DT02 Fighter Buggy DG

[El Gecko]

On 12/25/2022 at 3:30 PM, BuggyDad said:

Harder secondary springs for the end of travel? Would be interested to see what you've done here, eg spring size and how mounted? 

Here's how the rear shocks are set up at the moment. Had some extra Hornet front spring spacers which just happen to fit nicely. The springs rest on the smaller upper part, and the larger lower part works as a bumpstop. All up, with the bumpstop and springs, it's about 17mm. The springs themselves are 10-12mm tall. The chassis stops about 1/4" from the ground at full compression, and I'd like it just a bit closer, so I still have to tweak some things, but it's on the right track (I might also leave it this way due to variances in tire heights, if I decide to revert to buggy wheels for some reason, etc.). There's two sets of secondary springs to provide enough force, but only temporarily. I have some different springs saved on Amazon, just need to pull the trigger and get them here so I can try them out.

 

[BuggyDad]

3 hours ago, El Gecko said:

Here's how the rear shocks are set up at the moment. Had some extra Hornet front spring spacers which just happen to fit nicely. The springs rest on the smaller upper part, and the larger lower part works as a bumpstop. All up, with the bumpstop and springs, it's about 17mm. The springs themselves are 10-12mm tall. The chassis stops about 1/4" from the ground at full compression, and I'd like it just a bit closer, so I still have to tweak some things, but it's on the right track (I might also leave it this way due to variances in tire heights, if I decide to revert to buggy wheels for some reason, etc.). There's two sets of secondary springs to provide enough force, but only temporarily. I have some different springs saved on Amazon, just need to pull the trigger and get them here so I can try them out.

 

I think I see. That shock body shape is handy for keeping the secondary spring from scratching the shaft. CVAs wouldn't achieve that. 

Would be interested to hear how you get on with the amazon springs and what they are, as a point of reference. 

[El Gecko]

Still working on the spring setup, but I've been playing around with some new wheels and tires from @Frog Jumper and also swapped down to a 17t motor to try to rein it in a little. Still working on the hacked-together servo saver, too. I just need to get a new one and finally be done with it.

Mrs. Gecko said it looks "posh" which might be the first time she's said that about anything of mine

 

[El Gecko]

Servo saver success, finally!

Decided I didn't want to pay for a new servo saver, and I happened to have this broken spring from a pair of old bicycle brakes on hand, so I cut off a coil and did a quick and dirty Dremel lathe job on the plastic spring part to make a recess for it to sit in. (I used the flat plastic spring from the kit, rather than the stronger one with the ridge on it).

Works perfect! Much stronger than stock, actually stronger than any other servo saver I have! Yet still has a bit of spring action at the limit. And fits in exactly the same space as the all-plastic kit one with the ridge. Gonna do this to my Hornet as well!

 

[Andreas W]

Good and the clever mod. I think I'll copy that on the Terra Scorcher for the kids. The OE servo saver is not surpricingly sloppy. 

[El Gecko]

Well after a year with this car, fighting all kinds of electrical gremlins and steering gremlins and everything else, I decided that the gearing is just too tall for stadium truck tires... so it's come full circle back to buggy wheels!

And it's running great at the moment. Solid and powerful, and although it understeers like crazy, it's just unpredictable enough to be fun.

The high wing mounts make it look a bit Astute-ish, which I love, but it's hard to say if that position helps or hurts the aerodynamics

@BuggyDad I also switched up the rear secondaries recently, and the jump compliance is improved. Way more control as it doesn't get bounced funny unless it's a really rough takeoff. The springs are harder and shorter, and they're still sitting on the little black Hornet spacers like before, so the shocks bottom out before the skidplate. As you can see in the pic, they were attached to these standoff-type screws out of an old computer or something. I used the little white spacer things to keep the springs centered on the shock shafts, as the spring inner diameter is about 4mm vs. the 3mm of the shock shafts.

 

[BuggyDad]

On 4/3/2023 at 3:19 PM, El Gecko said:

Well after a year with this car, fighting all kinds of electrical gremlins and steering gremlins and everything else, I decided that the gearing is just too tall for stadium truck tires... so it's come full circle back to buggy wheels!

And it's running great at the moment. Solid and powerful, and although it understeers like crazy, it's just unpredictable enough to be fun.

The high wing mounts make it look a bit Astute-ish, which I love, but it's hard to say if that position helps or hurts the aerodynamics

@BuggyDad I also switched up the rear secondaries recently, and the jump compliance is improved. Way more control as it doesn't get bounced funny unless it's a really rough takeoff. The springs are harder and shorter, and they're still sitting on the little black Hornet spacers like before, so the shocks bottom out before the skidplate. As you can see in the pic, they were attached to these standoff-type screws out of an old computer or something. I used the little white spacer things to keep the springs centered on the shock shafts, as the spring inner diameter is about 4mm vs. the 3mm of the shock shafts.

 

Ah. I see what you've done there and think I could replicate it. I'd be interested to know where you got the springs from? Have you a link or any details? 

[El Gecko]

20 hours ago, BuggyDad said:

Ah. I see what you've done there and think I could replicate it. I'd be interested to know where you got the springs from? Have you a link or any details? 

Unfortunately as I mentioned it was just lucky that I found those little standoff screws from my "random screws, nuts, bolts, and detritus" bin, probably from some electronic gadget that died years ago. The springs were attached to the standoff screws (you can see one still assembled in the pic, next to the white spacers).

The white spacers were actually from a transformer board from something else--they came off the screws that held the power transistors to the heatsink.

The inner diameter of the springs is 4mm, and the length is around 8mm per the caliper in the pic, but they're closer to 10mm with the white spacers, and around 17mm with the Hornet spacers underneath, same as the previous setup. But these springs are much stronger so they don't need to be as long.

Not sure if they're available in your area, but Amazon has a few I was thinking of trying:

Amazon springs 1mmX6mmX10mm

Amazon springs 0.6mmX5mmX10mm

The first one should be a stronger spring like the ones I have. The second would fit the shock shaft better I think, but wouldn't be as strong due to the thinner wire gauge. Maybe not perfect for your application, but possibly a starting point. I was also thinking of trying slightly longer springs and taking out the Hornet spacers.

[El Gecko]

I'm not sure if I got the idea from someone here, but if I did, thanks! Since the brushed mod motors I'm using have two sets of mounting holes, I thought maybe I could swap down to a smaller pinion by using one of the alternate holes, and it worked! Got a 16t pinion to hook up with perfect mesh, unfortunately there's not enough room to move the motor any further forward to use any smaller gears. But the car drives great now! The 17t cheapo black can is peppy like it should be, and the steering glitches are all gone. The next test will be taking it back to the track for the first time since I nearly sunk it in a puddle.