Almost ready for battleshed just needs 10 min with a jigsaw 5 min with a soldering iron and anextra 4 screws.

Weight should be right over the wheels (ie it ballences on the wheels when stationary) which i beleve is important for a thwatbot.
I hope i am underweight i think i should be just.
Angled armor had to be abandond due to time constraints so all the spiners should have a field day on my armor but my major worry is the ibc box is right against the inner chopping board armor so if that is riped off or a big shock goes though there i could be in a lot of trouble.

my bathroom scales say it weights between 13 and 13.5kg so i may be slighly over.
my 3 other concerns are that the weight distrubution is too far back so when not moving the axe lifts up instead of all the weight over the wheels. If i am under weidht this can be fixed.
And ground clearence. it has more ground clearnece then any other bot i have made but i dont know the sydney areana so it may still cause some trouble if it does an angle grinder with grinding wheel and 5 min should fix the problem.

Driving inverted will be problomatic verging on non existanct but i do not have time to trim the sides so its a risk i will have to take and i will look into fixing it in a latter version

Cant weight for battleshed ill pack my bot 2morow

Well i just got back from sydney and a great event (dam plane was 40min late due to weather then another 80 min late becase someone never got off and it took them forever to remove there lugage.)

For a test bot with experemntal armor testing i think i went ok.


Round 1. vrs reapture if i remember right Lasted about 20 seconds. Soldering connecting battery to switch broke. a few hard hits and the first damage to the polycarb unfortunatly i died so quick angus could not rip it apart then move onto the other armor.

Round 2. vrs puncturer Lasted under 10 seconds. Hit Puncturer positive wire from battery broke at first hit or 2.

Round 3. Vrs flexo went well my first round i lasted more then 20 seconds all day. I learnt flexo is HARD. my axe came off second best compared to him. I think i won that but not sure it was a prity close match as no one took damage apart from a few missing chips of my axe


round 4. scissorhands. My aim was to test my armor for what i was thinking of as about 3 hits untill my ibc came out the back and i would tap out so i just tryed to ram him at all the spead i could get right into his weapon. At first he was toying with me and low speed but kicked it up into high gear later on. Huge panals came off but for the most part i was hapy with the shock absorption. need a better way to attach the second panal stage.
I once i lost all but one stage of back armor i decided to do the thwatbot thing of spin. Got the axe cought on his spinner i think for a little bit and then i think i may have atleast partly cut the one of the drive moters power leads looking at the him after a close look at the vidio will explain this better.
I do not know what hapend to scisorhands but i am quite sure i am increadably lucky. I left a lage amount of my armor in the areana (i lost 3-4 kg of plastic) great fun just box rushing him

round 5. bender? Rebuilt most of the bot to a reasonable strong level not quite as good as origonal but still prity dam good.
bender I was looking foward to this as i love bender and his teath i knew from plasique liked to dig into polycarb unlike scissorhands. Like expected bender took large panals out of my bot and was dominating for most of the match but he ran out of power and could not move in the end. This may have been partly my fault for in a bad way, Sorry Gary. basicly the film that covers bunnings polycarb was left on my polycarb outer layer (i often remove it and now will try to make sure i always do) This film got stuck in benders weapon for a bit putting his moter at near stall i think untill he fread himself. this drained his battery and helped lead to the loss of power. this could come close to being called intrapment which is forbiden in the robowars rules although it was not intentional in any way shape or form. Another reason he lost power was becase i beleve he was running a new more powrerfull motor.


round 6. vrs cobra. What can i say cobra is fast small and pushed me around like a rag doll. I think that sums the match up prity well.

Rumble. I lost drive within 30 seconds or so and the power light was still on which ment i feared the worced. I have opened the IBC box and found the ibc was just floating around the box with nothing holding it in place any more. Not suprising considering its box was mounted on the front of the bot (the axe is the back) which was the side i used to box rush scissorhands and bender so a lot of force may have been deliverd to the box. My reciver has a few bits of damage probably from the IBC flying into it but apears to be ok. Both IBC and reciver light turn on. Will test drive 2morow if all i get time.

NOTE: content in this is to the best of my memory

Things to improve.
a better way to hold the second stage of armor in place. I was thinking and Gary also segested Bolts a little too lose and in holes so they can move abit but it will hold it on far better then metle screws that half of what was in the first layer of armor did not hold at all becase it was the self tapping part of the metal screw.

Always remove the covering of polycarb when it is side armor.

Maby have a system so it is just as easy to have polycarb armor over chopping board as to just have chopping board (may be hard with using bolts) AS things like scissorhands it seams polycarb is good as he glanced off a few times. things like bender bad as he digs in and just rips

Check all wires prior to event.

Check IBC is where it is ment to be after any match where a lot of force is involved.

Do not mount IBC box with a thing layer of foam tape (that was compressed already) directly onto armor that is taking force of high KE spinners.

make robot a little smaller and axe poke out more.

Edit. compareing damage done on the chopping board with similar chopping board and conditions from robowars bender seams to be hitting quite a bit harder then he use to

Last edited by seanet1310 on Mon Sep 15, 2008 9:36 am; edited 1 time in total

your best off removing that film anyway, it will eventually bond with the plastic underneath it and will come off in little flakes. Looks like your robot has sun burn.
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Mechanical engineers build weapons, civil engineers build targets

Although happy with the way Rhino went at battleshed and it was way more fun to drive then zebra i think i need an attacking weapon bot to try and help avoid the boring fights that everyone hates.

At this stage i am thinking of bringing back my idea of C4 (check page 4 i think it was for some old cad designs) a drum bot LIFTER. this is not designed to be a high KE weapon at this time

I started the CAD again. main inclusions are a rhino style bash plate (the back similar to rhinos back for the spinners to enjoy)
The motor used is a Piranha Geared Motor from RMP but i checked and the computer calculates $48 shipping just to get it to Australia so i may need a new motor (it was always on the expensive side of things anyway)
The friction wheel is one of the new Banebot and a banebot hub the 2 7/8".
The drum is a steel pipe. I do not know if such a pipe exists as i could not find anywhere briefly on the net that lists pipe diameters and stuff it has an OD of 41mm and an ID of 35. If someone can inform me of the closest pipe they know of to this i would appreciate it else ill hit google one day. I got the rough dimensions from the bearings i am thinking of using.

I also don't now if something like the outer armour is possible with chopping board let alone how to attach it i will try it out at a latter date when i have access to mine. I think there would need to be a smaller radius if possible then in the CAD

View from the bottom up



view from the back


view from the side



view from the font

edit:
Estimated RPM is 1140 which i am thinking may be too fast for lifter so i may have to ditch the friction wheel for a belt if i wish to run it t a lower speed and keep a small OD drum. Not to mention reviewing the cad if it does manage to lift anything they would probbably not get far from my front or just end up on the friction wheel. I will investigate the possibility of a larger drum but i only have 2 or so kg according to CAD once i add in screws, bots, welds ect.

Ill have free time again shortly so i can get back to robot building.
There are some changes i want to make to the drum bot cad including changing the axle to a live axle. After seeing RAW the estimated RPM i thought was too slow may be insuficent after all.
I would prefer to make an electric lifter rather then a drum BUT i am having trouble coming up with a lifter idea i am happy with. About the only idea i have come up with to date is a leadscrew but i am seeing quite a few issues that may be hard to overcome. I have briefly looked into pnumatics i may follow that up more for a compressed air lifter instead of electronics.

I still hope to have one new bot that is not wedge or thwat ready for robowars with all going to plan entering that and rhino for the spinners to enjoy.

Once my chopping boards arrive i can replace the armor on rhino and bring it back to its useful armor. With new ways to mount most of the armor panels so less will come flying off until they have suffered critical or near critical damage. I see this as a process evolving over another 3-4 versions of rhino armor some will be backwards steps i expect. I am still contimplating ditching the polycarbonate outer layer as for bots like bender it is a nice chew toy and once they grab an edge it goes flying. Scissorhands did hit it with little damage delivered on more then one occasion so that is one of its saving graces.



As a side project i am also looking at creating a controller for non combat conditions bassed of the OSMC to practice programing an AVR. if i can get motivated the first version may be in zebra as a filler bot for robowars.

maybe you could get an electric window setup from a car? andrew used one in sproing and it was really powerful and quick too maybe theres some pics of it floating about
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www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz

Thanks for the tip, I decided to go with a linear actuator for the lifter instead to reduce complexity, For future versions I may make my own or at least modify the motor. Estimated speed should be reasonably good for an electric lifter if i can actually get under any one. It will not be invertible however so i have to remember to look into some form of self righting end to the lifter.
The bot atm is called Giraffe but that may change to hammerhead or something when finished. Once my parts all arirve ill start making it and post some pics .

The Drum bot is officaly on hold yet again. Sooner or later i must actually make one ive been talking about it for so long.

I have put on hold my custom speed controller for the most part I will most likely make a speed controller for the linear actuator but it will not have to be very current hungry. I am thinking something loosely based off Aaron's Pulse 50 or PRC modified to my needs and controlled most likly by AVR as i have more experience with them. That or just buy a SyRen Motor Drivers, singe channel Vantec or similar.

I have ordered parts so they should be arriving from around the world soon so i can get going including a sabertooth and dx5e.
I decided not to go A123 for this bot due to the cost of a charger and the cells due to the $$ best place I can find for A123's id in Australia at the moment by the time you pay delivery due to the dollar. Hope I can get my cp2400's charged for both bots at robowars in time, I will work it out when I come to it

My thick chopping boards are still delayed if i do not get them soon plans may have to change.

Rhino's amour will be held on by M5 fasteners instead of the random assortment of screws that currently make up its amour holding devices. Who knows how it will go, It cant go much worse then what happened in battleshed, If the chopping boards arive soon i should have some testing at Dany's next event unfortunately there probably will not be any spinner's to do a good test before robowars. Rhino is also getting an cosmetic job to look a tad more like a rhino.

Welder i have not decided yet what welder i will get but i will need access to one for my new bot or have to get someone to weld it up for me. Would not take an experienced welder long as there is not much. I am split between a cheep stick, an inverter stick or a TIG. I wont need to weld for a week or so. Mostly for part of the lifting mech I might try to outsource that to someone anyway so it will have a chance of lasting the distance of a full on event.

My critcal shortage in the correct dimention chopping boards apears to be over and 3 450x750x19mm PE boards (18+kg's worth) should be making there way from cans via courier soon.
I got the sabertooth 2x25 today. Looks solid enough. The caps have a little bit of movement (only attached via 2 legs does that) but should be fine.
I am wondering if i hsould add a heatsink to it or if active ventalation accorss the fins should be fine. Not sure where iwould get a solid block of Al anyway for it.

My weapon controler is comming along well so far. Tested it without a microcontroler and some PicAxes should be ariving soon (The cheapness + i decided it would be good to try another micro, If i need to go to AVR it wont be hard to do so) Basic drove me nuts for a while but i think my simple code should failsafe well But to be sure i will probably run it with the DX6 +BE6000 rather then DX5e+Ar500.
The picaxe will drive two SPDT 12v 60A relays via a ULN2003AN in a h bridge configeration.
A future project i might make try a poportional version but i cant see a huge advantage for the linear acuator and i want it ready and tested for robowars.

Still need to work out a welder so i can make part of the lifting mechanisum. It may not be ready for the vic backyard evetn after all.
I am a bit disapointed with the linear acuator under load and i know my lifting mechanism wil lbe a bad way with a high risk of bending hte sharft but o well.
I may post a cad later of it but a lot has changed sense the last cad i did on it.

Batterys ordered.
Just the Radio needed now. i was hopeing to sourse a DX5e from australia but i can not find anyone with one in stock at a remotly decent price so i may not have 2 Radios for the vic event.
Then need some 3mm steel sheet and some box section (metal land on monday if all goes well)

Picaxe stuff arived today and after a few stupid soldering stuffupsi think i have a board soldered up for the controler. i went around it with a multimeter and the voltages apear to be correct so the main problem will be my code. Its a real rats nest so i hpe it works (fititng 2 voltage regulators and the uln2003an on the prototype for the 08m i hard.
My other main concern is my lack of capacitors. There is a cap on the output of the 5V voltage reg but nothing on the input and nothing at all on the 12V reg.

Our experience with PicAxes running in Robots is summed up in one word..

Isolate !

Run the Micro from a seperate battery, optoisolate the inputs from the receiver (since it will share a common ground with whatever other ESC's you are running), use relays on the outputs, clamp the relay coil spikes with diodes and keep the power bus that the relays are switching seperate to the micro.

They really dont like the 100amp drain voltage spikes that are common in a robot, so you have to do everything possible to keep those nasty spikes out of the Micro.

Either that, or spend a lot of time with a 'scope and diodes,caps etc to make sure the Micro is well shielded from all the noise.. Micro's work on microamps and <5v. Massive Voltage Spikes are not a comfy environment for them

Last resort, put a visible status led on the bot, and have the micro flash it in different patterns according to what it is doing.. have a blink pattern for a reset-power-up, and various states, so you can tell if its having trouble and crash/resetting easily.
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Great minds discuss ideas. Average minds discuss events. Small minds discuss people

Thanks for the tips Brett, Would an AVR be any better (i cant see it being much better if any to the problems you mentioned)

Not that I know of. Any Micro will have trouble without a rock-solid power supply.

You might be able to use a Diode followed by some caps to keep the micro's power supply up momentarily, even if the main bus voltage sags, with some Zeners to clamp overvolt spikes..

Relay coils require good clamping as well to stop inductive kick from getting into the micro.. You would think a ULN driver would do it, but they dont always seem to.

As always with robots, the trick is to test well in advance to allow you time to debug and change. Dont finish your homebrew ESC a week before the event and expect it to work in combat, I guarantee it wont.. If you allow some time to iron out the wrinkles, you have a much better chance.
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Great minds discuss ideas. Average minds discuss events. Small minds discuss people

PIC's are generally more "robust" than AVRs
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Mechanical engineers build weapons, civil engineers build targets

Re. Testing thats why im working on it now for robowars and have a backup robot in case it just is not reliable enough (plastique) but i hope to have a testable version done for Danys backyard event it will be one of the best opertunitys i will have to test before robowars
Progress is good. i was surprised to find out that the code is working first try. I will put some delays in however to help smooth out the relay switching. Once i have a DX5e ill test the failsafe code but like i said previously it will run with a br6000 so the failsafe code will be an added backup i would like to have fully working.
I made it so it will only turn on at 85%+ of the stick as toavoid unintentional activation.

Thanks again Brett and Valen for the couple of tips especaly the relay coil clamping i would have left it to the ULN. This is my first time i have used a pic or pic based chip so its good to know in general they are more robust then an AVR.
im thinking for a start if i run a seperate battery to power the micro, opto-isolate the recivers servo input to the micro that should help with a couple of the problems discribed. With a cap the 12v that is common to the ULN and relays i thinking may be able to come from a 12v regulator.
like segested clamp the Relay coils.
That should be a start after testing im sure there will be other places for caps, diodes, ect.
Im also looking into switching the standard Voltage regulators (7812) with a dimention engineering switching regulator (only one i cansee that can go to 12v is the adjustable) if i can see a slight advantage in using it.

Over the weekend ill work out a rough idea of caps and diodes. ill aslo look over some of the pdf's i downloaded off the OSMC yahoo group and any other robot controlers to see how they handle the voltage sags and stiff like that.

On a side note ive got chopping board coming out of my ears. by mid next week i should have about 50kg worth in my room. No more shortages for a long time.

Edit:some of my idea for the isolation is pathetic adn would never work without a second opto-isolatior so im working on a new idea

Last edited by seanet1310 on Sun Dec 14, 2008 8:29 am; edited 1 time in total