Unnamed FW crusher build diary

[maddox10]

The Neptunes are well build conversions of a standard batterydrill setup with 540 motor. Powerfull enough for the avarage feather.

The Saturns with 775 motor are a lot heavier, and have enough power to do 4WD with ease.

[Al_]

Not massive progress to report due to Christmas, the New Year and what not, but I have still got a few bits done.

First up, the tips for the crusher arm, and the front wedge plates have been picked up from the water jet cutters. This means that for the first time I have been able to put together the chassis sides, the ram, the crushing arm with tip, and the wedge. It was good to have some assembled components in front of me for the first time.

Next, I fixed the hydraulic pump to the mock-up with a g-clamp and took the whole lot to the local hydraulic shop where the very nice people made a set of hoses for it with integral test point. I have to give them thanks for being very patient with a hydraulics newbie on what turned out to be a pretty fiddly job for a couple of hours. I don't know if I am allowed to give out names on here but if anyone wants the name of the company for the North Notts area, feel free to PM me.

One thing I wasn't aware of was just how much the hoses and fittings weighed, I underestimated that by a good 300g so the weight budget has just become a fair bit tighter. Unfortunately there isn't a lot I can do about the weight here so it will have to be saved elsewhere if it goes over. I have also got the shaft made that connects the new motor to the hydraulic pump. Once I get some more bolts delivered which hold this bit together, I shouldn't be too far off a first test of the weapon system.

I have also had a couple of questions pop up which I hope you may be able to help me with:

1) While reading the forums I came across some comments in a thread about a workaround in order to get full throw in all controller directions for the re-programmed Tz85A ESCs with the Spektrum Dx6i handset. Does anyone know if you still need to do this with the Dx6?

2) I'm looking at getting the fuse I have to fit inline with the batteries and the rules say it is determined by the pack capacity and the burst 'C' rating of the pack. Are there any rules or good practices that people would recommend regarding the types of fuses and blow time? For example the pack I am using has a 35C constant discharge rate and a 65C burst rate for 10 seconds. It seems to me if a slow blow fuse was fitted at a rating somewhere around the 65C rate, then there might be a possibility of battery damage before the fuse blows? Or am I over thinking this and its not a problem that tends to crop up? (As it happens I'm fairly certain I'll be a long way from the burst rate discharge of the pack and probably under the constant rate at nearly all times, but I thought it was worth checking.)

In the mean time, here is a picture of the latest progress. I must have taken it from a funny angle, it looks much taller in the picture than it actually is. Also as you can see, I'm still on the dining room table, the shed/workshop is taking longer to get sorted then I hoped.

IMG_20161221_115922122.jpg

[Al_]

Yay, it works!

I got the hydraulic power pack mounted to the chassis and all the hoses connected back up, filled it with oil and went for it. At first, no movement of the weapon, but it turned out just to be air trapped in the system. After bleeding it, I have the crusher going up and down smoothly. Its turned down to about 1/3 operating pressure and 2/3 operating speed, but it actually worked, I'm well chuffed with this. I didn't have chance to turn it up any higher as I realised the pressure test gauge that I had been supplied with was only 400psi and not 400bar like it was supposed to be, and without knowing actual system pressures I didn't want to risk it. Still it had nice chew on am off-cut of 2 by 4 (closest thing I had to hand to try in it) and its still working and in one piece afterwards! There are a few lesson I have learnt:

1) A couple of minor fluid leaks, one of which needs a new fitting, but easily fixable.

2) Hydraulic oil gets everywhere.

3) Get the pressure test gauge swapped and test it at higher speeds/pressures.

4) I must hurry up and finish the shed so I can finish building the rest of the robot.

[Al_]

Here is a quick clip of the testing, the robot is been held on its back by a not so glamorous assistant:

[Mouldy]

Looks great!

[leorcc]

It looks terrific an terrifying at the same time. Great job!

[Kenny]

Well Done Al, Looks great and look forward to seeing it in the arena!

[MattLampitt]

Looking awesome mate.... I'm looking forward to seeing the test vids piercing different stuff ;-)

[Al_]

Thank you for the kind words everyone! Not a huge amount to report (again) since the last update for 2 reasons. The first of which was finishing the workshop, but that’s done now so I should start to progress more quickly. Second is a serious bout of the man flu which has struck me down for the last couple of weeks.

I have had part of my plastics order delivered so I can start making the rest of the robot, but naturally, the first thing to do, was to try and put some holes in it with the weapon:

IMG_20170226_114246408_BURST000_COVER_TOP.jpg

That’s 10mm HDPE, no problem so far, I have some 20mm HDPE and some Delrin on back order due any day, I’ll see how it copes with those.

Before doing the testing I built up the front wedge plate and put it on the robot, 5mm tool steel bottom part for wearing and 5mm aluminium upper part to save weight. It still needs the side fixings into the chassis, but it fitted fine.

IMG_20170218_133309686.jpg

The next job was to strip the machine back down for the afore mentioned fixings and to drill out the other mounting holes into the chassis sides. I took the opportunity to check all the parts were still straight and true after playing around crushing things. The weapon has only gone to 50% power so far, but everything still looks good. Fingers crossed for some quicker progress from here on in.

On a final note, has anyone ever used the name Pressure Point for their robot? It’s the best I have managed to come up with so far.

[Al_]

A quick clip of it having a go at the HDPE. it took a couple of bites to get through the 10mm stuff at 30% power, but that crusher tip is still a blunt piece of steel, I think once I have that sharpened up a bit it would go easier. At 50% power, the 10mm was no problem even with that tip, so time to bring on the thicker stuff. Also, please excuse the use of 2*4 offcuts and spring clamps to give me something to help hold the test piece on, filming and operating it all at once is tricky

Edit: Weirdly, the annotation boxes only show up for me if I watch the video on YouTube instead of directly in the thread. To save time for anyone with the same problem, the first test is 5mm HDPE at 30% power, the second is 10mm HDPE at 30% power and the final one is 10mm HDPE at 50% power.

[Ellis]

That's looking very good, and scary! 10mm HDPE is easily enough to keep any axe/hammer out so if it doesn't even slow down when blunt @ 50%, it's going to suck to fight it at full potential!

[Runsler]

ouch... that will hurt.

did you also test it at some angle, so not only vs. box-shaped bots, but vs. wedges?

(And will we see a test vs. metals like ali, hardox and titanium?)

if you can get those as easily, it will be hard to build something that could stop you...

[Al_]

ouch... that will hurt.

did you also test it at some angle, so not only vs. box-shaped bots, but vs. wedges?

(And will we see a test vs. metals like ali, hardox and titanium?)

if you can get those as easily, it will be hard to build something that could stop you...

I'll be doing some more tests as the build progresses, so I'll try film what I can, different sizes and shapes for it to try. As for metals, I have some aluminium I can try on it, but nothing else. Any suggestions as to where I can get some small steel, hardox or similar offcuts from?

[MattLampitt]

Looking so good Al...
I'm finding it so so hard to find time to do mine... iv got drive system done and driving the kids around the kitchen but that's bout it lol..

so been as robotwars are advertising for for featherweights for season 3 will you have it done and enter do you think?

[Al_]

Looking so good Al...
I'm finding it so so hard to find time to do mine... iv got drive system done and driving the kids around the kitchen but that's bout it lol..

so been as robotwars are advertising for for featherweights for season 3 will you have it done and enter do you think?

I'm in the same boat, time is always tricky to find between work, the family and doing up the house, but thankfully I keep finding a few hours to have a mess about with things.

I would love to have put my name down for the season 3 feathers, but unfortunately the filming dates clash with a prior commitment. If these is a season 4 I'll put it down for that.