belt tensioners will probably help. lookin' great so far!!! (i love gears). working right now on a pair of Solar Panels and getting them to track the sun. I believe i'm going to use belts... dunno. Russ from Coral Springs Florida, USA
With regards to labelling, and Ive not used a cnc before, but maybe you could have the machine quickly carve a thin label into the piece before its finished and never have a worry? Heck while your at it, you might aswell start giving all the pieces serial/model numbers. And if you're already doing that, might as well make a large multinational manufacturing firm while you're at it too...
Unless I was to 'engrave' huge text with a 2mm end mill, that would require an extra tool change and resetting the z-height every time. Much easier to just write with a marker :)
Acrylic can be tapped just like aluminium. Also superglued can form very strong bonds with acrylic if you have nice surfaces and don't use to much. A super glue accelerator is also quite useful.
If you can monitor the servo current when gripping it will increase when you start to grip , so you could possibly decrease the servo current once gripped and reduce the stress on the servo , As long as the grip doesn't loosen with decreased current :-)
I'm about to pull the trigger on a PNP glider on Banggood, not sure if I can be bothered fixing my scratch-built one after I broke the main tail boom. Recently I have been flying my C1 Chaser quite often and getting pretty good glide times (like 10 minutes glide from 2 minutes of motor on), flying in FPV and enjoying that.
A while back I fell in love with Pinaut's micro-servo novelty robotic arm ( ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-bLnAJ-mSElE.html ). I experimented a bit with minimal success, and soon realised how much torque is required at full extension if each individual module is not counterbalanced. Sometime later I saw this video ( ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-K6rX1AEi57c.htmlm55s ) and eureka! This is a great example of how little force is needed for movement if the whole assembly is statically balanced. I bet the woman never envisaged someone using her artistic performance in a discussion on robotic arms! :o)
Is there a better way to drive this mechanically, other than belts? Seems like they are somewhat simple to implement - but add loads of variability , slop, and un-rigiditity to a system
Most of the time is simply waiting for the postman. We just need somebody to invent and mass-produce a teleporting device, then I could get things done much quicker :) I do record video for various projects fairly regularly, but there is very little connection between the regularity of recording and the regularity of uploads, this robot thing is a perfect example as I just uploaded about 5 months of sporadic progress all at once. Generally I try to keep it going up in some logical order. For example I have already made a web-based tool to track the location of the 'farm rover' and show it on a map, recording all visited locations for use by autonomous pathfinding later, and I can also remotely turn on/off a large 24v spot light for driving at night. www.iforce2d.net/tmp/roverCP.png But since I still haven't got the darn thing driving yet, that will be uploaded later.
I just discovered mynotification "Alert bell" had been deselected for your channel... fixed that quick! The mapping looks interesting, watching this space! :o)
Adding a rubber band to the little gripper will help to hold things, since the servo has to open the gripper and the rubber band will "force" it to close (but I really don't know if the servo likes this, or even want to "open" the gripper from the closed position just a little bit)
Hey! I am doing a project involving a 6 dof arm, and I was wondering if this project is still active? The arm design looks amazing and I was wondering if i could inquire with you about it through email! Best regards, JT
Yes, haven't had many problems for a long time now. The only recent issue was the z-axis seemed to get a bit sticky and I broke a drill bit when it didn't lift up enough, but I just used some WD40 type spray on the screw and it was fine after that. Probably not the best lubricant since it seems to dry out after a while but if I hit it with that again every now and then I think it will be ok.
These are nema17. This was actually a pretty bad idea overall, I don't think you want the plans. I think this kind of thing is better done with geared motors.
There are a couple of places that could really benefit from worm gear. I might make some changes later, but since I can make any GT2 gear myself I wanted to try this method first.
Its nice to see you got a way for the arm to work but take my advice, ditch the belts for direct drive. There is too much torque on the arm. Use a planetary gear system and a set of aluminum gears from the RC car world. If you were driving a linear rail, then go for it but for consistent repeatability, the bets will not last and the tension on them are too high. Just My Two Cents
Yeah I learned that the hard way. If I do any more on this, I will be starting from scratch and basing it on geared steppers, which are becoming cheaper all the time.
@@iforce2d You can use Nema 34 or even 23 as depending on the laminated core length, the higher the torque. It seems that companies make high torque steppers in Nema 23 or 34 these days. If you use timing belts and pulleys, then you need a tensioner on it. Consider using belt with tensioner for first stage reduction to increase the torque and direct gear drive for the second/final stage. So all hope is not lost.
