I was asked for some pics recently for a little mod I was doing, and since I have a few of these handy mods I'm starting this thread to showcase all my projects related to my E-revo and to dispense some tips and tricks Please be aware these are only my tips, there is much information available on these forums from people far more knowledgeable than me, this is just information I've picked up which I'd like to share. If you're new here you should start with the FAQ.
This is not going to be an all alu super creation, it will simply be a showcase of nifty little mods and ideas of mine towards creating a better basher. A basher should be durable, reliable and dependable, but equally it should be cheap and easy to repair, so that's what i'm aiming for. Hope you like it.
Since project logs must contain pics, here is a picture of mine when it was new:
To start with I have to explain a little background. I live in the UK and imported my E-revo when they came out. I was one of the first people here to get one I believe so I've had it since mid summer. I have never had a 1/8th scale electric truck before however I have been into electric R/C for a while. I have had my fair share of problems, it's part of the game, but some of it has been less fun than I would have liked. So here are some Tips for New E-revo owners:
-This truck may say RTR on the box, but don't be fooled. Maintenance is mandatory, and there are a number of problems that your truck may develop if you don't perform the following maintenance before your first run.
1: Check the steering servos. Many need to be aligned. Failure to do this will result in decreased steering performance and reduce servo life.
To determine if they need to be aligned, turn on the truck, preferably upside down, and wiggle the steering wheel until the servos are silent. If you cannot make them silent, they need adjusting. To adjust them, remove the servo horn from one servo and adjust the turnbuckle until the horn fits onto the servo without needing to be forced. It doesn't matter if one turnbuckle is shorter than the other as the steering travel is not limited by the servos.
2: Re-glue your tyres. This is much easier to do before you use them. The factory tyres can come off during hard cornering if you use the truck on road. Simply reinforce the factory glue by running a bead of glue around the edge where the tyre meets the wheel, front and back on all four wheels.
3: Check the gearbox screws. These are located underneath the chassis, they need to be very tight otherwise the gearbox can come loose.
These are just the problems I had, but I could have saved myself hours by knowing about them before running. Cleaning tyre edges is not fun.
And finally, break in your motors. The best way to do this is simply avoid high throttle starts for several runs. Many people have motor problems, but I broke mine in and so far so good. Since the problems with them seem to be related to the brushes, I definitely recommend this.
And now a word on batteries.
I have talked about my battery problems at length elsewhere, so here I just want to tell you what happened to me in the hope that you can avoid the same problems.
My E-revo spent 3 months off the road because all my NiMH batteries were destroyed. I am not certain why this happened, but in my opinion the gearing in the E-revo is too high for most NiMH batteries. I lost $200 worth of batteries, and it wasn't much fun. So if you intend to use NiMH batteries, I recommend you undergear by at least one pinion size.
Since i now use LiPOs i know there is nothing wrong with my truck, so there are three possible reasons why this happened.
1- The truck is over-geared from the factory.
2- My truck has higher than intended current draw due to a different batch of motors.
3- My batteries were not adequate.
Neither of those possibilities are my fault and none of them could have been avoided by me. The first two because that's the way it was from the factory, and number 3 because I bought expensive batteries from well respected brands, if it was the batteries there was no way I could have known.
I do not want anybody having to put up with 3 months of Revo withdrawal like I did, if you run NiMH batteries please watch temperatures carefully. If they are too high run in training mode until you can fix the problem. It might save you a lot of money.
If you have not yet purchased your batteries, I strongly recommend you purchase LiPO batteries. The performance difference is huge and they are worth every penny. I wish I had used them from the beginning. 2 Lipos is better than 6 NiMH batteries in my view, even of the same capacity. And my 2 LiPOs are way better than my 6 dead and dying NiMH bateries.
Ok, that's the boring bit out the way, my next post will contain mostly pictures
Last edited by jtek; 01-02-2009 at 06:46 PM.
The Jtek harness
This is the best way to fit an LVC to your E-revo. It's like the kraegar harness, only better
This is one end, and is made using a pair of Traxxas connectors, some 12G wire and a servo extension lead cut in half.
I fitted mine after soldering the voltage detection wires of the LVC onto the kraegar harness (pair of traxxas male and female connectors soldered together) only to discover I had forgotten to wire it through into the reciever box So i cut the voltage detection wires in half and soldered a servo extension lead, also cut on half, to each end.
On the Smartstop end is the other end of the servo extension lead (next to the EVX2):
Voila! Now you can take your smartstop out of the reciever box without de-soldering it, and you can plug it into either side of the ESC, or even use it in another vehicle.
If you're making one, don't cut the voltage detection wires. Just cut the servo extension lead, pull off the white wire down to the connector and cut it off. Then solder one end to the kraegar harness and the other to the voltage detction leads.
And that is how you make a Jtek harness!
Note: Don't get your connectors mixed up, if you plug a servo into the female you'll probably fry it. It doesn't matter which side you put the male and the female.
P.S Yes the reciever box lid does fit. Just. Every slot in the input hole is populated and there is even a servo Y cable stuffed in there. Do i get a prize for 'most stuff fitted into an E-revo receiver box'?
Last edited by jtek; 01-02-2009 at 06:51 PM.
good thread so far, keep up the good work, cant wait for more
erevo-mmm combo on the way, stampede vxl, revo 3.3
what type of glue did you use for your tires? Still trying to figure out that harness, great writeup and pics though.
Really useful post - I got my E-Revo in the summer too (in the UK) and I really wish someone had told me the points about NiMHs - I blew four packs before I finally gave up and went with lipos. In hindsight I would have gone lipo in the first place of course.
two little tidbits to add to your tips:
1. For the jtek harness, I would suggest the use of a BEC connector - it is that bit smaller as it only has two wires and (more importantly) you wouldn't ever plug it into the receiver by mistake. They are pretty cheap:
But if using the servo lead, just make sure that the end that is connected to the battery (i.e. the one on the harness) is the female, so that it cannot be plugged into the receiver by mistake. Could save a nasty fry up..!
2. If it gets a bit tight cramming the receiver and LVC into the receiver box, you can gain another mm or two of headroom by removing the sticky pad from the underside of the receiver, which is surprisingly thick. It's not like the receiver can move much, and it does make it easier to make the connections etc if you can move the receiver.
Anyway just my 2p to add to you very good tips!
Time is an illusion, "9am sharp" doubly so.
For tyre glue, use super glue also called CA glue. Like this.Originally Posted by xman111
Here is a connection diagram for the Jtek harness. bluefisherking is right about using a BEC extension lead (or a male and female connector) instead of a servo extension lead, it will work just as well and you are less likely to be able to plug it in to something you shouldn't.
Suspension, Sway Bars and Handling
The first mod I did to my E-revo was to tweak the suspension. I found that the stock setup (white and green) was far too soft, to such an extent that under heavy breaking the front bottomed out and occasionally caused the truck to flip. When accelerating the back end bottomed out causing the truck to under-steer really badly.
At first I tried the long travel rocker springs included in the kit (silver and blue), but they were too hard and made it less fun to drive. Then I tried the long travel front springs (silver) on the rear and the stock rear springs (green) on the front. This is the best setup with the springs supplied in the stock kit.
Then I upgraded to orange on the front and tan on the rear which is what I run now. I find that the front is fine but the rear is still a little soft. For off-road it is fine but for on-road or racing I would recommend black on the rear.
I also installed the maximum travel steering stop, which is supplied with the kit. I found the improvement in turning circle is very good, without it the turning circle is quite poor, however it makes the truck very easy to roll. You can limit this by playing around with springs and ride height but for me it has always been a problem. Off-road it is fine because the truck under steers instead, but on-road it will flip very easily. I installed the traxxas sway bar kit in the hope that it would help but it didn't. I really can't see much of a different with or without it, I think it has helped a little but the problem remains. The solution is to either become a better driver (learning to catch it on two wheels before it flips is great fun ), or limit the steering. I have a feature on my radio which lets me limit my steering, so now when running on a hard surface I can use that or just don't turn too hard.
If you intend to run on-road I recommend you don't install the max travel steering stop. For off-road though I think it makes it more fun to drive as it helps when getting the rear wheels to skid. Off-road 4wd drifting around a tree on wet grass is an awesome stress reliever If you do both you'll just have to try it and see.
The Battery Bay Fan Mod
This is a re-post of one of my first mods. I want to post it again in case anyone finds it useful, I don't use it any more.
I was having battery temperature issues, and i found that a 30mm fan (any depth), fits perfectly when you have your battery bays set up for 6s NiMH. If you use 7S NiMH you can probably use a 25mm fan or put the fans on the outside of the battery bay vents. I mounted mine with double sided servo tape and electrical tape.
I had one fan in each bay, and i found they gave me up to a whopping 10c (18F) temperature drop, which is impressive. Sadly it wasn't enough to prevent the batteries from frying The fans I used are these ones. They are very cheap, $5 compared to $10 for most of the others or more if you get the really over priced ones (*cough* Novak *cough*). Although they are 7.2v they work fine off the 6v BEC. To use two you would need a servo or BEC Y-cable.
I'm pleased to report that they are quite happy getting wet. They aren't so happy getting full of grit, and the water gets in the bearings, so after getting them wet i often had to spray them with motor cleaner and WD40.
Great thread, a good read and I will be checking back on here I'm another UK'er here, and as of yet I hae not yet had to take the truck to bits, apart from tonight when I broke a pushrod by crashing in the ice. I must say that just looking up parts in that manual is daunting Saying that though, I've said that about every car I have owned...
Drifting with something this big is a lot of fun. I also managed to break something though, spent too much time going sideways I think
I'll explain the single motor and talk about the wheelie bar in another post soon. I feel a bit silly posting so many posts in my own thread, so if anyone wants to add anything or let me know what you think please post away.
keep up the posting, don't feel silly, i look at your thread all the time..
yeah, I had the same problems as you with my e-maxx, I don't get it that traxxas could make something like this without alot of testing with batteries and then gear there truck lower, if they did that there would be far less problems with NiMhs.
By the way I'm from Belgium, not so far away
And, great thread man, keep posting it's veryy usefull
Another one bites the dust Now I just need to get some upgrades.
Actually the pic of the broken wheel was taken after removing the turnbuckle. But it was wobbling quite a lot with the turnbuckle on. Turned out the thingy had just popped out of the whatsit, so i popped it back in and all is well
RE the battery issues. Yeah i don't get it either, i mean how can i be having battery temp issues when it is only 10c outside yet they didn't have any in the Texas heat? Ahh well, i don't care anymore.
Project logs are supposed to be in chronological order but I'm afraid this one hasn't been. I'm explaining things that I have done and things of interest currently happening, so it got mixed up. Here is a timeline of where i am so far and what i have yet to show you/talk about:
-Tyres falling off (posted)
-Steering servos mis-aligned from factory (posted)
-Beginning of the battery issues (posted)
-Orion 5100 batteries, continuation of battery issues (posted, they blew like their predecessors)
-Sway bar kit (posted)
-Orange and gold springs (posted)
-Battery bay fan mod (posted)
-Power supply mod
[3 month gap with the E-revo off the road waiting for funds/time to go LiPO]
-2 speed transmission
-beadlock wheels, new tyres (ongoing project)
-receiver fuse mod (ongoing project)
-17mm hex adaptors
-LVC and Jtek harness mod (posted)
-lipo sack, balancer and lipos
-single motor upgrade (ongoing project)
-Brushless (long term)
-More Lipo batteries
-Summit bumpers and lights
-Summit body + body posts
-Summit remote locking differentials (long term)
-Body with new paint job
-4s LiPO charging with home made balancing plugs.
For a new body, this caught my eye in the erevo accessories page. I think the orange looks great.
Also, it occurs to me that as soon as the summit crawls into shops traxxas are going to have to start selling 5mm pinions, so the prices should come down which will be good.
Last edited by jtek; 01-06-2009 at 06:16 PM.
Unreal thread, I'm a electric newb, ran nitro since I was a teen until I saw the E-Revo. Your helping my build alot man, thanks and keep it up!!!
Update time! The Computer Power Supply Mod
This mod concerns converting a standard desktop computer power supply for use as a bench power supply or to power battery chargers.
Power supplies, herein referred to as PSUs are needed because batteries have to be charged at or around the voltage of the pack, somewhere between 6 and 12v and the power at the wall is either 110 or 250v depending on where you live.
Using a computer PSU is a good idea because they are much cheaper than R/C PSUs and work just as well. Many chargers have their own PSU built in, but a lot of the higher performance ones do not, including the hiperion range which is popular here. Here's my setup:
You're looking at 1 computer PSU, one plastic box with some connectors on top, 2 duratrax ICE chargers and one Trakpower balancer. Don't be put off by the mass of wires between the PSU and the box, this is a really easy mod and completely safe. If you have all the bits, it would take less than 10 minutes.
The box was intended to house the connectors and all the excess wire, in future i will bundle all the wire in there and tie-wrap it to the PSU so it looks nice and neat.
For this mod you need the following:
1- An ATX type computer PSU. These are extremely common, there is one in every standard size desktop PC and they can be bought from all PC or electronics stores. You need to read the label regarding the output and check that it can supply enough amps on the 12v rail for your chargers. This one claims it can supply 15 but cuts out at around 10+, so I get 5A for each charger. You should get a good brand because they can be had very cheaply but normally the really cheap ones won't supply the power on the label. This one is an example of a cheap PSU All PSUs work at both voltages, some have a selector switch on the back, but for most it is automatic.
2- You need a molex female connector. The easiest way to get one is to buy a molex y cable. All computer and electronics stores will stock these.
3- You need a jump start adaptor. Either buy one like this, or make your own using a piece of bent wire.
A quick note on safety, these are consumer electronics devices, and they normally touch the metal case of your PC so they are completely safe, providing you don't open them up. All the power that comes out is harmless and below 12v. If you short them, draw too much current etc what normally happens is they simply shut off.
First step, these PSUs have a master on switch on the back, but also have two pins on the main 20 or 24 pin connector which actually turn it on. This is for the on button on a PC. These two pins have to be connected together or jumped to turn it on. I use a plug like this, which you can buy at the link above or by searching specialist PC stores, it's called an 'ATX power supply starter':
But you can use anything, even a paperclip, to short these two pins together. There is only one connector with 20+ pins. The diagram below shows in red which pins to jump.
These pins can be left shorted permanently and you can use the switch on the back to turn it on and off. Obviously make sure you have the right pins.
The second step is to connect it up. The PSU will have a variety of connectors including some white 4 pin ones. These will plug into your molex Y cable. It is not possible to connect up your Y cable wrong as th connectors only fit one way. If you have the y cable plugged into the PSU then you have done it right. They have two black ground wires, a red wire for 5v and a yellow wire for 12v. You want the 12v. Cut the 2nd female connector and the 1 male connector off your Y cable so you have something like this:
Just connect the yellow to the red on your charger and the black on the charger to either black and you should be in business!
That's it for the minimum. For a better mod you can get some banana sockets, a plastic box, and a 5v resistor. These PSUs output power at several voltages and some work better if a little power is also being drawn from the 5v rail. To do this you would need a 5v resistor which can draw something between 100mA and 1A. Just attach it to the red wire on your connector.
This is what mine looks like:
Your right the orange looks great..
Good looking E-Revo
MMM/FLM 3905 E-Maxx
Love the orange! will be doing the PSU mod soon!
HB Ve8 w/ tekin (AWESOME)
Well, the time since my last update kind of represents the 3 month gap between my last NiMH blowing and my Lipos and 2nd and 3rd upgrades arriving. Up to this point i was having constant battery heat issues, and i now know that i wasn't experiencing full performance of the truck because none of the batteries could supply enough current to max out the motors. This thread is not in the present yet, it's still behind where i currently am but soon it will be up to date and then i can start asking questions and discussing possible future options.
If you like this thread, either post or go to the top of the page and click subscribe under thread tools. Then you'll get an email when there is a new post.
The 2 speed transmission
I decided i wanted the two speed transmission for a number of reasons. Mainly because i just like the extra dimension it adds to the driving experience, but also because the lower gears make the E-revo into an excellent crawler. In fact, switch over to the long travel suspension provided in the kit and you practically end up with a summit, minus the fancy diffs. This is the way to get a summit on the cheap, just add spools to replace the diffs and you're good to go. I believe the 2 speed transmission for the E-revo is actually identical to that used in the summit. If you want the slightly lower ratios of the summit just under gear by using a smaller pinion, or use a larger low rpm motor. The 2 speed kit allso allows you to have overdrive gearing, where you overgear to make 1st gear the same ratio as 2nd and then use 2nd for speed runs.
Transmissions are really designed for when the vehicle is powered by an engine, because engines have a very limited RPM range and a very unhelpful torque curve. Electric motors on the other hand have an almost perfect torque curve. I was annoyed i couldn't find a nice graph to demonstrate this so i had to draw one:
With an engine, torque is highest when RPM is highest. Not very good, because as soon as the vehicle, say, reaches a hill and the engine RPM drops so does the torque, so you have to change down. The Engine also has a very limited RPM range, and that is the other reason you have to have gears. Fortunately our 2 stroke engines have a better RPM range than larger engines, and we can over size them so we can manage without gears, but for higher performance nitros normally have to have gearboxes.
Electric motors on the other hand have increased torque as RPM drops, so as load increases torque goes up, RPM drops a little and it keeps on going. They also have a huge RPM range. Electric cars for instance have no gears compared to 5 or 6 for normal cars. So, the 2 speed kit is completely unecessary, but it does add an extra dimension.
Even with their massive RPM range motors are not flexable enough to do crawling, bashing and speed runs all with one gear. The E-revo at stock can do all of these things, but it only does bashing well. You could do this with a better motor, but it would cost a lot more. The 2 speed transmission kit allows you to do two of the above options instead of just one.
I have a couple of things to say about it. Firstly, the micro servo has very weak gears. If you manually actuate it with your hand, they break. This makes fitting it and attaching the servo horn very difficult, and i broke my firts one. Also, the kit is missing a screw to hold the spring onto the transmission case. Someone else reported this so i think it affects all kits. Use a washer and a standard screw instead.
The transmission shifts using a dog gear. I had no idea what this was or how it worked, fortunately ths site has a really good explanation: http://www.carbibles.com/transmission_bible.html
There is no syncromesh or clutch so it is effectively a racing gearbox. It cannot take 6s LiPO power and this will break the dog gear, but it can take mild brushless. One thing i wish i had known before buying, it introduces a lot of slop into the drivetrain. Forget buying CVDs with this installed unless the stock drives are breaking. Personally i don't mind but it's something to be aware of. When shifting you will want to adjust the speed of the motor as you shift, or you can just let go and the gearbox will pull or push the rpm to fit the new ratio. The nylon plastic is very resistant to wear so i reckon it will last. If the motor and wheel rpm are too far apart after shifting the dog gear will just ride the drive gear for a bit until the rpms close up and then it will click in.
I'm having trouble working out how the transmission in the Nitro Revo works, but as far as i can tell the 2 speed also uses a dog gear but has a centrifugal auto shift mechanism. For reverse it uses the same method as the E-revo, except it uses the opti-drive, which detects when the truck has stopped and the stick is pulled back and then uses a micro shift servo just like the E-revo to shift the dog gear. The design of the dog gears are different but i suspect power handling capabilities are similar. On other makes of truck often just use a pair of centrifugal clutches.
If you have any questions on the 2 speed that i haven't covered please ask.
The wheelie bar
There is one other reason to get the 2 speed. 1st gear makes wheelies a lot easier. Unfortunately it is too slow to produce sustained wheelies, but i suspect a few hours practice and i could shift quick enough to keep them going longer. I'm very happy with the wheelie bar, bit of a pain to fit but it works very well. I wouldn't bother with the metal wheels and tyres for it, the plastic ones seem pretty tough.
A lot of factors such as batteries, suspension, weight, slipper clutch, tyres etc affect whether you can wheelie from standing with the stock motors in 1st. I sometimes can, and i suspect some adjustments could fix this. As it is i'm happy to reverse a little, as long as it is slow it won't harm the transmission with the stock motors.
A quick tip on gearing that i picked up from here. Use one pinion and then get a load of different spur gears, they are much cheaper. Use brianGs gearing calulator to find a pinion with the 58t spur and then you get around 4mph more or less by changing spurs up or down as 58 is the middle. There is a link to the gearing calculator in the faq somewhere.
Just time for a sneak preview of my new wheels and tyres. They are axial oversize beadlocks and proline dirt hawg tyres. I test fitted one to see how it looks and i think they look awesome
I love my 2.2 dirt hawgs and these feel and look just as good. Can't wait to try them.
And some maximizer 17mm hubs.
wow, those are beasty!
People have said that the tyres fall off the axials. I will report back on that one. If they do, I'll try bigger bolts or glue the tyre to the ring and then de-bond it when i want to change to new tyres.
Is there anything i can do to stop the chrome, and the plating on the ring from getting scratched off?
Because they are black chrome it is black underneath so they won't look as bad as normal chrome but i still want to prevent scratches if i can. I was thinking of some sort of varnish perhaps?
The dirt hawgs are a decent tire, but weigh a ton. ik tend to break my E-maxx a lot more when using them over the maxx mashers.
HB Ve8 w/ tekin (AWESOME)
Interesting thread you got here jtek. I was just doing some research on the Axial beadlocks a few minutes ago, and stumbled back here again. I would like to hear your experiences with them and the new tires. Keep up the good work buddy.
ya would like to see a pic of them on the revo.
You may have heard that we've been having a little snow here in the UK. About 6 inches in total now
May not sound like a lot but for us this is a once in 50 years thing. And we have no snow ploughs. None at all. So everything comes to a halt.
Naturally I've been out in it having some fun Took some pics for you, of course
I only have one pair of batteries which is limiting my fun a bit.
Saw a few threads with the words 'NiMH' and 'heat' in the title on my way here. So I say again: The E-revo has serious compatibility issues with all but the very best NiMH batteries. It is almost impossible to tell if your batteries are compatible without finding out the hard way. If you can, buy LiPO. If you can't, under gear by at least two pinions.
RE the wheels, I have yet to try them. I want to investigate a way to protect the chrome paint from stones first. Having said that, from what I can tell without trying them they seem very good. I'll take pics when I do get round to trying them.
Though al the snow from Monday has melted here in the North West. Expected more on Sunday though
Outstanding thread. Lots of good ideas.
Sweeeeet. Moar snowsOriginally Posted by superbasher
How about another update. Replacing the Titan motors.
So, everyone knows the titan motors in the stock truck have issues. They have a very high failure rate, apparently because the brushes fall off. They also seem to get a bit slower over time. There are loads and loads of threads with people complaining of motor issues, however I've been lucky. I've had mine in use for about 6 months now and no problems at all.
Well, except for one problem:
It was my fault for leaving the gear cover unscrewed. One of the connectors got chewed up by the gears. It actually bent the motor shaft! Managed to bend the shaft mostly straight again, and the connectors, however that motor now vibrates inside its bushing which causes it to be less powerful and get a bit hotter.
Anyway, knowing I could have issues at any moment I bought a 785 size boat motor off ebay.
Couple of problems with that. Firstly, it doesn't fit in the motor mount, so i ground it out with a rotary tool. Second problem is I can't solder any motor capacitors to it, i just don't have an iron hot enough.
Does anyone know if the motor capacitors have to be soldered to the can, it will soldering them across the connectors work?
The final problem is it is far too slow. It would make a great crawler motor, but it's no use to me. Talked to Dan at Kershaw designs about it and he says it only has the power of a titan anyway. So I've had to put the titans back for now. While i had the single motor plate on I found running with just one titan actually works quite well, which is surprising.
I can't afford brushless and LiPOs, so my options are:
1- Stick with the titans and get them replaced if they die.
2- Get some other 550 motors... will the HPI ones work perhaps? They are much cheaper than the titans, cheaper even than getting the titans replaced.
3- Get a 700HO. It's very expensive for me to import, but if I go with overdrive gearing which turns my first gear into second and my second gear into a speed run gear, I can use this boat motor for crawling and bashing aswell.
The reason i can't afford brushless yet is i want to get more LiPOs and increase my run-time. That's more important to me. Any thoughts on those options?
I'm in the process of installing a Dewalt Motor. It's rated at 22,000 rpms at 18 volts and can run with up to 24V, so 6S Lipo is possible with the right controller. I read some great results from this motor on this forum.
Im on my way to buy a 300w PSU for 5 bucks right now
Well my thoughts are: definitely agree on getting more lipos first - you can enjoy the runtime and good performance right away... and get brushless for the summer. Then (personally) I would get the 700HO and overdrive gearing. When it snowed I put a single 700HO back into my E-Revo, and I was pleasantly surprised at how capable it is (on lipos), even with my 7.5" diameter snow tyres! I was expecting it to seem dull after the Neu, but actually I had a blast. And with the two-speed+overdrive you'd have even more fun.Originally Posted by jtek
Time is an illusion, "9am sharp" doubly so.
Thanks for all your replys and praise, makes the faffing about taking and uploading pics worth it
I think i mentioned this, but you don't want to get a super cheap PSU. The reason is, they tend to be unable to deliver anywhere near their rated power, and some have broken safety circuits. So you short it or draw too much power and it might go boom and take your charger with it.Originally Posted by MedicWill
If you must get a super cheap one, short it out when you first get it and see if it cuts out. If not and it dies, take it back. In fact that's a good test for any PSU, they should all just cut out if you short them. If I were you I'd avoid anything under $20, otherwise it will probably be junk. Still way cheaper than an R/C PSU.
Can i get those dewalt motors in the UK? Definitely leaning towards the 700HO. I'll get another set of LiPOs first though i think.
One of my steering servos has died. Checked the gears and they are fine, it just makes a noise and does nothing. I guess i have to phone Traxxas and send it in. Since its been in a mostly stock truck with a stock steering setup its yet another manufacturing defect. Gotta love Traxxas quality.
You can get the Dewalt motors from www.toolshopdirect.co.uk , though you have to know which part number you are looking for. e.g. look up the "DeWalt 18V New Style Drill Motor" on www.robotmarketplace.com which gets you http://www.robotmarketplace.com/prod...396505-22.html then you take the product code without the BP "396505-22" and search for it on toolshopdirect.co.uk (remembering to select spare parts!) which gets you http://www.toolshopdirect.co.uk/spar...&submit=search which has no real description, but the right part number!Originally Posted by jtek
The other drawback is that they don't seem to hold much stock, so will probably order in from the manufacturer which takes a couple of weeks... in fact I ordered one from them once because I was impatient wanted to play while I was waiting for a 700HO to arrive from Dan - I was expecting next day delivery or similar... in fact the 700HO arrived first!
So personally I would still go with the 700HO.
Time is an illusion, "9am sharp" doubly so.
Thanks for your help. Considering the price and the fact I'm going to have to get some pinions anyway I think the 700HO is my best bet.
Another question, I asked before somewhere but couldn't get an answer, does anyone know how the runtime compares between titans and the 700HO?
Another update to follow in a few days, managed to break something again. Yay.
my runtimes seem very similar with my 700ho. also, i changed to the included 20 pin pinion and it seems a tad slower than my dual titans.
i use a 19 tooth on my 700ho and it is a smidgen faster than the titans with a bit More torque also. as far as run times very about the same.
hey jtek, How are you liking that wheel and tire setup?
HB Ve8 w/ tekin (AWESOME)
Thanks very much for the runtime info. 700HO is definitely on the cards I think, but i may have to wait for the summer, very little time atm.
Sorry, I haven't tried them yet. Subscribe to the thread and I promise I will post when I do. The wheels are so expensive I am determined to do something to protect the chrome before I use them. The chrome on my stock wheels got scraped off pretty quickly.Originally Posted by Brushless Moose
In the meantime I'm actually enjoying abusing the battered stock wheels, the tyres are so poor I can spin them all day on any wet or loose surface The downside is no handling or wheelies . I've actually destroyed part of a garden wall on the corner of my track as a result, taken the top off and several bricks.
Ok update time!
I won't bore you with yet another tale of NiMH woe, it's all in my first post if you're interested. Suffice to say, and I can't say this enough, the E-revo is fundamentally incompatible with NiMH batteries, the solution is either to use super high quality super robust batteries that can take the heat and the current and the abuse, and knowing which cells do is difficult at best, or undergear, or use LiPOs. You can also alter your driving style to emulate undergearing but this was not something I was prepared to do because it limits the fun.
I decided not to undergear because I wanted performance at least as good as stock. I decided not to go hunting for super high quality NiMH cells because I was fed up of blowing them up, three brands is enough. So, time for some LiPO fun. Like many people I was uncomfortable with the safety issues, the balancing/LVC complications, the cost and was unsure if they could take the abuse and would be waterproof.
Because I am UK based and my favourite US retailer does not ship LiPOs overseas, and because I wanted local support if things went wrong, I was limited to LiPOs available in the UK. In the end i went for the Trakpower 4900 2s 25c packs, because:
-They have a 3 month warranty.
-They list all they specs including size
-The fit in the E-revo
-They are hardcase
-The specs are very impressive
-I like the balancing socket rather than the normal connector
And finally, because HighKalibre was kind enough to get some and find a way to get them to fit in the battery bays. Lots of pics and info in his thread
Well, they say you should invest in gold, so I did
I don't know if the LiPO sack is necessary because these are hard case, but I use it as a safety precaution anyway. I have probably around 30 runs on these now, for many of those runs the packs have been sitting in water and come out dripping wet, and so far no problems except some of the gold paint has come off around the connectors.
I bought one balancer but I've actually found these packs have never once been out of balance after charging, so at the moment I'm balancing every 5 or so runs just as a precaution.
For the connectors, having banana connectors on the top is a pain because there is only about 5mm of clearance between the top of the pack and the bay. My solution was to get some normal banana plugs and dremel the top down, then place the wire on flat and solder with lots of flux to make a really strong connection. This was then covered with heatshrink to prevent shorting. It actually works very well, fits fine and the connection is strong. I'm actually using 12AWG wire and even that fits, just.
I was surprised to find with the stock setup I saw a performance improvement with the LiPOs. It seems that none of my NiMH batteries had been capable of supplying enough current. These batteries barely get warm, 30-40c at most where the NiMHs were getting 60+. Because of this a 5000mAh LiPO has a much greater real capacity than a 5000mAh NiMH because so little energy is lost as heat. As far as charging is concerned, they take a while at 1c. about 90 minutes I find for a complete charge
I would like to hear some opinions about how waterproof LiPOs are and whether the hardcase is actually sealed, because I've heard some say water is very bad and others say its fine and only the connectors are an issue. What are your experiences with running LiPOs wet? Should I get some balloons or something?
I timed my runtime on a typical run and I got almost exactly 15 minutes. Does this seem right? It feels a little short to me
Other than that, I'm pretty pleased with them. They still cost too much, but the decision to go LiPo rather than brushless was the right one and I think several pairs of LiPos with the stock setup is a better use of money than brushless and NiMH or brushless and only one pair if LiPOs. So go forth and buy LiPOs, my fellow bashers
Last edited by jtek; 02-15-2009 at 01:05 PM.