Thanks, output shaft is 20mm stainless steel rod- I think I will have to support it at the far end but not sure what wheels I'm using yet so if I don't use much of the shaft then I may get away with it.
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Thanks, output shaft is 20mm stainless steel rod- I think I will have to support it at the far end but not sure what wheels I'm using yet so if I don't use much of the shaft then I may get away with it.
Both the gearbox and ram look great, nice work!
Just wondering, is it acceptable to have a mechanical linkage to activate the dump valve? Eg. You have to pull on a piece of wire to open the dump valve? Or pull on a lever connected with linkages?
As long the dump can be activated by hand.
I hope so as my dump valve is essentially a safety/pressure release valve, operated by a cable. I think it should be fine as long as I dont get my hands inside the robot or remove any access panels.Quote:
Originally Posted by Max
The piston and rod weigh 700 grams- do you think that's ok?
And here's a picture:
http://i1261.photobucket.com/albums/...1BFB59B205.jpg
Should work fine. On the other hand, the rod is a tad narrow to my taste.
But that's my own idea.
Thanks Mario, I'll bear that in mind.
Just before I order some batteries- how many fights should I expect at an event, assuming there are 2 shows? I'm getting SLAs so won't be able to charge them during an event.
Why can't you charge them during an event?
If you don't drop out due damage, expect 3 fights at least.
meaning, with your drive, @12V, 30ah+. And that's a tad on the low side.
No money for chargers I guess. Or to difficult to remove the batteries.Quote:
Originally Posted by razerdave
The problem is as Mario says I can't afford loads of chargers to charge them all and they will take ages to charge I imagine, easier I imagine to do what the saint team does and just have a battery pack per fight. I am still considering hobbyking lipos, there a good price as long as I can charge the packs between fights as I can't afford more than one set of packs.
Here are some pictures of the layout I'm planning:
http://i1261.photobucket.com/albums/...4CE1F5ED05.jpg
http://i1261.photobucket.com/albums/...4CBA6B6B6F.jpg
I think it is very large but I'm not used to heavyweights! Also as it is pneumatic but not a flipper it has to be quite flat to make it invertible so it has become very large.
You're planning to run the Bosch 400's @12V. That gives you 2 realistic options for LiPo. 3S or 4S. (5S is 18.5V, right in the ballpark for "overvolting", but then the gearratio is a tad low). A 8000mah pack will probably see you trough a fight.
This means you need 1 Imax B6 AC , cost, less than £50 delivered at your door. And that one can charge the 4S 8000mah pack from "safely flat to full" in less than 2 hours.
Pricetag together, a tad more than 1 45Ah gelcel or AGM SLA without charger.
Difference in weight..... huge. 1 kg compared to 12 kg.
4 kg of CO2. That's 2000 liters of gas @1 bar @ roomtemperature. Your ram uses per stroke 27 liters. That means 60 strokes at least(not counting losses due liquid CO2 venting). In a 3 minute fight it's an action every 3 seconds (or 6 if it's double acting)
I would say, use only 1 main storage bottle if size is bothering you.
It's 800mm long, about 900mm wide- not sure how that compares. The good thing is only the front needs heavy armouring as all the expensive parts are there, just need to protect those bottles from axes.
Losing the buffer could save some space but not very much, and by having the ram, buffer and valve inline I should get a nice flow, even with just one Burkert.
If I went for SLA I'd buy a number of 6v 10ah batteries then change them each fight, that gives me flexibility to upgrade to 18v and means I don't have a ton of weight! I feel I'd need 2 of those 8Ah lipos to stay safe with discharging, then I'd need 2 chargers as I can't charge them in parallel. I may see if a mate has one I could borrow for events, he does rc planes so should have one.
I would retain the buffer, such a 1.1 kg CO2 bottle is exact the size you want for that ram.
You can do the setup with 1 Burkert, use the same setup as most feathers use. The flow is enough to satisfy your ram.
Should have thought of that about an hour ago before I ordered 2! I meant just one burkert as an inlet, second for an outlet.
The advantage of going lipo is I won't need a voltage boaster to operate my 12v burkert, does it need overvolting?
A 12V burkert? You sure that's a 5404?
But even if it's a 5404 with 12V solenoid, you want 15V+ going to that. There is a small difference between every burkert, what makes that one will work reliably @ nominal voltage, and another will want overvolting, especialy when it is warm.
I'm unsure if I am getting a 12v or 24v coil, I thought it only came with a 24v coil but apparently not
For my featherweight I've bought 2 3s lipos, they will be run in series. Can I make up a connector to charge them in series as well? I'd also have to make up a connector to connect the balancing plugs, does anyone know what kind of thing I'd need for this?
Do you mean parallel? You cant charge in series haha and 2 3s in series would give you 22v
Euh, an Imax B6 charger can charge 6S LiPo. And the S stands for Series. If you hook up 2 3S packs and wire the balance leads as a 6S setup, you can charge 2 3S batteries as if it's a 6S pack.Quote:
Originally Posted by webby
But, I don't see the advantage. Chargers are rated in watt , and except the time to switch the packs on the leads there is no advantage in time or ease of recharging.
The advantage is that after a fight I can charge up both batteries for the same amount of time, so even if I don't have time to finish charging I know both packs have the same voltage so are safe to use together in series.
Although, I am not sure if a ballancr charger ballances the packs during the charge or at the end so I don't know if semi charging is dangerous.
I think there is a setting on my current charger that lets me change the voltage it takes the packs to, so I could reduce this so there is plenty of time between fights to charge both packs to this level.
Chargers like the Imax b6 balance when the voltage reaches the set voltage. (4.2V for liPo), it takes compared to "fast charging" ages.
What do people think of 2mm steel on top of 13mm marine ply as top armour for a heavyweight. Do people think that will stop most axe blows from getting through?
I doubt it would take it. One hit maybe but after that the ply's layers would have separated and the steel would be only thing stopping it, and 2 mm steel isn't enough on its own.
Besides, the cost of buying both of those may mean its better to jump straight to 4mm Hardox.
Weight of 1m² 13mm "durable plywood" is the same as 1m² 1.5mm steel.
Like Alex writes, better aim for 3.5 / 4mm wear resistant steel like hardox.
I am unable to afford/use hardox, my options are steel, aluminium, wood or at a stretch hdpe. I'm not sure which material would be most puncture resistant for the same weight. I thought steel and wood would be good as I get lots of thickness from the wood but the hardness of the steel.
The steel will tend to puncture and partially spread the load on the wood. The result will gradually obliterate the underside of the wood until, as Alex said, it might as well not be there, and you're protected by the thin steel.
Unless you go for much thicker steel (or much thicker wood, but I woodn't (heh) recommend it), HDPE might be your next bet. It will have to be fairly thick but it will absorb the impacts to an extent. 6mm HDPE just about holds out Little Hitter, to give you an idea on thickness.
For anyone who's interested, if you run a 24v Gimson on 36 to 1 ratio with 160mm wheels you get some smoke and a blown 25A fuse.
I may have to turn down the wheels to a smaller diameter
Strange, In Hannibalito 4 we run 9.6V GR01's with 180mm wheels @ 3S. The fuse is a 40A one, but I tested a 25A one too, and no problem there at all.
It could be a problem with the motor, it is one of the dodgy 24v ones. I've got the 18v replacements but thought I'd give the 24v ones a chance first as I don't want the extra speed from the slight overvolting.
I'll test the motor to see where the problem lies
I can confirm now its cooled down that the brushes on the motor snapped off so that probably caused the problem. But both motors were very hot so I will turn down the wheels to about 130mm to prevent future failures.
Do most people use a normally closed burkert valve for inlet to their ram and a normally open valve as an outlet? I've realised both of the valves I've ordered are normally open so is there an easy way to modify one of them to normally closed?
Most of the heavies use normaly closed valves , You need to give them power to open.
In your case, you need power to close them, making it a rather dangerous setup. Link up, hope the valves that need to be closed are powered (LED is your friend here), before you open the bottles, very very gently -turn knob valves, not fire-extinguisher handles- And if during combat the power fails, your weapon will be activated, but blowing CO2 right out of the exhaust valve too. White clouds anybody?
Modifying a Burkert. It's probably easy enough, but I myself never had the chance to look into a normaly open Burkert 5404 with 12V solenoid. Where did you order it?
Well I got my dad to order it from my pneumatic supplier so I had to guide him over th phone so I'm not entirely clear what type the valves are I'm getting! They should arrive today or tommorow so I'll find out exactly what I've got then get back to you, I wouldn't be that surprised if I get sent 24v nc valves.
Does anyone know if the electronize 30A have current limiting?
Because mine seems to keep cutting out for half a second then going for around 5-10 seconds then cutting out again
Never felt that on ours. From memory it sometimes felt like they'd delay a tad when trying to move an almost jammed motor (say bringing Tormenta 1's lifter down after hoisting the sofa), but nothing like you described.
Check your rx isn't being starved of power, if you're running a BEC. If the battery is discharged, or being too heavily stressed by the drive motors, the BEC might not keep the rx alive and so it'll failsafe. Once it "comes back on line" after the battery has recovered, it may take a moment to rebind, which might be delay you're feeling.
Just a thought.
It seems to be happening a lot with one esc and a very little bit with the other so I doubt the receiver is failsafeing, but the bec could be starving the escs of power