Mono 1 help

[boatman91]

hi all.

i want to get back into FE after a good 7 years out of the game. i want to have a bit of fun a first and hopefully race competitively next year in the mono 1 class in the north of England with http://www.ampdraggers.co.uk/.

i would like some advice of how to set the boat up for fun for know but could/would be competitive if raced.

race rules- http://www.ampdraggers.co.uk/documents/Nads%20Rule%20Book.pdf
basically i need to run 2s or 3s cells under 280grams for 6mins

my aim is to do this on a budget and wont be spending big bucks to get this going.

Fun set up Mono1-

Hull - not sure i think its a joysway ( any ideas?, see pics )
motor - MEGA 20/22/2 think its a 2880KV.(3.5mm connectors)
ESC- ETTI 125amp ( this has 5mm wire ) as i dont think i will get 3.5mm bullets connectors on this ESC i was going to buy a cheap ESC to get me going possible a Turnigy 100amp esc with thinner wire.
lipo's- i haven't bought these yet but i was thinking some cheap cells at 3s 4500mah 30c Turnigy ? as i would think 2s wouldn't get me the RPM ?
Prop - Not sure what this plastic one is 27mm maybe? can you recommend a size ?

Race set up -
Hull - same as above ( will need to fit safety circuit )
motor - Leopard BP2860/3D 80A 17V 1300W 3400KV
ESC - ETTI 125amp in the picture (hopefully motor wire will take the 5mm bullets anyone know if it will?)
lipo - please advise where to find cells under 280grams ( see race spec)
prop - please advise

i also don't have a lipo charger yet, i was going to purchase a IMAX 6 charger they seem to be well rated.
do i need a balance charger for this ?

i am no expert in this field so any help would be great thanks.

[Jesse J]

Wow, did you just join today? Welcome!
I too am on this path. See my post on setting up a stepped hull, goo stuff in there.

[NativePaul]

Welcome Boatman 91.

I race with the ampdraggers now too so maybe I can be of some help, currently all their races are held at Bridlington, are you close? It is worth the travel if not as it is the best boating lake in the country, the Nationals are held there every year and they are coming up on 7/8/9th of July, I would heartily recommend that you come along with your boat and run your questions past the mono guys who seeing the boat can give you more info than I can online.

I don't recognise the boat from those pictures, but it could be a Hopf, Karl Heinz Hopf in Germany has stopped now but made many good monos and hardware in the past, including some quirky stuff, so I wouldn't be surprised if it was one of his. Hopf liked rather large single steps and were very fast in a straight line.

Your 2 possible motors are both different sizes, the Mega 22 series being 36mm diameter and having M3 mounting holes on 25mm spacing, and the Leopard being 28mm diameter with mounting screws on 19mm spacing, what is the boats up for? It would be a shame to rip out the motor mount, and drive shift to fit a motor you are not sure about. If you want a 28mm motor maybe consider one from goolrc. They do one similar to the Leopard on eBay for less money and are gaining a good reputation.

It looks like a dog drive and if it has a 28mm prop on it, I suspect that it must 1/8" I would recommend switching to a m4 threaded shaft as the biggest you can get on 1/8" are 35mm and the lower lift props that suit Mono1s well are more common in m4. The Mega will need a Graupner carbon 2818 39 or 40.5 and a 2860 3400kv will want a 2818 36 or there are decent alloy alternatives from Tp and tenshock.

Save your money on the ESC, and solder 4mm connectors on the motor instead, don't cut off the old ones, unsolder them.

Both motors will want 3s, there are high capacity race packs available from Tenshock and Redzone, but they are expensive and fragile, on a budget I would recommend ignoring the weight limits and buying cheap <4500mAh packs, or saving up and buying an energy limiter which will allow you to running any cells you want, and since you don't have to flatten them you should get a much longer life from them.

I know some that use the i6 charger but there is a cheaper turnigy reactor charger that is popular too, again come to the nats next weekend and you can probably talk to users of each, to get the lowdown before purchasing. There is often used gear to be had too.

[martin]

Paul you mention the Goolrc range of motors, I have been looking at various size motors from them for some time now. But have been wary of them not knowing any feed back on them, what have you heard about if their any good as they are pretty cheap. Thanks Martin.

[NativePaul]

I know 3 or 4 in use, all the owners are very happy with them, are in competitive boats, and they rate them as good as any other reasonably priced motor (leopard, Tenshock, TP etc) but right at the low budget end of cost. I haven't tried one myself yet so can't say more than that. I don't know if they are new, or just new to our group, but the ampdraggers only discovered them this year so longevity is yet to be seen, but unless there is a string of breakages the next motor I buy will almost certainly be a Goolrc (unless I find another amazing deal on a used Lehner).

[boatman91]

Hi
thanks for getting back to me.

i live in manchester so its about 2.30 hours away, ive just had a newborn so i may not be able to make the meet next weekend.if i am allowed to get away theres a chance i could make the sunday, what are start end times ?. Are you around manchester ? i bought this hull and motor from a model shop in bury ( when amp draggers also raced at bury).

motor - i didnt realise that the motors had different diameters, i just thought that by now the mega would be hopelessly un competitive if i raced and my research said most used leopard.

shaft & prop- any pointers where i can pick these up from ? i had a look on hobby king.

Battery + charger - i will get some cheap 4500 turnigys to get me going( or any other brand you recommend? , i haven't heard of a energy limiter what does that do ? does this make you exempt from the weight limit ?. In general are more racers running a higher KV with 2s or lower with 3s ? i guess i could be easier or cheaper to find the battery weights at 2s ?

connectors - would you recommend using a standard connector thought out all your batts motors esc etc ? would 4mm bullets be a good standard ?.

some more pics of hull attached

thanks Chris

[NativePaul]

Congratulations.

Sundays at the nats are usually 8am till 4 or 5pm. I am in Bridlington.

Megas are still good motors, I rate them above Leopard, but their price has doubled since they came out and there is more competition in the mid range, so they are not the bargains that they used to be. Leopard are competitive and nearly half the price so it is easy to see why they are so popular.

Model Marine Supplies, Prestwich Models, and Ian's Boats, are all in the UK and all specialise in fast IC boats, but have some stuff that is applicable to us. OSE here has a huge range of FE stuff most of it is similar to the IC stuff and not really applicable to us, but that still leaves a lot that is suitable for Naviga style racing. Hydro & marine in Germany have a good percentage of stuff for Naviga racing. ETTI, and Tenshock in Hong Kong, and Ecomaster.torgg in Ukraine are all Naviga specialists and solely cater to us. You might also try emailing AStec Models, Allan at Astec has now switched his emphasis to RC lorries and his website show little boat stuff, but he used to be the UK FE source and I know he still has some stuff in his storage unit that is not on the website.

Batteries are a mix of tenshock/redzone race packs, and cheap 4500 packs you wouldn't be the only one on HK packs. an energy limiter is a little electronic device that plugs in between your battery, radio, and ESC, it measures your voltage and your amp draw to work out how much enerhy you have used and if you go over the predefined limit it cuts your throttle. If you fit one you don't have to conform to either the battery weight limits or the battery capacity limits, just the voltage limit. That way you could run whatever cells you like, say 2s 8000mAh or 3s 6000mAh but you can only use the same amount of energy as you get in current a race pack so you finish the race with some capacity left in them and they last much longer. At the moment within the UK it is only ampdraggers legal, but I am sure it will be made MPBA legal at the AGM during the nationals for next year's nationals, and am pretty confident that it will be made Naviga legal at the worlds meeting in august.

3s/6s is much more popular than 2s/4s, in the full size classes almost everyone is on 3s or 6s. In the minis 3s is more popular, but a much higher percentage are on 2s.

4mm caged bullets are by far the most common connectors, if you want to buy a safety loop rather than make one, they are all 4mm. Whether you standardise connectors is up to you, I started off standardised with 4mm as nothing came with connectors and it with only a couple of boats pulling similar amps and everyone else being on 4mm it was an easy choice, then my boat got more varied and some electrics came with connectors so I just matched what the it came with, but that proved to be a PITA so I standardised on 6mm that would cover eveything, but i got more heavily into minis and decided that having 4% of my RTR weight being connectors was silly, and I have broken away from standardisation again and use a mix of 3.5mm for minis, 4mm for most boats and 6mm for SAWs, it is a bit of a pain swapping charging cables, but worth it to me. Ideally I would use Kontronics for all the race boats and then I wouldn't have to swap charging leads but they aren't cheap or easy to get hold of, and they are tubular so you can't use them for safety loops.

I am pretty sure that is a Hopf hull but I cant tell you which, it is definitely not a Joysway.

[Speed3]

A setup I saw somewhere was the leopard 2860 3400kv, a 4500 3s nanotech pack, and a tenshock 36mm 2 blade prop.

[NativePaul]

I should have said, it is the black GOOLRC motors that have a good reputation, the blue ones are cheap crap.

[Speed3]

What I think could make for an interesting setup is a mono 1 rigged to use a 36mm motor, example a leopard 3674 3300kv, using 3s like the 2860 would use, for the shaft a .150 flex cable the prop would be an ocutua x438. A setup like this is likely to walk away from the other boats with the smaller motors example 2860 or 3650 size motors. When the smaller motors is lossing over 25 to 30 percent of its rpm under load the bigger motor might lose 5 to 10 percent of its rpm.

That is the smaller motor running 70 to 75 percent of 35000 rpm (24500 to 26250 rpm)

While the bigger motor running 90 to 95 percent of 35000 rpm (31500 to 33250 rpm)

The result being 120% to 128% vs 100% speed.

That is 48 to 51 mph vs 40 mph. The runtimes would be in the same region but the speed difference would be big. Boats would get lapped over the course of a 6 minute race.

[NativePaul]

I think it would be a poor setup, due to a 3674 being near double the weight adding over 10% to the RTR weight, having near double the IO, having a much heavier rotor so taking more power to accelerate, needing a bigger heavier driveshaft, not being able to run a straight shaft and running a big prop with quite a lot of lift and a heck of a lot of blade area.

I would be very interested to see that setup though, and I would be very impressed if it could get 25 laps, never mind being laps ahead.

I would also be interested in how you came up with those RPM drop numbers, when I plug in the KV, IO and RM numbers for both (taken from Leoapard's website) into Motocalc at 45A (the average current draw for a Mono1) and 10.7v, the 2860 3400 comes in at 90.2% efficient and gives 34,582rpm, whereas the 3674 at the same Voltage and Current comes out as 88.6% efficient and gives 34,788rpm.

[Speed3]

I have real world experience, I have a 2860 5050 kV, I did some test with a tacon 3674 2800kv on 2s, I ran even the leopard 4092 1730 on 2s, the 4092 2080 on 2s. Imagine the tacon 3674 2800kv on 2s push a impulse 31 faster than my 2860 5050 turning an octura m435 on 2s was able to push an exceed shark mono1. And I know the leopard 3674 3300kv would easily add a few mph over the 3674 tacon 2800. My leopard 4092 2080kv pushing the impulse 31 on 2s was very close to the fastest I got with the 2860 5050 in a much smaller lighter boat. So I am speaking from real would experience. I am running in salt water so maybe its loading up the motors harder than the fresh water thereby giving the bigger torquier motors a big edge. I have found my leopard 4092 1730kv on 4s turning an octura m545, is faster than the aquacraft 1800 on 6s turning a 4255 grimracer prop, so don't fooled with high kV and heavier motor. My 1730 4092 leopard while being about 10 punches heavier than the aquacraft 1800 3656 it is faster even on 2s with a m645 in a 30 inch boat.

[Rcsurfrider]

Have any of you guys tried using outrunners? I use em in rc jet boats and they pack on the torque at low weight. My 2836 12pole 2700kv outrunner jet boat on 3s is ballistic. And thats using the big 28mm kmb jet drive

[NativePaul]

Imagine the tacon 3674 2800kv on 2s push a impulse 31 faster than my 2860 5050 turning an octura m435 on 2s was able to push an exceed shark mono1.
Maybe you are unaware that Mono1 is a Naviga race class, not just the name of a boat. I don't doubt that a big motor can make a boat go faster than a little one, but the mono1 class has a battery weight limit which defines the amount in conjunction with a runtime sets the amount of power we have available, with current technology we have about 3200 watt minutes of energy, and we run a 10 second mill, a 6 minute race and an in lap so a total of 6.4 minutes runtime, which gives us an average of 500W to play with. While your bigger motor was able to push a bigger boat at close to the same speed as a small one, it took more watts to do it. Maximising speed per watt is the challenge of all the Naviga classes. The big motor's efficiency curve is still well under the peak at Mono1 power levels, and they com into their own with Mono2 that has double the energy and power available.


Have any of you guys tried using outrunners?
I use a similar Turnigy Rotorstar outrunner in my Mini Eco on 3s and it is a good motor for that application, but I've not seen an outrunner in a Mono1, not saying it cant be done, or wouldn't be good, just that I have never seen it.

[Speed3]

The bigger motor gives more power output with less input than a smaller motor. I have done this experiment many times. I did it a aqua craft Rio ep to. I had a 3200kv 2858 motor, and I ran it on 3s with the stock Rio ep prop. Then I took the 3674 2800kv with the same 3s and the same prop and it was 13 percent faster and the amp draw was significantly less with the bigger lower kV motor.

I have done these experiments too much, with recorded data. I even have videos to back up what I am saying.

[Speed3]

I think some motors can hold the rpm so well it wouldn't make sense to use a bigger motor. I am using the leopard 4092 1730kv in the aqua craft revolt and that motor on 4s with an octura m545 pushes the revolt faster than the stock revolt 1800 motor on 6s with the 4255 grim racer prop. Again a bigger motor putting out more power with far less input power.

[NativePaul]

They are hardly apples to apples comparisons, going from a RTR motor that was designed to be as cheap to produce as possible whilst working and has evolved over the years to be even cheaper, and switching to a decent budget mid range motors, of course you are going to see efficiency increases. That is like me saying I swapped from a Leopard 3674 in my hydro2 to a 3664 Lehner and dropping lap time whilst gaining runtime, it is little to do with the size of the motor and more to do with the quality of the motor.

If you have any data regarding size swaps with similar motors then you might be on to something, and I would love to see it. Until then I will carry on believing that knowing the KV, IO, RM and mass of a motor can predict its performance fairly accurately, and my experience of seeing the class evolve from all running 36mm motors to nearly all running 28mm motors (and those that don't running very short 36mm of similar mass).

[Flying Scotsman]

As usual a tactful and experienced response Paul.....As an aside, did you put your best duds on for the Goodwood Revival?

[NativePaul]

I like to wear my dad's duds for the revival, it really is an awesome day out, but I have no money for tickets this year.