Unnamed FW crusher build diary

[Theo]

£1400 quid? You sure you didn't order them in gold by accident?

I would definitely buy a few if you made them out of a decent grade bolt, anything has got to be better than the cheap Chinese steel that I assume they ones that come with the drill are made of.

They cost about £5 on eBay, give or take. He's ordering 300 in total, so they cost roughly £4.66 each. Still a bit unnecessary in my eyes, but it's really annoying when they break.

[Roboteernat]

Sorry, im not buying them, not for that cost, but i am machining them and silversoldering nuts on the end, so they would now cost pennies. Any one want any?

[Maxamuslead]

I might want some, got any images of them ?

[Al_]

I'd take a few spares please Nat.

[Al_]

Its update time again and first up, another attempt to test drive the bot for the first time. To recap, last time I attempted this, one of the left hand threaded screws sheared after a couple of seconds so I couldn’t go any further. After not being able to find a reason for this, all I have done is made sure the 3/8UNF inserts in the wheels are tight up to the shoulder on the gearbox output shafts. I have put in another L/H screw and tired again……and it works! I got to spend a good amount of time driving it around and getting used to how it handles. The 2 main observations I got from this was firstly, that with so much weight forward of the drive wheels, control is tricky but its hopefully something I can get used to with practice. The second is that driving on concrete was wearing the tread on my tires out very quickly, but at least this is easy to replace!

After this successful test my next job was to complete the armour. It was mainly the left hand side that needed finishing and few panels of HDPE cut and joined soon took care of that. The left side also has access for the link in it along with the power LED which was fitted and tested. Next I was able to fit the return springs for the self-righters. Now they just need the actuation cables fitting for them, but I am waiting on delivery for some crimps. Here is how it looks in its almost finished state:

IMG_20170529_133224814.jpgIMG_20170529_133236734.jpg

The test drive did show up a couple of problems which I have to fix, the first of which was that it lost of couple of bolts, so a quick strip down was required to replace these and make sure everything else is tight. The second of which was an intermittent drive issue on one side due to a damaged motor/gearbox. I modded my spare and swapped it in, I have yet to test it, but hopefully it should be ok.

The final job was a weight check on the scales and as I feared it is slightly overweight. I have a couple of places I can save weight including some light panels on the wedge and top. The other place is a lighter battery. I have a good idea of the amount of energy I’m going to need per 3 minute match now from my driving about tests. After adding a safety margin on to this, I should be able to get a substantially lighter battery if I need to.

Fingers crossed, I’ll be off to an event soon, so I have a couple of questions to make sure I’m fully compliant with all the safety things before I go. The cradle for the robot, I assume a simple wooden frame that holds the drive wheels off the floor would be sufficient for this? Also, the locking bar for the weapon, would something like a sturdy piece of material that fits inside the jaw of the crusher to stop it closing be suitable for this or do I have to have some sort of rod physically inserted through the crusher arm? Thanks for your help.

Al

[daveimi]

This is so nice! lol

Does your hdpe just screw together? Interested as looking to have a go with hdpe

[Al_]

Thanks David, The HDPE doesn't just screw together. The more structural elements such as the base plate are attached to the chassis using bolts that go into threaded box section aluminium bar. The armour panels screw into frame underneath them to give them a bit more strength and support. The only place one panel screws into another is on the top of the oil tank where the armour piece is nice and thick to try and stop axes and is therefore suitable (I hope) for attaching straight into. I had never used HDPE before now, but so far have found it really easy to work with using just basic tools.

[Roboteernat]

I have an image of the left handed bolts i can produce on another page: http://www.fightingrobots.co.uk/thre...883#post467883

[R9000]

To answer the safety questions, I think any kind of sturdy flat object to rest your robot on is fine, as long as it keeps the wheels out of contact with anything. The locking bar should just stop the weapon from moving I believe, though it has to be insertable without touching the weapon. I think Razer had a bar that went through its weapon and then down to the wedge, but maybe I'm thinking of another robot.

[Al_]

Thanks Rory, I can make a piece that jams the jaw open without having to touch the weapon itself, but I'll check with the event organisers before committing to it unless anyone else can chime with something different.

[Maxamuslead]

Al_ one idea could be to drill a hole at the base of the jaw, and slide a bar through the lattice through the hole and into the other side.

[Al_]

Drilling a hole through the arms and threading a bar through the chassis was going to be my backup option, but if I don't need to, then I'd rather not start drilling holes and risk weakening it. If I do have to drill it, an I correct in thinking that drilling through the center line of the arms is the place where it would weaken it the least?

In a mini update, the diet started today and I have saved a good chunk of weight off it, Just a couple of hundred more grams to go

[Al_]

Its been a fair while since the last update, but I thought I ought to tie the loose ends of this build diary together.

First up, through selective removal of material not deemed necessary for function (a.k.a. cutting holes) I'm happy I have the bot down to the required weight now. I have had it on 2 different sets of parcel scales, one puts it at 13.35kg and the other at 13.50kg, so while its close, I should be under the limit. I have also prepared a couple of lighter armour panels I can swap out should the official scales say that its a bit over the limit, but I hope it wont come to that.

Next up, I have taken care of the required safety features for the live event in the form of sharp edge protection and a lock for the jaw. I have also made a cradle out of some spare 2x4's that I had available.

I have got the steel cables for the self righting arms connected up and got them to actuate just over the last couple of centimetres of movement of the ram. This means that in normal operation they don't move, but if I need to self right I can shove the jaw fully open and actuate the arms.

Other than that I have just tidied up a few details like grinding the front wedge down to get it close to the floor, putting more of a point on the crusher tip and making sure everything is tight.

Its off to the Grantham event this weekend, no idea how it will go, but it should be fun finding out. To be fair if it doesn't come back in bits and it is still somewhat functional, I'll call that good. Likewise I'm fully expecting a lot of bugs and a whole list of things to work on or improve for the future. If things go to plan, I might get a chance to have a bit more testing / driving practice tomorrow morning which I definitely need.

No pics this time unfortunately, its been too mush of a rush to get finished in time. However I hope to take lots at the event and I'll post them up here afterwards.

[Al_]

It is the day after a great weekend at Robots Live in Grantham, so here is a quick write up on my, and the robot’s first event.

I had 3 melees over the weekend, the first of which was the second fight of the first day with about 8 other feathers in the arena. It was exactly as chaotic as you would expect and I can’t remember a lot of the details from the fight. Overall I was happy with how the robot drove and I was finding it reasonably controllable despite many driving mistake from me, such as lifting the jaw up when I had someone on the wedge instead of bringing it down – doh! A few of the flippers were having fun turning me over and over. When it landed on its back, it flipped back forwards on to its wedge as designed, so I was happy with that. However when I was flipped on its side and I went to self-right, the axle that the self-righter pivots around popped out of its housing. From then on I was dragging the righting arm around with me and occasionally getting hung up on it. Still it lasted the full 3 minutes and with the exception of the self-righting arm, it was still working at the end so I was well chuffed for a first time out.

Back in the pits I put the self-righter axle back in its housing and secured it in place with screws to stop it popping out again, then I charged the batteries and it was on to melee 2……

There were a few more feathers in this time, probably 11 or so, so even more chaotic than last time. This fight was 3rd on the second day and one thing I hadn’t thought of was the condition of the arena floor with all the chunks the heavies take out of it and the debris from those chunks. My side armour is low to the ground to try and stop flippers getting underneath. Unfortunately the flippers were still getting under it but I was also getting high cantered on the debris or hung up in a divot. Therefore the driving/handling this time was awful and after only half a minute or so explosion saw me struggling near the side and swiftly threw me clean OOTA.
In the pits again I decided to cut off some of the overhang on the side armour to increase ground clearance. I was getting flipped anyway, but I figured at least this way I could drive around better. Then charge the batteries, no damage to fix and off for melee 3….

With the higher ground clearance driving was definitely improved over the second fight and I could at least mix it up a bit. The fight was going pretty well until around half way through when I was flipped onto my side and it again failed to self-right. I knew the axle had stayed in this time but I didn’t know what was wrong. I was stuck on my side any only able to spin around in circles, and the fight went downhill from there. I was flipped across the arena to the house robot who kindly hit me few times with its sledge hammer. Then it put me under the red arena hammer controlled by someone from the audience who gave it some more hits. Still on my side I was able to spin away but the house robot grabbed my again, then did the spin around the in the middle of the arena, release and throw a robot to the side routine. Annoyingly it threw me right into the recess where it sits so it came over, grabbed me again, gave me a few hits from its hammer and put me on the arena floor flipper. The floor flipper had already thrown one feather up to the roof net, and I think it was Hatchet that it threw clean OOTA from the other side of it. I didn’t quite end up OOTA but had a direct hit into the arena wall. Then just for good measure and to collect the full set of hazards I finished the fight with a few smacks from under the blue arena hammer.

Back in the pits and I was amazed to find the drive and weapon were still working despite the damage to the other parts of the robot. A few pictures below show the damage. One wheel took a lot of the hammer hits, its cracked but still in one piece. Likewise I think it was the house robot that was hitting the armour over the oil tank which was bent out of shape, but the tank underneath was fine. The failure of the self-righting this time was down to the cable that pulls the arm snapping. I don’t know why it snapped, it should have the strength to turn the bot back over, but when I went to use it there were other robots around so maybe I was hung up on another robot as well. Either way I’m going to have to replace it with something stronger.

Armour Damage 1.jpgWheel Damage.jpgArmour Damage 2.jpgFront Wedge Scrapes.jpg

I have a number of ideas for tweaks and improvements that I’ll detail with some more posts in this thread when I get round to them. However I have to say the biggest one is probably lots more practice driving the robot. It’s amazing just how good some of the other roboteers are at driving their machines.

Finally I have to say that it was great to meet everyone who I spoke to and a big thanks to those that helped me out and answered all my questions. I had a fantastic time, the whole event was great fun and I’m already looking forward to the next one.

[R9000]

Well, that's it well bedded-in anyway! Glad it came back in one piece at least, did you get to crush anyone to a great degree?