Mechanical Speed Controllers (MSC)

Basic 3 Speed Tamiya Mechanical Speed Controller

Older or more basic Radio Controlled cars often utilise what’s know as Mechanical Speed Controllers. These are simple mechanical switches that have three possible positions in both forward and reverse, operated by a servo. Due to the robust nature of these devices, there is rarely a motor limit applied to them, meaning you can run pretty much any brushed motor on one with minimal issue. So your only constraint as which motor you run in your rc car will be what type of rc car it is. You could easily fit a 10 turn brushed motor in a buggy with a mechanical speed controller, or you could run a 55 turn motor scale truck with little or no concern for the speed controller.

Electronic Speed Controller (ESC)

This is where things start to get a little more involved. On the face of it, things can look a little complicated, but really it’s not. All electronic components have their limits, and the handling capabilities of those used in an Electronic Speed Controller for RC cars will vary widely. As a general rule, the more you pay, the more capable the components.

Tamiya's TEU-104BK has a 25 Turn motor limit

If you look at the instructions or specification for any ESC, you’ll notice there is always a “Motor Limit” specified. This is the lower limit and relates to the minimum number of turns that a motor can have when used with the particular speed controller you’re looking at.

For example, a Tamiya TEU-104BK has a motor limit of 25 Turns. This means you can use any brushed motor of 25 turns or more with it. Go lower than 25 turns and you’re asking for trouble. Any motor that draws too much current from the ESC will soon cause the ESC to overheat and fail.

Similarly, an HPI Sc-15wp Waterproof Electronic Speed Control has a motor limit. This means it can handle any brushed motor with 15 turns or more.

The same rule applies in general too with Brushless motors. Lower motor limits are again quoted in the ESCs specifications and instructions and you shouldn’t go any lower with the number of motor turns than the rated limit on the ESC.

Conclusion

Hopefully that helps explain what the “Motor Limit” rating is on an Electronic Speed Controller. Ultimate, don’t run a motor with a lower number of turns than the rating on your ESC. Always choose a motor with the same or a higher number of turns than the ESC motor rating and you’ll be fine!

Not sure what Motor Turns means? Click here for our Motor Turns Explained

It’s a corner of the site that I really must make more of a feature off as it gives you guys (my loyal readers) chance to show off your RC cars. Share your creations, hacks and paint jobs. Everyone needs a little inspiration sometimes and Readers Rides is just perfect for that. Submit your pics now using the form on the Readers Rides page. Don’t forget to post your pics to our Facebook Page too!

Check out the latest Readers Rides

Tamiya TNX 3.0 by Scott

A rather cool Tamiya Lunch Box Duo by Sam

One of my all-time favourite submissions from Eric… Axial Honcho SCX10

Check out more Readers Rides and Upload your own here!

Looks Cool!

Radshape Hotshot front bumper / skid plate

“The Radshape Aliminium Front Bumper /Skid Plate for the Tamiya Hotshot is strong, well made and very easy to fit. As an alternative to the ‘kit supplied’ plastic bumper it looks pretty cool especially if you add the Tamiya Dark Impact wheel/tyre combo too! As far as ‘aesthetics’ are concerned, it does look a lot more appealing than the stock plastic bumper supplied with the hotshot, and especially if the colour of the car is black which, of course, makes the bumper more noticeable

A little over exposed?

No protection for the front wheels & suspension unfortunately

From a practical perspective it looks strong enough to survive multiple head on impacts, be it from walls, rocks or other cars but my personal concern lies with any kind of impact where the front wheels take most of the hit, thus potentially damaging the rods, steering, etc. In that respect I’d prefer to keep the supplied Tamiya bumper, which, at least, protects the whole of the front width of the car. I’m just thinking on the lines of avoiding expensive repairs here!

Now if they made one almost exactly like the Tamiya original, or at least somewhere near the same width, in black or brushed aluminium, I’d be more inclined to use it with much greater peace of mind.

Fits Like A Glove

New bumper is a direct replacement for the original and uses the same mounting points

Regarding fitting – no problem at all – fits snugly into place and mounts in exactly the same way as the original Tamiya bumper. Easy!

Centre screw is too long for the new bumper - (Ed. Same applies to their boomerang bumper too)

As far as my Hotshot is concerned, I believe the central screw is the wrong type/length for the Radshape bumper (fine on the Tamiya type) as it doesn’t screw all the way in but I’m sure that can be easily remedied.

Conclusion

Looks superb, but could leave you open to costly repairs in an accident.

Overall a really good piece of kit that does what it’s supposed to do and looks very cool with it! It certainly gives your Hotshot a more realistic look than the original bumper. If you’re concerned about the vulnerability of your front wheels, steering & suspension and its suitability for bashing, use this for show purposes only, or when you’re running your car on open or in obstacle free areas. Compatibility wise, it’s a direct swap for the original hotshot bumper so fitting is a breeze, but they need to supply a shorter centre screw!

Where Can I get One?

• Radshape’s eBay shop has tons of nice goodies – Check it out!
• Radshape direct

Traxxas Slash 2wd Brushless Ready To Run

The tyres are worn but have plenty of life left in them, and the underside of the chassis on most of the chassis components exhibit the usual scratches and scuffs you’d expect to find on a used Off-Road RC truck. Fitted with Acoms 27Mhz radio gear and Traxxas steering servo. The receiver is mounted in a waterproof box and the esc is splash-proof so it can be ran in most weather conditions. Supplied ready to run with Ansmann fast charger and 8.4v 5000mah NiMh battery.

View The Auction For This Traxxas Slash 2wd Here

Ceramic Bearings For RC Cars

Ceramic RC Car Bearings

Ceramic bearings are thought of as the ultimate in RC bearings. If you want the best and your budget is unlimited, then this is the option for you. Ceramic bearings are substantially lighter than their standard steel counterparts, and their ultra-hard construction means they’re much harder wearing, can handle much more heat and indeed, much higher speeds. Personally if you can only afford a few ceramic bearings, the place you need to use them first and foremost is in your cars Ball Differential if it has one. I’ve lost track of the countless times I’ve replaced the steel bearings in my Ansmann XT Pro ball diff. I can practically change them with my eyes shut. They’re not cheap at all, but they outperform and outlast all other bearings.

If speed is your number one priority, then ceramic bearings should be high on your list.  If you’re a racer, these may well help to give you the edge over the competition due to lower weight and minimal friction. They’re also fine for bashing too.

Metal Shielded RC Bearings

Metal Shielded Bearing

If you’re on a budget, then metal sealed bearings will probably be your weapon of choice. If you buy a set of bearings off ebay or from your local hobby shop, this is more than likely the type you’ll get. Despite their low cost though, they do perform fairly well and have pretty low resistance as they can and do spin freely. By nature, the metal shield isn’t that great at keeping dirt and dust out of the bearing, so more regular maintenance will be needed to keep this type of bearing in good order.

Opting for this type of bearing will certainly give you better acceleration and longer run times but the overall life of the bearing will be shorter than its counterparts as they are heavy and run hotter too, which ultimately means faster wear. That said though, when used in motors, clutches and gearboxes, they can actually last longer than rubber sealed bearings as being all metal, they can dissipate heat quicker, resulting in less bearing failures.

Rubber-Sealed Bearings For RC Cars

Rubber Sealed RC Bearing

These are the first choice for most bashers who want to be able to thrash their machine all day long in the dirt, then just through it back on the shelf until next time. The rubber seals do an amazing job of keeping the internal moving parts free of dirt and debris and help reduce friction and increase speed no-end. The materials used and their construction is similar to that of the metal shielded variety discussed earlier which helps make them low cost, just marginally more expensive than the all metal variety. They offer decent performance too, so unless you really are a speed freak, you’re not going to be able to tell the difference between a rubber-shielded bearing and an all metal one when it comes to burning rubber!

They also have a good lifespan too thanks to the rubber seals doing such a good job at keeping the moving parts clean. So while the steal balls inside them will wear just like in any other bearing, the wear rate is certainly kept to a minimum.

Maintenance wise, again, the requirements are minimal with the rubber shielded type. You can pretty much run your RC Car in any conditions imaginable and never really give these bearings another thought until they fail completely.

Keep ‘em Clean

RPM Bearing Blaster

As with all moving parts on your RC Car, keeping them clean goes a long way to giving you many hours of hassle free bashing. All bearings need some maintenance at some point during their life, even the rubber sealed variants. All bearings will perform better with a little TLC every now and again, after all, there’s no such thing as a maintenance free bearing. With the exception of the bearings inside your cars sealed gearbox, dirt and debris is going to be present somewhere in a bearing at some point in its life, so don’t be lulled into a false sense of security with them. Grease on bearings does a remarkable job of hiding the sounds of dirt crunching around inside the bearing!

Maintenance of bearings is actually really easy though, and it’s worth doing as it’ll save you £’s in the long run an give your car better performance for longer. The hardest part of bearing maintenance is removing them from the car and reinstalling them afterwards. You often have to strip almost the whole car to get at them all, so make sure you have the manual to hand so you know how it all goes back together!

To clean your bearings, you can use proprietary cleaning tools such as RPM’s bearing blaster, which hold the bearing in place while you give it a good squirt of electrical cleaning fluid. Each bearing should be given a good soaking to flush out as much dirt as possible. If you don’t have a Bearing Blaster, or indeed any electric motor cleaner, just use any small container and healthy blast of WD40. Allow the bearings to drain and dry off any excess cleaning fluid with a rag before you move on to the next one. Once cleaned, give the bearing a drop of two of your preferred lubricant and give it a roll to coat the balls inside. Fit them back into your RC Car and you’re done.

What Lubricants Should I Use?

Just like shock oil, bearing lubricants come in a million and one varieties.  Some bearings are supplied packed with grease which is a generally heavier, thicker lubricant that helps protect the balls and their cages from damage and dirt, but these don’t move as freely as oiled bearings. Opting for a lighter bearing lubricant such as a dedicated bearing lube will help your bearings spin much faster. If you want to head down the grease route, choose Lithium Molybdenum Grease (Lith Moly) from any motor factors. This is my grease of choice as its performance remains the same whether your running your car in temperatures of -10 degrees or +30 degrees C.

If you’re really stuck and want to head down the oil route without breaking the bank, for bashing purposes you can’t beat a drop or two of the trusty 3-in-1 general purpose oil, available from most hardware stores.

Conclusion

So hopefully this has enlightened you on the subject of bearings and you’re now a little wise, or maybe bored you’re bored to tears and never want to hear the word bearing again! However you feel though, it’s well worth fitting bearings to your car. For the £10 or £15 it usually costs for a complete set to suit your model, it’s a worthwhile investment. Just decide which type will suit you best and give them a try.

HPI SC15 WP Electronic Speed Controller With Drag Brake

Waterproof & LiPo compatible

The HPI SC-15WP is a forward and reverse electronic speed controller with built in LiPo (Lithium Polymer) battery compatibility, which means it’ll cut power to the motor when the battery voltage drops to 3.0v per cell, protecting your batteries from damage. LiPo batteries are fast replacing the older NiMh type battery and the battery of choice for most RC enthusiasts, so having a speed controller with a built in cut-off saves buying add on LiPo alarms or cutoffs. It’s also capable of handling 6 and 7 cell (7.2v and 8.4v) NiMh & NiCd racing packs too.

The other added bonus of the HPI SC-15 is that it’s waterproof! Always a good thing in my book. There’s nothing worse than taking your car out for a spin in the rain and having it refuse to work because you drove through a puddle! Driving through puddles and getting muddy is what it’s all about, so HPI have taken every step possible to seal this ESC from the ingress of water and keep your car in full operation during wet conditions. Use with brushed motors down to 15 turn.

Faster Faster Faster!

Yes this is the second most asked question in the emails I get… How can I make my car go faster? Well, this HPI Electronic Speed Control certainly gives you the potential to go faster, a lot faster than most standard ESC’s allow. The SC-15 WP is capable of handling brushed motors down to 15 turns, allowing you to go much much faster indeed. Standard ESCs tend to have a limit of 21T or above, so this is definitely a marked improvement.

Slower Slower Slower!

For those among us that are getting into the exciting world of RC Crawling, this nifty little box of tricks also has a hidden feature which isn’t mentioned in most of the sales literature, but is mentioned in the manual… Drag Brake. This is where the ESC automatically brakes the motor when the throttle is returned to neutral, a feature that is constantly in use during rock crawling to give you much more accurate control over your crawler as you navigate difficult terrain… So if you’re looking for a budget rock crawler ESC, this is definitely one to consider.

Easy Installation & Setup

The SC-15WP is a like for like replacement for the TEU-101BK and other standard speed controllers in terms of connections, having a standard Tamiya battery plug, bullet motor connectors and a power switch pre-soldered onto a flying lead. So installation takes little more than a minute or two. Setup though is easy thanks to the in-depth instruction manual which walks you through the 4 settings – Start Power, Reverse Power, Battery Type & Drag Brake. Other than that there’s a little LED that indicates the status of the unit and that’s about all.

Features & Specification

• Waterproof!
• 6- or 7-cell NiMH compatibility.
• 2S LiPo compatibility.
• LiPo safety cut-off.
• Standard battery plug .
• Dual bullet-style motor plugs.
• Drag brake, making it perfect for crawling!
• Suitable for use with Tamiya, Ansmann, HPI and Traxxas RC Cars.
• Drop in replacement for most Stock ESCs such as the Tamiya TEU-101BK and TEU-104BK

The HPI SC-15WP is a standard part on many HPI RC Cars, but as I’ve mentioned it’s well worth considering as an upgrade for any new or vintage Tamiya, HPI or Ansmann car to replace the standard ESCs with limited functionality. I’m currently considering upgrading at least 3 of my cars to use this ESC (Tamiya Grasshopper II, Tamiya TL-01 Audi Quattro, Tamiya TA-02 based Bowler Wildcat.) and at £29.99 retail price it’s very competitively priced compared to ESCs offering the same spec and functionality from other manufacturers.

This ESC is a standard part for these HPI models:

• RTR BLITZ WITH 2.4GHz and SKORPION BODY.
• RTR E-Firestorm 10T 2.4GHz (UK 3-Pin).
• RTR SPRINT 2 SPORT 2.4GHz WITH BMW M3 GT2 BODY.
• RTR SPRINT 2 DRIFT 2.4GHz WITH 2010 CAMARO BODY.

Where Can I Buy One?

• HPI SC-15WP Electronic Speed Controllers On Ebay
• HPI Racing Accessories at Amazon UK
• Direct from HPI Racing Europe
• Your local hobby shop

Tamiya Hotshot 2 For Sale

This Tamiya Hotshot 2 has been used but is well looked after and will provide many hours of off road fun for its new owner. To get it on the road you will need batteries, a charger and a transmitter which can all be purchased easily from your local hobby shop of from Ebay for just a few pounds.

» See all the details of this auction on Ebay «

Model Specification

• Model number: 58062
• Model name: Hot Shot II
• Released: 21-May-87
• Drive: 4WD shaftdrive
• Suspension: Double Wishbone all round
• Chassis desc.: ABS monocoque
• Body: Lexan polycarbonate
• Motor: RS-540S
• Width: 235mm
• Length: 390mm
• Height: 160mm
• Wheel base: 262mm
• Tread front: 194mm
• Tread rear: 194mm
• Ground clearance: 15mm
• Weight: 1720g
• Scale: 1/10
• Front tyre: 30/88mm
• Rear tyre: 38/88mm

The rear suspension travel on the Tamiya CC-01 is a little too restrictive for crawling, and the stock plastic components are a little too toy like for hardcore crawling applications. The configuration is a 4 link type with is the setup of choice for crawling, but the plastic components just won’t withstand much abuse, not do they move that precisely or smoothly. But this is where another JunFac upgrade comes into place. Those clever Koreans have developed a rather nice kit to upgrade the stock plastic 4 link arrangement to a full aluminium setup. Their J100210 JunFac CC-01 4-Link Suspension Conversion kit also comes with a nice black centre skid plate to protect the central drive shafts & transmission.

CC-01 Original Rear Suspension Arrangement

Installing the kit begins by simply removing the current rear suspension links and associated screws, and removing the ball joints from the ends of the rear shocks.

Original CC-01 Suspension Removed

The JunFac upgrade kit comes very nicely packed in a tough polythene bag, but there’s one massive omission in my opinion… No Instructions! Which leaves you faced with a rather stylish looking aluminium puzzle, which take a bit of thinking about! So I began by separating out all the different screws, rods and brackets into sizes so I could try and work out, with the aid of the JunFac website, what went where and how.

Junfac CC-01 4 Link Upgrade Kit

No Instructions - Just One Big Fancy Puzzle!

It doesn’t take too long to work out what goes there though, and by measuring the hex screws against the various holes you can soon work out which ones hold which part in place. I used plenty of Liquid Thread Lock on all metal to metal joins such as the rods and brackets. There’s little chance of them coming undone but I didn’t want to take the risk! Hopefully these few close up pics will help show how the whole thing goes together .

Rear Axle Mounted Shock Brackets

Close up of rear axle brackets

Rear Aluminium Axle Brackets and 4 Link Kit Installed

Testing Testing 1, 2, 3

It’s pretty easy to test the whole setup once it’s in place. With the chassis upside down, give each rear wheel a press, compressing the suspension fully on each side one at a time, then press both wheels down, checking for any rubbing or straining on any components as you go. Finally, give the rear axle a twist to flex each side fully in opposite direction.

The JunFac upgrade gives very slightly more rear end articulation than the original set up, so you don’t gain a lot there, but what you do gain is a much more durable 4 link arrangement that’s less likely to break or get hung up on the rocks or other obstacles when you take your Trail Rig out into the wild.

Junfac 4 Link Suspension Kit Testing

Finally with the centre skid plate in it’s now ready for a proper test run.

Junfac 4 Link Upgrade Complete

In the next installment of the Tamiya CC-01 Pajero Scale Crawler project I’ll be looking at Tyre Upgrades. Thanks for reading!