Do you think I'd get away with the Scorpion XXL it does 20a
Just read the last post, I'm fine!
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Do you think I'd get away with the Scorpion XXL it does 20a
Just read the last post, I'm fine!
I dont understand why you want to use an XXL so much when the Victors on here will be cheaper and running much, much further away from their limits? :? Also, I had a faulty XXL that used to go into its safety type mode all the time and you just loose all movement and the motors twitch on and off every second or so, you probably want to avoid doing that. I also thing the old XXL's had a higher current handling if these ones only do 20A, I think mine is rated at 25A.
When I was asking around people who use the Golds I was told to look for something around the 30A mark for ESC's
I have a strict budget, ideally I'll get victorss, but I think a single Scorpion XXL would be cheaper, since I would need two Victors. Also, 2 q's:
1. Where do you get ball castors?
2.What sort of pressure do featherweights use, my tank is welded from submarine steel, and in theory should do 50,000psi, which is crazy, the main problem would be the seals popping out!
Also, I found out the checkerplate is 4mm, is it still OK?
The plastic is from the base of a windows, by the way. It should be up to the job, I couldn't snap it, nor could my father.
Dont know where you're getting Vantecs from, and they are dual channel. The Victors I linked you to are cheaper than an XXL, and thats for 2 of them so i'm still not understanding your logic.
1. Got mine on ebay
2. 1000psi is the maximum allowed, but you need all sorts of certification to run that, speaking of which, I believe there is also rules on what tanks you can and can't use but someone else will have to answer that one really.
Sorry, I meant Victors! They stated 65pounds each, so it would cost me 130 pounds. Also, I wasn't planning on running anything near 250psi, I was wondering what pressure I should use. I'll fix my post!Quote:
Originally Posted by Anttazz
Window plastic i think is PVC, it will break very easily, its far too brittle and thin. You can get ball casters from RS, ebay, technobots etc.
I I bent it about 30 degrees with all my weight, I doubt it will snap from pressure and it is about a 1.5 inch crosssection. It is the thick type, for windows that slide open. I'll check about PVC, if so I'll try and find something else, its no use if it snaps off! In the meantime, does anyone know what sort of pressure Featherweight flippers use? I'm thinking around 150psi?
All depends what system you are using. If your going low pressure (off the shelf stuff) then your looking at 10bar (145psi), which is what i suggest you do. If you go full pressure your anything from 250-1000psi depending on the temperature, but that then needs custom rams and hydraulic pipes/fittings.
I might go 200psi, the stuff I'm using is industrial, submarine steel, steel reinforced rubber piping, which are 50,000 and 500psi respectively. I don't have anything else yet, but I'll get it to them pressures. Everythings to be strapped down with steel straps. Thanks again.
the problem with pvc is it's too brittle. i have a 1.5m by 2.5m 3mm sheet of it in my shed.
OK, thanks, I'll be looking at something else.
I'll be using ordinary steel for the flipper, an oppurtunity has just come, I can get the body, the armour, made from submarine steel, which is slightly heavier than regular steel, but much stronger, and £800 per square meter. Forgetting the price, because I've got an offer, is it worth the extra weight for the toughness? Its the same stuff used on submarines, if the name isn't obvious enough :)
Sounds like an hardox equivalent kind of steel, more suited to the marine enviroment. And with DoD pricetag.
If you get the raw material for free, and the work don for a few beers, go for it.
I've gone for the deal, a few questions regarding design:
1. I can't find a size for featherweights, is there one? Or can I choose any as long as it does not obscure the match?
2.Do weapon restraints add to the weight penalty?
Thanks in advance, George
Read the build rules they should help. Weight is what you need to master, size doesnt really matter.
To answer the last part its no.
Thanks for your answer, I finished reading the build rules for the 5th time today, they are helpful. As for size, I'm doing about 45cm X 40cm chassis, is that small/large for a featherweight?Quote:
Originally Posted by billy breach
That's about the right size.
Just go on the roaming robots website and see what other people have there robots sized.
The size of the robot is dictated by the parts you are putting in it as the overall design, you want to keep it as small as possible for strength and weight. Get all your parts together and make a mock-up out of cardboard/wood to get your size and shape.
Thanks, I'll see how the model goes. I've been reading build rules, what is a pressure relief?
EDIT: I see, its the complicated name for a bog-standard valve!
A pressure relief device (PRV) is a device that relives a set pressure if the regulator fails.
Thanks, I found that out about 5 minutes ago though! I'm getting the bottle this week, does Technobots sell rams, I might go down there in a week or two, its a half hours drive?Quote:
Originally Posted by Hard Time
they do sell very small ones unusable for feathers, ebay is your best bet for lp rams, i got a 63mm bores x 75mm stroke one for a fiver
Sounds like a plan, plus I'm looking for quite a large one, I want to give Matilda a handful! :D I have a cylinder with a volume of about a litre, I think I should be able to get a reasonably good ram, problem is I want several flips out of it, maybe ten.
Google Sketchup just wont work, are there any other free programs to do the job?
EDIT:Also, how come when flippers fire Co2 can be seen, because I thought Co2 was invisible? This has perplexed me and my father, is it due to the pressure of the Co2?
I don't know about a free alternative to google sketch up but I do know about seeing CO2, when a gas is released from a high pressure it instantly cools down with CO2 I think it freezes as CO2 only goes to liquid under pressure
you could use prodesktop. a very different style cad program to sketchup and needs some getting use to but imo much better.
Thanks, and thanks to the 2 answers, I'll check out prodesktop tommorow
If you want a REALLY simple CAD program you can use the drawing features in excel to make a single 2D side/plan view of a machine. Just bring up the drawing menu, draw your shape, click on options and size it appropriately. Make sure to also unlatch it from resizing with the cells and then adjust the view zoom to see the whole thing.
Sounds awful simple but i've used it for a fair few work things when I've needed something drawing up quickly and scaled.
I don't have Excel, but I'm using the open office equivalent. I've been reading the build rules, will this pneumatic system work/be legal to the rules?
Also, what force in Newtons do most LP flippers have around, I used a calculator, mine should have around 2000N? Also, I'll be using between 7-10 bar.
http://img822.imageshack.us/img822/3...zzzzzzzzzm.png
EDIT: Fixed the picture to include the dump valve.
EDIT 2:Fixed the picture again because I don't need the second burst disc.
Hmm, seems a bit unusual to me, but maybe you just call things different names from what i'm used to.
Having so many inputs/outputs on the tank is unusual too. Eric Jr goes:
Tank-regulator----T-------3/2 valve-prv-ram
dump valve
Hopefully thats easy enough to understand. Also, if you're running anything LP you'd be strongly advised to get a Trev Regulator, can't remember if you have been or not.
EDIT: realise it doesnt look right when posted, the T section goes to the dump valve.
I think I've probably got some words wrong, but I thought the setup was
main tank, which has
a valve which will open at a dangerous pressure
a valve to fill it with Co2
a valve operated outside the robot to isolate the bottle when not in use
downstream there is
a valve to release the gas into the ram
a dump valve operated outside the robot
Would I need a regulator, if so it would go between the isolating valve and releasing valve? Sorry, I'm a bit useless at all this! :?
The main tank is generally a paintball tank, with a screw fitting at the top attached directly to a Trev reg, preferably. I believe you can buy em those tanks on the Roaming Robots page, or even ask John on here. So, it will only have one opening really.
Yes you need a regulator. It would go exactly where I put it on that drawing, screwed directly to the paintball tank, ideally.
A regulator takes the full pressure in your cylinder and brings the pressure down to the 7 to 10 bar you want the ram to operate at. Otherwise you are running a full pressure system.
Simple enough, saves me a load of weight! The PRV is the pressure relief device? Just wondering, you said a 3/2 valve, meaning there is an exhaust, why is an exhaust required?
Also, the rules require an isolation valve, where does that go?
Oh, I get that, so a regulator is for LP systems where you want a lower power ram, and FP systems have no regulator, so are more powerful, just need stronger components. Thanks for the great answer. The 1000psi pressure relief device required for FP systems is the PRV Antazz refferred to in the drawing?Quote:
Originally Posted by typhoon_driver
Before asking anymore questions, spend the rest of this evening reading through all the available threads on pneumatics, there's one just below this thread that's a good start. Then go on to use the search function.
You will still need a PRV in a LP system. The system I have drawn (ish) a diagram of is just Eric Jr (my LP FW) system. The exhaust allows the ram to return in conjunction with the spring/bungee. Isolation valve is on the paintball bottle itself, if you're lucky and have that type.
Most of this has been said/is being said in another thread at the moment, not to mention the dozens of other threads dedicated to this topic.
EDIT: What Gary said basically...
OK, I don't have any more questions now but I'll continue reading the other pneumatic thread, I've read up to about 3 pages, but theres something like 15 pages.
EDIT-Trevor doesent make regulators anymore, are there any particularly outstanding alternatives, or will any 10 bar regulator do?
Any regulator that can take 1000psi inletpressure or better will do.
Start here ....Quote:
Originally Posted by roketrhino900
http://www.teamdavinci.com/understanding_pneumatics.htm