MC5 1/8th Scale Setups

[rbeyer]

OK guys, let's hear about those setups that were used at MC5. Unless you have "secret setups", it might help others learn what works and what doesn't (or needs a bit more tweaking).

Motor
Geared Drive, if applicable
ESC
Batteries (# and type)
Hardware (rudder, strut, etc)
Prop
Weight of Hull


Thanks in advance,

Rick

[Paul]

Hello Rick,

Well, my boat ran a 2280/11 on a GB. Ratio was 1.07 I think, a x457 prop and 32 cells. (3300s) There was a lot of guessing being done on my part as to a setup but she was fast. My batteries where soldered the night before and I never really got to waking them up. Lots of speed left in my hull.;)

Paul.

[Andrewg]

Paul

what sort of speeds would you say ?
how did they ""fit"" the electric oval"?
which cells did you use ?
what was runtime like?

[Randy Naylor]

I started out with a 355/3t Plett on a 2 to 1 GB and a 447 prop and 32 3300 cells. Speeds were in the 45MPH range. It all worked good until I stopped the boat. When it sat in the water the heat came up and when I tried to get back on plane it blew the comp. I had tried several props but that was the best over all.

Next I put in the Plett 1800/3t and ran several short runs no problem until at the MC5 and I ran for 5 laps then the same thing happened to me, I stopped and blew the comp when accelerating. When I came in to the shore and let the motor cool off I had no problem.

Next I ran a 2280/12t with a one to one GR, 447 prop and a hacker 77 SC. Speeds were about the same. but this time the gears striped. Over and over, I did finish one heat and received a second place in one heat. My boat was the lightest in the pack.

Next I want to run the Lehner on direct drive.

[K.R.Joye]

My Conquers winning Valasko SQUIRE SHOP ran excellent with the Ultra 3300 5T D/D spinning a puny x450 prop on just 26 cells(3300). With the x450 its been GPS'd it in the 42-44mph range in earlier testing. On the nitro oval it only used about 1700-2000 mahs for the 5 laps. I still have some fine tuning to do, didn't use my speed prop either, wanted to make sure i finished. The boat starts to get flighty around 45mph.

RANDY i doubt your 1/8 was lighter than mine, RTR just under 11 pds no geardrive and 6 cells less gives me the edge.

[froggy]

Lightest of the pack what was your wieght? I read that they are a little flighty and need some wieght to stay on the water. Did you add any angle of attack to the sponsons? Starting to put a 1/8th into production,

[rbeyer]

Thanks for the info, guys. Who sells the Plettenburg motors? I have done numerous searches and info is hard to find. I did find the German Home Page but I am looking for any US (or even UK) distributors.

Right now I am just finishing my Circus Circus Canard and will be using a GRX-L for initial testing. I am not looking for competitive speeds (yet) but I want to price out what each motor / esc option is going to cost me.

Thanks again,

Rick

[K.R.Joye]

Got mine direct from Germany. Pm me for info

[rbeyer]

One more question: What steering servo did you guys use? With the heavier hull, I am curious if you had any issues in steering response / torque.

Thanks

[Randy Naylor]

Originally posted by K.R.Joye


RANDY i doubt your 1/8 was lighter than mine, RTR just under 11 pds no geardrive and 6 cells less gives me the edge.

You know what happens when you assume,:D I thought you had 32 too My hull weighted 2 pounds 15 OZ. I had not painted it yet and my scale only goes up to 10 pounds. I do know that the vlasco hulls are light but how light was yours befor assembly?
OH PLease PM me whare I can get the plett arms Igf you have a source in europe.

[Paul]

Hey Guys,

thought you had 32 too My hull weighted 2 pounds 15 OZ.

Not for nuttin (lol) but my scratch built wood hull was 2 pounds 8 ounces.

Paul.

[K.R.Joye]

Originally posted by rbeyer
One more question: What steering servo did you guys use? With the heavier hull, I am curious if you had any issues in steering response / torque.

Thanks

RICK a Hitec 625MG (or equiv) should do the job. The HS645 is slower thats why i favor the HS625.

RANDY my bare unfinished hull weight before CF mounts went in was just under 3 pds. Try these guys are great for motors fast and fair prices. They also will give you quotes on replacement arms for Plett and Ultra. I will be sending an order in about a month let me know. (more power) http://www.hoellein.com/websites_neu/kaonline/emotoren/empletti_eu.htm

PAUL you did a great job on your wood boat. I'll bring a scale next year to get some RTR weights. I'll bet you guys are within an ounce or 2 of each other but i'll still be the lowest. LOL

[Paul]

Hi Ken,

I'll bet you guys are within an ounce or 2 of each other but i'll still be the lowest.

Doubt it, my hull would come in at least 2 pounds lower than at least 3 of the glass slippers. Oh ya, you can be the lightest but I'll still be the fastest.:D

Paul.

[K.R.Joye]

Originally posted by Paul
Hi Ken, 2 pounds lower than at least 3 of the glass slippers. Oh ya, you can be the lightest but I'll still be the fastest.:D
Paul.

PAUL, yes ill settle for the lightest and`Best Looking' (for now), having one of the fastest shouldn't be a problem either after a bit of tweaking. But as you know the fastest boat doesn't always win.
I hope the reliability factor for the geared setups gets worked out it was nerve-racking dodging all the dead boats out there.

[eddieh]

I just wanted to say as someone in the midst of building I appreciate evryone stepping up and devulging their "secrets" this is generally the case and I like to hear what worked and what didn't, Ken I am assuming you are using the bigger ultras (relabeled Pletts) hoellein seems to be not carrying the 355/40's, 45's and 50's anymore, I am still hoping to get buy with the astro 60 6 turn, I also have 2 astro 60 7 turns, and 1 8 turn and I will post my results as soon as there are some.. I may send the 8 turn to astro to see if he will make me the 4 or 5 turn I wanted... but as I said the 2000watts is more then enough power.. I am going to put a sticky on this thread too so we can keep an eye on it, regarding the weight does anybody think that the 1950 aup's would have been ok?? Randy mentioned he had power to spare.. any thoughts?
was weight a real issue?? it seems that more weight was needed (impression from comments in this thread?)

how was the hardware? anybody have any thoughts on fins etc?

thanx again fellas...

[K.R.Joye]

Originally posted by Eddieh
Ken I am assuming you are using the bigger ultras (relabeled Pletts) hoellein seems to be not carrying the 355/40's, 45's and 50's anymore

Was weight a real issue?? it seems that more weight was needed (impression from comments in this thread?)

how was the hardware? anybody have any thoughts on fins etc?
thanx again fellas...

EDDIE, my Ultra 3300 is equivalent to a Plett 355/30 5T EVO with floating torque ring. It runs great on 26 cells D/D with no-load peak RPM in the 25K+ range. I may step up to a 355/37 or 40 for next season. If i can get one to run better than the 3300 on 24-26 cells.
BTW Hoellein does list all the larger Pletts you mentioned in their mailer catalog, just not on their website. I would get some R&D done with those Astros first, sounds like you will have plenty of HP whats the RPMVolt on the winds you mentioned?

Sure weight is an issue, its easier to add weight then remove it. On a 26 cells with my lower power setup its more critical. CG is the biggest factor,you don't want to flip these things to much at stake.

Hardware wasn't a big issue everyone had curved rigger type fins and ex-long wedge rudders. My boat uses a flat fin canted 6-7 degrees(like the real boats) and one of my Cleaver Blade rudders (HD 3/16 shaft) No one seamed to have any problems turning.

[eddieh]

ken the Astro 60 6 turn is 652 rpm/v, the shaft is suppose to be titanium (it doesn't look like plain steel) and the brush surface is huge, I will definately try them, but the lower rpm figures made me think that I should overdrive it a little to get into the 8-900 range ie 1.25-1.30, I was thinking 57mm prop, although playing with the fe calculator and a couple of different props I get estimates to low to mid 50's ???? I also think the astro with the huge aluminum body, the much bigger brush surface and the 4 brushes would take the hea better, they are made for 32 cells, it has the arm reinforced with kevlar thread to prevent flowering, but as you say needs testing .

when you say extra long rudder 3"? i wouldlike o make a scale rudder but I guess I could always make it a little longer and cut some off after testing...

I was looking at your boat again and it really is a beautiful boat!!:rockon:

I would love paul to post some pics of his close up that looks like a true beauty as well:hail:
l8r

[brooks93]

here you go Eddie sorry haven't been in this part of the forums before

http://www.brooks93.com/CAFE3/pauls8th.jpg http://www.brooks93.com/CAFE3/pauls8thscale.jpg

[froggy]

NICE!!:D

[Andrewg]

I have a feeling people will be turning up with Plett 370/50/A1 S; Lehner 2250/13 or maybe 2280/11.

In Europe people are hooking these motors up to 3-blade Prop Shop cleavers 5517/3 and running over 100kmh (62mph) in oval trim.

The most successful brushed motors were the Plett 355/45/4 on 32 cells running X455.

The Pletts 370 with paralleled packs of twin 32x3300 have been fastest and have been gpsd at over 120kmh (72 mph). {Ulling at least 80 amps continuous the acceleration is a knockout!

[K.R.Joye]

Its hard to believe but i've bumped up my speed atleast 10MPH since MC5. Changes i've made were motor, cell count and prop angle. Upgraded to a Plett 355/40 4T on 28 cells with almost no angle on the same x450 prop. I get plenty of runtime on 3300's R/C Hydro Emperor ESC works flawlessly. The boat really rocks now and will be a solid competitor for next season.:beer:

[AndyKunz]

Ken,

When I get back from Florida I need to telephone you.

Please e-mail me your phone number and put in the subject "Rum Runner" so my spam filter doesn't kill it.

Thanks.

Andy

[Andrewg]

Ken
would that put you up in the mid 50's? You must be pleased. Great job.

[hugh]

plettenburg has its own website with translation you want the 370/50/a1 s from the charts i looked at you gt more hp at 28.1 volts 2.9 hp at 20,308 rpm pilling 90 amps or id probably run 0 degress and a 1455 but here again im just taking a guess my dumas circus circus would be considered to us to be a fairly heavy hull and their plans start out with a x457 a friend of mine ken stone out of oklahoma city bluprinted my picco 67 with header length set up for torque to run on this boat the plettenburg above im my opinion would be a damn close equivalent probably more torque on the low end so thats why i say step it up to a 1400 series with lift and see what you get. I also have a andy brown 60 class rigger that im contemplating putting the motor in. The boat had placed in the nationals back in the late 90's owned buy curtis samuel and setup by ken stone of okc model boat club it was running a hot ops65 with a 1465 prom 10mm larger than what im talking about for the plett i dont know how that plet would measure up to that ops. Ken was one of the better engine builders on the scene back then and i put my money he still is but hes into scale aircraft and sailplanes now. You guys got any feed back on this info let me know

[hugh]

i retract my statements i truly think at this point after looking at some nitro specs these nitro motors like my picco .67 are putting out 4.5 to 6 horsepower more like 3500-4000 watts of electric power (dual pletts on a 1:1 gearbox)!!!! thats what i think would be good then maybe you could lower the voltage and run a parallel set for run time and less heat and gear up for speed to a 1:1.25 ratio. Guys????? or perhaps the big lehner looks not so pricey now if you can get 3500-4000 watts out of a direct drive set up with one motor you cant beat the price even with dual outrunners because of all the cost in cooling fans etc. id go with the big boy lehner the 500 dollar joint
cause to me just get what you really know you need for these hulls torque and power one time. Testing this and that can get expensive cheaper way find two 1500 watt or better generic inrunners and gearbox it you want your gearboxes to hold up get rid of those candy azz plastic gears they cant hold 4.5-6 horses on a sleigh be realistic my colleagues and dignitaries go with the metal gear like robinson racing in your gearboxes or cad some allthough aluminum gears will wear fast too.Be smart be strong go steel go stainless if you got a source. My 1/8th circus in the shot below

[petebarrow]

I run an 1/8th scale hull with a plettenberg 370BM50/A1 s motor.
I regulary run mine at around 6Kw with a x665 octura prop.
speed not sure. It out runs a 55mph rigger as if its stood still.
I run a YGE 200 navy and a hydromarine amp logger.
12s 2p 5000 20c at 162amps

cells temp after run 50c


UK dealer www.modellhaus.co.uk all big pletts to order takes about 3 weeks


Pete

[petebarrow]

I run an 1/8th scale hull with a plettenberg 370BM50/A1 s motor.
I regulary run mine at around 6Kw with a x665 octura prop.
speed not sure. It out runs a 55mph rigger easily, runs 80yards around 20%+ quicker.
I run a YGE 200 navy and a hydromarine amp logger.
12s 2p 5000 20c at 162amps

cells temp after run 50c


UK dealer www.modellhaus.co.uk all big pletts to order takes about 3 weeks


Pete

[K.R.Joye]

PETE great to hear of your setup. You just confirmed what we've learned over time using the 370 Plett, it runs better on 12S setups. Myself and some other 8th Scale racers sold our Plett 370s and went to comparable size NEUs & Lehners for better efficiency. See were limited in NAMBA competiton to 10S(max) for 8th Scale and could never seem to get the 370 into the sweet spot without adding a large prop, paralleling cells, therefore adding weight pulling big amps cost big $$s.
Do they have organized classes for 8th Scale competion in your area?

[Ntm]

i retract my statements i truly think at this point after looking at some nitro specs these nitro motors like my picco .67 are putting out 4.5 to 6 horsepower more like 3500-4000 watts of electric power (dual pletts on a 1:1 gearbox)!!!!

The nitro motors manufacturer's specs are usually wildly optimistic.
I know when it comes to helis, 4000 watts will absolutely bury a .90 glow setup.

Regards,
Nathan

[hugh]

i dont think they would over estimate 4 hp maybe so but being dumb as i am obviously i thought the pletts were maxed out at 30.2 volts pete how many volts is a 12s? the reason i thought that is because on pletts spec sheet they only go up to 30.2 volts duh on me. Pete whats your run time?But im still curious about the physics of it all? even if my picco put out lets say 3 hp that would still be about 2240 watts of electric power 2240 22.4 volts at 100 amps would supply this i thought? can yall help me? Pete using ohms law im assuming that youre around 37 volts? 30 cells in nimh but you are talking lipos is that about right for 12s 37 volts? or close to that?I also would like to say that around 50 to 60 mph is about where the nitro scales run on a stock blueprinted picco so 55mph is plenty good.IF youre faster than that pete in my opinion thats cooking the water with a big scale like my dumas circus.But at the same time that hull only weighs 8.5 pounds and i say "only" because my c class andybrown mongoose rigger is 5 pounds but believe me its alot faster than 55 more like 65 with a double glow plug modified 67 ops engine. If anyone remembers the mongoose hull it was fast in its day it was replaced by the andy brown eagle hull.

[Jim Caldwell]

3.4 volts with a 100amp load per lipo cell, so 12 X 3.4 = 40.8 volts.

[hugh]

Well jim how is pete running 40.8 volts times 162 amps and come up with 6000watts? or pete was that an approximation based by factoring electronic drag (heat)?cause i come up with more like 6,610 watts and people be aware if im not mistaken thats 8.9 hp. NTM (nathan) also id like to say just for the sake of conversation 4000 watts aint gonna bury a race prepped ops 90 hell naw id have to see it. ive seen those beast fold copper props like paper if you dont believe me just ask some expert nitro guyz theyll tell you those cmb's and ops's once built boy good god watch out! not to say that a concievable brushless set up can beat it but i bet it will cost more than that besides i would think a big heli "would" like the torque of the brushless versus a 2 stroke nitro at low rpm the 2stokes dont get into the power band til the carb unloads all that fuel as the rpms get up

[Andrewg]

Hugh

his output figure on 12S 162 amps is around 5882 on an 89% motors - motors are rated that way - thats 7.88hp

there are several factors determining how a boat runs - the electric makes most power where its needed as a boat enters a turn and runs out of it - an electric accelerates much faster - perhaps not to such a high speed but it speeds a lot more time in the upper end of its speed range.

[hugh]

Thanks drew efficiency (electrical drag more or less) true? Is that 7.88 horsepower legal in sanctioned scale events?

[Jim Caldwell]

Hugh, my numbers are Data logger numbers under load in a boat, on 30c 5000mah 1p cells and that is the max amps on 1P as the voltage drops quickly above that on 1P.
I have no Idea how anyone else developed their numbers.
You can't use advertised battery numbers for boats unless you are willing to buy new packs after 20 runs!

[hugh]

I got you Jim, that makes sense i used ohms law to come up with my figures voltage times amperage equals wattage( electrical hp) but that doesnt account for real-time losses your amp logger does.Where do you get one of these things?Hey pete you got enough power in that thing for a riding lawnmower lol. Thanks Jim

[Jim Caldwell]

Eagletree unit. I have had one 6 years

http://www.eagletreesystems.com/MicroPower/micro.htm

[Andrewg]

Hugh/Jim

* 7.8hp is legal, however, it is probably overextending a 10S 5AH pack, but well within a 10s 10AH pack.
* batteries are the only source of power so they have to be protected or will suffer damage. Because electric motors are sensitive to load, its important the pack is not loaded beyond its capability; the loggers are brilliant in this regard. Once you get to the amp limit of the pack improving efficiency thought boat setup and weight reduction are the most effective means of proceeding.
* motor efficiency is from from dyno charts on plett 370 (86%) and Neu 2215 (90+%)

* efficiency is the product of:
1. copper losses - increase with current
2. iron losses - increase as voltage/rpm increases
3. parasitic drag such as bearings and inertia
4. and they overlay the fundemental nature of an electric motor which sees it behaving as a gen and motor at the same time and is responsible for max torque at 0 rpm, max power at 50% of peak rpm & max efficiency at around 90% of peak rpm (for inrunner brushless). A mistake is many people make is that interaction of stator and magnets in an unpowered motor indicates its torque or efficiency levels - this is not correct. A dyno is the only reliable way to asses a motors potential.



Jim
what are your turn peaks?
do you use preheating?
have you tried the V2's ?
I also went to female/female plugs of the packs - male/female was too dangerous - shorts and over amps hurt these cells

[chuckc]

Just kinda interested, are any of who's working the link coming for the MC-9 ? Two days of 8th scale, 3 races on sat, 2 races on sun.

You guys are still on a MC-5 link :wave: That was 4 ago

[petebarrow]

12s charged = 50.76 volts
underload 40.8v
If you look on the webb the recommend number of nimh is 30 to 40 cells for the Plett 370BM 50 A1s.
Its not uncommon for Plettenberg to underate there motors.
I have had quite a few over the years and run some of them well over 50% more than they recommend. A bit like Roll Royce motor cars.

Pete