"Sioc" Build Diary

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ShootyMcExplosion
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"Sioc" Build Diary

Postby ShootyMcExplosion » Wed Jan 04, 2017 2:59 pm

So after many months of putting it off, I finally decided to make an antweight. All my parts have arrived, mostly what's recommended in the NanoTwo V2 kit, but using a servo lying around the house as a lifter instead. The working name is Sioc (pronounced like "shook"), and I've designed it to be a front hinged flipper. I'm planning to make the outer shell out of three bent pieces of 1.5mm thick Polycarb, Image
Front view

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Back view

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Side View

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Rear view

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Cardboard plan of the three pieces

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Details of the measurements

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electronics being used

I'm planning on getting a heat gun to bend the polycarb sheets into my desired shape, but for now my main focus is on sorting out electronics issues, such as why one motor takes longer to start than the other when I bend the stick straight up or down, or why I can't seem to connect my flipper servo to the robot and keep a signal. Will update when I can, which might be a little tricky since this is my first robotics build in general.

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Rapidrory
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Re: "Sioc" Build Diary

Postby Rapidrory » Wed Jan 04, 2017 4:59 pm

Looks good!

I'm planning on getting a heat gun to bend the polycarb sheets into my desired shape


You don't actually need a heatgun for 1.5mm polycarb, it folds very similar to stiff card when cold, and is how most of the polycarbonate robots are built.

one motor takes longer to start than the other when I bend the stick straight up or down


Need to adjust the aileron and elevator trims on your transmitter until they start at the same time

I can't seem to connect my flipper servo to the robot and keep a signal


If it's connected when you plug the battery in it should work. If the controller's going funny when you control the servo then that's because the servo's drawing too much current for the controller to handle, and you'll either need a seperate 5v supply or a different servo.
Rory Mangles - Team Mangler

Robots: Too Many...

NanoTwo antweight speed controllers. (viewtopic.php?f=1&t=2128)

ShootyMcExplosion
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Re: "Sioc" Build Diary

Postby ShootyMcExplosion » Thu Jan 12, 2017 7:51 pm

Hi there everyone.
Since last week, I've been able to do some more work on Sioc in my spare time. I've gotten all the electronics sorted out now thanks to finding the trim/adjustments settings on my controller and getting a new lifter servo that doesn't overload the circuit. The Polycarb has been a little trickier however. I don't know if it's the scissors I'm using or whatever, but I can't seem to cut basic 1.5mm Polycarb with them. I can use a box cutter, but for speeds sake I've built myself a custom clamp setup for cutting.

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Above is the setup, where I have two clamps attaching a plywood sheet to a table, and another two clamps holding the PC along a straight piece of wood so that I can run my saw along it. Below is the saw I'm using to make the cut.

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I've gotten about half of the work done with the cutting so far, and while I haven't gotten a heat gun yet, I still can't seem to bend the stuff (although in honesty I haven't really tried too hard yet, who knows, maybe a hairdryer will do the job instead.). Other then that though, things are moving along. It's not much of an update, but I don't want to be one of those people who abandons a build diary after their first post.

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peterwaller
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Re: "Sioc" Build Diary

Postby peterwaller » Thu Jan 12, 2017 8:40 pm

Rather than helping I have always found using heat to bend polycarb gave a much worse bend than just a pair of pliers or a vice.
For cutting I just score along the line and then just bend it again with pliers or a vice and it snaps along the score line.

ShootyMcExplosion
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Re: "Sioc" Build Diary

Postby ShootyMcExplosion » Thu Jan 26, 2017 7:12 pm

Sorry for the length between posts, but I finally have progress made that I feel is worth uploading. I've finally cut and bent the polycarb pieces into the shapes I want, and besides two little cuts I still have to make at the back of the top plate, the frame seems to have fallen into place.

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Here are the pieces loosely placed in their proper shape.

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Here are all 3 separately. For the flipper I'm planning to place the polycarb sheet over the cardboard mockup, and put the polycarb flipper piece over the cardboard where it bends.

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Here is the rough plan I have for the location of my parts. The motors seem to fit snugly on the 45 degree plane on the bottom sheet, I just need to figure out a way to mount them. I'm planning to lengthen the servo arm so that it has a longer reach to allow the flipper arm to reach out further, and have an elastic band attached to pull the arm back in when not in use.

My main technical issue as of now is that sometimes when I am controlling the servo, one of my wheels will start for a second out of nowhere, and then the electronics will stop moving entirely. Any idea what's going on?

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peterwaller
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Re: "Sioc" Build Diary

Postby peterwaller » Thu Jan 26, 2017 7:56 pm

This is normally caused when you use a servo that requires more current than the BEC in the controller can supply so the 5v dips causing problems for the receiver.
There are various things you can do.
Find a lower power servo.
Use a servo that can run from 8.4v and power it directly from the battery voltage.
Add a higher powered BEC.
Rory can probably tell you the maximum current the BEC can provide.
The polycarb parts look really good.

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Rapidrory
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Re: "Sioc" Build Diary

Postby Rapidrory » Thu Jan 26, 2017 8:42 pm

That's looking very neat! A cabletie works well for holding motors in.

As for the glitching drive, seems to be a problem with the new V2 controllers and those servos. Easily fixed with a 6.3v 220uF capacitor across the 5v line
Rory Mangles - Team Mangler

Robots: Too Many...

NanoTwo antweight speed controllers. (viewtopic.php?f=1&t=2128)

ShootyMcExplosion
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Re: "Sioc" Build Diary

Postby ShootyMcExplosion » Fri Jan 27, 2017 9:41 pm

Thanks. Also, to clarify, the 5V line you're talking about is the red wire on the servo? I still have a lot to learn on the electrical side of things.

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Rapidrory
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Re: "Sioc" Build Diary

Postby Rapidrory » Sat Jan 28, 2017 7:56 pm

Yeah, put it between red and black servo wire.
Rory Mangles - Team Mangler

Robots: Too Many...

NanoTwo antweight speed controllers. (viewtopic.php?f=1&t=2128)

ShootyMcExplosion
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Re: "Sioc" Build Diary

Postby ShootyMcExplosion » Wed Feb 15, 2017 8:59 pm

Again sorry for the delay, life had me busy for a moment, but here is another update:

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Here is Sioc as of now. It's actually been like this for close to a week, I just haven't been able to upload my progress until now.

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Here are the wheels, tied into place. I settled on one cable tie a motor, and it seems to be holding out alright. Before they were put into place the wiring connecting the positive side of the left wheel broke, but I soldered it back together.

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Here you can see the capacitor attached to the servo. It doesn't look pretty, but I haven't had any electrical issues since installing it. The main thing I've taken away from all of the soldering was just how well the Nanotwo kit was soldered in comparison!

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One last image of my current progress. Right now my main challenge is fitting the 3 polycarb pieces together. I was thinking of using tiny 90 degree metal brackets to connect the back of the machine to the top, but I'm still figuring out how to do the other connections. One other thing I've noticed about my control is that the turning circle going clockwise is much tighter then the turning circle going anti clockwise. Could this have something to do with weight distribution, or is it to do with the trims (I've fiddled around with them for a while and haven't found a solution).


(It's also becoming clearer to me by the day that my phone is terrible at high quality close ups...)

ShootyMcExplosion
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Re: "Sioc" Build Diary

Postby ShootyMcExplosion » Tue Mar 07, 2017 5:19 pm

Well the time between these posts is becoming far too long, but here's the next update:

So the best piece of news right now is that Sioc drives and self-rights! I've included a video showing both off below: https://youtu.be/uTgT_wc-waU

I've also included a link to an album detailing what the machine looks like in its current state: http://imgur.com/a/1Slkn

In its current state, it can technically compete. However, there are still a number of things left to fix should they need fixing

  • The largest, and also shown in the video, is that Sioc has far less grip on its left wheel when the right wheel isn't in use. The entire machine drifts left constantly when I'm driving it, but if the stick is in the bottom left or top right position, then there doesn't seem to be any grip at all, even when the wheel is spinning at full speed. This really puzzles me, as I don't know what else the weight of the machine can be resting on other than its wheel.

  • The placement of the servo operating the flipper has to be incredibly precise, and even a few millimeters can be the difference between self-righting or not. currently I'm using strips of blu tack to hold it down, and they seem to hold up well enough, only moving when so much weight is put on the flipper that it won't budge (eg. if it's held in your hand while you push the stick).

  • the machine can land on it's side and, if it's held there without rolling onto its back, then it will be unable to self-right. This happened very rarely to me during testing, but the possibility was always still there.

  • I'm still trying to find a way that holds all of the pieces together that doesn't involve tape. Tape seems to be holding out for me so far, but finding some sorta brackets that can bend to the angles necessary has proven challenging.

  • I still want to finish the "texture work" on it. I just need a color printer for that.

Those are the main issues with the bot at the moment. I'm considering starting another antweight shortly, or even possibly a featherweight.

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BeligerAnt
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Re: "Sioc" Build Diary

Postby BeligerAnt » Tue Mar 07, 2017 10:19 pm

ShootyMcExplosion wrote:
  • The largest, and also shown in the video, is that Sioc has far less grip on its left wheel when the right wheel isn't in use. The entire machine drifts left constantly when I'm driving it, but if the stick is in the bottom left or top right position, then there doesn't seem to be any grip at all, even when the wheel is spinning at full speed. This really puzzles me, as I don't know what else the weight of the machine can be resting on other than its wheel.

Because most ants have two wheels and just slide on the front edge of the body/chassis, any twist in the chassis or difference in load on the wheels will affect the drive/grip.

ShootyMcExplosion wrote:
  • The placement of the servo operating the flipper has to be incredibly precise, and even a few millimeters can be the difference between self-righting or not. currently I'm using strips of blu tack to hold it down, and they seem to hold up well enough, only moving when so much weight is put on the flipper that it won't budge (eg. if it's held in your hand while you push the stick).

Using blu tack to hold a flipper servo doesn't sound too reliable for full combat. Cable ties work well, but may need some double sided tape (or even blu tack!) to prevent any slight movement.

ShootyMcExplosion wrote:
  • the machine can land on it's side and, if it's held there without rolling onto its back, then it will be unable to self-right. This happened very rarely to me during testing, but the possibility was always still there.

If it can happen, then it will happen every fight! If you place it on its' side can you get it to topple over by firing the flipper and/or spinning the wheels? Sometimes it only takes a slight shift in weight to topple over to a better orientation.

ShootyMcExplosion wrote:
  • I'm still trying to find a way that holds all of the pieces together that doesn't involve tape. Tape seems to be holding out for me so far, but finding some sorta brackets that can bend to the angles necessary has proven challenging.

Tape works really well in antweights, particularly for light weight, non critical parts like wiring and receivers. Brackets can be made from polycarbonate sheet, folded as required, or from small blocks of polycarbonate, HDPE etc.
Gary, Team BeligerAnt

ShootyMcExplosion
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Re: "Sioc" Build Diary

Postby ShootyMcExplosion » Wed Mar 29, 2017 9:04 pm

Hi there, just a quick update (wow I'm terrible at updating this). Sorry for no pictures this time. The robot is now driving in a straight line, so that's my greatest problem done. I've added bulges to the sides of Sioc so that it can self right from any angle. The flipper arm has now been completely secured by a proper linkage, and can now retract itself rather than relying on the arm returning to the base position by itself. I'm also now planning to build a second antweight that will be 4 wheel drive and that I'm hoping will be very sewer snake-y.

TeamSeismic
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Re: "Sioc" Build Diary

Postby TeamSeismic » Thu Mar 30, 2017 10:48 am

Do you have an ESC connected to the motors or is it plugged directly into the receiver?

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Shakey
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Re: "Sioc" Build Diary

Postby Shakey » Thu Mar 30, 2017 11:05 am

TeamSeismic wrote:Do you have an ESC connected to the motors or is it plugged directly into the receiver?


He is using one of Rorys NanoTwo's for an ESC.
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