John was happy, and now is sad...

[3pointX]

I got my buggy back tonight with a fresh rear diff thanks to Hak, so I went to the BMX track with my brother in law to run his Ravager and my ZX-1 around a bit and work on the tune on mine. There's a lot of wide open field down there, and some small jumps on the track that the buggies handle just fine. So everything was fine for about an hour, I got it tuned in, dialed in the suspension, and then something went horribly, horribly wrong. I'm not sure what happened exactly, but it seems as though the receiver just lost power altogether while I was on the throttle. Whatever happened, the failsafe did nothing to stop it, and the buggy went wide open with no brakes, no steering. After launching itself off the back of one of the paved banks at the speed of death (and falling a good 30 feet), it took off and pretty much drove itself all over the place with me and Tony doing our best to run it down and catch it.

By the way, these things are friggin fast...

After it finally got stuck in the brush, I was able to shut the engine down and well, here's the damage list:

Bent the chassis plate in the rear to like a 30 degree angle.
Bent the rear drive shaft.
Bent the rear chassis brace - it's plastic, no biggie.
Busted the front hinge plate.
Split the front bulkhead around the screw hole.

I'm honestly amazed there wasn't more serious damage. All three diffs are just fine as is the clutch, even though the bell was quite literally glowing red hot. The engine is okay, it didn't lean out or get too hot, I actually started it up after I pulled it off the chassis just to make sure it's all good. All of this happened very quickly, but it felt like forever. I think my heart skipped a good twenty beats, I mean it was like watching a really bad train wreck because I couldn't do a damn thing to stop it.

Good news is I can fix the chassis plate and everything else is an easy fix. Not that I wanted to fix a $400 rig less than a week after owning it, especially after Hak bent over backwards to get it back on the road for me. BUt life goes on. I'd post the pics I took but I don't have the ability to do so just yet on this forum. Looks a lot worse than it really is.

[hakmazter]

I saw your thread in RC Universe and replied there...

Other members....Do batteries last for an hour, a day, etc...

As a novice racer, I charged my battery pack after every race and I know that there are 45 minute mains.....so they should last a while....but how long, I do not know...

Depending on the answers here, I am thinking that maybe it accidentally got turned on be myself or several others who looked at or were in posession of it. In the other post, I said to replace/charge the batteries and see if everything seems normal.

[razzor]

Where you using a rechargeable 6v battery pack for the reciever or 4 AA alkalines ???
One of the most important upgrades i suggest for my customers is always to go for a rechargeable reciever battery.

Alkalines dont work for longer than 25/30 mins before you have intermittent glitches.
Rechargeable packs can vary from +- 40 mins on a 1300mah to around a hour with a 1500mah.
I personally only use lipo 2000mah packs with a regulater and its good to go for around 1 hour 15mins easy.

Unfortunately what you experienced is rather common but all part of the learning curve.

[vnmsgt]

If you were using AA's and keep using them for now instead of rechargeables I would recommend getting electrical tape and wrapping the batteries a couple times after you install them. Some of my friends do that and it keeps the batteries from coming loose or popping out of the holder when running and that will cause what happened to you. One thing to remember.... A failsafe is useless without power and most besides spektrum only work if you lose signal, NOT if your battery goes dead. The spektrum will work when your battery gets too low AND when you lose signal for some reason.

[mikey]

i think he is running the ZX-1 RTR right, ......man...what happen...that is really bad,

i think its the battery go totally flat ...man,,,what fail safe did he use,

i think if the batteryis too love at V...it should stop working ....for most of the fail safe...

[3pointX]

Yeah that all makes sense. Mike, I'm going in to talk to Justin to see what parts he might have. It looks like the front hinge plate is pretty much the same as the one on Tony's Ravager, same with the bulkhead. The rear driveshaft should be pretty much universal as long as I get the right length.

Sadly, I was using AA's as I didn't have the cash for a pack at that particular point in time. But I just got paid so I'll probably pick one up today. So I did some investigating this morning and the power plug had wiggled itself loose from the receiver. I have no idea how, but it was backed out just a touch and I suppose it was enough to cause an open circuit. It could have been when I had the tray open to put in a fresh set of patteries, maybe I tugged the wire somehow. I knew it wasn't the batteries themselves because I had just popped in a fresh set, and I do tape them to hold them in place. I also keep a couple packs I use off of other cars we have lying around just in case, like already said, AAs don't last long, especially with the hi-tq servos. I had noticed earlier that it was pulsing the throttle like the failsafe was tripping but it wasn't, so I had just changed the pack. That was what boggled me, the batteries were pretty fresh.

Now, the failsafe I bought is supposed to trip if the voltage drops under something like 3v I think, so as long as there's SOME power, but below spec, it should still be able to set the brake. I don't know. I do know I ended up switching transmitters. The stock one for some odd reason just kept cutting out, like it wasn't putting out a signal or something. The other one I have, just another Futaba, doesn't have the endpoint adjustments which I hadn't even touched anyway, but it's never let me down. And the throttle and steering trims are on top by the antenna and are much easier to get at than the recessed ones on the stock one. I've got big fingers lol.

I really want to switch to Spektrum...

Oh, and MIkey, I'm using a Dynamite Micro failsafe. It's the one our local shop carries. It does work, I tried it out before I ever started the engine. But hey, if there's zero power, even the failsafe will fail.

[hakmazter]

Some people put a spring or additional spring on the throttle servo so if it loses power, it will be mechanically forced closed....

[Mr Fusion]

You need to have a throttle return spring... it's mandatory when racing. A spring or rubber band does not require batteries. ;)

[3pointX]

Okay well, I did some reconstructive surgery today and got the ZX-1 back together. I modified the front outer diff case so that rather than having screws hold the case and two more screws hold the front hinge pin boss, there are now to long stainless steel bolts that run all the way through and sandwich the diff, rear toe block, and front hinge boss together with lock nuts. Since I snapped the hinge boss at one end, I opted to fab up a carbon fiber piece instead of ordering one. At the same thickness as the original piece, I figure it's going to be about as strong as anything else. I also pressed the chassis plate back straight, and I also straightened the rear drive shaft because the local shop didn't have one the right length.

I did however have to order some new wheels, as one wheel is out of balance now, and I did order a new front outer diff case just for piece of mind.

I also took some advice and installed a return spring for teh throttle, however I think I need a stiffer one because it doesn't pull the throttle closed against the servo. It's just not strong enough and i'm not sure what spring to use. I'm using the stock steering servo for the throttle. Anyone have sugestions?

[hakmazter]

bring the spring to an Ace hardware in your area. The one on Merle Hay had a large selection....or I am sure Hobby Haven has something. They are both fairly close together. Glad you got it back together without spending $$$$$$. I was wondering about the battery thing as I was concerned it was something that someone else did to you accidentally, but that apparently wasn't the case.

Next time bring a video camera. I want to see this BMX track and if you do something else that is catastrophic, at least we can all feel like we were there. Let me know if there is anything else you need.

Mike

[mikey]

well, guys, we are also working on the return spring on the engine,

we look after you guys' needs,,,,hoply it will come very soon

[3pointX]

Yeah, it's funny you said that, Mike. I went to the one right there at Merle Hay and Hickman (I live on Urbandale Ave over by Westover lol). I just got the wrong spring. I picked one out, and Tony was like no, that's too stiff use this one. What a goomba. The one he picked out doesn't even put resistance on the servo at all so if this happens again I'm still screwed lol. I'll go back and get another one or see what Justin has for me.

[Mr Fusion]

You can also use a rubber band or women's hair thingy... wrapped around the carb and throttle linkage. Until you get a good spring.

[mikey]

or you can get a radio that have a build in fail safe....

[bc24fl]

Can anyone show a pic of where the rubber band goes and/or the spring? Thanks.

[Mr Fusion]

I don't have a pic handy, but all you need to do is make it pull on the carb closed. Hook it to the carb's linkage ball end...

[rrmccabe]

Can anyone show a pic of where the rubber band goes and/or the spring? Thanks.


This is a picture that ZigZag posted on another thread.

http://i41.servimg.com/u/f41/11/71/14/48/dscn5218.jpg

[Mr Fusion]

Good idea to use a long screw on the collar like that, for a place to hook a spring/rubber band.

[3pointX]

Is that actually strong enough to pull against the servo?

[3pointX]

Alright, well, I got a chance to actually drive my buggy without incident today. I need to check the diffs as they're making a bit of noise. It sounded a bit like it did just before the rear diff ate itself so I pulled the front and rear assemblies off and the mesh was fine on both of them. There was no visible wear, no shavings. I greased them just to be on the safe side, but there's still this odd grinding noise when I put power to the wheels. It's very noticeable and I want to figure out what it is before there's an issue. I'm too tired to mess with it tonight, but I have a list of things to check. I'm going to check the diffs' internals and make sure there's plenty of fluid, also I'm going to check the mesh between the clutch bell and spur gear, and I suppose it's also possible the rear drive shaft is rubbing the inner engine mount. I noticed there's very little clearance there. So far there's no noticable issues, but the noise I'm hearing just doesn't sound like it should be there. I suppose it could also be a siezed bearing so I'm going to check those too.

On a positive note, I absolutely love how this buggy handles, and though I have yet to unlock all the engine's potential, this thing is an absolute blast. It's definitely fast enough for my tastes, and the suspension is just superb. The brakes are a bit much, they lock up entirely too esily, but I've got them just about where I want them. All in all, it's turning out okay after everything I've dealt with so far. I'm considering making some caron fiber shock towers, some nicer looking hinge bosses and such, and possibly a carbon chassis plate. I know I could buy everything but I love to fabricate things. I've got a whole garage full of air tools just begging to be used...

[Mr Fusion]

Cool. You need to come by the track sometime.

I like to make stuff too... I would like to see the CF parts if you do some.

[3pointX]

I tried to run the track today when I went in to pick up a new wheel nut (one worked loose and it's in the yard somewhere) but we got what a half inch of rain last night I think? Anyway the sweeper on the south end past the driver's stand was a bit muddier than it first appeared. My tires just dug in and buried the exhaust and stalled the engine. I had to rip a few passes down past Taki's just to get the mud off! They were trying to get it all dried out but I don't know if they did. We went out to Jester Park and ran out there. Our usual spot is under twelve feet of water now, though so we're on the hunt for some new places.

[hakmazter]

breaking parts, losing parts, modifying parts, making your own parts. I love your stories and I am honestly glad you are our customer. But the next time I run into you, I am going to ask you for your visa because I am suddenly becoming suspicious of the possibility that you are zigzag, and you came to Iowa for an extended vacation.

you HAVE to start bringing a video camera every time you fire it up.....lol. Let me know if you need anything....

Mike

[3pointX]

Well, Hak, I went to the shop tonight after work just so I could have some track time with nobody around, and well, I had Justin order that front outer diff case, and you might as well have Cam send that aluminum hinge boss too, if he hasn't sent the case yet. That carbon fiber one lasted about a dozen laps before the front left wheel was draggin' like a ball n chain lol.

And making parts is what I love about this hobby. If I break something I at least have the ability to fix it!

And no, I'm not zigzag. We've met, remember? Honestly, do i look like zigzag? Keep in mind I've never met him nor do I know what he looks like so I could have just opened a can of worms on this one lol.

And I've got an idea. How about you come out with me and Tony some time and you can video tape for me?

[vnmsgt]

Here is zigzag!

http://casterracingusa.com/forum/showthread.php?t=35

[3pointX]

Looks nothing like me lol.

[hakmazter]

I know you look nothing alike. I am just trying to make others laugh without being offensive to anyone. Zigzag is a great guy and does a great job promoting Caster overseas and at other forums like truggyracers, etc....so realistically, it isn't a slam to either of you to be compared to each other, you both just seem to have crazy luck. I assume that after you get used to it, the problems will hopefully cease. You have also been amazingly Caster positive and you call things as you see them and I personally thank you for it. same with zigzag.....

Mike

[3pointX]

You're welcome. All of you guys. And yeah, I'm just sorting out the bugs. The way I see it, any of this could have happened with a Losi, an OFNA, an X-Ray, take your pick. What happened at the BMX track was nobody's fault and the resulting desire to make my own part to fix it was just in an attempt to get it running so I could drive it until replacement parts came in. And that new hinge boss wouldn't have broken had I cut it a little thicker around the hinges, that was my bad. At least I got some wheel time and so far I just love it. I really think I could be racing by the end of the season, we'll see. I was doing pretty well last night at the track so I think with a bit of practice I'll get the hang of things. I even figured out what that annoying grinding noise was. Turns out I managed to get the clutch bell and spur gear meshed a bit close. Problem solved. So all I need now is the front outer diff case and hinge boss and I'll be back in action again.