1/32 Bit help

I tried doing a test cut into MDF for project I’m making for a customer. I was using the 1/32 bit since there are some small details. I am very new to this so I don’t know much about feedrates and what not so I selected MDF from the materials list and put the .03125 but size and assumed Easel would properly set the speed and depth. Obviously not since the bit snapped as soon as it touched the MDF. I’ve tried searching for feedrates and depth using the 1/32 bit but am mostly finding info for 1/8 and 1/16.

Can anyone help or point me to some info for 1/32 bits and different materials? I need to get this project done soon since my customer has a deadline.

For the curious, my customer is a cake designer and wants a custom made silicone mold (specific Batman image in this case) for cake decorations so using @WarrenDownes Star Wars chocolate mold project as inspiration I am trying to make it for her but because it’s for a small cake and the design has some tight angles it needs to be a small bit, Easel is showing lots of red, uncuttable areas using the 1/16.


You may enter numbers manually, starting almost death feed rate like 0.001 and cut depth as well, until you feel comfortable. Because 1/32 is usually for carving circuit boards for electronics. Cutting will give big stress on it. I don’t use any bits smaller than 1/16. Good luck.

Thanks, I understand about manually entering the numbers, I just kind of assumed Easel would be close but I see it needs manual adjustment. I was just looking for a rough idea where to start. If it’s not feasible to use 1/32 in material like this then I guess I’ll work with 1/16. I did just get access to the two stage cut with detail bits, maybe I can use the 1/16 for most of it then just come along the edges with the 1/32 as a detail bit, maybe since it won’t be cutting much material it will work better. I’ll have to wait until my shipment of 1/32 bits from ebay comes since I broke the only one I had from the starter kit.

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Well I ran some numbers through Gwizard.
Used the following numbers.
1/32 2 flute carbide end mill, 1/2" stickout

WOC (Width Of Cut) .03125 DOC (Depth Of Cut) .003

RPM 14000
Feedrate (IPM) 8.293
plunge 4.1
Surface Speed (SFM) 115 Mfg’s surface speed (SFM) 1500

use Conventional milling

Deflection .0003

As you can see your SFM is very low compared to Mfg’s recommended
when I increase the DOC to .004" the deflection number goes RED at .0004"

Compare these numbers with what Easel said to use.

I did some machining of little pockets in bronze with a 1/32 bit with out problems but I do not remember the numbers I used other than my spindle speed was 18,000 rpm


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Thanks @JonathanYarum I’m glad you like my design. I used a 1/8thbit for mine.

I was talking to someone earlier in the week using the 1/16th bit and they had good success at .5mm depth and around 450mm per minute. But they did say it was very slow

One thing to consider is that it sounds like you’re doing more of an engraving cut. You might consider using an engraving bit like this one from Inventables. This type of bit is much more substantial than a straight 1/32" end mill.

@WarrenDownes, definitely a great idea, when I saw it I immediately sent a message to a friend who owns a dessert business and sent her the video and asked if she needed anything.

Unfortunately the image she wants for the mold and the size it needs to be has several small inside angles so that is why I wanted to use the 1/32. I think I might just run it with the 1/8 then 1/16th detail bit and see how it looks and if necessary I’ll just clean it up manually. Thanks!

@BillArnold, I’m trying to go about 3/8 deep to make the mold to be filled with silicone then that mold to be filled with chocolate and I want straight up and down edges, not angled lines so that bit won’t work but thanks!

@JonathanYarum: Yep, I should have read your post more carefully. I was thinking more about engraving. I’m old and my brain keeps leaking out!

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@BillArnold, no worries, I appreciate you trying to help!