Video of CNC machining a double sided part.

[Shinobiwan]

It definitely was interesting to see how you get a smooth finish to something you want made, i.e. roughing out first then going over to get rid of those stepped cuts. I have a couple of questions, hope you don't mind,

Yep same here. I always enjoy seeing how others tackled a job and it often gives me idea's. Utube has hundreds of cnc video's luckily.

how long did the whole job take, and did you watch the whole thing? lol

Too right I watched the whole thing! I'm still new at this so was shitting myself! Me and the machine don't quite have the level of trust where I'd walk off and go play some PS3 whilst it cut but we're working on it lol

Rear side took the longest and that's simply because that was the side I did first and bumped into all the problems there. By the time I'd flipped it over onto the front I'd got it figured out and things went like clockwork.


So for the rear side it was an entire day but only a couple of those hours were spent cutting. The rest was head scratching and making changes. The front side was 6 hours from start to finish including tool changes and pausing the machine occasionally to vacuum the chips.


If I did it again I think I could have it done within 8 hours quite easily, probably less because I was on the conservative side with speeds. I'll be doing some more two sided parts in the future such as wave guides but I want to make a permanent jig setup for those as its something I need to be able to do over and over rather than just a one off like these.

when you were roughing out the main shape why weren't you using the extraction, looks like there would be lots of recutting material?

To be honest I wanted to see what the cutter was doing since its the first time I've tried anything this complex. When its buried in a dust hood you don't see things going wrong! There was recutting going off but its only modelling board albeit the high density variety. Still its easy to cut although highly abrasive on cutters - think worse than MDF.

How did your numatic extractor cope when you was using it? I'm thinking of buying a similar type of HPLV extractor and wondering how the the container size coped with the volume of chips. Also what's their duty cycle like? Could you leave it on for a few hours?

Thanks Adil

The 35ltr drum fills up very quickly during a job like this. I think I emptied it 3 times and it does get tiresome however easy the numatic made it to do just that. If you can definitely go with a larger capacity. I'm going to be using an extra bin before the extractor that will add a couple of hundred litres.

It depends when talking about suitability and is up to the task. My model isn't quite up to the job when your cutting fast, the spindle makes more chips than the extractor can collect. If you slow the feedrate down for a short time it gives it time to catch up. I think really you want HVLP type for CNC's because the sheer volume of chips and dust, you need to be moving lots of air. Problem I had is I wanted a one size fits all sort of thing including power tool use so it had to be what I've got now. If I had more room I'd certainly have an HVLP just for the cnc since these are ideal.

I'm pretty sure the duty cycle is continuous on this one. I've had it running for hours. As a bonus it does kick out a fair bit of heat which is great this time of year!