You like 1/8 scale nitro buggies and truggies because of their speed and ability to accelerate even on the meanest of track conditions? You hate the noise and fuel fumes? Then an electric conversion or even a full-breed electric kit might be the way to go for you. Beside already equipped Ready-to-Run kits there are a lot of conversion kits or special kits, like Team Associated's RC8e or the all-new Xray XB808e, out there that additionally need some electrics like motor and speedo. For these kits companies like Tekin offer a lot of motors and speed controllers to suit your needs depending on what you have (buggy, truggy, short course truck) or what you want (punch, speed, both …).
Overview
On test we have Tekin's RX8 1/8 scale speed controller and T8 5030B 2050kv brushless motor. The RX8 features Tekin's to-of-the-line speed contoller that not only makes use of brushless but also old-school brushed motors although we are quite sure that in 2010 no one will ever dare to put a brushed motor in an 1/8 scale kit. But, we have to admit, it's nice to have the option to do so!
The Tekin T8 Redline motors come in two dedicated versions: a shorter 4030B type for 1/8 scale buggies and the longer 4038T truggy motor that should also suit 1/8 scale Short Course trucks like the Associated SC8e. Five different kv ratings (kv describes the RPM of the motor per volt) are available per version with our 2050kv motor being the second 'fastest' with a 2650kv above and 1900kv below in terms of power. Speedo and motor are available separately or as a set and so came ours.
Let's go into deep for a second. Skip this paragraph if you are not so into the technical stuff and just want to go fast or fly high. You are not going to miss anything interesting - honestly!
Those that are still with us: let's find out more about the T8 motor and the RX8 speedo. The motor can is machined out of 6061 T6 billet aluminum and features a ribbed heat sink for best possible heat dissipation. To this adds the black anodizing as black is meant to be the best colour when it comes to get heat away from a part. This might sound strange but it is a matter of fact! Check you favorite engineering book and you will find out. Although the motor back plate features a sensor wire connector the T8 can be used sensor-less if the speedo allows (and the RX8 does). The magnets are or a needy sintered type for maximum efficiency and the motor itself is rebuildable meaning you can disassemble it for maintenance and cleaning reasons. As you might know: brushless motors are nearly maintenance free thanks to the fact that they feature non-contact power transmission (compared to so called brush motors) but the internal ball bearings are still the weak point of every motor - especially when used off-road.
Tekin's RX8 speed controller is one of the smaller ones out there with dimensions of 38 x 56 x 36 mm. This makes installation easy. To this adds the possibility to mount the controller directly to the chassis plate or radio tray as it features four screw holes. This is quite handy as mounting heavy components with double-sided tape often is not an option as vibrations, heat and dust can lead to insufficient adhesion of the tape.
The RX8 features multiple software options that both help to get the most out of the motor and also help to save the motor, speedo and battery from damage due to heat or overload. Software-wise the RX8 offers adjustable ...
… Drag brake (this is some sort of auto brake function)
… Brake strength (maximum brake value)
… Current limit (increase or decrease power depending on track conditions)
… Neutral width (make the neutral point narrower or wider)
… Throttle profiles (changes the throttle 'feel')
… Voltage cut-off (to suit NiMH as well as LiXX cells and different cell numbers)
… Brushless drive mode (Forward/Brake or Forward/Brake/Reverse)
… Brushed drive mode (same as above)
Additionally the RX8 has so called 'one touch' programming to adjust the above software features without an optional device. But, if you wish to, you can also connect the speedo to your Windows machine via Tekin's own HotWire PC interface http://www.teamtekin.com/hotwire.html). This is quite handy if you want to update to the new 'Vegas208' software.
Last but not least: what's in the box you might ask. Beside the RX8 speedo and T8 motor you will find thick 12 AWG red, black and blue wire for connecting the speedo with the motor and battery, an additional fan some mounting hardware, two decal sheets and a comprehensive manual that not only decries the correct mounting and installation of motor and speedo but also goes into deep when it comes to set-up the speedo to different motors and batteries. All in all a very broad package that should suit the needs of beginners and racers alike.
Before you install the RX8 to the chassis it is time to solder all needed wires in place. To do so dry-fit the motor and speedo into the chassis to estimate the needed wire length. In our case we first cut the three wires for the motor to length and soldered them in place using Tekin's 'How to wire an RX8' Youtube video (see below) as a rough guide. We additionally put shrink-wrap over the solder posts for a bit of extra security and to prevent short cuts. The remainder of the red and black wire was soldered to the positive and negative solder posts of the speedo and protected by shrink-wrap also. Then the RX8 was mounted to the RC8's radio tray, followed by the final installation of the wires. The T8 motor has strong solder tabs that make soldering easy. Hidden somewhere in the box was a clamp and a countersunk M3 screw that at first we weren't sure how to use. But then we found a drawing on the Tekin homepage showing that the clamp can be used to secure the sender cable to the motor's endbell. Simply detach one of the screws, attach the clamp and reassemble everything with the new longer M3 fixing.
Track Test
The actual track test took place at a semi-permanent track near the area52 office. The track surface consists of smooth hard packed clay and rough, loose dirt parts with a couple of jumps.
Before the first run we had to change the Voltage Cutoff program as the default setting is 'none' as for NiMH batteries. As we used two 7.4V 2S Team Orion battery packs we adjusted the cutoff to value '4' (for 4S LiPo batteries). The remainder of the programs been left untouched for the moment. From the standstill it was noticeable how smooth the feel of the Tekin controller and motor was. Low speed maneuverability was awesome and some was the overall throttle feel. Our Associated RC8B propelled towards the first corner and when hitting the brakes it almost instantly changed to reverse throwing large quantities of direst and stones away. Despite the stock 'Forward/Brake/Reverse-delay setting the transition between brake and reverse was way too abrupt. To overcome this and as we don't like 'Reverse' competition speedo we changed the specific value on the RX8 to '1'. This means 'Brushless, Forward/Brake' and gives a much better feel for the brake. You can additionally adjust the full brake value on the controller with the 'Rev/Brake strength' mode. In Fwd/Brk/Rev' mode it changes the overall amount of reverse go, but with the 'Fwd/Brk' mode it adjusts the total amount of brake to your liking.
In Detail
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On/off switch The RX8's on/off switch offers three different mounting holes to secure the switch without the need of double-sided tape. Simply screw it down with a M3 screw. Team Associated's RC8e offers a mounting plate for the switch beside the speedo so of course we used it! |
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Does it fit? Before installing the T8 motor we weren't sure if the motor will fit the tight space given in the RC8's chassis and despite 42mm in diameter the motor fits in without problems. In case you'd like to use the T8 Redline motors make sure the chassis is able to hold 42mm diameter motors. Most of the current 1/8 scale buggies and truggies will do but better think twice and get the ruler out! |
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Setting the beast up Also Tekin's RX8 speedo features so called 'one touch' programming it actually sports two knobs for the set-up. Choose the parameter you wish to adjust by hitting the MODE button and increase the falue by pushing the INCR button. It's that simple and very good explained in the manual. |
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Technical data Tekin T8 2050kv brushless motor - KV (PRM/V): 2050 - Voltage range: up to 6s LiXX - Shaft length: 19 mm - Shaft diameter: 5.0 mm - Dimensions: 71 mm x 42 mm - Weight: 340 g Tekin RX8 brushless speed controller - Function: Forward/Brake/Reverse - Voltage range: up to 6s LiXX - Voltage Cut-off: none, up to 6s LiXX - BEC: 6V/5.0A - Dimensions: 38 x 56 x 36 mm - Weight: 78 g |
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Likes & Dislikes + Small sized controller + Complete package + Very good manual + Very good on-track performance - none |
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