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-   -   My BL Revo project (https://www.rc-monster.com/forum/showthread.php?t=1574)

Dafni 02.01.2006 03:10 PM

Yeah, I can imagine the face of your brother :dft002: LOL

Your list sounds good. You could also order from mike by sending him an email, and he will add the missing things when they are in stock again.

I can't think of anything else (you have a radio, right? LOL) I always like to keep spare rodends, spurs and wheel hexs. And make sure to shoot some pics when it's all done!

My fingers are crossed for your motor, mate!:dft012:

BrianG 02.01.2006 04:29 PM

OK, I'll email him. Tax returns should be in late next week or early on the week after. Actually I planned on getting an extra spur anyway. I already have some rod ends (are you talking about shocks?) and hexes.

I edited my post above with something else I thought of; 5.5mm motor plugs. I would really hate to get everything in only to realize I forgot something stupid. Other than the extra T/Emaxx slipper parts, is there anything else I need for the Mod1 slipper arrangment? Or for the center dogbones (do they come with pins, cups, etc)? Oh, and does a 15T pinion sound about right? I chose it based on what other people are running...

Yeah, I got a radio; the Spektrum DX3. No, I didn't get it from Mike :dft001:. I was at my LHS and they had the Spektrum with the extra receiver and I got impulsive. The only things I don't like about the spektrum is that the CH3 output doesn't latch on or off for the shifter (I might modify this), the CH3 button is in an awkward spot to use easily (I might modify this too), and I can't find a charger for the charging jack. Other than those things, the radio is freakin amazing! And talk about a TINY receiver!

coolhandcountry 02.01.2006 05:52 PM

That sounds like an unfair race.The tyco don't stand a chance. How many cells are you going to be running.

BrianG 02.01.2006 06:32 PM

I know it will be an unfair race, but it should be fun. I'll make it fair and run it in first gear only. :)

12 cells at first, then maybe 14. I can't fit anymore on my Dafni style trays without just piling them on anywhere there is space.

Eventually, I want to make another E-Revo using the stock Revo tranny and different battery setup so the truck uses more stock parts. The goal will be for an easy changeover from electric to gas and back with just a few modifications. Maybe then I'll be brave enough to try Lipos.

Dafni 02.01.2006 06:35 PM

Sounds like a realy nice radio!

I was thinking about rodends for toe-links and pushrods. I busted pushrod rodends in harsh crashs and those rear toe-link ends get tired when they get old (special rodend required there, btw, the ones with the ring)
But maybe it's just me, I just don't like slop.

BrianG 02.01.2006 06:43 PM

Quote:

Originally Posted by Dafni
Sounds like a realy nice radio!

I was thinking about rodends for toe-links and pushrods. I busted pushrod rodends in harsh crashs and those rear toe-link ends get tired when they get old (special rodend required there, btw, the ones with the ring)
But maybe it's just me, I just don't like slop.

The radio IS nice. It has more features than I'll probably ever use though. I was looking at the Spektrum mainly because I didn't want some of the problems other people have with glitching and noise interference. Digital Spread Spectrum and 2.4GHz should definitely help that since most truck induced noise is in the AM band.

Yeah, I somehow noticed the rod-end rings as I was putting it together. Lucky I guess. Although, in harsh crashes, I think I'd rather break a rod-end than bend/break a rod. My Nitro Revo has held up pretty well with mostly stock parts, although RPM arms are a must IMO. I must have broken 4 or 5 sets of lower arms when I first got the Revo. Since I installed the RPM arms, I haven't broken one.

Dafni 02.01.2006 06:49 PM

I guess we are not talking about the same rings, Brain. I meant the stock rodends for the rear toe-links (part number 5348) they have this small ring. They get tired, and sometimes loose the toe setting. Apparently the threads get stripped.

Agree about the rods. Replacing ends os definitely better.

BrianG 02.01.2006 08:27 PM

Quote:

Originally Posted by Dafni
I guess we are not talking about the same rings, Brain. I meant the stock rodends for the rear toe-links (part number 5348) they have this small ring. They get tired, and sometimes loose the toe setting. Apparently the threads get stripped.

Agree about the rods. Replacing ends os definitely better.

lol, I see what you meant now.

boss 302 02.01.2006 09:05 PM

tyco verse a revo there is no way that the race is even going to be close to fair take a picture of your brothers face when he sees your truck :036::036::036:

BrianG 02.02.2006 12:37 AM

Yeah, it's gonna be funny. He's always talking crap how he picked up this $100 MT and how fast it is and stuff. I've checked it out online. It uses a 7.2v batt pack and a brushed motor, which looks smaller than a Titan - maybe a 380 motor - it's hard to tell. I think it's this one (the tires can be switched).

I really shouldn't talk so much crap myself; with my luck, I'll blow an ESC first time out. No matter how slow his is, it'll be faster than a broken E-Revo!

I just really hope it's all together and working before I leave at the beginning of March! I still have quite a bit to do and if I forget any little thing, there won't be time to re-order. That's why I'm counting on all you experts to guide me in trying to think of everything I'll need to finish it in time.

boss 302 02.02.2006 04:32 PM

that is the funniest looking truck i have ever seen

BrianG 02.04.2006 09:04 PM

Quick question: The rc-monster site says the BK Wanderers require 5.5mm connectors, but the bk-electronics site says it takes 3.5mm connectors. Which is correct?

EDIT:
Something else; I was reading the warrior programming PDF at the bk-electronics site (http://www.bk-electronics.com/man_warrior_eng.pdf) and found this
Quote:

Since the EMK brake does redirect braking energy into the batteries it is possible to produce voltage spikes much too high if using a power adapter. This will destroy controller, power adapter or both.
By "power adaptor", do they mean a BEC? Has anyone found this to be an issue?

squeeforever 02.04.2006 11:05 PM

im not sure what they mean by power adapter but all the wanderers use 5.5mm connectors that are pre-soldered on them.

BrianG 02.05.2006 12:30 AM

Quote:

Originally Posted by squeeforever
im not sure what they mean by power adapter but all the wanderers use 5.5mm connectors that are pre-soldered on them.

Thanks squee.

Well, if the EMF braking feature does cause voltage spikes into the batteries (and therefore into the BEC), I suppose you could use something like a 36v Zener diode (at least 5w) to clamp the voltage. That should keep the spikes within a BEC's safe input range.

Has anyone had "issues" with their BEC during or after heavy braking? Something like unexplained radio signal loss for a few seconds, glitching, or other odd anomalies?

BrianG 03.24.2006 11:04 PM

Well, it's getting closer! I see the Mike got some Wanderers in! I still have to wait while my slipper is still on backorder and am having Mike re-make some CVDs since the ones I got were the wrong size (my fault). I can hardly wait until it's done! Anyway, I got bored, so I worked on a couple of things:

http://bgosselin.home.mchsi.com/e-revo/esc_holder.jpg

I was using a simple piece of thin aluminum as a bracket, but found it was "bouncy". Also, I've heard some horror stories about people's ESCs burning up. So I made another holder with sides and it is mounted much better - no bouncing. As you can see, I used foam padding extensively to help cushion it on all sides and to keep it electrically insulated from the aluminum bracket. It's pretty tight in there, so a zip tie should make it quite solid. Also notice the use of more foam around where the battery wires go through the Maxx motor mount hole to protect the wires from chafing against the metal.

http://bgosselin.home.mchsi.com/e-revo/radio_box.jpg

I got a Spektrum DX3 and found it uses a really small receiver, so I made a new home for it. :) It's just a RadioShack project box, but fits everything quite well. I added a power switch and power indicator LED on the side so I don't accidentally leave the power on. The LED (powered from the unused channel 3 slot) only draws 10mA, so it shouldn't effect runtime at all.

Then, I was thinking of making a wheelie bar, but am not sure if my heavy 25 pound setup (8XL / 20120 / 14 GP cells) will even be able to wheelie. Then, I was looking at this and was wondering if anyone else used it and how well it works. It's not a bad price. I like it since it mounts to the bottom of the skid plate; others I've seen mount it to the bumper mount, which I don't like.

Whadd'ya think?

maxxdude1234 03.25.2006 07:54 AM

Looks good, nice work! You sure that weighs 25 pounds? Thats a very very heavy truck if so.

coolhandcountry 03.25.2006 08:17 AM

I like that little box you got. I like to put my receiver in a box to keep the dirt and dust off it. The wheelie bar is nice. I would say 11lbs just a wild random guess. That is cool and nice truck. that esc holder you made is really cool. I run the ubec with the bk and have had no problems with it. I think they are refering to a voltage device between batteries and esc. Something the changes the voltage in larger means.

BrianG 03.25.2006 11:33 AM

Quote:

Originally Posted by maxxdude1234
Looks good, nice work! You sure that weighs 25 pounds? Thats a very very heavy truck if so.

Did I forget to mention that it is that heavy because everything has been re-done in stainless steel? :dft012: Seriously, 25 was a typo; I meant about 15 pounds.

Oh, and thanks coolhand! :)

coolhandcountry 03.25.2006 01:13 PM

15lbs i hope the diffs survive. That is kind of heavy.

Gustav 03.25.2006 01:20 PM

Are you sure it weighs that much,my BL LST weighs less than that with 12 heavy Ti plates making up the chassis,giant shocks,Ti arms(also heavy),alu beadlocks,8s lipo and a 1950 etc it's an absolute tank.

BrianG 03.25.2006 08:54 PM

Well, I'm not really sure, but it is noticeably heavier than my Nitro Revo even with a full tank of fuel. And that is around 10-11 pounds. Yeah, I'm kinda worried about the diffs as well, but is there something better that will fit?? I saw these a while back and figured they may be a nice combo to use with this and this. Add all those prices up and it makes for an expensive set of diffs though!

Gustav 03.25.2006 09:02 PM

The Nova RC diff cups are better (they're 7075) and they're only $20 each,we should ask mike if he can stock these.the cups and cases should add alot of strength.I wouldn't bother with the hardened gears,i wouldn't buy anything from hotracing anyway,their diff cups are a joke.

Are they Big joes?if you're running big heavy tyres the best way to save some strain would be some smaller,lighter tyres,like crimefighters.Maxxmashers are good allrounders and not too heavy.

BrianG 03.25.2006 11:53 PM

Quote:

Originally Posted by Gustav
The Nova RC diff cups are better (they're 7075) and they're only $20 each,we should ask mike if he can stock these.the cups and cases should add alot of strength.I wouldn't bother with the hardened gears,i wouldn't buy anything from hotracing anyway,their diff cups are a joke.

Are they Big joes?if you're running big heavy tyres the best way to save some strain would be some smaller,lighter tyres,like crimefighters.Maxxmashers are good allrounders and not too heavy.

No, nothing big, they're just normal Maxx size tires by Imex. They're the ones on this page, top left one. The rims are RPM "clawz" found here. Not the best combo maybe, but they worked fine on my Nitro Revo.

So, is hotracing.com bad in general, or just their cups? They seem to have quite a selection of parts. At any rate, do you think that the cups and diff cases that Mike has are OK? They have to be better than the stock ones, if a bit expensive.

Gustav 03.26.2006 12:16 AM

Yeah the diff cups and cases Mike has are good,the FLM cups are good quality and 6061 alloy,the Novas are 7075 though(harder alloy) and are only $20.

Hotracing is a bit like GPM,zillions of parts but not much reputation for quality.It's mainly the diff cups i was referreing to,the alloy ones that some of us tried for the LST were a very soft cheap alloy,the bevel shafts ate right into them,most use the Nova cups now,they hold up well and shrug off bevel gear failures without a scratch.I've been using maximisers but the Novas are a bargain alternative.

BrianG 03.26.2006 12:37 AM

OK, thanks. I might PM Mike to see if he can get those Novas.

BrianG 04.06.2006 08:49 PM

It's Done!!!
 
Yay! It's finally done!

I have a Strobe slipper on back-order from Mike, but was able to snatch the last one at hobbyshopnj.com and now my Revo is finally complete. When Mike's arrives, I'll just have a spare for maybe another version, or if I somehow mess this one up. :)

All I have to say is: Wow! It's crazy fast and powerful! I'm using 51/14 and it's pretty quick - way faster/stronger than the stock Nitro 2.5R, even with the fact that this Revo is heavy. Count me as a brand new BL convert!

I may need to order some more slipper pads though. :dft001: I thought they were tight, but they weren't and now have some wear to them. I have the slipper quite tight now and even lightly sanded the plates so they grab better. And yes, I cleaned the grease out of the bearing. :)

Runtime isn't bad either. In my yard doing general bashing, I got around 25ish minutes on 14 GP3300 cells. Doesn't cog unless I try to go REALLY slow (<5mph).

Temps of motor and ESC was warm at about 120*F, the batteries at about 90*F. I noticed everything was cooler when running at high speed. Only at low speed (5-10mph) did things reach those temps. Is this normal?

I'll try to snap a final picture and post it later tonight.

boss 302 04.06.2006 09:12 PM

it is normal for a motor to heat up a good bit when only running on partial throttle especially the ones without segmented magnets

BrianG 04.06.2006 09:32 PM

Quote:

Originally Posted by boss 302
it is normal for a motor to heat up a good bit when only running on partial throttle especially the ones without segmented magnets

Cool, thanks! So, if I read other forum posts correctly, the fact that my motor and ESC are about equally warm means I have the right gearing ratios, right?

HotnCold 04.07.2006 05:32 AM

Yep - sounds spot on...

BrianG 04.09.2006 09:59 PM

Well, I took it out for a while today and had a blast. Runtime is still right around 25-30 minutes and I can't figure out why it's so long. The truck is heavy and is using GP3300 cells. :032: That calculates to 6.6A average current draw. And I'm not really easy on the throttle either...

I got a wheelie bar and it was working good until I landed on it from a jump and bent it. Oh well. Now I have to find a new one that will last more than one bashing session. Is there a good one that someone can recommend? I also bent the roll bar I made all to hell. Hmmph. That'll teach me to run without the body.

Man, the thing is hard to control! The power is almost too much. I ended up reducing the throttle to 85% and the brake/reverse to 60% on the transmitter. Otherwise the tires break loose when I goose it or it does forward flips when I brake. Seems like a waste to keep the EPA so conservative. Kinda makes me think I should have gone with a 9XL or 10XL instead of an 8XL? Is there a way to program the ESC so it will take longer to go full throttle if I "floor" it? According to the manual, it says there is a pre-programmed 0.3 second ramp-up time for the throttle. I was thinking maybe a 0.5-0.75 second ramp-up might help.

maxxdude1234 04.10.2006 03:34 AM

I believe you can adjust the throttle curve on some transmitters, so that there will be a smooth progression when you floor the throttle.

Sylvester 04.10.2006 05:44 AM

I think you need the programming cable for that? Ask mike, he should know.

squeeforever 04.10.2006 08:26 AM

not sure about your transmitter but im pretty sure the m8 has a feature like this. ill try it out and let you know later. i kinda had to be a little easy on the trigger last night. i have the 10xl on 14 cells for now (soon 16 or 6s lipo). i ran it last night for th first time on my new ib 4200s and it was INSANE. top speed was about 40 to 45ish with 20/51 gearing. lets put it this way...i had no problem ketching up with the cars going by at 35 to 40 mph....

BrianG 04.10.2006 08:39 AM

Maxxdude: I have the Spektrum DX3, which I don't think has that feature.

Sylvester: I thought I heard there was a programming cable, but when I looked, I only saw the Castle link. I just went there again and saw the one for BK in the controllers section. I must have looked in the "motors" section before for some reason, which only lists the Castle link. Doh.

Something else I noticed, but not sure if it's the batteries. I also have two 6-cell packs that I was using and it seemed to reduce the speed to about what I'm looking for, but runtime was half of what I had with two 7-cell packs. All four packs are GP 3300 cells, but the two 6-cell packs are packaged differently. Does it make sense that runtime is reduced using a lower voltage? I would think that a lower voltage on a relatively constant motor resistance (impedance not included) would create less current, increasing runtime.

Assuming 1.2v/cell (I know they start out a little higher), what is the minimum number of cells recommended to use with the 8XL? For max cell count, it seems like 18-20 cells will keep it in the 45k rpm range, but that would be wayyy too fast for me. 14 cells equates to 31,500 rpm.

coolhandcountry 04.10.2006 08:54 AM

Well you have a tendency to run the motor with more throttle on the 12 cells than the 14. You have more power to use so you accually are easier on the trigger so you get more run time. If you launched it the same every time the 6 cells would or should last longer.

squeeforever 04.10.2006 08:59 AM

i was under the impression the higher the voltage the better the runtime up to a certain point when the efficiency falls? maybe im loosing it :confused:

BrianG 04.10.2006 11:56 AM

CHC, what you say makes sense, but then Squee's response sounds right too.

boss 302 04.10.2006 01:30 PM

i also think that what squee said makes sense and sounds right

maxxdude1234 04.10.2006 01:36 PM

In short, they are both right! CHC's is right from a scientific view. In that a higher voltage will increase current. However, in the context on rc cars it is slightly different. Because when we add voltage we 'gear down' (ie. use a smaller pinion) the motor has to work less hard, and hence we draw less current. This is how squee is also right.

BrianG 04.10.2006 02:05 PM

Ah, but I didn't gear down...

There must be a point where the ESC sends an "ideal" signal of pulese where the BL motor operates with the most effieciency, and this ideal range is based on voltage and wind. I'm sure the AC reactive properties of the coils must have something to do with it, but without inductive ratings, and the frequency of the ESC pulese, it's pretty hard to tell.


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