New Limitless build thread

[ahr43]

Looks slick. Nice work. Hi-vis for sure.

Be interesting to see the numbers this body puts up in comparison to the open-wheel. Looks like you extended the fences on the wing to mini vertical stabilizers.

Cheers. 'AC'

 

[Edough13]

Looks slick. Nice work. Hi-vis for sure.

Be interesting to see the numbers this body puts up in comparison to the open-wheel. Looks like you extended the fences on the wing to mini vertical stabilizers.

Cheers. 'AC'

Thanks Ya just wanted some kind of vertical stabilizers and didn't want to have to butcher the rear to make the regular winglets work. Also they would only stick up about half as high so wouldn't be a lot of help either. Still have to think about a goal for next season thinking maybe 160 to 165mph which would be amazing for sure. May talk to one of my sponsors and possibly see about getting the new Castle 1721 2400kv or go to the 2028 1100kv but I think I'd rather go with the 1721.

 

[Greywolf74]

Thanks Ya just wanted some kind of vertical stabilizers and didn't want to have to butcher the rear to make the regular winglets work. Also they would only stick up about half as high so wouldn't be a lot of help either. Still have to think about a goal for next season thinking maybe 160 to 165mph which would be amazing for sure. May talk to one of my sponsors and possibly see about getting the new Castle 1721 2400kv or go to the 2028 1100kv but I think I'd rather go with the 1721.

Why not go for a high kV motor from TP Power? Something like the TP 4070-SCM (3930KV 6S)

 

[Edough13]

Why not go for a high kV motor from TP Power? Something like the TP 4070-SCM (3930KV 6S)

I've ran 3 different TP motors and personally don't like how unefficient and hot they run. I currently have a 4060 2620kv in my stretched Typhon and even with an 8s cap pack running only 4s at 106mph I'm getting higher ripple than my castle 1717 1650kv on 8s at 145 in my Limitless with xlx2 and no cap pack. Also 3930kv is way too high that would be like a 3s-4s speed run motor maybe 6s but wouldn't last too long as even my 2620kv gets hot on 4s. Haven't ran it 6s yet but will next season as know a couple people that have pushed 140's with it on 6s.

 

[Greywolf74]

The 3930 is a 6S motor. I didnt realize you were running 8S in your limitless or Id have recommended the TP 4070-SCM (2950KV, 8S). Theyre all gonna get hot when you're doing speed runs so I'm not sure why thats a concern. Do you want efficent or do you want to break speed barriers? If you're getting too much ripple then buy a bigger cap pack. Just a thought

 

[Edough13]

The 3930 is a 6S motor. I didnt realize you were running 8S in your limitless or Id have recommended the TP 4070-SCM (2950KV, 8S). Theyre all gonna get hot when you're doing speed runs so I'm not sure why thats a concern. Do you want efficent or do you want to break speed barriers? If you're getting too much ripple then buy a bigger cap pack. Just a thought

Ya not exactly lol my castle 1717 1650kv on 8s doesn't even break a sweat at 145mph, the motor is maybe 95-100°. my TP 4060 2620kv on 4s hits 120°. Not sure what bigger cap pack than 8s there is not to mention again running 4s with 8s cap pack and have the bad ripple with the TP. The 40mm cans don't produce near enough torque needed not to mention TP customer service is non existent. Only motor from TP I'd consider is one of the 56mm cans in like ≈1400kv. No offense but I talk with some of the best in the world for advice and nothing your suggesting has been mentioned or suggested. I appreciate the suggestions but I think this is a bit out of your wheel house. The new 1721 2400kv motor from castle is going to change speed running and push speeds up quite a bit considering its very new and there's already been a 190mph pass made with it after only a few weeks of running it.

 

[Greywolf74]

Ya not exactly lol my castle 1717 1650kv on 8s doesn't even break a sweat at 145mph, the motor is maybe 95-100°. my TP 4060 2620kv on 4s hits 120°. Not sure what bigger cap pack than 8s there is not to mention again running 4s with 8s cap pack and have the bad ripple with the TP. The 40mm cans don't produce near enough torque needed not to mention TP customer service is non existent. Only motor from TP I'd consider is one of the 56mm cans in like ≈1400kv. No offense but I talk with some of the best in the world for advice and nothing your suggesting has been mentioned or suggested. I appreciate the suggestions but I think this is a bit out of your wheel house. The new 1721 2400kv motor from castle is going to change speed running and push speeds up quite a bit considering its very new and there's already been a 190mph pass made with it after only a few weeks of running it.

Yeah, you're right, I've never done speed runs with a rig as big as what you're using so I can only draw on my knowledge of electronics, 1/10 scale speed runs, and RCs in general but its not exactly rocket science. Put the biggest kV motor in it ya can with the shortest gearing and best battery you can. Other than that all you have to do is tune the car so it stays on the ground and drives straight. I mean I dont want to over simplify it cuz tuning the kit requires a lot of work and trial and error but the electronics and gearing portion of it isnt hard to figure out. Is there more to it than that or something I'm not taking in to account?

Not sure why 40mm cans are too small, Thats what the infraction and felony both come with and those kits are the same basic size and scale as the limitless. Granted they will get hot faster than 46mm or 56mm cans but its not like you can't do a handful of runs with it and then let it cool down. Unless your goal is to just keep repeatedly doing speed runs for a period of time because its what you like then thats different than just chasing a PB number I suppose.

I'm really not sure how you're getting a ton of ripple using an 8S cap pack although "8S cap pack" is a very vague term cuz all that really means is that the capacitors in the pack are able to handle 8S voltage but you can buy a 35V 250mF capacitor and call it an 8S cap pack but it wouldnt have enough capacitance to be effective. The IR of the caps plays a big part in how they perform too so I wonder if your 8S cap pack is insufficient in either of those ways and maybe thats why you're having that issue? IDK, just wondering.

When you say you get "bad ripple", what percentage of ripple are you getting? Anything up to about 9% is considered an acceptable level of ripple. I should have said bigger and/or better cap pack I suppose. You can get them all the way up to 12S and you can build one really easy thats higher than that if one were so inclined. Plus not all cap packs are created equal in terms of IR. Just like lipos, caps come in all manner of different quality levels.

120F isnt that hot for a motor. Why is that an issue? When I said that theyre all going to get hot, I meant they would all get hot if your pushing for higher and higher speeds. If you're doing that then at some point your motor (whatever size it is) is going to start getting hot. If your 1717 is only hitting 100F why are you not gearing shorter to get higher speeds? That motor isnt overheating until 170-180F. Just curious

The new 1721 motor will be an interesting one. It will be interesting to see how they do and how popular they become.

Sorry if this all sounds argumentative. Its not meant to be, I'm just genuinely curious.

 

[Edough13]

Yeah, you're right, I've never done speed runs with a rig as big as what you're using so I can only draw on my knowledge of electronics, 1/10 scale speed runs, and RCs in general but its not exactly rocket science. Put the biggest kV motor in it ya can with the shortest gearing and best battery you can. Other than that all you have to do is tune the car so it stays on the ground and drives straight. I mean I dont want to over simplify it cuz tuning the kit requires a lot of work and trial and error but the electronics and gearing portion of it isnt hard to figure out. Is there more to it than that or something I'm not taking in to account?

Not sure why 40mm cans are too small, Thats what the infraction and felony both come with and those kits are the same basic size and scale as the limitless. Granted they will get hot faster than 46mm or 56mm cans but its not like you can't do a handful of runs with it and then let it cool down. Unless your goal is to just keep repeatedly doing speed runs for a period of time because its what you like then thats different than just chasing a PB number I suppose.

I'm really not sure how you're getting a ton of ripple using an 8S cap pack although "8S cap pack" is a very vague term cuz all that really means is that the capacitors in the pack are able to handle 8S voltage but you can buy a 35V 250mF capacitor and call it an 8S cap pack but it wouldnt have enough capacitance to be effective. The IR of the caps plays a big part in how they perform too so I wonder if your 8S cap pack is insufficient in either of those ways and maybe thats why you're having that issue? IDK, just wondering.

When you say you get "bad ripple", what percentage of ripple are you getting? Anything up to about 9% is considered an acceptable level of ripple. I should have said bigger and/or better cap pack I suppose. You can get them all the way up to 12S and you can build one really easy thats higher than that if one were so inclined. Plus not all cap packs are created equal in terms of IR. Just like lipos, caps come in all manner of different quality levels.

120F isnt that hot for a motor. Why is that an issue? When I said that theyre all going to get hot, I meant they would all get hot if your pushing for higher and higher speeds. If you're doing that then at some point your motor (whatever size it is) is going to start getting hot. If your 1717 is only hitting 100F why are you not gearing shorter to get higher speeds? That motor isnt overheating until 170-180F. Just curious

The new 1721 motor will be an interesting one. It will be interesting to see how they do and how popular they become.

Sorry if this all sounds argumentative. Its not meant to be, I'm just genuinely curious.

The ripple is common with TP motors I'm by far not the only one having the high ripple. I've had over 2v ripple running 4s which is over the 10% mark but I've seen others have as high as 6v ripple and again with a good cap pack running a TP and castle esc. Sure I could add a better cap pack but shouldn't have to running 4s with a cap pack made to handle for more.
Yes to an extent you want a higher kv for more rpms but also the higher kv the less torque which doesn't work with an 18+lb rig and say 40t pinion and 29t spur. The 56mm cans have the torque needed to gear high enough and push higher speeds over a smaller 40mm can that struggles with the bigger heavier rigs and gearing. Most common used TP in a higher kv for 8s is the 4070 2700kv. Also the esc's don't like the higher kv and amperage, wattage etc produced resulting in cutoffs. Yes the Infraction etc use a 40mm can but also not intended for 140+mph speeds but instead for bashing. I've not ran 8s with my 4074 2050kv stock motor but have pushed it to 119mph on 6s. Again its more than just high kv and good batteries as torque needed plays a big role and the 40mm cans just don't produce like the bigger 48mm+ cans do. That's also why the top guys run the 2028 1100kv, 56mm TP motors etc as they produce enough torque to gear for higher speed. Now sure if you don't want to run over say 140-150 a 40mm can will work but over that you need the torque over kv and a bigger can. For heat yes 120 is not bad but considering only making one pass and only 16.8v, 12v under load it's a bit high. I will be gearing up more with the 1717 but also it has its limits and haven't been able to run lately between work and weather. Haven't seen many run higher than 155-160mph with the 1717 either that's why again I'll go to the 2028 1100kv, TP 56xx 14xxkv or now the new 1721 2400kv designed specifically for speed runs. Trust me I wish it was as easy as throwing in a high kv motor, good esc and lipos but it's far from that. I had issues due to the center driveshafts for a long while as they produced too much vibration which would cause the motor/esc to desync. There's a lot that contributes to speed running from vibrations to aerodynamics besides kv/torque needed and good lipos. Like I said I talk to some of the best from Raz Shifrin, Phil Jolley, Liberty Francis etc and have learned quite a bit besides personal trial and error. Like they say if it was that easy everyone would be running 180mph which is far from the case.

 

[Greywolf74]

The ripple is common with TP motors I'm by far not the only one having the high ripple. I've had over 2v ripple running 4s which is over the 10% mark but I've seen others have as high as 6v ripple and again with a good cap pack running a TP and castle esc. Sure I could add a better cap pack but shouldn't have to running 4s with a cap pack made to handle for more.
Yes to an extent you want a higher kv for more rpms but also the higher kv the less torque which doesn't work with an 18+lb rig and say 40t pinion and 29t spur. The 56mm cans have the torque needed to gear high enough and push higher speeds over a smaller 40mm can that struggles with the bigger heavier rigs and gearing. Most common used TP in a higher kv for 8s is the 4070 2700kv. Also the esc's don't like the higher kv and amperage, wattage etc produced resulting in cutoffs. Yes the Infraction etc use a 40mm can but also not intended for 140+mph speeds but instead for bashing. I've not ran 8s with my 4074 2050kv stock motor but have pushed it to 119mph on 6s. Again its more than just high kv and good batteries as torque needed plays a big role and the 40mm cans just don't produce like the bigger 48mm+ cans do. That's also why the top guys run the 2028 1100kv, 56mm TP motors etc as they produce enough torque to gear for higher speed. Now sure if you don't want to run over say 140-150 a 40mm can will work but over that you need the torque over kv and a bigger can. For heat yes 120 is not bad but considering only making one pass and only 16.8v, 12v under load it's a bit high. I will be gearing up more with the 1717 but also it has its limits and haven't been able to run lately between work and weather. Haven't seen many run higher than 155-160mph with the 1717 either that's why again I'll go to the 2028 1100kv, TP 56xx 14xxkv or now the new 1721 2400kv designed specifically for speed runs. Trust me I wish it was as easy as throwing in a high kv motor, good esc and lipos but it's far from that. I had issues due to the center driveshafts for a long while as they produced too much vibration which would cause the motor/esc to desync. There's a lot that contributes to speed running from vibrations to aerodynamics besides kv/torque needed and good lipos. Like I said I talk to some of the best from Raz Shifrin, Phil Jolley, Liberty Francis etc and have learned quite a bit besides personal trial and error. Like they say if it was that easy everyone would be running 180mph which is far from the case.

How did you solve the driveshaft vibration issue?

 

[Edough13]

How did you solve the driveshaft vibration issue?

I went from the regular spool and long stock length shaft in rear to using a longer Pinocchio spool that uses a shorter rear driveshaft. It stopped the desync and vibration issues and I gained 7mph.

 

[Greywolf74]

I went from the regular spool and long stock length shaft in rear to using a longer Pinocchio spool that uses a shorter rear driveshaft. It stopped the desync and vibration issues and I gained 7mph.

Where you able to buy the new spool and shorter drive shaft or did you have to mod the existing ones?

 

[Edough13]

Where you able to buy the new spool and shorter drive shaft or did you have to mod the existing ones?

I bought it from someone that custom makes them. As you'll see it is quite a bit longer than the stock spool so your able to run 2 front length center shafts. Here's a pic of the Pinocchio spool and stock spool to compare. Also here's a pic of the driveshafts the top is the stock length rear and bottom is front stock size which I now run in the rear. As you could imagine that rear shaft being so long bows and flexes really bad even at say 80mph let alone 130+. The one I used and had issues with was a thicker titanium version so there was more rotating mass even producing the bad vibration.

Here's a couple videos if you listen to the passes you can hear a huge difference. With the longer shaft it almost hummed and with new spool setup you don't hear that one bit. With longer shaft has the high pitch hum

Very next pass exact same everything besides the new Pinocchio spool and shorter rear shaft and gained 7mph

 

[Greywolf74]

Wow, thats a pretty bad ass mod. I wonder how hard that would be to build.

 

[Edough13]

Doesn't seem to crazy if you have the tools needed as he pumps them out all the time and in different lengths depending on the rig it's for. He does these like mine that are full carbon rod and also does full steel rod for drag racing.

 

[Edough13]

Finally after an 18 day wait from texas got my can of white to finish backing the GT body and get it finished. Still of course have to decal it up and make some fine trimming but color is all finished. Then to figure out layout of the XLX2 and if I'm going to stay with the 1717 1650kv or go to the 1721 2400kv or 2028 1100kv over the winter. For now definitely done for the year with the Limitless but still may get my stretched Typhon put for a few more runs.

 

[Greywolf74]

Lookin' good!

 

[Doom!]

@Edough13 I know your not done with stickers yet! Lovin' the neon colors!

 

[Edough13]

@Edough13 I know your not done with stickers yet! Lovin' the neon colors!

Thanks! Yep going to slap some on this morning before work Also have some coming from RCProponent later this week that will go on as well

 

[Edough13]

Got a few on it before I headed to work, some on the side also but only took a front shot real quick. I'm kinda anal about placement so even these few took some time to figure out where i wanted them to go and the layout for others still to come.

 

[ahr43]

Special Project: LUDICROUS SPEED. Applying 8s Power to the Aarma Limitless All-Road Speed Bash Roller.

RCCA (Radio Control Car Action) Magazine, January 2022. Hit my mailbox yesterday. A heads-up for you, Edough. Haven't read it completely yet, but any article taking up six pages in a magazine has to be good. Right? Cheers. 'AC'