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06-16-2023, 01:18 AM
(This post was last modified: 06-16-2023, 12:48 PM by Dyne.
Edit Reason: Photo of new tube on Antenna
)
I have a working (if ugly and somewhat overly complicated) antenna mechanism.
First, I reversed the servo mount mentioned last time (orange) to move the servo further to the starboard side of the head, since I needed a bit more space between the servo rotation plane and the antenna. I didn't need quite as much space as that mounting position provides, but if I moved it less then I'd completely block the screw holes that attach the mount to the head.
Instead I made the hub of the printed servo horn (yellow) taller to make up the difference. At the end of the servo horn is a small standoff sitting against a 623zz bearing.
![[Image: 20230613-antenna-prototype-01.png]](https://www.niflheim.net/droidbuilding/images/LD-F1/20230613-antenna-prototype-01.png)
Surrounding the bearing is a bearing retainer (red). This is basically a slotted track that permits the bearing to slide forward and back. This is necessary because the servo's rotation carries it toward/away from the antenna (black). The retainer also has a small protrusion that is screwed onto the end of the antenna mast.
![[Image: 20230615-antenna-prototype-02.png]](https://www.niflheim.net/droidbuilding/images/LD-F1/20230615-antenna-prototype-02.png)
The result is that rotating the servo moves the retainer up/down, and the antenna goes with it. It's not a huge range of motion -- a maximum of 34 millimeters, which is the diameter of the arc described by the center of the bearing -- but it's better than nothing.
Some of the wobble you see there is because there's a little bit of interference near the top. I think there is slightly less clearance between the antenna and the head geometry up there. I was seeing similar interference in the same place on the previous prototype. The rest of the wobble is because the Antenna is a bit loose in the hole in the head. I can't do much to stabilize that on the inside of the head -- as you can see in the video, the top of the servo range puts the retainer very close to the part of the head that the antenna goes through.
Instead, I have cut a small piece of styrene tubing that has an ID that more closely matches the antenna mast's OD, and glued it to the outside of the hole in the head. I might make a shim as well.
![[Image: 20230615_183133-smaller.jpg]](https://www.niflheim.net/droidbuilding/images/LD-F1/20230615_183133-smaller.jpg)
I could revise the hole diameter in the head model, but may not ... it could cause issues if the exact tubing isn't available, or the hole doesn't print as cleanly (it's horizontal in the normal print orientation).
In any case, with the antenna working, I'm considering putting the top door on the head (blue) and making that functional as well, mostly just to give LD-F1 a little more life. I would need to make some sort of hinge (probably involves cutting a few holes into the head) and come up with a mechanism to attach the servo to the door. Fortunately, the servo mount that I built in for this purpose is a lot more conveniently oriented than the built-in antenna servo mount was.
![[Image: 20230616-top-door-servo.png]](https://www.niflheim.net/droidbuilding/images/LD-F1/20230616-top-door-servo.png)
In the meantime, I've redone the receiver-to-servo control lines. This involved a lot of faffing about with JST SM connector crimping and rehousing, which is always a bit of a pain. Part of the goal was to remove the loop of extra green, yellow, and white wire in the head (which you can almost see as a background blur on the left of the Antenna closeup photo), but mostly it was to add new lines (red and blue) to support these new servos, as shown on this updated power plan. There's also a new wire for future use (I have long had something in mind that I could put in the side bay instead of those vents, but I'm not ready to commit yet.)
![[Image: power-plan-3.png]](https://www.niflheim.net/droidbuilding/images/LD-F1/power-plan-3.png)
BTW, I swapped the Left and Right Tilt Servo on this diagram compared to earlier versions, in order to match the actual wire color order. I also added black rectangles indicating JST connectors for the servo signal wires and the LED sequin.
Incidentally, we've now passed the anniversary of what I consider the true start of this build (back in Post #13 on June 15th, 2022, one year ago yesterday. This post was started and would've been made on the actual anniversary, but I needed to get more screenshots and pictures.)
Almost everything prior to June 15th consisted of 3d sketches, concept work, and models that ultimately were rebuilt from scratch (body shells) or weren't used at all (flexible tracks).
First, I reversed the servo mount mentioned last time (orange) to move the servo further to the starboard side of the head, since I needed a bit more space between the servo rotation plane and the antenna. I didn't need quite as much space as that mounting position provides, but if I moved it less then I'd completely block the screw holes that attach the mount to the head.
Instead I made the hub of the printed servo horn (yellow) taller to make up the difference. At the end of the servo horn is a small standoff sitting against a 623zz bearing.
Surrounding the bearing is a bearing retainer (red). This is basically a slotted track that permits the bearing to slide forward and back. This is necessary because the servo's rotation carries it toward/away from the antenna (black). The retainer also has a small protrusion that is screwed onto the end of the antenna mast.
The result is that rotating the servo moves the retainer up/down, and the antenna goes with it. It's not a huge range of motion -- a maximum of 34 millimeters, which is the diameter of the arc described by the center of the bearing -- but it's better than nothing.
Some of the wobble you see there is because there's a little bit of interference near the top. I think there is slightly less clearance between the antenna and the head geometry up there. I was seeing similar interference in the same place on the previous prototype. The rest of the wobble is because the Antenna is a bit loose in the hole in the head. I can't do much to stabilize that on the inside of the head -- as you can see in the video, the top of the servo range puts the retainer very close to the part of the head that the antenna goes through.
Instead, I have cut a small piece of styrene tubing that has an ID that more closely matches the antenna mast's OD, and glued it to the outside of the hole in the head. I might make a shim as well.
I could revise the hole diameter in the head model, but may not ... it could cause issues if the exact tubing isn't available, or the hole doesn't print as cleanly (it's horizontal in the normal print orientation).
In any case, with the antenna working, I'm considering putting the top door on the head (blue) and making that functional as well, mostly just to give LD-F1 a little more life. I would need to make some sort of hinge (probably involves cutting a few holes into the head) and come up with a mechanism to attach the servo to the door. Fortunately, the servo mount that I built in for this purpose is a lot more conveniently oriented than the built-in antenna servo mount was.
In the meantime, I've redone the receiver-to-servo control lines. This involved a lot of faffing about with JST SM connector crimping and rehousing, which is always a bit of a pain. Part of the goal was to remove the loop of extra green, yellow, and white wire in the head (which you can almost see as a background blur on the left of the Antenna closeup photo), but mostly it was to add new lines (red and blue) to support these new servos, as shown on this updated power plan. There's also a new wire for future use (I have long had something in mind that I could put in the side bay instead of those vents, but I'm not ready to commit yet.)
BTW, I swapped the Left and Right Tilt Servo on this diagram compared to earlier versions, in order to match the actual wire color order. I also added black rectangles indicating JST connectors for the servo signal wires and the LED sequin.
Incidentally, we've now passed the anniversary of what I consider the true start of this build (back in Post #13 on June 15th, 2022, one year ago yesterday. This post was started and would've been made on the actual anniversary, but I needed to get more screenshots and pictures.)
Almost everything prior to June 15th consisted of 3d sketches, concept work, and models that ultimately were rebuilt from scratch (body shells) or weren't used at all (flexible tracks).