Personal Projects


#764

You should make a bigger model with bigger flamethrower! Would be a great weapon for self defence :smile:


#765

That’d be too much effort. Also this one is already kinda sorta illegal. :stuck_out_tongue:


#766

Oh selling it? But why? :thinking:

Nice gif s there … :fire: :smiley: flame thrower!


#767

Because:

In short, it’s too unreliable, I have nowhere to drive it and it has drained me of an idiotic amount of money.


#768

Worth selling :+1:


#769

Time for 2 Hellhound PRRs. I did two night runs with Hellhound a couple of days ago. The first one didn’t end too well, the second wasn’t too bad.

One the first run I had a couple of issues, the first was that I ran out of compressed air mid-run (turns out flamethrowe fuel economy isn’t that great), the second is a slighty more concerning issue. I was testing out the flamethrower which was browning out (more on that in the run two report) and suddenly the car started reversing despite my finger being nowhere near the trigger. To this day I still don’t know what caused it and I haven’t managed to replicate the behaviour since, hopefully it was just a one-off glitch.

Unfortunately, the sudden reversing damaged one of the gears in the transmission. Luckily it wasn’t the diff, so I had a spare gear from the second wild eagle I had. The bad news is that now I have no more spare gears, that means that if one more gets badly damaged, Hellhound will be no more. Replacements don’t exist as far as I know, given that this is a toy-grade RC that was first released in 1995 (I got mine in the mid 2000s) and custom building spares will be a pain.

Other observations I made during the first run is that I made a good decision in not buying the more powerful ESC and motor combo since this one is more than enough. The ‘improved’ suspension isn’t doing anything in the way of smoothing out the ride (though the camera mount isn’t great either) and I don’t know what more I can do to tune it. My camera isn’t good for night runs when I haven’t got an LED bar (no surprise there). And that the car takes medium crashes fairly well.

Also I needed a flamethrower arming / safety switch on account of me nearly setting fire to some people. I’m used to switching Banshee’s lights on when I come around the corner of my street to let people know that I was there, on Banshee’s transmitter, that would be a switch at my thumb. The switch at my thumb for Hellhound is the flamethrower trigger…you can see where this is going. I was coming around the corner when I heard some people coming, so I thought I’d switch the lights on to let them know I was there, just as my thumb moved to switch them on, I realised that it was Hellhound and stopped myself just in time.

The night two run was a lot better, I put in fresh can of air and didn’t set fire to anyone and I fashioned a safety switch for the flamethrower to prevent accidental triggering. In fact, I even triggered it around several people just to see their reactions. Pretty much everyone did a double-take. There was also a man who gave me a thumbs up, I doubt that would have been the case had he seen the fire (he didn’t seem like someone who’d be amused by it).

During the run I noticed some brownouts again like I had in the first run. They only occured when I used the flamethrower. Simialr to what was happening to Banshee and its light bar. The cause was the ESC’s internal BEC. It’s rated for 3A, but that’s on 2S; apparently with internal BECs, the higher the input voltage, the lower the output current. And if you have to high a draw from one of the channels on the receiver, the system browns out. In the case of Banshee it was the LED bar only just pushing over the current limit and in Hellhound’s case it’s the servos drawing too much current. So I’ve ordered a cheap BEC for Hellhound too.

Other than that, I noticed that the motor was getting worryingly hot, it reached ~73C after the second run and I hadn’t even pushed it hard, at no point during the run did I even reach full throttle. Now I know why everyone says that 3S on this specific system is pushing it (despite it being within it’s rating).

Here are a couple of photos of the ruined gear, the falemthrower safety switch and a couple of gifs from the runs. I’ll get better gifs during a day run. The frist one is a crash, the second is just the flamethrower firing.


#770

New update on Camazotz, turns out I won’t be selling it. Not because I suddenly changed my mind, but because I don’t expect it to last more than a week with a new owner, if it does go wrong and the buyer complains, I lose the car and the money and my mum’s account gets a bad reputation so I won’t risk it. Instead I’m going to try a different approach to the track problem. I’m going to try and get some of the roofing material and have it as a roll-up track, kind of like one of those kids’ play mats with roads on it. I’ll be placing it in the tiled area where the Hellhound test footage was taken.


#771

Hellhound FTV3 PRR 3:

Yesterday I installed the BEC I ordered and took it for a run while there was a little light left. I’ve got the car pretty much where I want it now. The only thing I need to change is the camera mount, it is ridiculously unstable to the point where it can be seizure inducing. Other than that, the motor is running at the limits of its capability in terms of temperature. Designing a cooling system is not an option due to the incredibly awkward and secluded position of the motor, I might come up with some way to channel air to it, but I’m not sure how well it would work. I was also completely surprised at just how much run time I got out of a single one of the 2200mAh LiPos I got for it. I was out in the stomping grounds for about 25mins with mixed driving and the battery still had juice in it when I got home. I’ll only be running a pack at a time since longer runs will kill the motor even faster.

Hellhound is a project with a very limited lifespan unfortunately. That’s mainly down to its age and lack of replacement parts. Once I’ve used up all of the replacement parts, that’s it, Hellhound will be no more. I’m not willing to go through the effort of custom designing and making parts for it and the odd (and very rare) Ebay listing of the same car is usually asking a price that I’m not willing to pay. Now it’s just a question of what gives first, the motor, or something mechanical.

Here are a couple of gifs from the run:

I’m not sure what happened on the second gif, the actual footage is unwatchable. The gif maker seems to have smoothed it out for some reason.

EDIT:

This is what the second gif should have looked like above.


#772

That’s a flame!! :heart_eyes: :heart_eyes: :star_struck: :smile: :fire:


#773

So Hellhound actually is a timebomb… good to know :sweat_smile: :joy:
That first gif is so awesome, riding through the flames like a true terminator.


#774

Here’s a 3 in 1 post of PRRs and updates. Strap yourselves in, this one might get lengthy.

Camazotz update:

So the roofing felt option for the track surface is a no go, because according to my dad it crumbles too easily and makes a mess, luckily he said he knows of a type of wood to substitute for it.

Hellhound update / PRR:

I’ve decided to not run the action cam on Hellhound since I can’t find a good spot for it. It’s not too much of an issue as I won’t be driving it that often. And as it turns out, flamethrowers have really bad fuel economy. I ran out of compressed air after just 2 runs, each with only a few bursts of fire; it was maybe a grand total of 12-15 bursts of 1-2 secs.

Also, its limited lifespan is shorter than I had initially anticipated, I went for a run the other day with no cam, before the run I had replaced the bushings in the front wheels as the wheels had a lot of play in them. 15mins into the run I notice some play in the front wheels, so I go to check them only to find that the bushings have been shot to bits (almost literally). It seems they can’t handle even a mild amount of force during cornering, I’m going to try and replace them with bearings at some point to see what happens. Hopefully they’ll handle some more abuse.

During that same run I was trying out an improvised cooling system in the form of a couple of pipes sending air to the motor when the car is moving, as well as adding a motor heatsink that I had lying around. The pipes didn’t make a blind bit of difference, but the heatsink dropped the motor temp by about 5C which is better than nothing. I can add a fan to the heatsink but don’t want to spend the money.

Banshee PRR:

Took Banshee for its first run in about 2 months today. The classic phrase of ‘you don’t know what you’ve got until it’s gone’ rings very true. After spending the last few runs with Hellhound I was able to appreciate just how good a truck Banshee really is. The responsiveness and speed of the steering, the turning circle, the nippiness, the blinding speed, the suspension, the quiet transmission and the low COG. It was such a joy to run it after Hellhound, which in contrast was not that great to drive. The one thing that I noticed today was that the acceleration wasn’t quite as explosive as I remembered…and then I went past quarter throttle from a stand still and it took off like a rocket.

But alas, this run wasn’t perfect as I had the rear left wheel nut come loose on me yet agian, I feel like I’m replacing this specific nut every other run. I don’t know why it’s that one specifically, but it’s driving me mad. I’ll buy some flanged and serrated locknuts (the current ones are normal locknuts) and see if they work. If they back out too I’ll try some mild threadlock. Now that I think of it, driving on a loose nut multiple times might have been the cause of the bearing obliteration a couple of PRRs ago.

Here are some gifs from today:

I got some unexpected air time in this one as I hit a bump I didn’t see.

Also here’s a comparison between Banshee and Hellhound’s ride quality on the same stretch of path. The shaking on Hellhound is partly down to the camera mount.

Banshee:

Hellhound:

This is the one that got smoothed out the other day, I made it with another gif maker this time, I’ll edit the other post to include this too.


#775

From the gifs Banshee seems really go smoother than Hellhound…especially on the bends…first gif it turned like there was a driver in it literally… :dizzy_face: buuut Hellhound has a weapon… fire weapon… and that’s not usual and not easy to work with… :smile:


#776

I could weaponise Banshee too, but I don’t want to. Also it would seem like it had a driver even more if I was running an FPV system, but I don’t want to spend the money as I don’t really need it.


#777

This is a quick Hellhound and Banshee update and new mini-project announcment.

Hellhound:

Hellhound’s bearings came in today so I swapped out the stock bushings, but at a cost. Hellhound uses some idiotic propriatary axle diameter that was about 1mm (or maybe even less) too big for the inner diameter of the bearing. This launched me into a world for problems. Brute forcing them on didn’t work, so I decided to fit Banshee’s stock front castor blocks and steering kncukles. Of course it wasn’t as easy as just swapping one part out for another, Banshee’s parts needed modding. 2 hours of blood (literally), sweat, rage and swearing later and the task was complete…sort of. The price I’m now paying is altered front geometry for the worse in the form of different toe that I can’t do anythign about and toe in when the suspension compresses, (even under the car’s own weight) and even more play than ever in the front hubs. The result of my effort is completely underwhelming, it’s also quite a botched job that I’m not too happpy with.

Hellhound is driving me up the wall as of late so on account of that and its limited lifespan. I’m retiring it. It will remain in storage for most of its life and will only come out on select days such as Halloween or when I feel like it (much like a real classic car). That way it remains in one piece longer and I don’t have to get angry at it when trying to repair and upgrade it. I might give it a run in the next few days just to test the geometry.

Banshee:

I’ve mentioned this before, but Banshee uses front wheels with bearings in the hubs, this is an old standard and the new standard is now a 12mm hex hub. It also uses a pin type rear hub, but I’ve upgraded that to a hex hub. The fronts on the other hand are not so easy to upgrade because I’m running inline axles (as opposed to the stock trailing axles). If I was running the trailing axles, a hex conversion would be easy as they are sold in packs.

Now, the reason I want a front hex conversion is because front wheels with bearing slots are becoming a complete rarity and any that I find on sale tend to be too expensive for what they are. For now I’m fine for two fresh sets of tyres as well as some glued ones I’ve got waiting to go, but when I use those up I’ll be in trouble. Yesterday, however, I got the idea of making my own hex adapter for the front axles. My idea was to get some 12mm hexes and drill in some slots for the bearings, but then I realised they don’t sell bits in the stupid imperial sizes I need. So I’ve come up with the idea to 3D print hexes with bearing slots in them.

I’ve no idea how this will turn out or when I’ll be able to print them as I think the uni 3D printer is out of comission for now, but I think a friend has one so perhaps I can ask him to print them for me once I design them. As of now this isn’t urgent so it’s not my priority, but it is something I’m working on.

Mini project:

Recently a friend showed me a video of a guy bolting an RC car motor to a shredder, so I thought I’d give it a shot too. Since Hellhound is being retired I’ve decided to take its ESC and motor, I also bought a servo tester and found a rubbish electric shredder we had kicking about in the house. So now I’m ready to put mine together. If it goes well, I might step it up with that massive 24V drill motor I salvaged from my dad’s old drill. It’s brushed, but it’s a monster of a motor.

Here’s the original video (you’ll need to turn the subtitles on):


#778

:frowning: so no flames no more… :cry:

I want to see how it’ll go with the shredder! :smile:


#779

Pretty much, also, I’m out of compressed air. It was always a side project, it got far more attention and glory that I had initially intended.


#780

Because it deserved attention… :slight_smile: well hope to see it around sometimes…


#781

Sit rep on the shredder project, took apart the electric shredder I found at home yesterday only to find that it isn’t suitable for the conversion. The stock motor had a helical shaft (like a drill bit) as opposed to a pinion to mesh to another gear, even if I could mod it to accomodate my motor with a pinion, the next problem is that the remaining gears have a big MOD 1.5 pitch and are arranged in such a way that modding becomes a pain. Instead I’m going to buy a manual shredder like my mum’s good one as I’ve seen the gears in that and I think I could work with it.


#782

Since most of the pain in my body has subsided (especially in my hands :stuck_out_tongue: ) I’m back to project work. I’m designing my bearing to hex adapters for Banshee and a shaft adpater for the shredder today. My friend offered to 3D print the designs since the uni printer hasn’t been calibrated properly and is out of commission for now.


#783

Sit rep:

My printed parts came in yesterday, and they prove that the concept works, however, it looks like I didn’t measure the hexes properly and they’re a mm or two too big. Though in my defence, getting the rim thickness measurement is a pain. Luckily my friend saw this coming (it happens to him too when he prints) and has offered to print the redesigns. I also designed some washers, but the inner diameter was completely wrong, I’ve no idea what I was doing when I designed them, perhaps confused one of the dimensions in my notes.

I’m surprised nobody tried to make money off of a design like this back when the standard was moving from bearings to hexes. It’s far too late to start making these and post them on ebay since nobody really runs bearings anymore and a hex conversion exists for the standard trailing axle for my truck specifically.