ballscrews bellow the work surface (a) for maximizing X travel and (b) for better dust protection

These two snippets are the essence of this build.

Btw, I’d be curious to see/compare the grabcad model you discovered if you have a link.

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X plates, check.

Showtime…

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It looks great!

Awesome!

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Congratulations that really looks like a very capable machine.

really interesed to hear your first impressions and things you would have done differently in hindsight. if any :slight_smile:

Hey everyone, thanks for the stamps and everything :slight_smile:

@anon68752607 some preliminary testing has shown that compared to my X-Carve double material removal rates are possible. When I started I was aiming for 30% time savings. It now looks like 50% and I am confident it can be pushed even further with appropriate tuning of toolpath parameters. Considering that the #1 goal of this build was “sleep more”, this only makes me happy.

One thing I would have done differently which has also been mentioned earlier in this thread: I would get the ballscrews with their ends premachined and ballnuts as a kit. The cost savings were not worth the time penalty. It was almost a couple of extra months of waiting for shipments and trial & error.

Design-wise there is room for one more thing that I have been thinking lately. I might leave this for a sequel… Building B-Carve Season 2: The Return. We’ll see. The script is there, I will have to talk to the director and producers :smiley:

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Get all the bugs worked out then start making kits!

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