Are you searching for a new, cheap power supply for your CNC project? Well, here you have two options for a 24V / 8A supply.
I bought Sonyang for $35 just here. I don’t remember how much I paid for the MW one, but for sure it was in the same range. So here are the guts, Sonyang on top, MW below.
Some things to point out:
- Yellow plastic cover on MW is not well designed: can’t be fully opened (I will just remove it).
- Soldered fuse on MW, socket fuse on Sonyang.
- Dual output 24V terminal on MW; triple on Sonyang.
- Way better output rectifier heatsink on Sonyang.
- Overall larger components on Sonyang.
Of course a visual inspection of the boards doesn’t tell the full history, but to me, there’s a obvious choice.
Update: Second power supply brand is “Meang Wel”, not “Mean Well” as I thought. Real Mean Well power supplies seems to be a lot better.
I’ve got these motor mounts from rattmmotor88 ebay seller for just $15.67 each one, shipping and hex screws included. Shipping was really fast (fedex), just eight days (I use to wait 30 to 50 days for items from china).
Packaging could be better; there are some scratches, but nothing you can’t fix with a file. Internal milling is great. External sanding finishing looks nice, but flatness is somewhat compromised; milling finishing for mounting surfaces would have been great. I don’t understand why they make motor recess 42mm diameter when it should be 38mm; anyway this is not a serious issue. Of course a critical parameter in these mounts is the space they add between motor and mount surface; 40mm in this case.
As this kind of mount allows a lot of play between leadscrew axis and motor axis, you should be careful every time you install X or Y motors, especially if you’ve got heavy motors and/or your couplings are “flexible type”.
Posted in All, CNC
Tagged new stuff, reviews
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Cheap chinese routers: will be worth? That’s the question (or was, for me). So here’s my new machine; well, just a frame. US $1040, shipping included. Here’s the link. I’d rather choose this machine instead the most popular chinese router … Continue reading
I’m quite tidy. But when I’m working, I should move from my chair to get any tool. So every tool I grasp ends on my table (because I’m too lazy to put it back), and after some days my work area turns into a mess, so later I should spend a lot of time putting everything in its place. But now I have this:
This is a really cool tool organizer: compact, cute, wheeled. Having your tools at hand, fast and easily, makes a difference. I’m in no way associated with Keter, and for sure there’re another brands similar products, but this is a great product.
When I was a CNC girl, I thought things like “Once you make one, you can do thousands, easily!”, “Acetal is the perfect plastic for precision parts and cuts like butter!”. OMG I was so naive. Making these parts were really a pain in the ass. That’s why.
Acetal has internal stresses. This mean that if you remove a significant mass from a block of acetal, the final shape will warp a bit. I knew that. But what I didn’t know was that sometimes this natural “stress relief” can take hours. So one day I was turning a lot of these parts, everyone having a perfect bearing fit. But then, on the next day, the bearing fit was really tight; the parts have had shrank a little bit. May be acetal I got wasn’t annealed? Or may be I should anneal these parts? (yes, plastic annealing is a topic).
BTW, in this specific case, a bearing housing should, ideally, not divert more than 5-7um from the nominal size: 10um less and the bearing will not fit; 10um more and the bearing fit will be too loose.
Now the other issue: long aluminum crosslide = noticeable thermal expansion. So the table temperature will change after stepper warm-up. And, it will change again after some machined parts. From what I remember a machined radius can easily divert 0.03um because of thermal expansion. And re–homming after temperature changes can be a bit misleading.
The good thing is that, once you understand these issues, making something to avoid or reduce them is not too hard. The bad is that now I have a full bag of black plastic decoracion parts (not the ones in the pictures, of course).
Posted in All, CNC, Sherline