Yeah have ordered red and black wire from the above ebay link so should be all good :)Quote:
Originally Posted by Roboteernat
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Yeah have ordered red and black wire from the above ebay link so should be all good :)Quote:
Originally Posted by Roboteernat
Looking at wheels now, I have gone through several build diaries on here and people seem to be using scooter style wheels mounted directly onto the drill motor shaft, seen people use 3/8" inch threaded inserts, are they the right size threads to fit the drill motor I assume?
Trying to get everything in place for W/C 29/07 as booked the week off work to finally get something built :)
Yes, the drill output shaft has a 3/8" UNF thread. I think a lot of people use a brake union fixture as a hub, as they are quite long (so they can go all the way through a wheel). The outside is a 1/2" hex.
I used circular inserts (from here: https://www.gwr-fasteners.co.uk/38-u...el-50571-p.asp) press fit into scooter wheels. Scooter wheels unfortunately have quite hard tyres so may not be the best, but if you do use them I think Yak wheels are quite cheap and are reasonably soft. You'll need the 22mm OD inserts, and there's a flange in the middle of the wheel hub that has to be drilled out with a 22mm spade drill.
yep, we usually use those fittings, and heat press them into nylon wheels using a drill press (or you can bodge a rig with a couple of G-clamps). Then just cut and screw a bicycle tyre to the outside of the wheel and it's happy days.Quote:
Originally Posted by AdamST180
Ellis Ware made a nice how-to video:
https://www.youtube.com/watch?v=AcIIUGBJzJM
Or there is this vid i made quickly for someone :) https://www.youtube.com/watch?v=CqsOMvnnRtk
Looking at this charger now https://hobbyking.com/en_us/turnigy-...E&gclsrc=aw.ds and have to confess im confused :eek: talks about so many different kinds of wires, im sure can figure it out from the book when it arrives but do I need to order any other wires to work it from USB or mains?Quote:
Originally Posted by Ocracoke
When I was originally getting my charger, I was puzzled by how to power it as well. Luckily, some folks do sell a power supply for it (https://www.ebay.co.uk/itm/Power-Sup...0/223447307905).
The wires it comes with cover a lot different types of battery connectors, you'll need to know what sort of plug your battery has and wherever the charger comes with it by default or if you need to get an extra one, like I did when I needed a XT90 connector rather than the bundled XT60 connector the charger came with. If you are building/buying an Antweight, the JST plug on the multilead (the 2 pin red rectangle connector) is the one I usually go for.
Team Death use these chargers. The power input is a standard DC jack, so any power adapter with a DC jack at the end will work, as long as it is between 11 & 18 volts out. The more amps the adapter can provide, the higher your charge rate (up to the maximum of the actual battery charger), we use 4-5A adapters.
Spare laptop charges may be advertised as DC jack, or look very similar, but they are quite often not the exact right fit despite being on eBay with 'DC jack' labelling, and at worse, they might fit but have the positive and negative reversed within the charge jack (yay proprietary things).
The LiPo battery itself will have the majority of cables you need attached to it, always make sure you have put the balance plug in the right port of the charger (there will be lots, for different cell count batteries), and, make sure you have a lipo sack/bag to charge in, on the off chance the battery catches fire, it is unlikely but always safe, and if you start going to events, you'll definitely need one at that point.
The charger has many different charge modes, for many different types of battery. You can even charge a car battery! (which I had to do when my car died :lol:)
Attachment 8992
(this is the previous model, that I have. Basically the same, just without LiHV charge capability, and runs a bit hotter due to no built in fans)
Just be sure you've got the charger in LiPo mode, as it might not be smart enough to detect if you have selected the wrong battery type, and it might damage the battery or worse.
I've accidentally done this from time to time. The charger defaults to LiPo but I use LiFe batteries and I can confirm it isn't smart enough to know what battery type it is connected to (and I am not sure how it would ever know) so I have started off charging LiFe batteries in the LiPo mode, which if I didn't check, would probably cause a smoke show. Luckily hasn't nuked any of my batteries yet.Quote:
Just be sure you've got the charger in LiPo mode, as it might not be smart enough to detect if you have selected the wrong batterty type, and it might damage the battery or worse.
Apologies for the double post, I've just noticed that the power supply I've linked to wouldn't work with that specific charger as it needs a barrel type connector and the power supply comes with a XT60 connection (though I should note, the power supply that I have came with a barrel to XT60 converter as well) so that may not work. For reference, this is the charger I use - https://hobbyking.com/en_us/turnigy-...v-capable.html
No worries, so that adaptor would work with the 80w charger you use or do I still need a different one?Quote:
Originally Posted by Ocracoke
I can't see how the XT60 connection is made in the item listing but this might serve you better - https://www.ebay.co.uk/itm/Turnigy-A...x/321661460833
Cheers for that, is the 80W one worth the extra bit of money over the 50W one? As found a 50W cheaper https://www.ebay.co.uk/itm/Turnigy-A...mivFi56-vw_FzgQuote:
Originally Posted by Ocracoke
Thanks
The difference between the 80W and 50W versions appear only to be that the 80W supports a higher charge rate looking at the specs. Either would do for a Featherweight.
As an alternative, I use one of these: https://hobbyking.com/en_us/pd606-charger-uk-plug.html
I don't think it's as well-featured a piece of kit as the Accucell ones but it does have advantage that the AC/DC conversion is done inside - i.e., it comes with a UK plug so you can just run it right out of the box, rather than having to get an external 12VDC supply (it can run from an external DC input as well, if you're "in the field" and running from a car battery say).
I might go with that as simpler the better for me :talker:Quote:
Originally Posted by McMullet
I might aswell get a LiPo at the same time then, people have suggested https://hobbyking.com/en_us/turnigy-...html?wrh_pdp=1 but its out of stock, can I get a different mah or S rating?
To drive 2 x argos drill motors and potentially a linear actuator?
Cheers
I would recommend sticking, for your first machine, with as similar spec as you can. Stick with 4S (which is the cell count in series, meaning 14.8v) if that is what the various components in your robot can take, namely your motors and speed controllers. I would say perhaps this - https://hobbyking.com/en_us/turnigy-...ack-xt-90.html. Only slight hiccup is that the battery appears to only be in the EU, not in the UK so the delivery charges are going to be more.
If you are not going to have a linear actuator, I know that at least 2100mAh is OK, The Honey Badger used 2x 2S LiFe batteries in series originally and even Azriel, with its axe, still uses 2100mAh LiFe batteries in 5S LiFe (2S and 3S in series). If you are going to use a linear actuator, I would recommend at least 3000mAh.
Shipping is actually the same strangely! I will need XT-60 to XT-90 adaptors it seems, would I be right in saying the battery is the female connector?Quote:
Originally Posted by Ocracoke
Ah, I had missed it was a XT-90. You would need one of these - https://hobbyking.com/en_us/xt90-mal...-2pcs-bag.html - to make the connection.
Sorted, cheersQuote:
Originally Posted by Ocracoke
This robot building is expensive! :talker:
Hahhaa, that it is. I once totaled up how much my second version of The Honey Badger cost me. Close to about £400 but then again, I was things like a pricey transmitter at the time and such.
Yeah lol, I managed to get a second hand DX6i for not too much, but between the ESC and everything else plus tools its cost a fair bit and this is just the prototype, got to get the HDPE next :eek:Quote:
Originally Posted by Ocracoke
The thing is, as a one off, it is expensive, yes but you do end up reusing tools and components from one machine to the next as you go along. My Middleweight needs a new body but the parts from the current version can easily be transplanted so that will only cost me about £300 or 400 to get the parts and for me to machine them to make it work.
Expenses wise, the worst part is always starting up. Once you're up & running it's not so bad & as Lucy said the vast majority of it can be reused & more expensive things like transmitters usually don't get damaged in combat. I've had a pretty rough run over the last couple of events (1 lipo fire, 1 other lipo die & multiple big hits from spinners) but once I've added it up it was less than half what I spent on the hotels for the events.
Yeah most of it is reusable thankfully! Just gotta price up the HDPE once got the design finalised.
LiPo and chargers ordered and dispatched from hobby king, so think I have everything I need now :)
Im sure i remembering reading it on here before but looked in many threads and cant find it.
How do I work out what fuse size I need for this; https://hobbyking.com/en_us/turnigy-...ack-xt-90.html
The max current from your battery is the capacity in Ah multiplied by the C rate (in this case you have a burst and continuous C rate, so use the lower of the two, i.e., the continuous rating). That's 4.0 Ah x 60 C = 240 A. The fuse must be less that that.
However, with two drill motors and a linac you'll never get close to 240 A. So to protect your motors and ESCs you are probably better off with something around the 100 A mark, or even less. We have an 80 A fuse for a similar setup to yours.
You work out the burst amperage of the battery and get a fuse below that amperage as per the rules:
So in that particular batteries case, it is 4 amps * 120C = 480amps (240amps constant). That, to me, sounds crazy and you'll likely never draw that much. I'd figure on it being a quarter of that, so 120amps but from experience, a 60 or 80amp fuse will be sufficient. I've yet to blow a 80A fuse in either my Featherweights or my Middleweights.Quote:
7.8.3 Fusing
A fuse rated below the maximum burst discharge of the battery MUST be fitted. The maximum burst discharge current is calculated by multiplying the C rating by the capacity. E.g. 25C 2200mAh = 55 Amp
Looks like we're largely in agreement here Lucy!
Hahahahahaa, that we are Sam :D
It is also worth bearing in mind the extra rules regarding LiPo batteries under section 7.8.* in the build rules though they are fairly common sense ones like batteries have to be charged in a sack, battery chargers must be capable of balance charging and such.
Thanks both
Its like a fountain of knowledge and im trying to absorb as much as i can! :lol:
I have a LiPo charge bag and a charger so thats all good, will go for an 80A fuse then :)
One of the best ways to get a sense of what is used is to come to events and see the robots up close. I guess you might have done this with the VIP tickets for Extreme Robots and/or Robots Live but if you are interested, I'll be having my heavier weight class robots on display at the BotFest event I am running in September. I'd be happy to walk you through the internals of them.
Yeah that would be amazing, never seen any up close, been to one Extreme robots last year but booked late so missed out on VIP :(Quote:
Originally Posted by Ocracoke
Found your thread on that and sounds good :)
Got this fuse from RS, not 100% sure its the correct type?
https://uk.rs-online.com/web/p/car-fuses/7874407/
But figured could wrap the wire around the hole and then solder? For a strong connection.
The type of fuse that can be used in the rules isn't limited, so long as it does the job of being a fuse.
With that type, I would get some ring crimp connectors, crimp the connectors on both wires (making sure to cover the exposed electrical ends in heatshrink or electrical tape), run a bolt through each ring connector to the fuse for both sides and then wrap the connections in electrical tape so nothing shorts.
Oh yeah that makes sense, I feel bad asking all these questions but as they say its the only way to learn lolQuote:
Originally Posted by Ocracoke
https://uk.rs-online.com/web/p/crimp...inals/0534216/ & https://uk.rs-online.com/web/p/grub-...crews/0525789/
That sort of the right size parts?
That's a strip fuse. you can get proper holders for them that include the bolts and a protective case.
This appears to be the right holder, with bots and snapshut protective case: https://www.ebay.co.uk/itm/Heavy-Dut...MAAOSwPIhZ6Kcd
Double check that is the right size case, as you can get midi and maxi strip fuses. I think you have the latter,.
Another alternative i have done at BW & FW sizes where the weight of bolts might hold you back, is soldered the wires onto the bare metal, and then heat shrinked the entire thing to encase it in a protective layer. This is a lot more lightweight than a proper holder. If you do that, write the rating of the fuse on the outer layer so its obvious to you and any tech checkers what the rating of the fuse is.
You can also get Midi & Maxi fuses off eBay, and in my experience cheaper than say from RS or other providers. Midi fuses are generally 20 to 80A, then heavy duty / maxi ones are 80 to over 250A (not all holders support stuff this highly rated). If you search ebay for "Midi fuse", you'll get all sorts of useful fuse related results for this hobby. You can also use car fuses ('Blade Fuse'), and relevant holders. Team Death use a mixture of both blade and midi/maxi fuses.
Got lots of stuff but making no progress lol
Realising I don’t know what I’m doing :talker:
Attachment 9057
Don't give up Adam, -simply solder or get a friend to solder -A red wire 20 cm long from the removable XT link to your fuse and at the other end of the fuse solder a 20 cm length of red wire then wrap some insulation tape round the ends-job done.
You probably won't need the TV remotes or the energy drink for this :) .