Bit holder for CNC Engraving machine

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On Saturday morning, I bought a Linksprite CNC Engraver at MicroCenter store. Last night, I ruined one of two bit holders made of brass. One end has 1/8" hole for bits and other end has 5mm hole for motor shaft. I tried to search the Internet for stores that sell spare parts for CNC engravers, routers, and 3D printers but I couldn't find a store that sells the bit holders. I'm thinking of building a larger CNC machine that can engrave, rout, and 3D print. I want to buy the parts that I need from one store. Any suggestions?

Given that the way they're holding onto the tool is going to guarantee a certain amount of runout, which is fatal to small high-speed tools. But it was a very cheap machine. I find it odd that the brass coupler failed instead of the tool - or did the tool destroy the coupler when it broke? Won't they sell you more of those couplers? It looks like you can send this thing back if it's been less than 15 days. Real CNC engraving machines cost a lot more, but they work better too.

I've got a list of machine parts suppliers on my site, but I doubt you'll be able to find one that sells everything you need to build that combo machine of your dreams; you're likely going to have to get the printer parts from one or more vendors, the router parts from another, and source a real engraving spindle with a collet system (and not just stick a bit holder onto the end of a motor shaft).

Andrew Werby
www.computersculpture.com

I forgot to set the cut depth per pass and the bit went almost through the thin plywood into the aluminum bed and I couldn't stop the machine right away because it doesn't have E-Stop button and I had to click on the "Abort" button in the software that controls the machine. The bit was not broken. A set screw came off the bit holder and the end holding the bit was ruined. I already have a Dremel rotary tool and I want to 3D-print an adapter that holds the rotary tool in the motor clamp but I don't know the size of the threads in the housing where flexible shaft is attached.

I wouldn't bother; Dremel tools have a plastic frame which heats up and distorts when they're used as CNC spindles. Keep that for occasional hand work and get something else that will last longer than an hour or two into a cutting job. I've heard that some people have had pretty good luck using a Proxxon IB-E as a light-duty spindle for use with small cutting tools, and it has enough speed for engraving with ball-end tools: http://littlemachineshop.com/product...ProductID=2891

What about the Quiet-Cut Spindle at https://www.inventables.com/technolo...et-cut-spindle ? I may need a speed controller and a 24-volt power supply.

Any suggestions for machinable plastic sheets?

I like paper-reinforced phenolic, which machines cleaner than most plastics.

I found shaft couplers in correct sizes at https://www.servocity.com/set-screw-shaft-couplers