My first ant was not a success: Onto the second!

All things antweight

Moderators: petec, administrator, BeligerAnt

User avatar
Shakey
Posts: 929
Joined: Sat Mar 13, 2010 8:38 pm
Location: Reading

Re: My first ant was not a success: Onto the second!

Postby Shakey » Thu Apr 20, 2017 7:48 am

That flipper linkage is looking a lot more capable geometry wise. Also I think i spy a pink servo, I started using these as they have so much power that you can afford to have some inefficiency going and they'll still be more than happy. You should be alright torque wise for self righting.

It might be worth shortening B to just the servo arm then you can get the AC connection nice and close to the back of the bot with a long link bar (A). Looks like that'd give you the best angles in the setup. It's also at this point I think I should have picked a better naming scheme than just some letters in that diagram! :D
Alex Shakespeare - Team Shakey:
AWS 44, 45, 49 & 51 Winner - Far too many robots to list!
I sell Antweight Parts, 3d Printing and Custom Designs!

tomchaps
Posts: 24
Joined: Thu Jul 28, 2016 4:51 pm

Re: My first ant was not a success: Onto the second!

Postby tomchaps » Thu Apr 20, 2017 4:37 pm

Yep, I made the servo arm too long on purpose, with a lot of different holes to try out. It turns out the second hole worked best, so I'll trim it. And yeah, it's the servo that was recommended here (https://hobbyking.com/en_us/turnigytm-tgy-306g-hv-ultra-fast-high-torque-ds-mg-hv-alloy-case-3-7kg-0-05sec-21g.html), although it's not really pink.

And, it works! It even self-rights, barely. https://www.youtube.com/watch?v=RC0DYZd2GDw

The flip is pretty fast, but I do wish I had bent the titanium about 15 degrees at the bottom, so my flippy-victim would be less likely to slide off. Next time!

Thanks for your help. Off to fight in Robogames...

User avatar
Shakey
Posts: 929
Joined: Sat Mar 13, 2010 8:38 pm
Location: Reading

Re: My first ant was not a success: Onto the second!

Postby Shakey » Thu Apr 20, 2017 5:54 pm

tomchaps wrote:And yeah, it's the servo that was recommended here (https://hobbyking.com/en_us/turnigytm-tgy-306g-hv-ultra-fast-high-torque-ds-mg-hv-alloy-case-3-7kg-0-05sec-21g.html), although it's not really pink.


Yeah we still call it the 'pink servo'! :P

It's looking pretty good, good luck at robogames!
Alex Shakespeare - Team Shakey:
AWS 44, 45, 49 & 51 Winner - Far too many robots to list!
I sell Antweight Parts, 3d Printing and Custom Designs!

Occashokka
Posts: 423
Joined: Sun Nov 30, 2014 9:34 pm
Location: Stroud,Gloucestershire

Re: My first ant was not a success: Onto the second!

Postby Occashokka » Fri Apr 21, 2017 12:25 am

But shakey why call it the pink servo when TGY-306G-HV rolls off the tongue so easily?
Team Badger
Has a 3d printer now yay
-£4.82+VAT (intact)
-cool modulated printed thingy
-not yet built nasty mean spinnt thingy

I'm gonna build something huge and stupid, try and stop me :P

tomchaps
Posts: 24
Joined: Thu Jul 28, 2016 4:51 pm

Re: My first ant was not a success: Onto the second!

Postby tomchaps » Fri Apr 21, 2017 4:51 am

Help! Finalized the chassis, got everything in, but when practicing driving I realized that I have an electronics problem.

When I actually try to lift anything, the receiver browns out. With no weight on it, it flaps up and down happily, but if there is any torque on the servo, it just dies.

I'm using tinyESCs from fingertech, which should be able to handle this.

Argh! What can I do? Safety checkin is in about eleven hours!

User avatar
peterwaller
Posts: 3476
Joined: Fri Feb 15, 2002 12:00 am
Location: Aylesbury Bucks
Contact:

Re: My first ant was not a success: Onto the second!

Postby peterwaller » Fri Apr 21, 2017 7:53 am

Usually the brown outs are due to the servo taking too much current when loaded and the BEC can't keep up.
Are you running the servo from the 5v rail if so try connecting the servo power wire direct to the full battery voltage (it is rated at 7.2v) and see if that helps it will give you more servo power as well.

User avatar
Shakey
Posts: 929
Joined: Sat Mar 13, 2010 8:38 pm
Location: Reading

Re: My first ant was not a success: Onto the second!

Postby Shakey » Fri Apr 21, 2017 7:53 am

tomchaps wrote:Help! Finalized the chassis, got everything in, but when practicing driving I realized that I have an electronics problem.

When I actually try to lift anything, the receiver browns out. With no weight on it, it flaps up and down happily, but if there is any torque on the servo, it just dies.

I'm using tinyESCs from fingertech, which should be able to handle this.

Argh! What can I do? Safety checkin is in about eleven hours!


Is the Pink servo's red wire going to the LiPo? These servos are used as they get their power right off the LiPo giving them that little bit more power. At the moment it sounds like you may be drawing from the BEC and causing the 5v rail to dip when using the weapon.

If not try and find a 200-500 uF capacitor and jam it on the 5v rail.

EDIT: ninja'd by pete
Alex Shakespeare - Team Shakey:
AWS 44, 45, 49 & 51 Winner - Far too many robots to list!
I sell Antweight Parts, 3d Printing and Custom Designs!

tomchaps
Posts: 24
Joined: Thu Jul 28, 2016 4:51 pm

Re: My first ant was not a success: Onto the second!

Postby tomchaps » Fri Apr 21, 2017 1:44 pm

Okay, so to be clear: I remove the red wire from the receiver, and instead wire it directly into a splice on the red wire from the LiPo? Leave the other two heading into the receiver as before?

Do you just solder it directly in? I'm guessing I'll want to use this servo in other, better bits later on--so I'm a bit nervous about messing with it...

Thanks for all your help!

User avatar
Shakey
Posts: 929
Joined: Sat Mar 13, 2010 8:38 pm
Location: Reading

Re: My first ant was not a success: Onto the second!

Postby Shakey » Fri Apr 21, 2017 2:26 pm

tomchaps wrote:Okay, so to be clear: I remove the red wire from the receiver, and instead wire it directly into a splice on the red wire from the LiPo? Leave the other two heading into the receiver as before?

Do you just solder it directly in? I'm guessing I'll want to use this servo in other, better bits later on--so I'm a bit nervous about messing with it...

Thanks for all your help!


Yeah just cut the red wire from the receiver and connect it to somewhere that's the full battery voltage. Leaving the black and yellow going into the receiver. I normally just solder it on, it's easy enough to desolder the single wire later.
Alex Shakespeare - Team Shakey:
AWS 44, 45, 49 & 51 Winner - Far too many robots to list!
I sell Antweight Parts, 3d Printing and Custom Designs!

tomchaps
Posts: 24
Joined: Thu Jul 28, 2016 4:51 pm

Re: My first ant was not a success: Onto the second!

Postby tomchaps » Fri Apr 21, 2017 2:39 pm

Need to leave in about 45 minutes, plugging the soldering iron in now!

Cutting it a tiny bit close...

Thanks again.

User avatar
peterwaller
Posts: 3476
Joined: Fri Feb 15, 2002 12:00 am
Location: Aylesbury Bucks
Contact:

Re: My first ant was not a success: Onto the second!

Postby peterwaller » Fri Apr 21, 2017 2:57 pm

Yes you connect it to a point after the on / off switch if you have one so when you switch off the servo is also powered down.
The 0 v and signal wires still go to the receiver as before.
If you don't want to cut the servo lead it is possible to to remove the red wire and socket pin from the servo socket shell and use a header pin to connect it to the battery voltage as below, though you would need to insulate it.
Image
Alex beat me this time I had trouble uploading the picture.
Last edited by peterwaller on Sat Sep 16, 2017 2:56 pm, edited 2 times in total.

tomchaps
Posts: 24
Joined: Thu Jul 28, 2016 4:51 pm

Re: My first ant was not a success: Onto the second!

Postby tomchaps » Sat Apr 22, 2017 4:07 am

Made it with maybe ten minutes to spare, and the fix worked great--I had a ton of power in the flipper, no brownout issues at all. Again, thank you!

Of course, the first match I forgot to bend over one side of the paper clip that was the linkage to the servo, so I couldn't self-right after the first hit. (My flipper now has enough power that basically all it does is flip over and self-right, so that was frustrating.)

Second match, the servo arm came off, since I forgot to put that little screw into the center. Again, oops.

Still, it was a blast--I got to be in the pits with all the serious teams, and gossip with the local insect-bot folks, watch 220 pounders smash around. And I learned a lot--mostly about double-checking stuff.

I'll upload videos when I have them...

tomchaps
Posts: 24
Joined: Thu Jul 28, 2016 4:51 pm

Re: My first ant was not a success: Onto the second!

Postby tomchaps » Tue Apr 25, 2017 10:44 pm

Finally found a video of Swarf at Robogames--the 3-person rumble at the end. I finally made a polycarb linkage rather than a paper clip, and it was the first time the servo arm didn't detach. It also meant the titanium didn't go all the way flush, so I grabbed a bit of plastic and duct tape, and extended the flipper a bit. It worked so much better! (I know you all told me to tape a bit of plastic to the front, but I didn't listen...) The scrap of plastic had the word "HAMMER" written on it, which turned by flipper into a hammerbot, I guess?

The rumble was against two vertical spinners, including the terrifying Rip Up (https://www.youtube.com/watch?v=g9XjRXr1ATI&feature=youtu.be)

The minirumble: https://www.youtube.com/watch?v=PrAz98QV3uw&t=13s

tomchaps
Posts: 24
Joined: Thu Jul 28, 2016 4:51 pm

Re: My first ant was not a success: Onto the second!

Postby tomchaps » Fri Sep 15, 2017 10:35 pm

Does anyone know what screw to use on "the pink servo" (linked above at Hobbyking) for attaching the horn? I seem to have lost mine, and can't find the specs online.


Return to “Antweights”

Who is online

Users browsing this forum: No registered users and 1 guest