Featherweight Discs

[s8nsmum]

Featherweight Discs

I havent seen the build quality of Ewans machine so I am in no place to say if it is safe or not but i know for a fact that spinners can be run directly off a motor shaft. At Inspire Black and Blue was allowed to run without any concerns been raised about the strength of the axle, this may be because the builder is much older than ewan (and therefore more sensible?) and it survived the entire event (well the spinner did anyway). People seem to like commenting on things that they know very little about. I dont know if Big Daddy is safe or not so I am keeping quiet untill it has been examined in a tech check like every other robot, it is one thing to advise someone that there robot may not pass a tech check to save them turning up to an event and not been allowed to run but telling them that it is not safe fullstop without ever examining it seems a bit OTT.

Joe Townsend

[stu]

Featherweight Discs

Correction - the motor shaft is supported on the other side Joe. I know it dont look it, but it is. Thats why the other side of the chasis moves funny when you push his blade round with your hand.

Mr Stu

[geoff]

Featherweight Discs

Ewan,
€œLike it or not This robot is safe€€¦.With all due respect, that is a decision that will be made by the Technical Officer at an event ! I really don€™t think you are qualified to make that call.
If you really feel that it€™s safe and is capable of doing what you claim€¦Bring it to the Featherweight Smash at Halesowen in March, or any other live event you wish, and I will be more than happy for you to put it in the arena with my machine.
I will then let my team mate, John, give you a practical lesson in the benefits of a rock solid drive and a properly constructed spinner. (Maybe Stu would like to comment on the probable outcome!)
I have tried to offer constructive criticism based on 4 years of practical robot building involving high speed spinners. Yes, we have had our own problems and the odd failed design over the years but we have learned from our errors and by asking questions were necessary. But if you chose not to take advantage of the huge amount of freely available knowledge within the roboteering community then I€™m Sorry Ewan, that is your loss!

Geoff,
Team Scorpion.

[ewan]

Featherweight Discs

If you drive into a 6kg bin, at full speed, with your weapon going, then you simulate an impact quite well... The motor has some of the biggest needle roller bearings at each end, that I have ever seen...
Oh, and your being ageist
Cheers, Ewan (age 12...)

[s8nsmum]

Featherweight Discs

sorry geoff, I didnt read the word unsupported when talking about the disc. Ive just seen a picture of black and blue and it does have an extra supporting bearing on the other side of the disc. My bad

Joe Townsend

[ewan]

Featherweight Discs

I agree that the technical guy makes the decision in the end, but when you see this bot in the flesh and start to push on certain spots etc, you begin to see its real strength. Oh, and I have just begun to make the motor shaft supported at both ends...
And finally I would like to go against your spinner, I do personally admire it as a very well build machine. Your heavyweight is one mean machine as well...
THE END (maybe)

[teammad]

Featherweight Discs

Ewan iv said it twice today, stop going on about how you say your robot is great and safe, as Geoff said its not your call. Use the advice people are giving you!

[stu]

Featherweight Discs

and start to push on certain spots etc, you begin to see its real strength

Im pushing on this drinking glass at the mo that i use to drink out of, seems real strong. But i know it will shatter apart if i put more than 0.5Kj a spinner mounted onto it.

If you want to line up a 1v1 with Scorpion JR at FWSmash you are welcome to Ewan.

I can see if Jonno would allow it to run in his MAIN Roaming robots arena, as i dont think it would damage his arena nor bits fly out when Big Daddy smashes apart. But you running that at home just worrys me. It also maybe a different story when it comes to running that at a small Feather Arena.

I aint saying anything more on this subject. If an event organiser gives you the OK to run ur spinner at their event, then i hope their arena holds up to it when it smashes up, or they get lucky that the disc loses all its energy before it hits the roof/wall.

You have been advised that it does not look safe Ewan, dont be disapointed if you turn up to an event and your told its not safe to run.

Mr Stu

[ewan]

Featherweight Discs

So, from what you have seen already stu, will you let this weapon run at the FW smash?
I run the weapon in a part of my my back garden, which has a concrete floor. When operating it, I put all the switches on etc, and I go to the second floor of my house, I look out (airiel stcking out window) and operate the bot from there. This is as safe as you can get when testing...
I will never run a weapon like this at close range, or in an arena incapable of containing it.
Cheers, Ewan

[blazerbotics]

Featherweight Discs

ewan, a 6kg dustbin doesnt put up as much as fight as another robot.

put dig daddy in with alpha at RCwars. We can see how tuff the robot is then.

[ewan]

Featherweight Discs

Ok, also can Scorpian JNR go through 12mm polycarb?
(Thats how thick the front armour is)

[robjones]

Featherweight Discs

Also worth noting is that the motor in BlacknBlue was fully modded. The internal bearings at either end are bigger and more secure,there are extra cables to the brushes and the original shaft was carefully tapped out and replaced by an 8mm shaft that the local engineering firm gave me. They make gear for rock climbers and said that it was hot rolled high yield steel. The far end of the shaft has a thread cut in and a nyloc nut keeps it together. Nevertheless the shaft was already slightly bent at Inspire, causing more vibration. Ive since replaced it again, but Im on the look out for some chrome-moly steel which which will bend back after big hits. Another factor is how much damage occurs to the shaft when the disk is first attached - In BlacknBlue the blade is attached using the two Tarantorque fittings so no holes or flats are needed on the shaft itself. Im not that happy with the length of the shaft as this weakens it but I cant see a simple way around that.
I think 8mm is OK for big feather disks if supported at both ends but dont expect it to last that long. 12mm or 1/2 would be better.
Despite its apparent strength Ive never run the weapon indoors or in car parks/gardens etc, only in arenas, its far to dangerous. And after Inspire 2002 only if theres a roof on the arena
We build lots of feathers in the Young Engineers club at my high school but I wont allow any of the students (inc. sixth formers) to build spinners. None of my students have ever seen BlacknBlue in action - that how careful we are.

[geoff]

Featherweight Discs

Ewan,
I have just spotted your age!€¦I had no idea you are only 12! Now I€™m even more pleased that you are so enthusiastic about robot building. This is exatly what our community needs€¦ Roboteers, The Next Generation!! It also explains a few things!.
But that said, It still doesn€™t change my advice to you regarding the dangers of this type weapon, something that you will come to learn in time and I hope its not the hard way.
Please take my, and a lot of other peoples advice and take advantage of the vast amount of knowledge out there€¦Remember, all you have to do is ask.
I€™m sorry if you thought I was being hard on you but all I€™m trying to do is promote a responsible attitude towards safety.
Keep working on that machine but be careful and do some serious work strengthening that spinner mounting.
Oh and by the way, 12 mm of poly will not save you, its not a question of thickness of armour, but how many times can your robot stand the shock of being smashed into the air and crashing down again before something vital breaks. Another thing you will learn about spinners, not all of the damage involves tearing large pieces off your opponent Sometimes the shock of impact on a robots internal parts can kill a machine far quicker than any damage you can do to the outside!
Now you know why I go on about having a rock solid drive and a strong chassis.
So take it easy, and work safely

Geoff,
Team scorpion.

[ewan]

Featherweight Discs

If I have a workshop with a pillar drill and jig-saw machine (dont know the name) at the age of 12... I wonder what Ill have when Im 18
But still, I do take the fact that being 12 does not give you an excuse to build less safely. I will try to upgrade Big Daddy as much as possible, because I still think that it is a workable design. One of the problems about being so young is not having the money to get anything CNCed or using so many good materials. If I could afford a version of vortex, then thats what Id build. If anyone wants to send me money then do so! (yes that is a desparate call for cash!!!)
Cheers, Ewan

[s8nsmum]

Featherweight Discs

If you have a bandsaw and a pillar drill you should be able to build a robot very similar to vortex. If you dont think you can machine the bulkheads and baseplate out of aluminium like vortexs then use some of that 12mm polycarb, that can be machined as if it were wood and should be plenty strong enough and a lot lighter. If you manage a copy of vortexs chassis then use a fat bar instead of the disk, dimension it to fit your speed controllers/batteries/motors etc. not Eds then it should be a very impressive robot that costs no more than Big Daddy did. The only part you may need outside help with is the axle that the disc goes on, I imagine lots of people on this forum will have access to a lathe and could whip up an axle to your specs for a small fee. CNC is a luxury not a necessity. As for the good materials I agree with you much more on this point, it can be quite depressing when you hear about the cost of decent grades of titanium but if your build quality is good a robot armoured with 6mm polycarb will be very hard to stop even with a robot like vortex. Like Geoff said above it is normaly the shock breaking the internal workings of the robot rather than cutting through the armour that ends the fight.

Joe Townsend