Twin engine (post crash) rebuild.

[Greywolf74]

Wow, just Wow... I'm quite jealous!

 

[Nitrotrout]

Looking like a whole lot of engineering went into that idler gear/tranny combo. Amazing.

 

[Rolex]

That’s it for this weekend., I’ll start on the front end after the new year.

WHAT? NO updates till next year? Are you kidding me?

 

[Snook Man]

Looking like a whole lot of engineering went into that idler gear/tranny combo.

Yep, it made me go Hummmm, quite a few times.
Gear mesh was the most difficult after determining what gears to use to fit into the space I had to work with. It took several templates and a few attempts to get it right. The spur gear is 22 T and the clutch bells are 18T. I most often change the gear ratio internally of the transmission but can change spur size buy shimming up the transmission to fit a larger spur when/if necessary for a more subtle change.

In before the New Year

This is the front upper chassis brace; it serves several purposes other than just a brace.
The throttle bell crank, throttle/brake servo, steering posts and receiver box all attach too it.
It also ties into the front bulkhead.

More later this weekend.

 

[Rolex]

That's not going to be very strong. With all those holes you've drilled in it, it almost looks like pegboard.

 

[tvjv2009]

Great observation Rolex...

 

[Rolex]

 

[Snook Man]

That's not going to be very strong. With all those holes you've drilled in it, it almost looks like pegboard.

I know, right... Somehow all my builds have that look

Got a little more assembled today.
Steering bell crank: It’s a combination of a 4Tec and RS4 parts. I set it up for good throw and clearances and cut upper and lower bushings to size to set the height.

Front suspension: 4Tec parts for the most part. I made a custom shock tower to go with the shocks I’m using to set the ride height. I broke an aluminum bulkhead in the crash and they are hard get a hold of now so its back to a stock plastic bulk. I don’t remember what brand the aluminum suspension parts are but they were anodized blue and I removed the ano and re-bushed all the hinge pin holes.

With shocks mounted:

Front clip: Splitter and brace.

The canards are made from a 1/8th scale wing which is cut in half, modified and then sandwiched between the splitter and brace with a filler in between the 2 wing halves.

Body mounts bolt directly to the splitter. I haven’t drilled the holes for body clips yet because I haven’t determined the final height of the body.

A Super RS4 front bumper was modified to fit on the lower section of the splitter/canards It fits the contour on the front of the main chassis deck for mounting.

The front clip bolts to the chassis deck with 5 screws. (A front brace/battery tray attaches from the splitter to the bulkhead later for added support)

And 1 more overall pic that doesn’t look like a peg board And yep, that’s an RC on a white living room carpet (wife’s not home today).

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That's not going to be very strong. With all those holes you've drilled in it, it almost looks like pegboard.

I know, right... Somehow all my builds have that look

Got a little more assembled today.
Steering bell crank: It’s a combination of a 4Tec and RS4 parts. I set it up for good throw and clearances and cut upper and lower bushings to size to set the height.

Front suspension: 4Tec parts for the most part. I made a custom shock tower to go with the shocks I’m using to set the ride height. I broke an aluminum bulkhead in the crash and they are hard get a hold of now so its back to a stock plastic bulk. I don’t remember what brand the aluminum suspension parts are but they were anodized blue and I removed the ano and re-bushed all the hinge pin holes.

With shocks mounted:

Front clip: Splitter and brace.

The canards are made from a 1/8th scale wing which is cut in half, modified and then sandwiched between the splitter and brace with a filler in between the 2 wing halves.

Body mounts bolt directly to the splitter. I haven’t drilled the holes for body clips yet because I haven’t determined the final height of the body.

A Super RS4 front bumper was modified to fit on the lower section of the splitter/canards It fits the contour on the front of the main chassis deck for mounting.

The front clip bolts to the chassis deck with 5 screws. (A front brace/battery tray attaches from the splitter to the bulkhead later for added support)

And 1 more overall pic that doesn’t look like a peg board And yep, that’s an RC on a white living room carpet (wife’s not home today).

[/URL

 

[Rolex]

that’s an RC on a white living room carpet

It shouldn't be on anything else, other than maybe white silk.
Damn, that's beautiful. People here need to stop accusing ME of bling.

 

[Snook Man]

It shouldn't be on anything else, other than maybe white silk.

Or a long straight smooth road!

Rear shocks: I don’t remember what cheapo brand these are but they are aluminum threaded shocks I got for a TMaxx many years ago. They were leakers from the get go and I tossed them in a box and forgot about them until this build. I de-anoed them and polished the bodies and caps and replaced the bladders and shaft o-rings with higher quality parts and they turned out to be a decent set of shocks.
I also installed the rear toe links which are HPI savage turnbuckles with trx ball ends to make the short links I needed for the narrowed suspension.

Rear wing mount: Ofna LX series wing mount which bolts directly to the shock tower. I removed the wing stay from the mount and made custom stays from aluminum angle to get the exact angle and height I wanted for the wing. I also replaced the plastic posts in the wing with aluminum for added bling. The wing is a Proline 1/8th scale HD wing.

Splitter brace/battery mount: Simple piece of aluminum attached to the front bulkhead and splitter.

The RX battery is a 6V 1600 mAh flat pack which I wrapped in gorilla tape for extra security and the CF effect. I then wrapped the battery in high density foam padding.

I made a custom bent strap from stainless steel that has a hook on the top end which hooks into the shock tower and the bottom is secured with a screw. It only takes a couple seconds to install or remove and is very secure. Hopefully the shift of weight with the battery now forward of the front axles will help keep the front planted.

I’ll probably install the electronics tomorrow.

 

[Rolex]

Wow, just wow. Call me for waxing tips.

 

[Greywolf74]

Freakin' beautiful!!!

 

[Snook Man]

Thanks for the Wow’s… And Rolex, I’m out of wax :0
Greywolf, My wife calls it my Art work and wonders how I manage to keep it so shiny when my hands are so dirty:lol:

A couple of Savox 1256 servos installed for steering and throttle/brake duties.

Throttle linkage: It was problematic from the start of this build. I tried to set it up with available off the shelf parts but after several attempts I had to make a custom bellcrank with the dimensions to fit the space available and correct length and angles of the arms.
I cut this out of a hunk of T6 and machined it to accept 2 flanged bearings. The little stubby post mounts on the front center upper chassis brace and bearings fit the post.

A threaded rod with thumb adjuster makes the connection from servo horn to one arm of the bellcrank. The connection from the other arm to the throttle valve(s) installs later.
The time I spent making that little bellcrank was well worth the effort. The throttle works perfectly now with no binding and a solid return to the idle position on both engines.

Receiver box is a modified old school TMaxx box that’s been cut down (shorter with an off/on switch add to the area where the rubber plug fits.
It mounts directly on top of the front chassis brace with a couple plates for quick & easy access.
I use the Traxxas TQI system with docking base and my Iphone. I know a lot of people don’t like the tqi but I haven’t had any issues out of mine and it has great range compared to others I’ve tested. The traxxas link app makes it easy for me to set everything up or make little changes. I may also invest in the GPS they finally have available.
I will say that without the docking system I wouldn’t use the TQI. It’s just too complicated without the app.

Transmission: This one is a custom 2 speed with the lowest ratio possible within the confined space of the housing. There just isn’t any more room to install larger gears.
My theoretical calculations put the rig at 121mph top speed. Comparing that to what I know it has done in the past with other gearing I should get close to a 113mph if all goes well. The rear center driveshaft is the HPI savage wheel shaft I mentioned earlier in the thread.
The brake is a custom setup with a steel rotor and replaceable pads mounted to aluminum calipers I made. The spurs gears mount directly on the input shaft without a slipper clutch.

.
Chassis side plates: 1.5mm thick T6. These just bolt to the edge of the main chassis deck to make up the final outline. The cutouts are to shed a little weight, let air in/out and look cool

Mounted to chassis.

Power plants: Novarossi .28’s with Nova headers. I’m trying a different clutch setup this go round with composite shoes (3) installed in the leading edge configuration. I ran Buku komposite clutches prior to this but have worn out 6 sets of shoes with the tall gears.
Pipes are ERCM end bleeds that Robin made for me with custom bent stingers. I have now cut the stingers off (sorry bud) and will be adding some with a different bend and slightly longer to fit through the body better.

I also de-anodized the top/bottom and outer edges of the cooling fins on the Nova heads for a little more bling. With a little push I may polish the entire cooling heads on a rainy day.

Extensions for the ERCM pipes. These are just bent out of plated copper to get the right angle/bend for now. I have to order some stainless tubing and black silicon sleeve to make the connection.

I got more done than I thought I would today, must have been that extra pot o coffee.

 

[tvjv2009]

Real nice snook.. can't wait for video!!

 

[Rolex]

I can't take it. I'm starting to shake uncontrollably, thinking that it might get dusty out on some lonely road.
I must try to stop you at all costs. Have you considered medication? It worked for me.

 

[BamaFan]

WOW!! Man you got skills. I can't wait to see a video of this beast running. Are you having to use steel gears in the tranny? That's a lot of power.

 

[Snook Man]

I can't wait to see a video of this beast running. Are you having to use steel gears in the tranny? That's a lot of power.

I dont have any plans on running it until April or May and I may need to borrow some of Rolex's medication before I go WOT

This tranny does have all steel gears but I have several more set up that use a combination of steel and plastic gears. I haven’t had any issues shredding gears with the 2 engines but have had lots of failures of shafts, pins and one way bearings.
The 3 speed though has an appetite for OWB’s. Once it hits 3rd gear the bearing can’t take the high rpm’s and heats up quickly. The heat causes the bearing to expand (best way to describe it) and it starts to grip the shaft tighter and tighter causing more heat until it either acts like a brake, or fails all together and causes catastrophic damage.
That’s one of the main reasons I’m now using the 2 speed, the OWB can handle the rpm’s and it leaves room for a larger primary output gear to make up the difference in ratios.
Stock gearing of the forward primary (middle shaft) and output (lower shaft) is a 28T primary turning a 26T output. This setup has a 34T primary turning a 20T output. Imagine a clutch bell (primary gear) increase of 6T and reducing the spur (output gear) by 6T, then factor in the 18T engine clutch bells turning the 22T spur gear ratio and things start to turn really fast

I could talk transmissions and gear ratios all day but would probably start to bore you.

 

[BamaFan]

Do you have any video's of it racing before the crash?

 

[Snook Man]

I’ve only ever uploaded 2 video2 of it, 1 was just testing it with the wheels off the ground and the other was its maiden voyage with throttle restricted to about 50% to find the gremlins. (Note to self) Looking back at the video it was stupid of me to be using an old am tx/rx but I got impatient to give it a test run and threw it in. 100’s of hours of work could have went ah bye bye. Throttles were not returning to idle correctly in the vid and I was adjusting the throttle trim on the fly.
I had several more videos and carnage pics (good ones) but procrastinate uploading them and lost them all when a PC crashed.
Here’s the 2 vids if you haven’t seen them.

 

[hotrodrob]

Outstanding as always snookman,..i always enjoy your builds/rebuilds ....i see you've created a flex point in Robins stinger,was that due to a bent one or just preventative bendadge?