Limitless Kaladeth's Limitless V2 - Technical Race Build

[kaladeth]

Objective

Be able to turn in decent lap times at the Warm Springs Raceway in Fremont, CA! Stretch goal is to compete and not crash in one of the scheduled Arrma races this year .

Bill of Materials

Chassis	Arrma Limitless V2
ESC	Mamba XLX2
	Castle Link USB Adapter
	Castle Link Quick Connect
Motor	Castle 2028 1100kV
	2x M4*10mm Flat Head Screws
Sliding Motor Mount Plate	Arrma ARA320722 56 Series Plate
	2x M4*20mm Hex Socket Head Cap Screws
Motor Mount	Practical Proto Grublock Motor Mount
Pinion	SpeedTek RC 32t pinion
Spool + Spur	SpeedTek RC 46t spur
Servo	Promodeler DS635BLHV
Servo Arm	Promodeler PDRS25-15T
Receiver	Radiolink R8FG V2.1
Radio	Radiolink RC8X
Wheels	GRP 1/8 GTJ04-XM3
Batteries	2x SMC HCL-HP 11.1V-6500mAh-150C with QS8 connectors
QS8	RCP QS8 Series Harness with Tinned Ends (to be soldered direct to XLX2) RCP QS8 Charge Lead 10 awg (for my charger)
Transponder	MYLAPS RC4 Pro

General Design Considerations

* Target max speed = 72 mph on the straight
* Run on 6S (2x3S)
* Caster needs to be removed from front end of car to make it steer.
* Need to avoid overpowering the car. Guys with faster motors and running on 8S have a hard time keeping control of the car.
* TBD - Shock and diff oil settings (stock 2k/10k cst)
* Surface = Asphalt
* The PP motor mount will be a bit delayed - so will try to use the stock mount in the interim.
* Re: diff vs. spool, interestingly I have been told the spool actually makes it easier to drive on the track. The diff is more of a benefit for loose traction in dirt. Even on the large MCD cars that come with a diff the guys are changing the diff out for a spool to make them easier to drive. Will report back on this once I get to a few of the races and get to talk more with the guys directly. @SrC @qstone

Questions

1. Am I missing anything from the BOM? Thank you to @Moirae for pointing out the sliding plate!
2. The V2 tray allows for max 51mm x 150mm battery. What batteries do you guys use that fit the stock tray?
3. Will I still be able to use both battery bays, given the space the XLX2 and 2028 take?

 

[LibertyMKiii]

Seems like fun. That track is so cool!
At some point you may want to look at other setups where the rig can be lighter, but at that point you may just want to build a 1/8 scale instead.

I'd say try it out and see how you like it before investing more.

 

[Arise0185]

Awesome, sounds like fun! What kinds of Arrma rigs do people normally run?

IDK if the Limitless drives anything like the Infraction, but in stock form I felt it was incredibly difficult to drive like a proper on-road car. I'm sure that could have been vastly improved with tires and diff oil tuning.

 

[TN-RC]

Objective

Be able to turn in decent lap times at the Warm Springs Raceway in Fremont, CA! Stretch goal is to compete and not crash in one of the scheduled Arrma races this year .

Bill of Materials

Chassis	Arrma Limitless V2
ESC	Mamba XLX2
Motor	Castle 2028 1100kV
Sliding Motor Mount Plate	Arrma ARA320722
Motor Mount	Practical Proto Grublock Motor Mount
Pinion	SpeedTek RC 19t pinion
	SpeedTek RC 28t pinion
Spool + Spur	SpeedTek RC 46t spur
Servo	Promodeler DS635BLHV
Servo Arm	Promodeler PDRS25-15T
Receiver	TBD
Radio	TBD
Wheels	TBD - Most likely GRP 1/8 GT
Batteries	TBD - Most likely SMC 2x3S HCL-HP 6500 150C
QS8	TBD - QS8 (might not need if I go single pack)

General Design Considerations

* Target max speed = 50 mph on the straight
* Run on 6S (2x3S)
* Caster needs to be removed from front end of car to make it steer.
* Need to avoid overpowering the car. Guys with faster motors and running on 8S have a hard time keeping control of the car.
* TBD - Shock and diff oil settings
* Surface = Asphalt
* The PP motor mount will be a bit delayed - so will try to use the stock mount in the interim.
* Re: diff vs. spool, interestingly I have been told the spool actually makes it easier to drive on the track. The diff is more of a benefit for loose traction in dirt. Even on the large MCD cars that come with a diff the guys are changing the diff out for a spool to make them easier to drive. Will report back on this once I get to a few of the races and get to talk more with the guys directly. @SrC @qstone

Questions

1. Am I missing anything from the BOM? Thank you to @Moirae for pointing out the sliding plate!
2. The V2 tray allows for max 51mm x 150mm battery. What batteries do you guys use that fit the stock tray?
3. Will I still be able to use both battery bays, given the space the XLX2 and 2028 take?

Since you have the V2 you should be able to keep the motor mount in the stock position. Yes, you should be able to use both trays.

 

[kaladeth]

@LibertyMKiii - I was planning to work my way up to 1/5 actually . Have you had a chance to try your Limitless on a track yet?

@Arise0185 - I think it’s mostly Felony, Infraction, and Limitless in the Arrma class. Yes some folks have actually suggested using the Infraction (center) diff to replace the spool on the Limitless to improve track handling. Seems there are two schools of thought.

@TN-RC - Thanks! The SMC website has an error I think, it says the SRD-V3 11.1V-6200mAh-250C fits but it’s longer than the Limitless V2 tray's 150mm limit. They are currently checking with their sources.

 

[LibertyMKiii]

@LibertyMKiii - I was planning to work my way up to 1/5 actually . Have you had a chance to try your Limitless on a track yet?

No road course tracks exist where I live. The closest thing I have is a parking lot...

 

[TN-RC]

The SMC website has an error I think, it says the SRD-V3 11.1V-6200mAh-250C fits but it’s longer than the Limitless V2 tray's 150mm limit. They are currently checking with their sources.

Unless you have big cash to spend on this project, I would look at CNHL batteries. Look for a combo deal, that is what I did for my pair of 4S packs.

 

[kaladeth]

The new radio and receiver came in so I thought I’d give it a shakedown using my Big Rock ESC servo and lights. All looking good and I am loving the radio!

 

[TN-RC]

View attachment 342782

The new radio and receiver came in so I thought I’d give it a shakedown using my Big Rock ESC servo and lights. All looking good and I am loving the radio!

I wonder who they got the design idea from for the radio?!?!

 

[kaladeth]

@TN-RC I have absolutely no clue... but I want a 10PX.

 

[kaladeth]

Servo is A-OK.

 

[Notorious J]

Objective

Be able to turn in decent lap times at the Warm Springs Raceway in Fremont, CA! Stretch goal is to compete and not crash in one of the scheduled Arrma races this year .

Bill of Materials

Chassis	Arrma Limitless V2
ESC	Mamba XLX2
Motor	Castle 2028 1100kV
Sliding Motor Mount Plate	Arrma ARA320722 56 Series Plate
Motor Mount	Practical Proto Grublock Motor Mount
Pinion	SpeedTek RC 19t pinion
	SpeedTek RC 28t pinion
Spool + Spur	SpeedTek RC 46t spur
Servo	Promodeler DS635BLHV
Servo Arm	Promodeler PDRS25-15T
Receiver	Radiolink R8FG V2.1
Radio	Radiolink RC8X
Wheels	TBD - Most likely GRP 1/8 GT
Batteries	2x SMC HCL-HP 11.1V-6500mAh-150C with QS8 connectors
QS8	RCP QS8 Series Harness with Tinned Ends (to be soldered direct to XLX2) RCP QS8 Charge Lead 10 awg (for my charger)

General Design Considerations

* Target max speed = 50 mph on the straight
* Run on 6S (2x3S)
* Caster needs to be removed from front end of car to make it steer.
* Need to avoid overpowering the car. Guys with faster motors and running on 8S have a hard time keeping control of the car.
* TBD - Shock and diff oil settings (stock 2k/10k cst)
* Surface = Asphalt
* The PP motor mount will be a bit delayed - so will try to use the stock mount in the interim.
* Re: diff vs. spool, interestingly I have been told the spool actually makes it easier to drive on the track. The diff is more of a benefit for loose traction in dirt. Even on the large MCD cars that come with a diff the guys are changing the diff out for a spool to make them easier to drive. Will report back on this once I get to a few of the races and get to talk more with the guys directly. @SrC @qstone

Questions

1. Am I missing anything from the BOM? Thank you to @Moirae for pointing out the sliding plate!
2. The V2 tray allows for max 51mm x 150mm battery. What batteries do you guys use that fit the stock tray?
3. Will I still be able to use both battery bays, given the space the XLX2 and 2028 take?

Following. Never considered the Lim as a track car. Should be interesting to watch. Good luck

 

[Jerold]

Objective

Be able to turn in decent lap times at the Warm Springs Raceway in Fremont, CA! Stretch goal is to compete and not crash in one of the scheduled Arrma races this year .

Bill of Materials

Chassis	Arrma Limitless V2
ESC	Mamba XLX2
Motor	Castle 2028 1100kV
Sliding Motor Mount Plate	Arrma ARA320722 56 Series Plate
Motor Mount	Practical Proto Grublock Motor Mount
Pinion	SpeedTek RC 19t pinion
	SpeedTek RC 28t pinion
Spool + Spur	SpeedTek RC 46t spur
Servo	Promodeler DS635BLHV
Servo Arm	Promodeler PDRS25-15T
Receiver	Radiolink R8FG V2.1
Radio	Radiolink RC8X
Wheels	TBD - Most likely GRP 1/8 GT
Batteries	2x SMC HCL-HP 11.1V-6500mAh-150C with QS8 connectors
QS8	RCP QS8 Series Harness with Tinned Ends (to be soldered direct to XLX2) RCP QS8 Charge Lead 10 awg (for my charger)

General Design Considerations

* Target max speed = 50 mph on the straight
* Run on 6S (2x3S)
* Caster needs to be removed from front end of car to make it steer.
* Need to avoid overpowering the car. Guys with faster motors and running on 8S have a hard time keeping control of the car.
* TBD - Shock and diff oil settings (stock 2k/10k cst)
* Surface = Asphalt
* The PP motor mount will be a bit delayed - so will try to use the stock mount in the interim.
* Re: diff vs. spool, interestingly I have been told the spool actually makes it easier to drive on the track. The diff is more of a benefit for loose traction in dirt. Even on the large MCD cars that come with a diff the guys are changing the diff out for a spool to make them easier to drive. Will report back on this once I get to a few of the races and get to talk more with the guys directly. @SrC @qstone

Questions

1. Am I missing anything from the BOM? Thank you to @Moirae for pointing out the sliding plate!
2. The V2 tray allows for max 51mm x 150mm battery. What batteries do you guys use that fit the stock tray?
3. Will I still be able to use both battery bays, given the space the XLX2 and 2028 take?

Dude, I'm right down the road I have a place to speed run it in Milpitas.

 

[kaladeth]

@Notorious J Thanks! I have no clue what im doing but i bet it will be fun.

@Jerold - Awesome! Plan to get into speed runs at some point. Thinking 200 mph Big Rock .

 

[kaladeth]

 

[kaladeth]

SpeedTek Spool installed

 

[kaladeth]

The motor fits. The ESC also fits.

However…

Two issues with the motor setup so far:

1. The two screws that secure the motor mount to the motor need to be flat screws so that there is enough clearance to tighten the set screw on the pinion gear. Need a trip to the hardware store once I get my car back.

2. The 28t pinion is too small. The teeth barely engage the spur with the sliding motor mount pushed all the way in. Will likely need 29t or 30t. Will have to place an order. Is there an easier way to know what is the minimum size that will have a proper fit?

 

[kaladeth]

Need a little help on the servo install.

What determines which of the three holes is best to use on the servo arm?

And is this servo link setup ok? The servo arm sits at the same level as the servo link, so I had to push the link down a bit.

Lastly, the servo wire comes out the front. It’s probably better (safer and neater) to route it to the back. But it will have to be bent with a really small turn radius to send it from the front of the server to the back.

Any other suggestions?

 

[Jerold]

Need a little help on the servo install.

What determines which of the three holes is best to use on the servo arm?

View attachment 343257

And is this servo link setup ok? The servo arm sits at the same level as the servo link, so I had to push the link down a bit.

View attachment 343259

Lastly, the servo wire comes out the front. It’s probably better (safer and neater) to route it to the back. But it will have to be bent with a really small turn radius to send it from the front of the server to the back.

Any other suggestions?

Ideally you want three right angles, but that's not critical as long as you get full lock. However, in a speed car I typically reduce the travel to kept me from jerking the wheel.

What becomes more noticeable is the speed and torque. The longer the arm the faster the steering but you sacrifice torque. Shorter arm you get more torque but it's slower.

 

[Arise0185]

Need a little help on the servo install.

What determines which of the three holes is best to use on the servo arm?

View attachment 343257

And is this servo link setup ok? The servo arm sits at the same level as the servo link, so I had to push the link down a bit.

View attachment 343259

Lastly, the servo wire comes out the front. It’s probably better (safer and neater) to route it to the back. But it will have to be bent with a really small turn radius to send it from the front of the server to the back.

Any other suggestions?

Based on that first photo, it looks like you'd want to use the middle hole on the servo horn so everything is as close to 90 deg as possible.

For the second photo, seems fine as long as nothing binds, but if you really wanted you could use some spaces to raise the servo a bit? Probably not a big deal though.

Regarding the wire routing, I have the servo wire coming out the front on my Mojave. As long as it's not in danger of rubbing against any moving driveline components, and you're not putting too much strain on the rubber strain relief/seal where the wires exit the servo, it's probably fine?