Bits

[Robert]

I just completed my first project. I made a sign but had a lot of tear out on the top. What is the best bit to use for pocket letters and shapes. I am trying to attach a picture for comments and suggestions. I used a 1/8 end mill bit. Upcut. 12000 60 speed and feed. Am I able to add a picture?

[Terry]

Switch to a sharp downcut bit. And also make sure that the wood doesn’t move or shake. I use a temporary wasteboard and several screws staying away from my bit path.

[Trevor]

I am having the same problem. My zero was set on the top of material. My cut depth was set at 1″, my material is .760. in the g code i noticed that the last z was at .5300. I am lost with this.

• This reply was modified 3 months, 3 weeks ago by  Trevor.

[Robert]

I am in the CNC kick start program. N the Kick start starter guide, you list 1/4″ Downcut Bit, 60° V-bit, Surfacing Bit, Bowl & Tray Bitas the bits to start with. I purchased those bits. Now, in the lesson 2, you have listed a 1/4 inch down cut bit. I had to stop the lessons and now go looking for a new bit.

Is there a list of all the bits that will be needed through out the course? Maybe an update to the starter guide?

Also which bits do you recommend?

[Miranda]

Hey Chuck,

Since your router maxes out at 10,000 RPM, you are right to slow things down and not just run the included settings as-is.

Inside VCarve, make sure you are editing the actual tool assigned to each toolpath, then recalculating that toolpath after the change. Some toolpaths may still show the old values until they are recalculated. Also double-check that you are updating each toolpath separately, because the pocketing, engraving, and profile cuts use different bits on the Flag Tray.

For this project, the order is pocketing first with the 3/4″ bowl and tray bit, then engraving with the 60° V-bit, then the profile cut with the 1/4″ downcut bit. Re-zero Z after each bit change before running the next toolpath.

If VCarve itself is not saving the tool change, not updating the tool callout, or acting like it is not responding properly, that sounds like a VCarve-specific software issue. In that case, the best next step is to reach out to Vectric support directly. They’ll be able to walk through your version, tool database behavior, and any settings that may be causing that.

Hope that helps!

[Miranda]

Hi Robert,

Congrats on finishing your first project, that’s a big step. Nice work getting that sign made!

For tear out on the top surface, the first bit I’d look at is a downcut endmill. A downcut bit pushes the wood fibers downward as it cuts, which helps leave a much cleaner top edge. That’s why we use a 1/4″ downcut bit for pocketing and profile cuts in several of the course projects.
For pocket letters and larger shapes, a 1/4″ downcut bit is usually a great starting point. For smaller details or tighter areas inside letters, you may need to use a smaller bit, like a 1/8″ bit, depending on how fine the design is. In the Cutter Caddy project, the larger pockets use a 1/4″ downcut, while smaller detail pocketing uses a 1/8″ bit.

A few things to check too:

Make sure your bit is sharp. A dull bit will tear fibers instead of cutting cleanly.

Lightly sand and inspect the surface before cutting. We recommend checking for knots, cracks, warps, or rough areas before machining.

Also double-check your speeds and feeds. Tear out can happen when the bit, material, feed rate, RPM, or pass depth are not working well together.

Hope that helps!

[Miranda]

Hey Robert,

As you move through the CNC Kickstart projects, the main bits used across the course are:

1/4″ downcut bit
60° V-bit
3/4″ bowl and tray bit
Surfacing bit
30° V-bit
1/8″ upcut bit
1/4″ compression bit
1/8″ ball nose / 3D carving bit

The starter guide gives you the core bits to get moving, but a few later projects introduce more specific bits depending on the technique being taught — like inlays, plywood cutting, small detail pockets, and 3D carving.

For recommendations, Andy’s course playbooks commonly point students toward IDC Woodcraft bits, especially for the 1/4″ downcut, 30° V-bit, 1/8″ upcut, compression bit, and 3D carving bit.

Hope that helps!

[Andy]

I wanted to follow up. Did any of these solution work for you?

[Yvette]

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I’m very new to this I’ve got a cubiko cnc and its 1/8 bits, and the course is asking 1/4 bits, do i need to get the 1/4 for my cnc or just get the bits 1/8? I know there’s 4 different bits i need to get but again there so many, so any help would be great. looking forward in doing the course. yvette

[Miranda]

Some course projects use 1/4-inch bits, while others use 1/8-inch bits. For example, the Bit Organizer project uses both a 1/8-inch upcut bit and a 1/4-inch downcut bit.

Before buying any 1/4-inch bits, check whether your Cubiko’s spindle and collet can safely hold a 1/4-inch shank. Since every machine is different, Cubiko’s manufacturer or support team will be the best source for confirming which bit shank sizes your specific model accepts.

If your machine only accepts 1/8-inch shank bits, don’t force a 1/4-inch bit into it. You can still follow the course to learn the workflow and core techniques. Your machine may limit certain projects, but the skills you learn will transfer if you upgrade later.

Hope that helps,

Miranda

[Terry]

For a quick reference guide, I had Claude.ai create a feeds and speeds guide. Below is the link to the document that it created. Claude was trying to optimize it based on chip size and minimize bit heat and wear. Because of the 79 IPM limit on the 4040-Pro Max, it counters this by lowering the RPM for bigger chip sizes. These seem way different than the feeds and speeds from the CNC kickstart course. For example, the 1/4″ and 1″ flycutter at 6500 RPM seems low. For those with practical experience, what do you think of these? I prefer good quality CNC work over maximizing bit life. What would be the recommended changes?

https://1drv.ms/w/c/4db315dd20528edc/IQCPNuVwPr2FQ5TPjD_iWVBVAW93GcpuL010TQBgFKQeMMk?e=CnRKkf

1drv.ms

Genmitsu_4040-PRO_MAX_-_Feeds_and_Speeds.docx

Genmitsu_4040-PRO_MAX_-_Feeds_and_Speeds.docx

[Miranda]

Hi Terry,

Great question. I can see why those numbers caught your attention. A spindle speed of 6,500 RPM is much lower than the settings used throughout CNC Kickstart.

For the Genmitsu 4040 Pro Max, the course generally uses these starting ranges:

• A 1/4-inch downcut bit runs around 50–75 IPM and 16,000–18,000 RPM, depending on the material and project. – A larger 3/4-inch bowl and tray bit runs around 30–50 IPM and 14,000–16,000 RPM, with lighter 0.05–0.07-inch passes on a budget machine.
• A 1/4-inch roughing endmill is shown at 50–70 IPM and 18,000 RPM on the 4040 Pro Max.

Based on those course settings, I would not automatically lower the spindle to 6,500 RPM just to reach a larger calculated chip size. The course takes a more practical, project-based approach. It keeps the RPM in a normal working range for the bit and adjusts the feed rate and pass depth to match the machine.

Since your priority is cut quality, I would start with the CNC Kickstart settings rather than replacing them with the Claude chart. Keep the feed rate within the 4040’s limits, use the lighter pass depths shown for the budget-machine setups, and test the cut on scrap material before running the finished project.

The biggest thing to remember is that every chart is a starting point. Material, bit condition, machine rigidity, pass depth, and workholding can all affect the finished cut. Make one small adjustment at a time and judge the result by cut quality, machine sound, and how cleanly the chips are clearing.