I’d like to build a simple 2 DOF planar arm (so you can attach a pen as an end effector and draw on paper). See the 1st image below.
The arm is mounted to a table or platform so it can move in the axis of the paper it is drawing on.
I can’t figure out from the servo erector pages how all the brackets, hubs, extensions etc. work.
I want 2 links, 2 revolute joints, a fixed base that I mount to the table / surface.
Tech support indicated the ASB-09 and ASB-10 and ASB-04 would be useful. I did find two pictures of arms that contain the first 2 links I want to build but I don’t know what the parts are, and I’m not sure what to use to mount to the table. I see some aluminum tubes too that would work as the links between the brackets.
Say the 1st 2 links of the 1st arm below which looks like its just brackets, and another option the 2nd 2 links of the 2nd arm below which use the aluminum tubes as links (ignore the rotating base).
Can anyone identify those parts? Much appreciated. Also will these brackets work with HS-425BB servos? See 2nd image below.
Thanks Jim, I had looked at the AL5D parts list and diagrams while waiting to hear back, I still can’t figure out the 2nd joint.
I’ve attached a picture from the “about the servo erector…” page with callouts asking about the parts. I think this is what I’d like to base our arm on.
If anyone knows what the parts are or has a better idea, please let me know.
The base joint looks like an ASB-04 with a long C bracket ASB-10? I could mount the ASB-04 to the table?
Looks like the C bracket goes to a hub and then a tube, then a hub and another C-bracket?
The 2nd C bracket connects to the servo horn, and the servo is in a bracket, but I can’t tell what it is, looks different or maybe it’s just a different angle?
From there there’s a hub, tube, hub and L bracket looks like. I would use a C bracket as the end effector rotated 90 degrees to attach a pen through the holes (where the servo shaft axis would be).
Can someone please confirm those are the parts I’m seeing there? I feel like I’m not getting the 2nd joint right.
Thanks!
Nick
PS: The reason I want to do a 2DOF arm is it’s easy for the kids to understand, it does something fun immediately (draws on paper) which they can program very easily. I also don’t want to cannibalize our AL5D kit, I want that to be 100% when we have time to put it together.
Yes it’s an ASB-06.
Yes another HUB-08 + tube.
Yes that is an ASB-09 and ASB-04 and ASB-06.
Yes, it’s an ASB-10. No, that is an ASB-13 it holds two servos. It is similar to the ASB-04.
You lost me on the last question. We have two methods of rotating.
BR-NS lynxmotion.com/images/produc … m/br01.jpg
HDMAP-NS lynxmotion.com/images/produc … mab-kt.jpg
Got the arm built thanks to the parts list replies. As expected due to long links and both joints being identical servos, the base joint hunts after moves. We want to shorten the links and lighten the load on the base link by using a “micro” servo and parts for the 2nd joint and link.
I bought some of the Lynxmotion micro servo brackets ASB-301 and an ASB-22 (which was the wrong part). Please see the questions in the attached photo. Want to make sure I get the right parts to make the 2nd joint and link use a micro servo.
Also to be specific, what Lynxmotion calls “micro” servos (e.g. the HS-225) are what we’d call “mini” in the RC world I think? Micros are 9g and less typically at least in the heli world.
Don’t know what you are talking about. We call the 225 a mini servo. We call the 85 and the 81 micro servos…
HS-225MG (67 oz. in.) Mini Servo
Size = Mini
Range = 180°
Voltage = 4.8 - 6.0vdc
Torque = 67 oz.-in.
Weight = 1.1 oz.
Speed = 0.11s / 60 degrees
Full specs
The 300 series brackets are for the HS-85 (micro). The 301 fits around the servo, the 302 and 303 are the mating “C” brackets. The only bracket we have that fits the 225 (mini) is the ASB-26.
There is no easy way to get 270 degrees.
The hubs and tubing attach to the micro brackets with HUB-08, same as the standard and 1/4 scale brackets.
