The lock-down hop-up Dark Impact

[Mozzie 26]

That's well impressive, didn't think it would be possible to fit.  Great paint job too!

[rwordenjr 1890]

4 hours ago, Juhunio said:

I love a driver figure, and with this DF03 being a Senna tribute I really wanted to get one in there. But as we know, the DF03 is unbelievably tight under the shell

I picked up an Avante driver (9225125) from Tonystamiyaparts, figuring it might have an outside chance of fitting under the Avante II shell?

Started with a test fit and straight away it needed a lot of trimming. And then needed quite a bit more along the way. Everything circled in red ended up going

Turns out the main challenge with the fit isn't the drive shaft, it's the steering rod. The adjuster at the servo end kept catching the area around his right shoulder, so continuous trimming eventually ended up like this

Obviously he's now been painted! As there is no Camel Yellow X paint pot I ended up mixing X6 orange with XF3 flat yellow at about 70/30 to get a close enough match. Then took plenty of time adding a little bit of detail to the cockpit. Shame the Avante driver doesn't have a full wheel, but hey ho

I managed to find a set of 1/10 scale stickers for Senna's Lotus race suits (for both JPS and Camel, funnily enough!), which were really good quality. I spent ages trying to peel the backing off the first one, it just wouldn't come off, to the point I was about to fire off a complaining email! Then noticed on the backing sheet that what I had were called decals, not stickers.

Decals....that brought back a memory of childhood Airfix kits, horrible little water floaty things. Surely not? Surely yes! 

Having worked that out, and got a little saucer of water, they all went on pretty well in the end. 

My detail painting is scruffy and leaves a lot of room for improvement, but compared to how terrible I was at it when I last did any model making 35 years ago, I'm happy with my progress!!

Even with all the trimming, to get the helmet to fit under the canopy he needed to be anchored further back in the shell, meaning the front of the cockpit didn't sit square with the end of the window, it was about 25mm further back. So I ended up masking the shell off and spraying some of the window black, to fill the gap and help it blend in. Might but a black pinstripe along the window edge to tidy it up a bit

Which takes us to fitting. I used Tamiya double sided tape cut to shape down each side, then added a bit of Gorilla tape as an extra fix

Also needed to slightly lift the right hand side of the shell. It naturally sits lower than the left hand side as the motor and battery cables lift that side slightly. So I put a strip of velcro along the top right hand side of the chassis to "fix" that side of the shell a bit higher and create a bit more clearance between the driver and the steering rod adjuster 

And that's it. He's in! The shell sits nice and flat on the chassis, and the steering works cleanly and without obstruction. Not sure how well it will work in the real world, it probably won't take too much shell flex for the steering rod to start knocking, but we'll cross that bridge if we come to it

Now just waiting for the bank holiday hurricane to die down so I can take it out for a blast!

So good on the driver figure! And yea I think a Black pinstripe around the the cockpit area would look sweet. Just a thin one that goes all the way around the cockpit and connects to the black you already painted. Like this but black where I outlined in red and obviously much sharper than I could draw on phone lol 

[Juhunio 6830]

18 hours ago, rwordenjr said:

So good on the driver figure! And yea I think a Black pinstripe around the the cockpit area would look sweet. Just a thin one that goes all the way around the cockpit and connects to the black you already painted. Like this but black where I outlined in red and obviously much sharper than I could draw on phone lol 

Good shout, I think it works pretty well!

[rwordenjr 1890]

5 hours ago, Juhunio said:

Good shout, I think it works pretty well!

That was fast! And yea, it looks clean!  Great job!! 

[Juhunio 6830]

So a few updates to this one based on trial and error...

Firstly, those Xtraspeed Kyosho knock off shocks looked lovely but were a bit leaky. I only really bought them to compliment the JPS livery, but as the Avante II shell is a better fit for the electronics I've decided to stick with the Camel livery, so changed the shocks

I had a set of Tamiya DF03 shocks on the shelf, so they're on now. They are so much better, and less leaky 

[Juhunio 6830]

The other (aesthetic) consequence of settling on the Camel livery was it meant I could use the blue motor plate and transparent M parts tree that I had bought at the beginning of my hop up trawl last year, but decided against (cos JPS!). So they're on now too...muchos muchos blueness....

[Juhunio 6830]

At a more functional level, I'd made a right hash of the gearing!

This is all a big learning curve for me, and I've recently learned that if you read the manual that comes with your motor and ESC, it tells you the FDR you should be looking for for different types of vehicle

The 8.5T Hobbywing in here is looking for an FDR of 8.5-9 for a 4WD buggy. I'd just casually used the 26T pinion that came with the kit, and the 82T spur gear that came with the slipper clutch; an FDR of 9.64!

I did some FDR maths on the chart that comes with the slipper clutch to work out the conversion factor (3.056)...

Which showed me I would need to use the 29T pinion to achieve that FDR. Unfortunately, the 29T pinion doesn't fit with the 82T spur, it's way too big

Thankfully, that table also tells you the FDRs if you use a 78T spur. I'd got a job lot of DF03 spares from the Far East in an eBay sale, and as well as the bits I wanted there were some random bits and bobs too, including this selection of spur and (I think?) idler gears..

The one on the top right, as it turns out, is a 78T spur gear from a DF03ra kit, in the same black material as the DF03 slipper 82T spur

So, I've fitted it to the slipper, and being much smaller it easily accommodates the 29T pinion. It also just about takes the 32T, but it is a bit tight, so not compelled to run it yet.

But for now, I've got the right ballpark FDR for the motor. I've only run it once and forgot my speedo, but it felt quicker and smoother and definitely didn't get as hot. Which is nice.

[Juhunio 6830]

Oh, and Ayrton is for the shelf only. He does just about fit, but not really safely or securely enough to run. If I had my time again, I would ream a hole through the top of his helmet to secure a narrow body post in there somehow, and clip him to the roof of the shell. The hole would be concealed due to his position in the shell, and he would be much more secure.

But there's just too many other things to do for now...

[Toad16v 282]

On 4/8/2020 at 1:40 PM, Juhunio said:

Again, it took AGES and serious pressure on the diff spring to get the lock nut down far enough for the diff screw to bite and thread. Has anyone found an easier method for this step?

I know a bit of time has passed since this thread,but I keep coming back to it as I hop up my own Dark Impact. When you installed the diffs, did you pus the nut fully into the plastic insert and then the plastic insert fully into the diff drive? Mine went together easily when I did that, I did push one in a bit further to get the screw to engage at one point as it popped back out but was fairly smooth.

 

How is the car running now? The gearbox mount for the lower arm snapped on mine on my first proper run out. Hopefully fixed soon enough though.

[Juhunio 6830]

14 hours ago, Toad16v said:

I know a bit of time has passed since this thread, but I keep coming back to it as I hop up my own Dark Impact. When you installed the diffs, did you pus the nut fully into the plastic insert and then the plastic insert fully into the diff drive? Mine went together easily when I did that, I did push one in a bit further to get the screw to engage at one point as it popped back out but was fairly smooth.

Yes, that was the bit that took a while to work out, but I got there in the end. I've built a few ball diffs since this one and they've all been easier, just by learning as you go

14 hours ago, Toad16v said:

How is the car running now? The gearbox mount for the lower arm snapped on mine on my first proper run out. Hopefully fixed soon enough though.

I ran it quite a bit last summer and autumn, and it's been rock solid

The big change I made after a couple of runs was in the powerplant....I made a bit of a mess of the brushless install, and it was never anything but super tight and very crammed in and it got a bit glitchy, probably due to my awful soldering

So I swapped it out for a Hobbywing 1060 ESC and Tamiya Super Stock BZ motor, which has been great. It's a much easier fit, nothing is crammed in, it's super smooth and just as quick as the HW Brushless system I had in before, the shell fits better....

Same fun, less hassle

[Frankster 2033]

Just found this page.  Great build!

[Juhunio 6830]

On 2/19/2023 at 8:58 AM, Frankster said:

Just found this page.  Great build!

Thanks very much! I just tracked down the proper Tamiya blue prop shaft so at some point over the next few weeks I'll be stripping this down to swap out the 3 Racing shaft 

This was only my third ever kit build and I've done plenty more since so I'm looking forward to uncovering all the mistakes I made and putting it back together properly