Heavy Weight Speedos

Ok, been thinking about getting Mute back up and running for a bit of weekend fun every now and then. Seeing as weve been out of the loop for a while I need some info and advice.

Basically were looking for some new speedos which:

1. Can handle LEM-130s... without flaming out
2. Can handle upto about 100A with current limiting, although 70-80A will be fine
3. Preferably 36V

The smaller the better for obvious reasons. All sugestions welcome so please fire away :)

Also are there any new rules and regs that have been introduced which Mute may not be compatible with?

Welcome back!

http://www.robotpower.com/products/sidewinder_info.htmlhttp://www.robotpower.com/products/sidewinder_info.html

James Baker sells them in the UK.

welcome back daniel. i presume adam and batty boy are coming back with you? and which event are you aiming for getting back. northampton would be the obvious starting point for me. unless you fancy a drive to swindon without the robot just to catch up and chat for the day. anyway great to have you back and a good year in order i think. :) :)

Sidewinders and LEMs will NOT go together due to the very low inductance of the motors... unless James can tell otherwise ?

Yes theyre current limited but theyll still go pop

Daniel - dont you run the Dogs Bollox controllers in Mute ?

Edit - Just thought, I think they were based on the OSMC controller which is also quite compact and fan-cooled. That might be worth a look ? Also quite field repariable.

Ed
http://www.teamstorm.comhttp://www.teamstorm.com

(Message edited by storm on January 24, 2007)

there have been interesting conversations about LEMs and sidewinders. It is possible, the most obvious solution being an inducter on the motor to get rid of that super low inductance. we have discussed software modification to speed up current limiter response. There is also the option of switching the sidewinder to Cobra mode, which combines both sides of the controller to offer 160amps continuous 300 peak.

I am planning to run LEMs in my new heavy, with the sidewinder, so it depends on how much of a rush you are in. I could do the testing for you?

Let me know what you think, but if you are after anything from robot power, ive a delivery due, so ill tack it onto that.

the sidewinder is £270 delivered to your door.

Lems on a Sidewinder is definatly a no go. Perhaps the cobra controller James?

And the sidewinder, RS80, and Dogs Bollox are all based on the OSMC controller. The implementation is different though.

was gonna post actually daniel. does ed run lems in storm 2. what do you run in storm 2 ed. do i remember they are custm built? what about the old 4qd or would they be too big. i remember mario knowing of some. or mabee you could downgrade your motors mabee to the good old realible bosch on 36v. mabee you should come to swindon and chat about it. mabee i should shut up. :)

You just beat me to it James.

Considered a roboteq? There not to big, Behemoth uses one with lems, not sure what voltage they run though? Ask Kane..

Mutes coming back :S ..Better sharpen our flipper tip:)

Hello Everyone :)

Swanny, no idea which event. Depends on available funds after my Westfield is back on the road. And Bosches wont fit anymore, not enough space with 4Kg of gas.

Ed, yeah we use the Dogsbollox speedo, but weve melted our LEM 3 times now due to too much current. Not to mention we tend to unsolder the power connections on the speedos while its running :proud:

Im looking for something with absolute current limiting so I can say with 100% certainty we wont trash our motors again... theyre rather expensive to repair!

James, what kind of time scale are you looking at? Some test results would be nice before we buy. Weve got some other upgrades to do first so its not a rush at the moment.

A HC Roboteq is an idea but it depends on space, I might have to mill some of the fins off.

Keep the ideas coming guys, all very helpful!

Welcome back!

Our RoboteQ AX2550HE has been perfectly reliable, but its still not a perfect design. The FET package used will not handle more than 30 amps continuous (although they are paired) and the current limiting is in software (like the sidewinder and Dogs Bollox) so its never going to be fast enough to truely protect the FETs. Its also based around the same H bridge chip all these controllers are... That said, weve been running the RoboteQ for a long time now and it hasnt broken... Neither have the LEMs. Its a well developed design and I think itd work well for you.

There isnt a better product than the RoboteQ for the LEMs unless you want a bespoke design that will cost thousands. Or you can wait a couple of years for something better.

A Spectrum DX6/ DX7 would be a good buy too
:)

Im not aware of anything out there that will run flawlessly with a LEM with the potential exception of the custom controllers that Storm II uses (though they have blown one FET in the 4 years theyve been running).

I would go with Kane - the RoboteQ is probably your best bet (in its HE configuration) just so long as you can shoehorn the thing in !

Ed
http://www.teamstorm.comhttp://www.teamstorm.com

Ok, heres another question, has anyone had any experience of 36V 2.3Ah Li-Fe batteries (A123 Systems)? Ive been reading about them and they look ideal replacements for our 24V Nicads. Theyre about half the size of the packs we run at the mo and seem to have good discharge ratings.

Good idea or only good for a BBQ?

Ill bring the burgers Daniel......

Ed
http://www.teamstorm.comhttp://www.teamstorm.com

Lithium batteries are no longer allowed in heavy-weights. Only for feathers, and low voltage cut-offs and other things need to be used with them.

Thats a bit of a bugger, theyre using em in airplanes and power tools. http://www.slkelectronics.com/DeWalt/index.htmClicky

Yer, I use them in my feather weight and they are the best upgrade ive made!

If the rules change, check out http://www.realraptors.co.uk/zen-cart-v1.1.3/index.php?main_page=product_info&cPath=100&product s_id=1288http://www.realraptors.co.uk/zen-car...roduct_info&cP ath=100&products_id=1288
These are the higher discharge version of what I currently use. I think they sell them in 37V packs also.

It might be worth asking for a exemption for these particular cells.
http://www.a123systems.com/html/tech/safety.htmlhttp://www.a123systems.com/html/tech/safety.html

Ive followed the australian discussion on them and several robots there have been equipped with them. Because of the way there are built they are inherently safer than LiPo or Li-ion without electronic gadgets. They do require a specific charger, regular LiPo chargers do not work.

I would not be opposed to exempting these, although i would still not use them in a heavy.

like grant said, the newer Thunderpower cells are good for upto 50C burst, and come in higher mah rating than the A123 cells

my dream pack would be the TP9000-10S2PX, a 37v 9Ah lipo pack. about 450Amp burst :P

yep, i was looking at those for a heavy before they were ruled out. But with the current ratings on Li-Po packs i think they are becoming safer to use aslong as a low-voltage cut off is in place.
With the minimal weight they take up, alot of padding can be put around them making them very secure and safe.

About time we saw Mute again, only rule change that would effect you, not sure if you know about it....

2.3.
Total weight is measured without consumables - e.g. fuel up to the 500ml maximum, and gases up to a total of 2kg for heavyweights and .6kg for featherweights.
Further gas bottles and gas are permitted to be installed, but are to be included in the overall maximum weight of the particular weight class.

Why do you need speed controllers, just get a some huge relays, nobody will know the difference if Adams driving! But a HE Roboteq is probably your best bet.

How about the 4QD controllers from technobots (the 300amp ones)? Anyone got any experience?

I have seen 4QD 300s smoke on Perms.

Currently, it seems the only brand of PWM controlers for LEMs are the bigger commercial ones; Like Zevcon or Curtis.

Maybe that the single mosfet leg Albright SW88 changeover relay speedos from the Dutch Docproc can do it. But thats untested on LEMs or perms. Also, these are not small (not Dog Bollocks sized either)

Thanks for the info guys.

4Kg of gas and weight aint a problem, if were over weight we can ditch a bottle easilly... we used to run with 1Kg of gas ages ago :)

Who would I speak to/e-mail about trying to get an excepmtion for these cells, or at least some form of permission to test? We are looking to source them direct from the states with a dedicated charger if were allowed.

Mario, the Perms are a different beast to the LEMs altogether.

4QD200s ran the LEMs fine Daniel, I believe they were what was in Storm II when you took it on in New Blood. Never had an issue other than us cracking a PCB as a result of my driving.

They use analog current limiting thus theyre a lot better at clamping current than something PIC based will ever be. Not as big as the 300s either.

Ed
http://www.teamstorm.comhttp://www.teamstorm.com

Pro-120s will run the LEMs :)

But the response time is slow enough to make a drink before turning again.

Wasnt that just ya driving Kane ;o)

Daniel - the 4QD 150s and 200s dont have the relays that the 120s have that Kane used so give an instant response

Well worth a look IMHO. The ONLY reason we no longer use them is when Mentorn asked us to fit a weapon into the robot, we had to find the space from somewhere !

Ed
http://www.teamstorm.comhttp://www.teamstorm.com

Good point Ed, I was wondering if they had the laggy relays on them.... Ive just found my old 4QD NCC-70s with the welded relays and melted capacitors... they really dont like LEMs :lol:

Ill have to get my measuring tape out, do some head scratching, drink some coffee and see what we can fit. The Roboteq still looks nice though.

Hmmm, ive got a spare pair of 4QD 200s, just need a spare pair of LEMs!

Daniel, if you want to make sure the current limter can act fast enough on LEMs with the roboteq all you need is to add a suitable sized choke on both motor wires, If you can find out from the manufactures what the minimum inductance the roboteq needs then a choke (inductor) of that size or bigger will protect the speed controller and limit the motors current.

The problem will be in order to fully protect it from a stalled motor that you will find that power will be quite low, I guess around 200 watts or so, so you will seriously be down on power, and the choke will be quite big.

Why not try the MAG28-400 motors thats what we now use in big nipper with the Dogsbollox controllers, dont know if they will fit in mute though :)

Haha, nice, I bet Big Nipper is fun running on Mags.

Im not too worried about peak amps, a short burst of 100+ amps doesnt matter, its more the sustaned high amps. We want to cut Mute back to about 80-100 amps to protect the motors. As it was we were heating the armature and warping it until it was touching the magnets... not to mention turning the spindle blue. Lemco advised us to use 100 amps max for 5 mins to prevent damage :sad:

The only reason Im steering away from DogsBollox is that Ive got no idea what the current limit was set to on our speedos as they are de-restricted. I guess its gotta be high as we were de-soldering the anderson connectors (both on the board and the incomming wires).

Is there any way to know what the current limit is without trying to stall our motors and measure it? If there is, two new FET boards will be the cheapest and easiest option.

Daniel - borrow a clamp meter and 50m of bell wire submerged in water !

Ed
http://www.teamstorm.comhttp://www.teamstorm.com

Hmmm, ive got a spare pair of 4QD 200s, just need a spare pair of LEMs!

make me an offer, i might let my 2 lems go.

The 3 fet boards in big nipper, are set around 120 Amps (ish) but for some reason the weapon one (Still on CIM2 motor) causes the motor to cut in and out when on the current limit. This did happen on one of the MAGs also but we increased the current limit (dont know what it is now) and the problem went away.

We set this by stalling the motors and measuring the current! No stalling it for more than a few seconds at a time. At least the fet boards have a small LED that lights when you hit the current limit.

I doubt Dogsbollox will current limit the LEMS to any reasonalble level, as they use a hall-effect type curent pickup on the battery +ve which I assume will have a relitatively long delay before the current limit kicks in, due to this and the LEMS low inductance, basically I cant see the current limit working without a choke, but a choke might still be the simplest solution.

Tantos Eteks are fine with my Roboteq

Id forgotten about Craigs...

Thats a good example of the RoboteQ handling a high power application :)

jus about thou

sent you an email Daniel