Where to buy good enough engraving bits for PCB milling - Page 1
Forum section: electronics / projects

author: suspension
author_rank: Regular Contributor
timestamp: November 29, 2020, 08:57:58 am
content: I have done some PCB milling before and it works fairly well. However the cheap engraving bits I used break easily and I am looking for better options with possibly international shipping to Asia. I already checked these from companies who make PCB CNC machines such ashttps://wegstr.com/but feel their prices are too much. I have been buying various CNC cutters from the UK shop in the past (When I lived in UK) and as very happy with quality of their tools. 0.1mm engraving bit is available from them for 3 GPB which is fairly priced. I am looking for a supplier with similar pricing but who provide international shipping. Any pointers please?

author: Esquared
author_rank: Contributor
timestamp: November 30, 2020, 06:58:09 am
content: I started writing my reply thinking you where talking about a FEM for some reason lol. I have a lot of experience with PCB milling and I have never seen an engraver fail for no reason. Is it one of the super steep angled ones? I have experience with 60, 30, and 20 degree 0.003" engravers and they are reasonably durable. I have heard the 10 degree ones are finicky so maybe that could be your culprit? Making sure the stock is flat in the machine and has good work holding is essential. When you say break you mean the end of the tool snaps off? or do you mean it won't hold an edge for long or the engraver chips apart? For sure Wegstr is way overpriced and not much better quality wise as the run of the mill stuff on amazon which is where I would recommend buying from as that is how my university stocks the makerspace it runs.

author: suspension
author_rank: Regular Contributor
timestamp: December 02, 2020, 04:55:12 pm
content: yes, I end of the tool breaks. And if I remember right I have tried 30 and 20 angles. . Maybe I was not very careful previously so will give amazon a try once more. I hope you are referring to products such as these:https://amzn.to/3mAZPdBBTW, what you mean by FEM?

author: thm_w
author_rank: Super Contributor
timestamp: December 02, 2020, 10:11:43 pm
content: As mentioned, if its breaking its due to some unexpected force on the tool:- RPM too low- feed rate too high- uneven surface (cutting too deep)- spindle runout too highIf you are in China, buy from Taobao, if its somewhere else in Asia, maybe aliexpress.https://www.aliexpress.com/item/33058654975.html

author: cncjerry
author_rank: Unknown
timestamp: December 03, 2020, 04:38:06 am
content: Tips break from overheating in certain fiberglass boards. Even when they don't if you turn the lights out you can see them glow. If you can somehow cool the tip with forced air they will last a lot longer but the air has to be constant.

author: suspension
author_rank: Regular Contributor
timestamp: December 16, 2020, 03:03:41 pm
content: I already have a coolant/air setup so cooling down is not a problem. Nice tip,I will try that. Thanks.

author: Gregg
author_rank: Super Contributor
timestamp: December 16, 2020, 05:05:32 pm
content: Chatter is a major cause of breaking brittle cutting tools like carbide milling cutters. It basically is vibration between the cutter and the medium being cut that can set up a resonance that snaps the cutter. There can be many causes: The circuit board might not be held tightly enough or the holding clamps not near enough to the cut. The cutter may not be running true and/or the spindle bearings are not smooth. Sometimes changing the speed and feed can reduce chatter to an acceptable level. Sometimes just adding mass to the circuit board near the cut can stop the resonance vibrations; something like a small block of lead. Sometimes adding mass to the machinery will dampen vibration.