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”.
This gallery contains 16 photos.
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).
Have you ever checked your nose?. I did. Three ones. Here’s how it looks just after some retouch (saddly I didn’t take a before pic):
And here’s a nose from a new spindle (9/16″ through hole version). It’s not just aesthetics… trust me.
Now, if you are happy with your nose, please don’t worry.