Budget RTC Build

By Axial Staff on Apr 29, 2009

We received the first few RTC kits here at the Axial warehouse a couple days ago. I snatched one up as soon as they hit the floor out back. I drove it for a couple packs in bone stock form, and it works very well. But, I decided to make a few basic mods to see how capable I can make it, while keeping the money spent down to a bare minimum.

First up…………a few pics of the new box. Our marketing department even included a list with all our hop-up parts on the bottom.
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Here’s a couple pics of the RTC straight out of the box.
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Here’s a few tips on converting Axial’s new RTC rig into the most capable crawler possible on a tight budget. Some of the best mods can be done for little to no money. First off you’ll want to drill a couple breather holes in each wheel at 180* from each other. This will let the tires wrap around obstacles better. I used a body reamer to poke the holes in the wheels. Open them up so they measure about an 1/8″ in diameter. I drill the holes as close as possible to the inner bead seats. Because I’m also going to add a little weight to each wheel for better traction and stability. And I don’t want the weights to block the breather holes.
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Now you’ll want to remove the tires from the wheels to add weight. I use standard 1:1 wheel weights for balancing real car tires. These can usually be found at your local tire shop. I’m going to add about 7 1/2 ounces to each front wheel, and about 4 1/2 ounces to each rear wheel. This will help the suspension cycle better as well as keep weight down low for a better center of gravity. The lower you can keep the bulk of your rigs weight, the better off you’ll be on steep climbs, descents and off camber situations. Again, just make sure you don’t block the breather holes you drilled in the previous step with the wheel weights.

Front
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Rear
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Next, I installed the included clear lexan upper link plate on the front links. This will be where I place my 2 cell 1100mah MaxAmps lipo battery. For those that aren’t ready for lipos a standard flat 6 cell 2/3A battery pack should fit as well. I also switched out the stock Tamiya battery connector for a male Deans plug to match my battery.
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Another option for mounting batteries is taking the stock standard 6 cell stick pack hook and loop straps that come with the kit and mount them on the front axle for 2/3A split packs which will lower your center of gravity even more. Just poke a couple holes with a punch through the straps, and run some short M3 screws through the holes into the axle housing.
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Next thing I want to do is called siping the tires. The Pro-Line Hammer tires work good in stock form. But, cutting a little tread out of them will help the rig stay planted in off-camber situations. You can do this a few ways. One is using a couple cut-off wheels stacked back to back on a Dremel, but that gets very messy in a hurry. I personally prefer to use nice sharp wire cutters to cut sections of lug out of each tread block.
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Here you can see I cut about an 1/8″ out of the solid lateral lugs on the right, compared to the stock lugs on the left. Now, I will go ahead and notch all the solid lugs on all 4 tires to match.
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That’s pretty much it for now. I’m going to try and get a video shot/edited with these few modifications done asap. I’ll get it posted here as soon as it’s finished. These few mods should really take this RTC to the next level as far as performance goes, without breaking the bank.


83 Comments:

  1. Default_avatar Jeff Posted on 2009-05-12 17:47:35

    I have the axial AX10 RTR scorpion and I’ve been looking to put my battery on the front axle, but its a 6 cell, I asked at my local hobby shop and they said theres no way to do it unless I make one myself. So I started to make one but couldn’t think of any way to mount it without it looking like to much of a hack job. So I’m wondering can I use one of those Upper link plates on an AX10 RTR and put my 6 cell battery there?

    Thanks a lot!

  2. Default_avatar Bender Posted on 2009-05-13 15:37:38

    A standard 6 cell battery pack is probably too big to fit on our upper link plate. You may be able to zip tie it to the top of the servo so the battery runs back between the front shocks. I’d put some velcro on top of the servo and underneath the battery too, so the battery doesn’t slide around during rollovers. Otherwise your best bet is probably a 2/3A cell split saddle pack like I show in the photos.

    Bender

  3. Default_avatar Jeff Posted on 2009-05-13 16:08:15

    Ok thanks I think I’ll just invest in some saddle packs. Thanks a lot really appreciate the help!

  4. Default_avatar mark Posted on 2009-05-26 06:08:34

    how long does the 1600 mah last in the rtc. cant drilling into the axle housing mess the rc up. what is the wheel travel on the rtc

  5. Default_avatar Bender Posted on 2009-05-26 08:15:22

    Depends on the cells being used. If it’s a standard 6 cell stick pack it’ll last a little longer then the 2/3A cells. Either way you should be able to get about 1/2 hour run time, maybe a little more. It all depends on how fast you are driving, and if the rig is being bound up constantly, run time can vary greatly with these issues factored in.

  6. Default_avatar mark Posted on 2009-05-26 09:29:33

    what is the wheel travel of the rtc

  7. Default_avatar mark Posted on 2009-05-26 11:22:45

    which of the axles models do you think is the best

  8. Default_avatar Kiley Posted on 2009-06-17 10:49:58

    I filled my tires with half and half of BB’s and softair pellets, as well as the tires weights. Truck is heavy, but I can strap the biggest battery to the top and it doesn’t effect it.

  9. Default_avatar William Posted on 2009-06-21 06:46:00

    I just bought one of these for my wife as her first r/c. I put 1/2 size lead egg sinkers for the wheel weight in. They can be found at any walmart and they are cheap. So there is anouther way to keep the cost down.

  10. Default_avatar Rob Posted on 2009-07-13 13:41:12

    Have you notched the set of solid lugs from the inside or outside edge ?

  11. Default_avatar Bender Posted on 2009-07-13 15:04:30

    I notched both the inside and outside rows of solid lugs. I just didn’t show a finished picture of the tires after I was done.

  12. Default_avatar Bender Posted on 2009-07-13 15:06:05

    It’s about 7″ of total travel on the RTC stock.

  13. Default_avatar Bender Posted on 2009-07-13 15:07:26

    The RTC crawler is tough to beat. The ride height is nice and low, it includes a small battery plate for the front upper links, the tires work pretty good and the shocks are the nicest ones we offer.

  14. Default_avatar Tony Posted on 2009-07-13 21:57:35

    These are some great tips, it begs the question though, why didn’t Axial just make these modifications a part of the out of box design in the first place? When you added your wheel weight did you put the foam back in or leave it out? As far as the holes in the wheels I decided drilling the holes directly into the tread of my tires would be better. This way when I get water in them either from a course obstacle or cleaning I can park them with the holes down and the water has an easy way to drain out.

  15. Default_avatar Bender Posted on 2009-07-14 08:52:48

    I do still have the stock foams in my tires. I think running them without foam will hurt performance by allowing the tires to fold over too much.

    The biggest reason we don’t add these mods to the RTC kit is because a lot of people have their own personal preference as too how they vent their wheels/tires. Same goes for siping/cutting the tires. Some guys like to sipe their tires others don’t. Also, the amount of weight people run in their wheels varies greatly. So, we leave those last few final set-up steps up to the end user.

  16. Default_avatar Jay Posted on 2009-07-14 12:32:23

    How much torque does the stock servo have???

  17. Default_avatar Bender Posted on 2009-07-14 15:48:20

    It’s about 130 ounces if I remember right.

  18. Default_avatar tony Posted on 2009-07-26 09:23:45

    What do u recommend for cutting the stock tire foam?

  19. Default_avatar Kaur Posted on 2009-07-26 20:15:50

    i have a couple of questions .Are both of the diffs locked .and shoudnt the stock esc burn to 3cell saddle pack lipo .I would wery appriciated if somebody would answer me

  20. Default_avatar Bender Posted on 2009-07-27 07:33:16

    Regular lexan body scissors work fine for cutting tire foams.

  21. Default_avatar Bender Posted on 2009-07-27 07:35:17

    Both the diffs are locked. I’m only running a 2 cell lipo battery in this rig, not a 3 cell. A 3 cell lipo would probably be too much for the stock ESC.

  22. Default_avatar tony Posted on 2009-07-28 14:58:20

    When i asked about cuttin the foam i meant what stye. Sorry i should have been more clear as to what i was asking.

  23. Default_avatar tom Posted on 2009-08-02 17:52:39

    i just my rtc and i am very pleased witj it. however, there seems to be a proble with esc. supposedly, the esc is supposed to prevent accidental reverses by having some sort of delay. this function doesn’t seem to be working on my truck, rather vice versa, i can go from full forward to full backward with no stop. please help!

  24. Default_avatar Bender Posted on 2009-08-03 07:42:45

    I just trim the outer edges to the foams so there’s a slight angle, about 1/2″ wide, on the outer edge instead of a sharp corner.

  25. Default_avatar Bender Posted on 2009-08-03 07:52:55

    Sounds like your ESC is fine. We set the speed control up to have instant reverse on the RTC. So, when you are trying to drive up something steep and the truck starts to flip over backwards you can hit reverse and save it from rolling over.

  26. Default_avatar john foit Posted on 2009-08-08 15:52:55

    can you get better steering with out the servo sever,and would it harm the servo

  27. Default_avatar rc fanatic Posted on 2009-08-12 08:09:19

    OK, I plan on changing the nimh battery to LiPo. So what your saying is that I DON’T need to change any wiring or electronics except for the plug in the reply to “Kaur”? I called your tech support and they said I would need to change the speed controller if I were to switch to LiPo. You also recommended to use a 2 cell 1100 maH, but at 7.2 volts? Thanks a bunch, as I am looking forward to getting experience in this new form of radio control hobby

  28. Default_avatar crawler newb Posted on 2009-08-14 14:29:49

    Can the stock esc go lipo if so how many cells.. if so are you getting longer run times with the lipo battery

  29. Default_avatar Bender Posted on 2009-08-18 06:59:16

    Your steering will be more crisp without the servo saver. It shouldn’t harm the steering servo either. You won’t really get more steering angle though, unless you install CVD’s.

  30. Default_avatar Bender Posted on 2009-08-18 07:03:46

    You can get away with a 2 cell lipo with the stock ESC. But, a 3 cell will be too much voltage. The 2 cell lipo is 7.4V the 3 cell is 11.1V. I would suggest changing out your stock battery connectors to something better if you do go lipo as well, like Deans plugs.

  31. Default_avatar Bender Posted on 2009-08-18 07:06:06

    You can run a 2 cell lipo with the stock speed control, but 3 cells will be too much voltage. I’d also suggest installing a voltage cutoff for anyone going to lipos to ensure your batteries stay healthy.

  32. Default_avatar tony Posted on 2009-08-21 19:39:50

    Cut the fenders off the stock body. gives more clearnce it helps alot. like in benders videos. sorry but it gives more clearance for the tires it helped me alot. thx rccrawler.com!

  33. Default_avatar The Dude Posted on 2009-08-27 19:28:04

    I love my RTC. I want to pick up a color pack, do I need any thing else to install it? I was also curious,when people say to trim the foams ,how exactly would you do it. Fronts(star pattern,and taper),rear(taper),would that be correct?
    Thanks for all the top notch info,we really appriciate it!!!!!

  34. Default_avatar Bender Posted on 2009-09-02 07:04:49

    You’ll also need rod ends and the long M3 set screws for the rod ends to go along with that color pack. You can re-use your stock ball studs in the new rod ends.

    I usually just trim the outer edges of my foams so there is a 1/2″ wide 45* chamfer on the outer edges. You can cut a slight star pattern in the front foams if you want to get a little more traction.

  35. Default_avatar tony Posted on 2009-09-02 17:38:20

    look 4 the rtr hardware upgrade kit it comes with all the screws and ends to use with ur new links if thats easier for you

  36. Default_avatar Bill Posted on 2009-09-28 23:52:47

    I have been having a problem with the setscrews at the transmission end of the drive shafts backing out on occasion even with the use of loc tight. I canged the set screws to a set that traxxas uses on their shafts that go all the way through. Will it hurt the out puts on the transmission since i had to drill a hole through them for this type of set screw or do you think they will be ok? Thanks

  37. Default_avatar Bender Posted on 2009-09-29 06:56:11

    The outputs will probably be ok. You may twist the ends off them eventually over time though. I double up on the set screws on the driveshafts, so there are 2 set screws per yoke. They loosen up once in a while, but it’s nothing that happens very often.

  38. Default_avatar Rick Posted on 2009-10-05 10:41:52

    We purchased a RTC for our son for his birthday and it is a great starter. One question I have, it does not stop or “hold” on steeper angles when the controller is left in “nuetral”. Is there some type of adjustment to be done or is this typical for the RTC. I have built the kit for myself and it will hold on anything. Thanks.

  39. Default_avatar Bender Posted on 2009-10-05 10:49:45

    Unfortunately there is no adjustment to fix this. Our stock electronic speed control (ESC) doesn’t have “drag brake” built into it. So, the rig will want to roll on steep obstacles. What ESC are you running in your kit? I’m guessing it has drag brake built in.

  40. Default_avatar Rick Posted on 2009-10-06 08:33:39

    I am running the Novak Rooster in my kit. I have several nitro trucks and know these well but I am new to battery powered, they are just plain easier for my kids (at least for me). So what you are telling me is that I could replace the ESC with the Rooster or something similar and that should fix this. Am I on the right track here? Thanks again for your help and time.

  41. Default_avatar Bender Posted on 2009-10-06 08:46:42

    Correct. If you replace the stock ESC with Novak’s Rooster on your son’s crawler he’ll have the same control on descents as you do.

  42. Default_avatar Jeff H Posted on 2009-10-10 12:33:34

    I just picked up an AX 10 RTC today, just to do some screwing around with, nothing serious. The crawler is great, but im having a problem with the controls. The problem is when I go to climb something its like there is no power and the motor just sits there and glitches and jitters but dosn’t spin, then it will take off or you have to reverse then go foward to make it move at all. This makes it very hard to creep through tight spots. It also seems that the crawler is faster in reverse than foward.

    Any help would be great. Thanks

  43. Default_avatar Rob Posted on 2009-10-14 18:34:40

    I think the motor is wired backwards intentionally. this gives it more torque in forward, than speed. I just got my RTC last week, and I love it. I’m waiting on my SPEKTRUM DX3S to arrive , this should elliminate the glitching problem. a better ESC/motor steup is next. I have the 30 deg bent rear arms ordered.
    Oh, by the way, Bender, how lucky are you to have a job like yours? I think it is great that you get on here to help answer questions from us rock crawlin’ newbs.

  44. Default_avatar Rob Posted on 2009-10-17 13:45:50

    i have a question about the tire foams. when you cut them, how do you do it, and with what? are you only cutting the outter edges off at an angle? can you use lexan scissors?

  45. Default_avatar Rob Posted on 2009-10-17 13:48:17

    Sorry, I guess if I would have backed up a bit, I would have seen both of those questions already answered.

  46. Default_avatar Rob Posted on 2009-10-17 13:54:29

    do you recommend cutting out a slot out on the inner section on the foams to make room for the wheel weights? or just let the foams conform to the wheel?

  47. Default_avatar Jake Posted on 2009-10-25 13:49:27

    Why is the RTC the lowest ground clearance?If I buy it and need more clearance like the KIT has,how do I adjust?Thanks

  48. Default_avatar Bender Posted on 2009-10-26 07:49:38

    I don’t channel the center of the foams for the wheel weights, I just let the foam conform to them.

  49. Default_avatar Bender Posted on 2009-10-26 07:51:22

    We lowered the RTC to keep the weight of the chassis as low as possible. You can raise the ride height by running longer rod ends on the lower shock mounts if you want a little extra belly clearance.

  50. Default_avatar Jeff H Posted on 2009-11-01 17:48:57

    Is it possable to rebuild the RTC shocks? Mine are pouring oil out at the shaft seals. Is there a kit offered with new O-rings.

  51. Default_avatar Bender Posted on 2009-11-02 08:41:16

    You can re-build the stock RTC shocks. The part number for the new lower cartridge o-rings is AXA1202. Each bag has 10 o-rings in it, enough to re-build all 4 shocks plus have a couple spares. I’d suggest using grease on the o-rings when you install them during the re-build. This will help prevent the o-rings from tearing when you install the shock shaft.

  52. Default_avatar stevel Posted on 2009-12-13 20:30:29

    I just bought the RTC today. My question is what did you do with the antenna? I see it is not protruding out of the body but they give you a huge antenna pole to run the wire through did you just trim it short under the body? Thanks.

  53. Default_avatar Bender Posted on 2009-12-14 17:18:54

    I just zip-tied the antenna and antenna tube to the body mounts, so it is protected by the body.

  54. Default_avatar Mark M Posted on 2009-12-30 17:25:58

    This write-up is a fantastic starting point for all of us new guys. As usual, I really appreciate your contributions to the crawling community, Bender. I’m wondering if you could write a follow-up that might discuss durability mods on the cheap, ie; driveshaft collars, steering links, and so on. Great stuff and thanks again!

  55. Default_avatar Andrew Posted on 2010-01-03 21:03:05

    Hello, i was wondering what the max amount of wheel weights should i use for the rims, is the amount you listed above (15 ounce front/ 9 ounce rear) the best all around weight? Thanks

  56. Default_avatar Bender Posted on 2010-01-06 14:54:49

    Thanks Mark. I’m glad you found this post useful. I will see if I can get something written up per your suggestion soon too.

  57. Default_avatar Bender Posted on 2010-01-06 15:00:04

    The weight I suggested is the maximum I would add personally. Any more weight may make the crawler unpredictable in certain situations and cause parts to break prematurely.

  58. Default_avatar Andrew Posted on 2010-01-06 20:40:10

    Thanks for the reply. So to get 4.5 ounces for the rear tires, you added 18, 1/4 ounce pieces, but how did you get 7.5 ounces for the front rims? In one of the pictures, it looks like you have 2 layers of weights, if that is the case, wouldn’t that make it about 9 ounces per rim? Thanks again.

  59. Default_avatar DANNY Posted on 2010-01-07 15:54:46

    what kinda of runtime do you get with your 2 cell?

  60. Default_avatar jay Posted on 2010-03-31 00:59:32

    i was wondering if it was ok to cut the foam insert and add bbs as well?

    it would prob unbalance the tire but would it work if i balenced them

  61. Default_avatar Bender Posted on 2010-03-31 09:15:29

    You can, but your tires will be out of balance. Plus, with BB’s your rig will surge as the weight sloshes around inside the wheels. You are better off with stick on weights for a more consistent feel.

  62. Default_avatar marvin q Posted on 2010-03-31 20:23:29

    how can i make my ax 10 scorpion turn better

  63. Default_avatar Danny Posted on 2010-04-18 11:20:28

    What batteries do you recommend for all of these option places to mount the batteries and the batteries for the original place they go.

  64. Default_avatar Joey Kingery Posted on 2010-05-21 07:17:45

    I was just curious how you stuck the wheel weights to the wheels? Are they backed w/ adhesive?
    Thanks,
    Joey

  65. Default_avatar Bender Posted on 2010-05-21 09:40:16

    Installing CVD inner axles is the best way to get more responsive steering out of the RTC. Upgrading the steering servo is another good way to get better steering.

  66. Default_avatar Bender Posted on 2010-05-21 09:41:58

    I still like the 1100mah 2s lipos from MaxAmps, but the 2/3A cells work good too. I don’t think you will be disappointed by either option.

  67. Default_avatar Bender Posted on 2010-05-21 09:42:51

    Correct. The wheel weights have double stick tape on the backside of them. Peel the paper backing off and stick them to the wheel as needed.

  68. Default_avatar Paul Posted on 2010-05-23 00:12:39

    what i really need to know is the chassis the same for the kit as with the rtc? Also do you think id be better off buying the kit or rtc to compete with a losi night crawler. A group of guys and i are just starting into the crawling aspect of rc, so far traxxas summit, and a losi night crawler will be my competition, i am very impressed with axial and will have no other but i cant decide between the rtc and kit. building is not a problem nor would modifying the rtc but i want the most bang for my buck. if you could help me with these issues i would really appreciate it.

  69. Default_avatar Bender Posted on 2010-05-24 14:15:41

    The chassis is the same from the kit to the RTC. The biggest difference between the 2 trucks are the shocks, body and tires. The RTC comes with a plastic version of our competition shocks, which are a lot nicer then the standard kit shocks. The Pro-Line tires are another nice touch for the RTC. The RTC also has HD lockers, the kit lockers are aluminum. The kit does have aluminum links instead of plastic though. I would personally go with the RTC myself.

  70. Default_avatar Jessee Posted on 2010-07-06 08:34:47

    Is the RTC water proof? will it mess up if it gets wet???????

  71. Default_avatar Danny Posted on 2010-07-09 13:49:03

    What is included with the Axial RTC.

  72. Default_avatar Bender Posted on 2010-07-12 10:15:38

    Everything you need is in the package aside from the 8 “AA” batteries for the transmitter, and a 7.2V battery pack/charger for the truck.

  73. Default_avatar Bender Posted on 2010-07-12 10:16:21

    It isn’t waterproof. If you get the electronics wet it will damage them.

  74. Default_avatar Nick Posted on 2010-07-25 15:55:37

    2 on the average life of your lipo 2cell? Thanks in advance bender.

    cheers.

  75. Default_avatar Nick Posted on 2010-07-25 16:04:10

    I just had that same issue with a buddys ax10 yesterday and we were wondering what could cause this issue?

    Cheers Nick

  76. Default_avatar Scorpion_Ax Posted on 2010-09-24 20:45:38

    The best way I have found to cut the foams is a Wallmart 9$ electric knife …..works awesome and very quick ….just be careful as it will hurt the hands if you slip with it…….

  77. Default_avatar Scorpion_Ax Posted on 2010-09-24 20:51:38

    When i cut my hammers with the electric knife….If you look at your tire foam standing up and from the side i took 1/2 in wide and 1/2 inch deep V shaped notches.across the top flat all the way around so it would look like a star ….this allows the tire to grab as it rolls over objects and like Bender i also took a little off the out side edge not much though or you will greatly affect the side hill flop of the tire…..

  78. Default_avatar Scorpion_Ax Posted on 2010-09-24 21:02:48

    I used Canadian tires pencil lead …you get it from the fishing tackle area and it is 1/4 in in diameter and you can just straighten it out and rap it around the inside of the rim and then wrap it with electrical tape to keep it still….very affective.

  79. Default_avatar corum Posted on 2010-11-03 17:30:53

    have you tried cutting some of the foam from the inside of the tire

  80. Default_avatar emma watson Posted on 2011-01-26 07:10:23

    Fascinating blog on Budget RTC Build, not like the others!

  81. Default_avatar Jason metzer Posted on 2011-05-12 03:45:15

    I just bought a ax10 RTC after having a losi crawler. Axial is so much better and has so many extra parts that can be modified. My questions are – Will a proline body made for a scx10 fit on a ax10? Is it possible to swap a ax10 frame for a scx10 frame and still keep all the same axles , shocks and drivetrain, motor, esc for the purpose of being able to run different body styles???

  82. Default_avatar HeerPhesy Posted on 2011-06-15 14:24:39

    get cheap chanel knockoffs for more detail

  83. Default_avatar Douglas Posted on 2011-07-29 10:09:57

    hey man if i may say this helped me out allot but im a bit disappointed with my steering servo so is there a way i can take the steering servo saver off i put a futuba s3305 on it which is allot better but i want to know if i can put a different steering horn on i got one that came with the car but i dont know how to hook it up to the linkage

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