Rc Formula OffRoad
Autot => Unlimited EP - 1:8 autot => Topic started by: Penguin on 29 April, 2009, 21:44:05
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ESC............................ Hobbywing EZRUN 80A
Motor.......................... EZRUN 3674 SL, 2350kv
Receiver...................... Futaba R603FS, 2.4 GHz
Transmitter.................. Futaba 3PM
Batteries..................... 2 x Flightmax 5000 mAh 3S 25c in parallel
Maximum current........... 250 A constant (batteries), 80 A constant (ESC)
Servos........................ 2 x Traxxas 2075 (0,88 Nm)
Tires........................... Pro-Line Maxx Paddle
Wheels........................ Hong Nor 17mm White 1/2 Offset MT wheel
Chassis....................... Stock E-Revo chassis
Suspension.................. Stock E-Revo suspension
Battery connectors....... Traxxas High Current
Transmission................ Stock E-Revo four wheel drive
Drive shafts................. Traxxas Revo stock plastic drive shafts
Body........................... 1. Stock E-Revo body
2. Land Rover Defender G4 130 HCPU - Tangerine Orange
Colour......................... Red / Orange
Shocks....................... Traxxas GTR
Spur........................... E-Revo stock spur ??T
Pinion......................... Castle Creations 17T 32P
Dimensions:
Wheelbase:.................. 358 mm (stock)
Length:....................... ? mm
Width:......................... 450 mm
Height:..,..................... 260 mm
The beginning of building project
It is time to start a new project. This time story in English as the owner and driver of the truck is Brazilian and our best common language is English.
Basis for this new truck is new, unused E-Revo with brushed engine.
(http://media.share.ovi.com/m1/s/0814/dd2f278c4a144cddbdd248ae1cf69edd.jpg)
Plan is to remove EVX-2 and Titan motors and replace those with Hobbywing 80A ESC and eZrun 3665SL motor. Other modifications in the beginning will be LiPo batteries and paddle tires. Remains to be seen what modifications will follow, but I have already started development of new extended chassis for Revo. This time completely different approach compared to Revolution.
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Sounds cool. It'll be nice to see what you can get from scratch as E-Revo. Looking foward.. :D
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Battery building, crawling and birthday party has kept me busy as well as spring sale in our rc garage. Despite of that I received the Revolt yesterday and it is practically unused E-Revo with two stock (brushed) engines. First we need to rip such underpowered and failure prone toy motors away.
(http://media.share.ovi.com/m1/s/0817/bb1a1a776aad47e6a62db7aa136e3bd6.jpg)
Now there is room for new power line ordered yesterday.
(http://media.share.ovi.com/m1/s/0817/cdd137aeb674437ea0377fe830dd1b1b.jpg) (http://media.share.ovi.com/m1/s/0817/34895b72ca584ebb8ad6c8d5a25a4342.jpg)
Remains to be seen how it will perform with these budget parts.
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Cool ;D I cant wait to see this one finished
c",)
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I was looking for new driving places today and I visited in local Hong Nor retailer too. From there I found suitable monster wheels for Revolt.
(http://media.share.ovi.com/m1/s/0831/3a6c1812d2be47fab14245393394aaf7.jpg)
Maxx Paddle tires ordered from LiquidRC will be installed on these wheels and Traxxas 17 mm hex hub & nut will be used to mount the wheels.
I also received a confirmation that ESC and motor combo has been shipped. According to Hong Kong Post the shipment will leave Hong Kong for its destination on 9-May-2009 which is today.
By the way I did found couple decent places to drive with Unlimited class truck, but unfortunately both places had fences blocking road access to the pit. I have been looking good places from Google Earth and I still have about 20 gravel pits to check in capital area of Finland.
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I visited post office and what I found was quite a big ESC + motor + accessories.
(http://media.share.ovi.com/m1/s/0844/37ce822167554ea280d9f5ca7b97935e.jpg)
Everything printed into box says there is 150A ESC inside, except small label attached to back of box. It says:
EZRUN-80A-N
Program Card
3674SL-2350KV
19T-5mm-32P-Gear
Lets look inside the box.
(http://media.share.ovi.com/m1/s/0844/c8cf066a0a5b4f30bd0041d037c7c066.jpg)
From the box we can find Hobbywind ESC which is fairly big.
(http://media.share.ovi.com/m1/s/0844/5749af27e50d4d9fba228afc365193ff.jpg)
(http://media.share.ovi.com/m1/s/0844/253baee44ee24a91bc0653b73fc4f303.jpg)
Motor is EZRUN 3674SL 2350kV V2 with heat sink and fan attached
(http://media.share.ovi.com/m1/s/0844/68a206425f4d477cbe4eb42e0e75ace5.jpg)
(http://media.share.ovi.com/m1/s/0844/64ced4d8604447beac059315ae89024f.jpg)
(http://media.share.ovi.com/m1/s/0844/97bda0e6755a41d29c558c5507a015d7.jpg)
Programming will be done with Hobbywing program card compatible with multiple Hobbywing speed controllers.
(http://media.share.ovi.com/m1/s/0844/9ec633ef29ce449b8c85541f50065f61.jpg)
May be not as many configuration options and variations than in Castle Creation Mamba controllers, but I have one smaller ESC + motor combo and with that those available configuration options are enough.
Pinion by the way is 21 teeth but otherwise all printed in the small label match with the content. There is also collection of heat shrinkable tube, 10 cm of 10 AWG silicon cable, screws and stickers included. User manuals for the ESC and programming card where included too.
Lets see if I have time to install these tomorrow...
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Lets compare this new ESC to old EVX-2 which is not the smallest speed controllers in market.
(http://media.share.ovi.com/m1/s/0844/a8490b474cf2475aa1b08a89892a252a.jpg)
This new one is really big indeed. Much bigger than e.g. Mamba Monster.
Edit: I had to test how motor and ESC will fit to E-Revo chassis.
(http://media.share.ovi.com/m1/s/0844/e2084e14f94d46118dcfbf86bcdf9653.jpg)
Quite well. I thought front mounted motor could be better in foff. I installed 17 teeth 32P pinion from Castle Creations. Hobbywing ESC fits perfectly to EVX-2 place using even same screw holes. Stock motor cables from ESC are too short and have to be changed. I will do that tomorrow and then it will be time for test run.
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Unfortunately I did not have time to solder new cables to ESC and test the truck as I was in my daily job instead. Today new 17 mm hex hubs and nuts arrived with Traxxas wheel wrench. The wrench did not fit inside HongNor wheel and I had to use turning machine to grind the wrench and reduce its outer diameter by 2 mm.
(http://media.share.ovi.com/m1/s/0846/3b784218c66a4526b08bfa7bc1383ba2.jpg)
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Maxx Paddle tires arrived today from Liquid RC.
(http://media.share.ovi.com/m1/s/0848/bea1300836974831817d805a52c1a061.jpg)
I could not wait before installing them to the wheels. I also assembled those to the truck with hex hubs to see how Revolt looks like with paddle tires.
(http://media.share.ovi.com/m1/s/0848/d8b70239ba614073af19996640d7e858.jpg)
It looks almost like formula offroad truck.
(http://media.share.ovi.com/m1/s/0848/d77d89768a04456ea9a24b54409a747c.jpg)
Update:
I soldered new motor cables to ESC and connected those to cables from motor by soldering those with silver solder. Traxxas high current battery connector is also soldered, but an adapter cable is still needed to connect two batteries. I have not decided yet, if we will use two 4S batteries in parallel or two 2S batteries in series.
(http://media.share.ovi.com/m1/s/0848/39cac716ae9e4a7d8d0c0eb48e85355a.jpg)
Then I closed all air vents in battery compartments by filling the vents with silicone.
(http://media.share.ovi.com/m1/s/0848/1d71024d52bc4118ae2db03a749dd810.jpg)
Now everything is ok, only receiver box needs to be closed and antenna installed. Giga radio is still missing, but even without it Revolt starts to be ready for testing.
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ESC died with second set for 4S batteries. Now I am waiting for reply from Hobbywing...
Anyway it was fun to drive whole 20 minutes with first battery set.
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I sent a message to Hobbywing if they would give any hints what could be the problem with ESC and how to solve it or if they would change or send a new one. Famous "usage smoke" did not leak out from it nor can I see any damaged component in circuit boards.
While waiting for new ESC we have keep the feeling with these videos:
- First run and everything still ok. (http://share.ovi.com/download.aspx?media=edelman.10164)
- Second run is very short and ends without any drama. (http://share.ovi.com/download.aspx?media=edelman.10162)
There is one problem with the driving of the Revolt: It does not turn in loose sand. I have few ideas in list what to do and changes will be done in differentials, springs and shocks.
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I just received a confirmation that ESC has arrived to manufacturer in China for repair.
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Repaired ESC has been installed and so far everything seems to work. We made some additional spur covers to second motor mount and silicone has been used to close other holes. We are planning to test this truck on Sunday in Mänttä and participate to World Championships three weeks later. Everything depends on if the ESC works this time longer than 10 minutes.
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It looks cool and very fast :)
You should upload those videos to YouTube
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Todays short test run was short but successful. This far everything seems to work properly. I also bought center differential today to reduce major under-steering we are struggling with.
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First tests with center differential where promising. Handling is much better although it seems that center differential oil is too thin for the purpose. I ordered new thicker silicone oil and while waiting for the order I cleaned and re-installed two alternative front differentials for the truck. The original one from E-Revo (Revolt) with 50K fluid and one originating from Revo 3.3 (Revolution) with 30K fluid. Purpose of two differentials with different fluids is to test which will be the best setup for front differential.
It was also interesting to notice that parts inside E-Revo and Revo 3.3 differentials are different. I do not know if it because of age of the truck or because of model. Anyway externally those are transferable so it does not make big difference.
Center differential will get either 50K, 100K or 500K fluid inside depending on which works best. Anyway more testing with different setups is needed before this truck is ready for World Championships.
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The E-Revo diff is the newer one
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Heavy tuning is ongoing still just before World Championships next weekend. Suspension and transmission tests have been continued by testing with different silicone oils in differentials and spring rates to adjust driveability. Turning has improved a lot from stock E-Revo. Spring setup for the next weekend race is final, but central differential needs to tested with latest adjustments although I am quite sure that is the final.
I started to make body for the Revolt by taking a new body for Revolution and cutting about 100 mm away from front of the bed. Currently the body is in two pieces but target is to weld those into one piece tomorrow evening.
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New body is forming and looks quite good already. With this length the body looks even
better than in Revolution which looks little bit overstretched.
(http://media.share.ovi.com/m1/s/1103/7504b88cc7b84fbc8f3880c7e7179eb7.jpg)
I have welded front and rear pieces together and now the seam is waiting for drying and
hardening until tomorrow. Then I will sand the whole body and finalize the welded seam.
Body should be ready for painting on Thursday.
(http://media.share.ovi.com/m1/s/1103/9a4d43c175ae4c98a94569fafc5440c9.jpg)
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Body has been sanded, filled and sanded again. Front bumper is now installed and rear bumper mount made as E-Revo has originally wing mount and rear wing which does to fit with LR body. Bumber mount could be replaced with original one from Traxxas later, but there was no such available before the weekend.
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Lets add some graphics from data logger. I tested Revolt very shortly with data logger installed during the last Finland Cup event in Mänttä.
Batteries used in testing where two 4S Zippy Flightmaxx 2650 mAh in parallel.
The first graph shows battery voltage and current (amps) in Y-axis and time in minutes is shown in X-axis:
(http://autorata.com/rc-autot/revolt/Revolt-090802-AmpVolt.jpg)
To the second graph I selected X-axis to show cumulative mAh used from the battery and power (watts) and battery voltage to be shown on Y-axis:
(http://autorata.com/rc-autot/revolt/Revolt-090802-WattVolt-mAh.jpg)
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...and then some pictured results from last night advancements:
(http://media.share.ovi.com/m1/s/1109/b9f669e8a22547dd96d13330029dec52.jpg)
(http://media.share.ovi.com/m1/s/1109/d2d704bc218b460e93278d5343aef637.jpg)
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World championships were first ever race for Revolt with two new drivers in Autorata Racing
Team: Tino from Finland and Eduardo from Brazil. Already in test track we experienced some
difficulties with broken rear bumper mount and broken body weldings. With tool help from tuunari
we managed to build temporary bumper mount solution and body was fixed with adhesive tape.
(http://media.share.ovi.com/m1/s/1126/2badc0d26d934d0ca96a74c281424d01.jpg)
"Race was ok, but tracks were slippery" could said in words of Tommi Mäkinen, former Finnish
rally driver and four times rally world champion. Both our drivers were unexperienced in Formula
Offroad. Tino has driven two times in Foff Cup in modified class with his 2WD truck and has
raced in our team competitions in 2WD class. This was however his first ever race with real
Formula Offroad truck. Eduardo has been sponsoring our team by providing the original Revo 3.3
used to build Revolution. Eduardo also owns this Revolt truck modified to brushless and Formula
Offroad by undersigned and PaulJr. This was his first ever driving in gravel pit and with paddle
tires.
(http://media.share.ovi.com/m1/s/1126/fe116b898b2d444c87356e34355597c7.jpg)
There were no problems in truck during the race and despite of my idea to adjust central
differential for the second day, we did not do that as Tino thought there is no need to make
such change. Of course this truck has too short wheelbase for this event and thus it gives
advance for other drivers. Thus only real competitor for our drivers was Daniel with his Summit.
We have to be satisfied as Tino managed to beat Daniel in his first ever race and Daniel has
been racing earlier in last year world championships and in Estonia.
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Daniel has drived only one race ;D WC's 08. Allthough Tino had really good race. He will be contender in next few years ;)
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Yes, that's what I understood plus Daniel has driven some races in Estonia according to his web site. May be with different rules, but anyway.
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Revolt will make it's second appearance in Formula Offroad race next weekend and this time Tino as the
only driver. Land Rover Defender race body got some damage in last race and this time Revolt will show
up with factory made lexan body. Other changes will be extended wheel base. PaulJr installed new rear
suspension arms which allow either 10 or 19 mm extension to wheelbase. Our selection was the latter
one with total 377 mm wheelbase. Not much compared to any other racer, but this truck is supposed
to be made with low budget.
(http://autorata.com/rc-autot/revolt/trac5341.jpg)(http://autorata.com/rc-autot/revolt/trac5333.jpg)
Extended wheelbase arms on the left vs. stock arms on the right
Wheelbase extension is also another reason for body change as extended wheelbase arms does not fit
with our Land Rover body without cutting wheel arches.
Revolt has not been made for serious Formula Offroad racing nor will we modify it to such purpose. It
serves as good truck for practicing for Tino until new next season race truck called Sörsselsön will be
ready.
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This car has just grown out of Unlimited class rules with its second rear axle and six wheel steering. Car will be still easy to convert back to two axis and front wheel steering only, but target is to finalize this build before Christmas holiday season and return the car back to owner.
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Driving today on very soft and wet snow ended with drama. Revolt was in super unlimited class setup with six wheel drive using paddle tires. After 1 minute and 50 seconds driving it stopped. ESC was dead. To be exact one phase is dead and thus motor can not operate, while ESC operate otherwise ok. That does not help as it is anyway useless ESC now.
It used 2650 mAh charge during drive (1m 50s) which means 87 A average current. Now wonder that 80 A Hobbywing Ez-run did not last it.