INVADER - Nitro Slash drag car

[WickedFog]

Dude, that is so badass!

 

[Doom!]

Looks badass on the line when your warming up the tires.

 

[johnnydmd]

Painted my spare body finally. Decided on a metallic backing to the green bits, matches the logo better. Still have to cut the splitter yet, and add a few minor details. Not the most complex paint scheme, lol, but I like the overall look. This body will be for "show and shine" unless otherwise needed (as in, I crash and destroy the other one).

Meanwhile, all of the parts for the second SE build, the 67 Mustang have arrived, and this evening I'll start cutting the chassis with my router. I'll start a new thread for that build

 

[WickedFog]

Very cool. Do you print your own decals? What's your setup if you do?

 

[johnnydmd]

Very cool. Do you print your own decals? What's your setup if you do?

I did print the logos and grille decals.

The logos are on the inside, and painted over. What I did was print clear stickers in reverse, then put clear vinyl stickers over them. The grille I print on vinyl stickers, then put a clear sticker over it for protection. All other stickers are from the kit, or manufacturer stickers.

 

[johnnydmd]

Switched to mod1 gears. Roughly the same gear ratio 18t/40t vs 24t/54t (2.22 vs 2.25). Benefit is aside from a bit more durability, that I now can use much nicer 1/8th scale clutches like Reds Tetra, along with a vented Reds 18t clutch bell.

I also am using a heavy duty slipper, pretty necessary if you want to use a slipper with a big block - which is also a necessity because you *really* need the slipper to keep the tires hooked up shifting to second gear.

Getting the gears meshed was difficult to say the least. This combo, both gears are a little smaller diameter than the equivalent 32p gears that I was using, and so sliding the engine back, the mount and bolt were butting up against the trans and not giving me enough space to get them meshed. I wound up having to grind a corner of the mount on the engine block down a bit, and switch to a cap screw to get enough clearance. I *barely* had enough.

Next problem - the clutch bell was in as far as possible, and the spur was not lined up well, maybe 3/4 on it, and rubbing the clutch bell slightly. Ugg. Only solution was to shim the spur where it bolts onto the slipper out some, but there's not a lot of room before the slipper bolt guides aren't inside the socket holes on the spur. Here I had shimmed it about 1mm or so, but it still needed a little bit more, so I added another washer and now the spur is 100% on the clutch bell gear. Probably only 1mm at best of that peg in the socket, but it shouldn't take much to not shear the bolts(if that's even possible anyway). If I decide to change gears, I'll need to get a larger clutch bell - probably custom - but I think this ratio is actually pretty good and balanced.

Can't wait to see how the clutch responds. From experience, the Tetra comes in quite a bit later than the HR 3 shoe clutch, even on the low spring tension setting, so I'm starting with that. Might switch to "m" and see the difference. This Sunday we are doing another TNT before we head out to a big event later in the month.

 

[johnnydmd]

Got my HR Dual Wave brakes installed. Man these things are nice. Much better solution - though kinda weighty. This drivetrain is pure beef now though - all steel gears, driveshafts, and now the brake upgrade.

The car is getting too heavy again though. Next week I'll cut the new chassis and wheelie bar, and see about dropping some weight. Possibly that alloy rear bulkhead as well. I'll certainly get it moving in the right direction with the wheelie bar and chassis change though.

 

[johnnydmd]

Forgot I had this video from last week. Another run where I had not yet realized I wasn't releasing the trans brake right away. Sad thing is that after this run I finally *did*, and laid down a hit that was spectacular - and of course my wife was busy talking to my teammate's wife and didn't get it recorded. Looks like a 2.5 second run based on the video timer (and confirmed using a stopwatch). We are re-convening in two weeks to do another TNT, then after July 4th weekend we have a team race set up with some boys from Jersey, and we'll also do a cash days and some grudging. I will get some more videos then.

Actually I take it back, looks more like 2.3 ish. Launches at 25.4 hits finish line at 27.7 so not too bad. Well next time the timer will be functioning again.

I notice that it pulls the front wheels at 26 seconds, that's when it veers left, and it's probably doing it there because that's when I let off the trans brake.

It's on the wheelie bar here and you can see the open air under the front splitter:

 

[johnnydmd]

I finally finished the new Invader body.

Bit cleaner then the OG, and I really like the matte CF splitter vs shiny. Well now I have a spare body to tote along.

 

[Doom!]

Showroom fresh!

 

[johnnydmd]

Showroom fresh!

Not anymore! I pulled the chute just after passing the trap at 60mph and it lifted the car right up into the air, cartwheeled and ended up on it's roof. Amazingly, there was only one small scuff mark! I have noted that I most definitely need to cut a larger center hole out on the chute!

I made about a dozen passes. All were very straight. We started at 10am, and it was about 80 degrees and my first four or five passes were all 2.3-2.5 seconds. Then it started getting hot. I mean really hot. 90+. The tune was lost, and I spent the rest of the day fighting the heat and humidity, and trying to get that early power back, as well as just keep it running right. 2.6-2.7 was all I could do in the afternoon. Car was either pig-rich, or starving. Very, very narrow tuning window. After I flipped the car, I decided to call it a day and watch the others, and then pack up.

I don't know what pass this one was - looks like one of the slower ones going by the video clock.

The tree worked very well, and the new reflector adjustable stilts worked great. It's so nice to not have to fool with that GNSS, which is so inaccurate to begin with(provided you even GET satellites to work right). Just line up, run, and look at your time on the tree. The day was awesome, my wife fired up the grill, we ate burgers and dogs, bunch of family and kids came to watch, everyone had a blast for what is probably our last TNT before the first event in a few weeks.

 

[johnnydmd]

I replaced the Kyosho carb with one I had from an extra SH .28-8. The SH carb is just much better built than that molded plastic Kyosho one. I also like how the SH carbs hold their tunes better. I'm also going to add an inline fuel cooler between the tank and exhaust. I've used them on my MT's and they work well.

The main thing I'll be doing to Invader is cutting the new custom chassis that's on Hissed Off and using it on this car, going to do that this week. I've gotten things sped up a bit, so I can get the chassis cut in 7 hours now. Once I cut a few of these to sell, I'll use the proceeds to get a second router and be able to cut the shock towers and wheelie bars out at the same time. I'm also going to build some kind of box to house them in that will catch the dust in a bag that can be thrown out rather than having it just blow all over my yard.

 

[johnnydmd]

Cut the entire bottom pieces out last night. Will do the upper plate this evening and tomorrow evening.

I realized though that I need to devise a way to collect the dust/shavings/etc instead of just blowing them out into my yard and letting the rain wash it into my soil if I'm going to be doing this often. I don't want a graphite/fiberglass dust bowl back there! Best to avoid that scenario. Also, because I'm running a high power fan across the cuts, small parts that I cannot screw down after the first holes are cut get blown off the router and I have to sometimes track them down.

Sooo...I came up with an idea. I have a carboard box that the router is partially enclosed in that is on the opposite end of the blower. The rear of the box is cut out and covered with some filter cloth to allow the air to escape. The part of the box that is around the router is flayed out a bit like a funnel to better catch the air. The box is about a foot long - I think I actually will extend it another two feet though. This will help prevent dust from blowing back out of the box which happened last night a bit. The table and router had some I had to blow off(and of course I was wearing a respirator!). I will also put a course screen to catch the solid parts about six inches in so that I'm not digging around in a pile of dust for them. Ideally, I'll be able to vacuum the dust out of the box when done cutting and dispose of it properly.

 

[johnnydmd]

On second though, I think the best way to do this would be to extend the box beyond the cloth filter, and attach a shop vac with a hepa filter that is sucking the stuff as it's blowing in. That should keep the majority of it contained and disposable, and get rid of the stuff that is most noxious.

Thinking I'm going to build a sound proof box too. I'm sure my neighbors are sick of hearing that little machine running

 

[Doom!]

Sounds like a better solution.

 

[johnnydmd]

Sounds like a better solution.

Found a mini shop vac for 60 dollars on Amazon that has cloth and wet foam filters. I might even stick another filter sock over the exhaust of the vac too.

 

[johnnydmd]

Well this setup didn't work Kinda made a mess actually. Good thing I do this stuff outside! Shop vac did come in handy to clean up, but there was dust and fibers everywhere. Took an hour to clean up my table and deck. I think that the blower is just a bad idea period.

So...trying something else. I'm going to put the entire router inside a trash bag with some tenting to keep it off the moving parts, and seal it while it runs. When it's done I'll toss the bag, and use the shop vac to clean it up. Either way, I think I'm only going to cut things for myself or testing prototypes. Just too much hassle and mess. I'll see if I can find somewhere to farm out cuts once the design is right.

 

[WickedFog]

Carbon fiber dust is so lightweight, you don't want vacuum with a lot of velocity. You want lots of cfm, but spread over a larger inlet area. The heavier bits that don't float into the air at the slightest breeze, you can just pull up with your shop vac. Just make sure it has a good filter in it. We used this kinda stuff wrapped around the filter basket in our shop vac, along with the standard filter, and it was also used in the overhead dust filters...

https://wioboy.com/products/hiton-p...-DA-2TFRFNFRX3VAd4wCy8BwXLzxfXthoC_JEQAvD_BwE

 

[johnnydmd]

Carbon fiber dust is so lightweight, you don't want vacuum with a lot of velocity. You want lots of cfm, but spread over a larger inlet area. The heavier bits that don't float into the air at the slightest breeze, you can just pull up with your shop vac. Just make sure it has a good filter in it. We used this kinda stuff wrapped around the filter basket in our shop vac, along with the standard filter, and it was also used in the overhead dust filters...

https://wioboy.com/products/hiton-p...-DA-2TFRFNFRX3VAd4wCy8BwXLzxfXthoC_JEQAvD_BwE

Cool, thanks, yeah I was using the very "wide" attachment when cleaning up the area. I did use a smaller one though for cleaning up the router. I'll buy some of that wrap for sure, plus a bunch of the standard filters, I'm not about cleaning them, just toss them in the garbage in the plastic bag with the dust. I can't emphasize enough the need for eye protection when cutting CF, I was startled by the amount of 1-2mm fibers I saw laying on the table! Weren't you the one that got one in his eye?

 

[johnnydmd]

So the "shove it all into a plastic bag and clean up with shop vac" worked pretty well actually. I was a little concerned about jamming and whatnot because the amount of dust and debris is startling when you see it piled up on the cuts, but there was zero issues.

When finished, I took it outside, and used my mini shop vac to clean it all up. I was sure to still wear a respirator while cleaning. Tossed the bag in the trash, cleaned the router thoroughly, and then put it in another bag for next time and to keep any missed dust or fibers from getting anywhere.

Waiting on a quote from Xometry.com to see how much it'll cost to have them do it. At first glance, it may only cost me about 20 dollars more then it costs me now to do it myself for the entire chassis!

So with everything cut, it was time to get to business....

This was the OG Invader chassis. It's a scary sight seeing a car that was already running in the low 2's torn apart like this. But, you can see just how "hacked" this thing is. Good bit of trial and error, and massaging holes to make things fit and line up. I debated selling it, but I think it's going into a glass case as an "artifact". My team mate said I should set it back up with a Slash drivetrain just to have a "different" car, but man I really made a promise of "no new RC cars" after I finished Hissed Off.

I started assembly of the new chassis...

It's definitely cleaner, and considerably lighter than the OG. More on that weight difference(and other differences) at the end.

I started on the front piece first. Assembly indicated improvement over the Hissed Off cuts, but would need very minor tweaking for the final design on a couple of holes. I only need to very lightly massage them to get things bolted up. Next cut will be 100% spot on. I also note that the 4.5mm diameter holes for the M4's are very tight - but that's good - even though it's a little tedious getting them initially through the holes. The M3 holes at 3.5mm are far easier.

The transmission mounted perfectly. Whew. Nothing to do other than bolt it up.

Mounted up the shock towers and engine. Everything but the engine mount adjuster slot was perfect. The slot needed to be moved to the left 1mm, so I dremeled it, then updated my design. I had to work on my shock tower to allow it to bolt up to the transmission, greatly reducing rear chassis flex. I've since designed a new one that I'll print out for the ones I'm selling.

The completed chassis! Everything lined up nice. I didn't have to adjust even a single turnbuckle.

All body posts lined up correctly as well - and the body height was all still as before.

The car dropped a pretty significant .3 lbs of weight overall between the new chassis and wheelie bar. Invader weighs .9 lbs more than Hissed Off, largely due to big block engine, all steel gears/shafts, and aluminum beadlock front rims, as well as the parachute assembly. So approximately 20% heavier, but likely 50% (or more) more horsepower and torque. Note - if Hissed off wasn't using aluminum shock towers vs CF, the weight difference would be larger, but that car would not hook up for sure if any lighter.

My only issue for concern is that the chassis is decidedly springier than the OG one, and how that'll affect big block power transfer, etc, remains to be seen. I could, or redesign the coupler to have an extension back to the engine mount to eliminate that if needed, but it might not be necessary, and it might even help with traction for the chassis to absorb some of the force. Though, I think some people may prefer it not to have any flex, so I'll probably work on that.