Niekname's janky Punisher basher build

[Niekname]

Hi all,

I have my Punisher for bout half a year now, and it's been a great rig! Recently I started spending more time here on the forum, and noticed there is only one Punisher build thread, so I wanna add mine to that now.

The Punisher is actually my first 1/8 rc car! My very first car was a Granite 4x4 mega (so the brushed). Which was a great car to learn to wrench and drive, but eventually I just wanted MORE POWER!! I am also still a teenager, and RC is actually quite hard to get in without to much money to spend, so if there is a cheaper way, I am doing it. I don't see it as a problem, I like the challenge of coming up with my own (janky) solutions. In this first post want to catch y'all up to were it's now.

The story how I got my car is actually quite fun, ofcourse I bought second hand to save money, but the person I was buying from was actually a reviewer. If you watch dutch RC content you probably know em (RCblog.nl). This was great as I got to meet him (I also did a video with them later), but also because they only used the car for the video, so I could see exactly what they did to it, and it was basically new.

The first thing that broke was the wing retainer, I 3d-printed a replacement:

This printed version also didn't last much longer than stock, I could probably design one strong enough but decided that was not worth the trouble, or at least not right now. So did I buy I new one? No, I drilled two holes in a piece of wood and called it a day XD. But cmon, it looks glorious:

(Sorry that it is a bit blurry)

Next I noticed that the motor got hot quite easily, even on 4s (never driven it on 6s). So I bought an RocketRC fan from AliExpress and printed a holder for it. This was a pre-made model, as I wasn't that good at CAD at the time. I am going to design my own as I would like to improve some things, but I will talk about that later.

\

Then I did some tuning, I will make a quick sum up:
Increased ride height: noticeably quicker on grass, on the road it slides a bit more, but I find that fun to drive.
Shock fluid rear: instead of stock 500 CST, I put 550 CST. This made jump lips feel WAY smoother. Also a bit easier to get the rear end out, which I like, as mentioned.
Chamfer rear: I played with this, but eventually left it on stock. This felt like the right amount of slipping for me, on asphalt at least. Didn't notice that much difference on grass, but also didn't test as extensively on grass.
Shock fluid front: from stock 600 CST (I believe), to 640 CST. This made jump lips and landings feel even smoother. If you want to tune you Punisher I would recommend starting with stiffer oil, maybe even stiffer than me but I haven't tried that. I feel like you could definitely go stiffer though.

Then my shock pistons broke, took me a bit to realize what was off. I haven't seen this problem much, so I'm curious, has anyone else has this problem?

I didn't wanna buy new ones, as they broke quite easily, so I went for another janky solution: 3D-printed shock pistons! Honestly I wouldn't have even thought this was possible if I didn't come across a model of these by accident. I tried that model first, they even broke faster then stock but I knew it was possible, so I designed my own and this time made them thick! This is the second gen, but I am going to make a third gen. On this gen I made a cut out for the bolt, but only after I printed them I realized it made way more sense to make a bore that the O-ring fits in.

(Sorry for the bad picture, it was quite hard to photograph it from the side)
I haven't tested these ones yet, as my car is broken at the moment. When taking of the shock where I needed to fit this piston, I stripped the bolt connecting the shock to the arm. Even with a kobalt bit I couldn't get a hole deep enough to use a screw extractor. So my brother took the arm and shock with him to try on his drill press. Do you guys have any tips to remove stripped screws? I also noticed my bits are starting to get dull, which is leading to easier stripping. What bits do you have and how are they holding up? My screwdriver takes 1/4" bits. The bits I have now are random amazon cheap ones, so I am not surprised they are starting to fail. I have also taken a look at the Wera wrenches, although they seem great in not stripping screws, they don't look that comfortable. Does any one have any experience with them? Any help is appreciated, and thanks for reading!

Also, I forgot to mention I also 3D-printed custom wing holder "tabs". See the details here:
https://makerworld.com/en/models/403812

Another addition, the things I want to do to my car in the future are (in order):

1. Servo saver tightening, maybe I wanna see if I can create some sort of damper with TPU, instead of thightening the spring all the way up or buying a custom spring.
2. Custom cooling duct: as mentioned, I want to create my own cooling duct with directed airflow.
3. Stiffer fluid in center diff, to have a bit less ballooning at the front wheels.

 

[Horatio]

Great info here. I love the plywood wing washer. Can you make me some - I'm out of ply!

I baby my XTR around, albeit very rapidly, but I've been warned that the shocks are weak and the standoffs snap etc.

There are lots of people just using Kraton shocks and titanium standoffs, which apparently helps.

My rig still looks like this from 2021:

To be honest, it's so unbroken, I must be doing it wrong....

Regards your servo saver - the only acceptable solution is to change the spring for one of these:

Stock on left, upgrade on right.

Lee Spring LC 085J 0 M - it was ordered to spec and bought in a batch of about 20 springs.

Full details are discussed in a thread here:

https://www.corallyforum.com/threads/shogun-and-servo-high-torque.1166/#post-16669

Hope this helps.

 

[Niekname]

I forgot to mention, but I have indeed snapped a standoff, the rear ones aren't HD stock, replaced them both with HD and never snapped them again. I have thought about getting kraton shocks, but I think with stiffer oil these shocks are fine. They could be even stiffer, but I could also print a shock piston with smaller holes to get the same result. Maybe I'll look into that.

As for the servo saver, I read that thread yesterday and the spring is quite a good find. But I love tinkering around with stuff like this so I am going to try some things with TPU. If I cant make something acceptable I'll just tighten it up and see how long it lasts, if the lifetime gets shorter and shorter I'll probably replace it but for one spring the fees are so expensive. Mabye I gotta buy them in bulk as well and sell them.

I have seen your rig in other posts as well and absolutely love it! Also never seen it dirty XD. Do the carbon inserts in the arms actually make a difference? To me it always seems like they make the more brittle because the arms can flex less, but that's just looking at them.

 

[Horatio]

I forgot to mention, but I have indeed snapped a standoff, the rear ones aren't HD stock, replaced them both with HD and never snapped them again. I have thought about getting kraton shocks, but I think with stiffer oil these shocks are fine. They could be even stiffer, but I could also print a shock piston with smaller holes to get the same result. Maybe I'll look into that.

As for the servo saver, I read that thread yesterday and the spring is quite a good find. But I love tinkering around with stuff like this so I am going to try some things with TPU. If I cant make something acceptable I'll just tighten it up and see how long it lasts, if the lifetime gets shorter and shorter I'll probably replace it but for one spring the fees are so expensive. Mabye I gotta buy them in bulk as well and sell them.

I have seen your rig in other posts as well and absolutely love it! Also never seen it dirty XD. Do the carbon inserts in the arms actually make a difference? To me it always seems like they make the more brittle because the arms can flex less, but that's just looking at them.

You can tighten the spring right up - but then you have no servo saving action.

You may as well just 3D print a solid crank with no cam. Unless you can 3D print a spring!

Love the idea of custom shock pistons! Very cool. I suppose there'd be nothing stopping you from making your own bypass pistons - like the 16mm MIP bypass1 jobbies.

 

[Niekname]

Im going to see how it does when thightend up halfway, and then Im gonna play with some flexible 3d prints to see if I can create some sort of damper.

And I guess you could probably print those pistons, not the valves though. But it would make more sense to just 3d print a lot of pistons with different sizes. They cost basically nothing to print.

 

[Jeffwazz]

Good to see another Punisher on the forum Most definitely the nicest looking of the Corally 6s bodyshells!

The stock shocks are under-sprung and under damped. I've currently got a set of Kagama shocks (check the eBay breakers/Jenny's), or fit the hard springs, HD pistons, HD rod ends, and 1000wt shock oil. This helps on hard landings and general bashing about.

I also went up to 300k syrup in the centre diff - stiffens it up, but not too much to risk excess drivetrain wear/damage.

Also the wing washer - I thought about plywood, but I just cut another from a bit of spare packing I had. I made a couple for spare so when I get a 'skill deficit', the bolts can pull through without breaking the wing.

 

[Niekname]

I've seen your wing washer yeah! Definitely looks better, but I am surprised that it holds up well enough, it looks quite thin. For me I sometimes tore trough them when scraping in a wheelie. I am also not too concerned about the wing breaking as it is quite flexible. And if it breaks I will just 3d print a new one .

For what I do, the shocks feel quite decent how I got them right now, only not when jumping. For jumping they could be way stiffer, but I mostly drive around on grass and pavement.

 

[Chuzz]

Great info here. I love the plywood wing washer. Can you make me some - I'm out of ply!

I baby my XTR around, albeit very rapidly, but I've been warned that the shocks are weak and the standoffs snap etc.

There are lots of people just using Kraton shocks and titanium standoffs, which apparently helps.

My rig still looks like this from 2021:

View attachment 6282View attachment 6283
To be honest, it's so unbroken, I must be doing it wrong....
View attachment 6284

Regards your servo saver - the only acceptable solution is to change the spring for one of these:

View attachment 6285
Stock on left, upgrade on right.

Lee Spring LC 085J 0 M - it was ordered to spec and bought in a batch of about 20 springs.

Full details are discussed in a thread here:

https://www.corallyforum.com/threads/shogun-and-servo-high-torque.1166/#post-16669

Hope this helps.

I bought some of these springs too, definitely needed in the Muraco, the Radix steers much better so will only upgrade it in that soon enough, be interesting to see how it effects the Radix… TBC

 

[Niekname]

Last weekend my bits finally came in (my old ones were rounded of so I didn't want to take a bet), so I have been busy wrenching this week. I tightened up the servo saver all the way, then backed it of by about 2mm, so I it has 2mm of "servo saving action." I am going to test drive this weekend and see how it feels. I'll probably get the custom spring as everyone is suggesting. I played around with the idea of 3d printing a damper out of a flexible material but it is probably not going to work here.

I also gave the front and rear a rebuild to clean everything, the only thing I didn't open up was the diff cases. Man its so nice having a clean car! Apart from the scuffs it feels like new again! I was also tempted to clean the center. But when it's open I also want to add some stiffer diff oil, and because I also messed with the servo saver and the steering I want to first feel what difference that makes. If I then dislike something, I don't have to diagnose two different possible causes.

I also iterated my shock piston design, as I stated in the first post it made way more sense to make a bore for the washer, so that's what I did:

If this doesn't break, which I don't expect it to, this will be the final design. I will then post it on makerworld or printables so anyone can download it. I also made some version with smaller holes, so I can play around with shock tuning. It has the same effect als thinner/thicker shock oil, but this way it is reusable, and way cheaper (with a 3d printer).

When cleaning I noticed my diff outdrive cups are pretty badly notched:

I'm probably going to get the swiss spring steel ones from TC to hopefully have them last way longer. Or are there any other upgraded diff cups I don't know of? The TC ones are pretty pricey, especially for the whole car. (probably only need front and center though, the rear seams way better).

I also found out my center diff has quite a bit of slack in this direction:

I figured it isn't a thing to worry about, since it is moving alongside the pinion. But do I need to be worried? And how do I fix it, does it need to be shimmed?

 

[Horatio]

Last weekend my bits finally came in (my old ones were rounded of so I didn't want to take a bet), so I have been busy wrenching this week. I tightened up the servo saver all the way, then backed it of by about 2mm, so I it has 2mm of "servo saving action." I am going to test drive this weekend and see how it feels. I'll probably get the custom spring as everyone is suggesting. I played around with the idea of 3d printing a damper out of a flexible material but it is probably not going to work here.

I also gave the front and rear a rebuild to clean everything, the only thing I didn't open up was the diff cases. Man its so nice having a clean car! Apart from the scuffs it feels like new again! I was also tempted to clean the center. But when it's open I also want to add some stiffer diff oil, and because I also messed with the servo saver and the steering I want to first feel what difference that makes. If I then dislike something, I don't have to diagnose two different possible causes.

I also iterated my shock piston design, as I stated in the first post it made way more sense to make a bore for the washer, so that's what I did:View attachment 6388View attachment 6385
If this doesn't break, which I don't expect it to, this will be the final design. I will then post it on makerworld or printables so anyone can download it. I also made some version with smaller holes, so I can play around with shock tuning. It has the same effect als thinner/thicker shock oil, but this way it is reusable, and way cheaper (with a 3d printer).

When cleaning I noticed my diff outdrive cups are pretty badly notched:View attachment 6386
I'm probably going to get the swiss spring steel ones from TC to hopefully have them last way longer. Or are there any other upgraded diff cups I don't know of? The TC ones are pretty pricey, especially for the whole car. (probably only need front and center though, the rear seams way better).

I also found out my center diff has quite a bit of slack in this direction: View attachment 6391
I figured it isn't a thing to worry about, since it is moving alongside the pinion. But do I need to be worried? And how do I fix it, does it need to be shimmed?

Nice job on the pistons! It's good of you to share the files.

The diff shouldn't have more than a tick of end float with it. Ideally, you should use 0.2 shims to remove the slack.

My Sworkz T2E needed 2 shims - 1 each end - removing about 0.4mm of float.

 

[Niekname]

When I open my center diff soon I will shim it!
I also went to install some mudguards, but my M3 screws don't fit. I have searched the whole forum and internet but can't find what hardware is needed to bolt them on my rears suspension arms. Is it M3 or M2? If it is M3 I probably got a little defect, although that seems strange because it is on both arms.

 

[CCB-MN]

I’m not sure about the Punisher arms but the Kagama arms use a m3 10.

You might be able to find some oddball screws that fit, otherwise you could try drill them out a hair and run a small tap through them.

 

[Niekname]

Thanks for the reply! I believe it is M2.5, it is to small for M3 and too big for M2 and I don't think TC is using imperial measurements. I don't have any M2.5 on hand though so I can't test it. I also read in Horatio's build thread that the graphite inserts are fastened on the arms with M2.5 screws so that would make sense. But then I looked at my arms and the holes for the inserts are way smaller, so that leads me to believe again it is something with my arms. Overall a bit confusing, but I will probably drill them out and then tap them as you said.

Anyways I crashed into something and bend my lower suspension arm mount, and the casing over the mount.

I already straightened the mount but the screw holes are both ripped on the plate, and one on the case. Which leads to the right side of the mount mount lifting up. Basically adding ~5 degrees of caster. It I kept on driving after the crash and only noticed it when I came home, so it is still drive able. I have bend my top suspension arm mount as well (dumb accident, my wing had broken off when I was driving to my speed run spot. When we arrived my friend started doing speed runs and I forgot my wing was missing so I got into a massive cartwheel when I braked). This leads me to believe it is a bit of a weak spot, especially in cartwheels and when hitting something with your front wheel.

Because it is maybe a bit of a weak spot, I was looking at some upgrades and there are quite a bit of options:
The stock option:
C-00180-240: https://corally.com/en/product/C-00180-240/team-corally-suspension-arm-mount-front-aluminum-1-set
with:
C-00180-051 https://corally.com/en/product/C-00180-051/team-corally-suspension-arm-mount-front-composite-1-set

Same setup as stock, but with 7075 aluminum:
C-00180-419: https://corally.com/en/product/C-00...nsion-arm-mount-xtr-front-7075-aluminum-1-set

Exactly the same but 7075 T6 aluminum (I am not sure it fits on the Punisher though, seems to be for 2020 and 2021 models):
C-00180-683: https://corally.com/en/product/C-00...7075-t6-3mm-hard-anodised-black-made-in-italy

7075 aluminum mount, but this one makes use of bushings:
C-00180-139: https://corally.com/en/product/C-00...ension-arm-mount-pro-fr-fr-aluminum-7075-1-pc

I find it strange there are so many options, but which would you go with and why? The last options seams to be the most durable but is also most expensive. I might just buy the stock and not crash into anything, or the T6 if I can find it available. I am also a bit concerned about upgrading these as they protect the arms and turnbuckles by bending. And the bending isn't the problem, it's mostly the holes ripping.

I also have seen hinge pin mounts from erik van ravenstein on the forum, but no pictures and I can't find his parts anywhere.

 

[KnowAir]

Last weekend my bits finally came in (my old ones were rounded of so I didn't want to take a bet), so I have been busy wrenching this week. I tightened up the servo saver all the way, then backed it of by about 2mm, so I it has 2mm of "servo saving action." I am going to test drive this weekend and see how it feels. I'll probably get the custom spring as everyone is suggesting. I played around with the idea of 3d printing a damper out of a flexible material but it is probably not going to work here.

I also gave the front and rear a rebuild to clean everything, the only thing I didn't open up was the diff cases. Man its so nice having a clean car! Apart from the scuffs it feels like new again! I was also tempted to clean the center. But when it's open I also want to add some stiffer diff oil, and because I also messed with the servo saver and the steering I want to first feel what difference that makes. If I then dislike something, I don't have to diagnose two different possible causes.

I also iterated my shock piston design, as I stated in the first post it made way more sense to make a bore for the washer, so that's what I did:View attachment 6388View attachment 6385
If this doesn't break, which I don't expect it to, this will be the final design. I will then post it on makerworld or printables so anyone can download it. I also made some version with smaller holes, so I can play around with shock tuning. It has the same effect als thinner/thicker shock oil, but this way it is reusable, and way cheaper (with a 3d printer).

When cleaning I noticed my diff outdrive cups are pretty badly notched:View attachment 6386
I'm probably going to get the swiss spring steel ones from TC to hopefully have them last way longer. Or are there any other upgraded diff cups I don't know of? The TC ones are pretty pricey, especially for the whole car. (probably only need front and center though, the rear seams way better).

I also found out my center diff has quite a bit of slack in this direction: View attachment 6391
I figured it isn't a thing to worry about, since it is moving alongside the pinion. But do I need to be worried? And how do I fix it, does it need to be shimmed?

I don't know what region of the globe you're located in, but Jenny's RC is THE place to get the upgrades you need, well TC branded upgrades that is.. basically all the 6s drive parts are the same across the line, with the exception of driveshaft lengths and spur gear tooth count.
While I realize you probably don't need entire diff assemblies, the price of them from Jenny's just makes sense to buy the whole thing and keep your originals for parts vs buying just the spring steel cups alone elsewhere..
Center diff,
https://jennysrc.com/products/team-...ear-xp-6s-c-00285?_pos=1&_sid=14f60f382&_ss=r
F/R diff,
https://jennysrc.com/products/team-...ith-bevel-c-00288?_pos=1&_sid=2891e7760&_ss=r

As to the freeplay at the center diff mount, like @Horatio said, shim it out. Eventually you'll likely need a new composite mount as they do take quite a bit of abuse. There are aluminum upgrade center diff mounts available from TC and possibly others too. I just buy the composite and replace as needed, they're cheap enough, buy 2 at a time, LOL.
Does it get any cheaper than this? For the whole motor mount even!! LOL
https://jennysrc.com/products/team-...ert-cover-c-00182?_pos=1&_sid=bdd6eedac&_ss=r

BTW, I love the "wing washer"!! if/when it breaks, free tooth picks!!

 

[Niekname]

I'm from the Netherlands, so I can't order from JRC. The RC community is quite small in the Netherlands, which is a bit sad. There also aren't any reliable Tekno resellers, otherwise would love to buy a MT410. Maybe I gotta start my own hobby shop .

I don't get how JRC can sell them for so cheap though, literally half the price from other sites.

I also 3d printed a hinge pin holder "case"(this and the aluminum part are both called hinge pin holders, but this is more a hinge pin holder holder ):

It is probably gonna rip through the screw holes with a small hit to the tire, because the aluminum doesn't reinforce the screws anymore:

But at least I can keep on driving now. And I don't need to buy the new suspension arm holder "case".

At first I wanted to 3d print a wing washer, but I think im going to keep it now!

 

[CCB-MN]

I’m not sure on the Punisher dimensions but I know that many of the Corally rc’s have good cross compatibility. Maybe check out M2C Racing’s Beefcake stuff. It’s tough as nails but it’s not cheap.

Just a thought.

 

[Niekname]

Had an amazing bash yesterday! Perfect conditions: 20 degrees C, dry but not dusty, freshly cut grass and a sunset . Before that I added some mudguards (this picture was after driving though so don't judge the dirty car):

3d printed out of TPU 95A, which is flexible and almost indestructible. They work great for the arms, but the shock body still gets a lot of dirt on it. I will see if I can raise them, but maybe then they will rub on the body when the suspension is loaded. We will see .

I had a lot of lid landings, most on grass but some on black top and I broke the body:

Honestly I am surprised this didn't happen earlier, as this part always felt weak to me. I reinforced my body with tape, but nothing special. I am going to try 3d printing something for it. Probably out of TPU again, but maybe that will be too flexible and I will try using a more brittle filament.

My wing mount also broke, first time this happened with the custom 3d printed one:

I have revised the design and added more material where it looked like it started breaking:

I have taken a look at the M2C suspension arm mounts and they look amazing, but for 50 euros I just can't justify it. Probably going with the 7075 T6 one and the 3d-printed case.

So the things I am planning to do right now:
- alter mud guards
- refill and shim center diff
- model motor mount
- model front shock protectors

Also, I was looking at some extra batteries for longer run time, but I am hesitating about 4s or 6s. I have never driven my Punisher on 6s as 4s is already really powerful, but there is decreased wear. I am pretty sure I could handle the 6s power, but I just don't know if I would enjoy it. What do you guys mostly drive on and why? Also could 5s be an option (3s + 2s pack)?

 

[Niekname]

Sorry for the long wait on updates, I was on a vacation. Yesterday we got back and today I could get to wrenching . I opened up my center diff to refill it, and make it stiffer. On my last run it was REALLY hot, the motor was still pretty cool, probably ~45 C, but the center diff was way to hot to touch. As expected it was pretty empty:

I only had 10k, 30k and 1 million diff oil, so I topped it up with 1 mil. I am hoping it should be around 500k cst when it mixes with the factory 100k. I didn't calculate it or anything just a rough estimation. I will probably get some 100k, so I can mix some different weights. Or I could just mix the 1 mil with 10k. Also my drive cups are pretty worn:

I didn't shim it, because my shims haven't arrived yet. I am waiting for some different parts to come in stock so I have to pay shipping only once. But when I do shim it, the shims will go between the bearing and drive cup right?

So that eliminates the play between the diff and bearing, and therefore the bearing housing, so the motor mount. However this won't eliminate play from the bearing itself, which it has a little bit. Could you shim the bearing or would you need to get a new mount?

Also I was reading this thread back a little, and I want to apologize that sometimes the text and pictures are a bit messed up. I usually type this on my vertical monitor so it all aligns differently. But I will check it on my main monitor now

 

[Horatio]

@Niekname - the shim or shims go between the bearing and the diff mount.

Typically shims are 0.1 or 0.2 mm thick, so depending on how much end float you're trying to eliminate, you'll need to choose how many to use.

In the photo above, I had about 0.5 mm of unwanted float, so I used 2 x 0.2mm shims - 1 each end - to remove 0.4mm of float. You don't want it tight - there should be some clearance, just like with gear mesh.

Those diff outputs are end of life too. Get the HD ones and you'll find the outputs will last much longer. You'll just need to replace the dogbones more frequently instead, which is a much quicker job and dogbones are cheaper.

 

[Niekname]

It's been a while since I updated this thread. I am in the car right now but I will see if I can update it later today, otherwise later this week. I made some nice changes...

Anyway, my fan broke a little while back. Probably due to inadequate protection. I only had a thin grill. It was a rocket 40mm fan. This afternoon I was going to place an order but I am debating if I should get one of those 1A server fans or another rocket fan.

I can get both for around ~€12,-. Currently I run my BEC at 6v. I don't know if I should put it to 7.4v because I am still running stock servo and I hear some people burn them out quickly on 7.4. My Esc doens't get too hot, but it is a bit close. With the rocket fan my motor was OK. Only on the hotter days when I pushed it hard it got too hot.

So which voltage do I run?
And what fan should I get?
- server fan: better cooling, harder on BEC.
- rocket fan: less cooling, easier on BEC.
Is there a difference in durability?

I really don't want to run external BEC and/or extra battery. Maaaybe if I can keep it under €10.