Heng Long Tanks - Advanced Modifications

[CanadianBulldog22]

Hello All,

Before I go into the list of recommended modificaitons I will briefly go into why I decided to put this thread together.

History

I have been working with RC cars since the early 90's, before brushless motors or even digital speed controllers existed. I have always been at the cutting edge of rc technology, my current 1/5 scale HPI 5T truck runs a liquid cooled, 7hp sensored brushless motor. Radiator, water pump and all.

I have an undergraduate degree in mechanical engineering and have been working as an industrial applications engineer for 4 years now.

Reasoning

Too many people across a wire scope of forums claim to have the best upgrades for your rc tank. Most of them are quite simply wrong, and have too much money to burn. I am putting this thread togehter to weed out the good modificaitons, from the ones that are a waste of time. Enjoy.

First Topic to follow....

[CanadianBulldog22]

Reducing Rolling Friction

Any rotating parts biggest enemy is friction. If friction can be reduced, it helps across the board. Heng Long as a means of making these tanks inexpensive only supports the (10) load bearing wheels (inside the track, lower 5 on each side) with plastic. The plastic wheels rotate on small plastic bushings, this generates a large amount of friction that the drive motors must overcome, also at higher speed this generates heat.

First and BEST MOD to do right off the bat is to purchase (10) Metric roller bearings 11mm x 5mm and modify the wheels to run on proper bearings. You will also need a 11mm drill bit. You will have to drill out the wheel hubs to 11mm diameter, but only 4mm deep. Then press the 11mm x 5mm (5mm is the internal diameter to match the plastic bushing, they are 4mm thick) into each wheel. Now each wheel spins on a stainless steel roller bearing, reducing noise, friction, and heat. This will increase your acceleartion, top speed, and manoverability. As these (10) wheels are the only ones to carry the load of the tank, they are the only ones that require modifiying.

BearingsDirect has them on sale for 50% off right now.


Chris

[CanadianBulldog22]

Topic #1: Reducing Rolling Friction

Topic #2: 360 Degree Turret Rotation

Topic #3: Metal Upgrades

Topic #4: MFU Explained

Topic #5: Drive System upgrade (Brushless System)

Topic #6: Replace MFU with stand alone electronics

More topics may follow...

[Merlin707]

Your title for this thread seems rather elitist and rather insulting to say the least!

Why do you have to be an expert to do these modifications?
The idea of your thread is to help people, so why have you alienated a large number of people on this forum by only targeting a specific tier of modeller?

I don't think it is above anyones ability to insert a bearing or utilise metal upgrades.
Some of the newer members of this forum may now bypass this post because they think they are not capable of doing these modifications.
Surely this forum is here to help every skill level and every ability type to enjoy this hobby.

Please re-think your post titles before submission.

[FreakyDude]

not to pick on you either but most of your mods have been done several times with lots of variations

[Saxondog]

Just to voice the long standing and I will add successful attitude of our forum, The only dumb question is the one not asked.

Simply meaning we have no elite here,we have people constantly striving at their own pace,budget and ability to model armor.Benefitting from the shared experience of the group.

I began as a novice and with another Newbie. We began three Tigers,we were instructed by a man who at the time received criticism for sharing his techniques openly with two fresh,first time tankers/ Me and Bran were just that.Never had I in my life modeled an RC Tank.

Thanks Oz. viewtopic.php?f=151&t=2429

The post became the most viewed post in forum History and remained so until the crash in 2010 killed the Photos.14 boards of step by step painting and weathering, I stripped my tank twice before finishing. Point being the changes in attitude this caused has served our forum very well.

Everyone has skill,if only shown technique,I am pleased you're willing to share your Engineered approach to this hobby. Its one I share.

Yet possible a little more subtle delivery might generate a wider interest? Just suggesting as a new member obviously attempting to share with others valuable techniques that you possibly slow down a bit so guys like me can keep up. I am still very much a novice, and will always be.

Seriously
Thanks for sharing
Saxondog

[ALPHA]

AW SHUCKS!!!! Hope Bulldog82 don't get scared off lol.......................I read his mods...didn't want to be rude with a reply... just felt like in time...by the time the list of mods were finished...you may have well have got a Tamiya

The tolerances on these Toy Tanks aren't that great....the rolling resistance isn't that high...I'm definitely no expert...but to me the little friction that is caused is more of a braking kind of effect that something totally detrimental ....people sometimes grumble about the speed of the HLs ..putting bearings in will multiply the gripe

All of the drivetrains on my tanks are stock...I do do a little tweaking here and there...but have no need to install bearings...I don't even grease or oil surfaces..as the lubricant can destroy the plastic ...I just prefer to fine hone parts to where they move freely

I think the one thing I share with Bulldog is how the HLs can be improved....that meaning that the model does have it's challenges... I like that....it's better than having a tank that is all laid out for you....the best thing is the platforms are very user friendly...meaning upgrades are relatively easy to do... unlike some other brands which do not allow any leeway especially in the running gear...the cream on top is that they are very affordable for what you get in the package

Never think there are any experts at anything.. being an expert is just a state of mind...I'm no expert because I still learn...basically relegating me to be a student ...a student of life...amongst other things

ALPHA

[wibblywobbly]

Although it is always good to see members modifying tanks and improving them, there is a fine line between cost and effect.

If the wheels on an HL tank have been assembled correctly at the factory, they are free spinning and generate very little rolling resistance. The one thing that a tank is not noted for is speed, and many modellers modify their tanks with reduction gearboxes and upgraded electronics to slow them down. So, yes, fitting roller bearings is a feat of engineering, and will reduce friction, but the benefit is not going to be noticeable.

Sealed bearings are still going to get caked in mud, water and grass, so if they are run off road, the resistance is going to come from the muck that the wheels and tracks pick up rather than the bearings. In this respect HL's are easy to clean, and can be washed.

My view is (based on real life vehicles) that if a tank is running off road then unsprung weight is more of an issue. CanadianBulldog may be able to confirm or trash the notion that in order for suspension to work effectively, the weight attached to suspension should be as low as possible. If you push down on a tank it takes a lot of pressure before the suspension moves. Fitting stiffer springs makes it worse.

Off road, the tracks hit a bump, the track pushes on the road wheel, and the road wheel pushes on the spring. If the force of the upward movement is less than the spring resistance, the wheel does not move. The force is then transmitted through the suspension and simply lifts the tank. At this point the suspension is not working at all, so the whole tank lifts.

Lower unsprung weight together with a weighted tank that is balanced at the point where the suspension starts to work, and softer springs, should in theory allow the upper hull to stay where it is, and the road wheels to move on the suspension arms. Adding unsprung weight like metal road wheels, bearings etc etc creates more mass to be moved when the tracks go over a bump, so more work for the suspension to do in terms of momentum/inertia etc.

It would be interesting to hear whether what applies in the automotive world applies to plastic tanks, I have always wondered? It is a genuine question

RobG

[jarndice]

One of the biggest problems that arises on conversing on the www is the inability to view the "speaker", it is amazing how much information one gains from merely seeing the features of a speaker, add to that the lack of inflection and the nuances of flowing speech are lost and often what was spoken is received with the exact opposite meaning. an awful lot of people are perceived as arrogant when they are gentle souls wanting only to impart their knowledge, Enthusiasm added to knowledge often produce's poor English grammar and this particular Forum has ( I AM GLAD TO SAY) many members whose first language is not ENGLISH/ENGLISH, those of us who are fortunate enough to be English (SEE WHAT I MEAN ABOUT SOUNDING ARROGANT)should think of those times when on Holiday/Vacation struggling to get one's self understood, when I come across messages such as the one from Bulldog82 I look at what information is being imparted and if I perceive it to be relevant I disregard the diction. shaun

[cannedheat]

I say old chap ,well that's me out of the category......[expert] wot wot ...... I am Selwyn frogitt of this tanking business ........