Metal and plastic bearing weight

[El Mexican]

Has anyone ever thought that placing metal ball bearings in a kit increases the actual weight of the model and with that eliminates the friction-fighting advantange of putting them in the first place?

Seems to me that while plastic bearings are cheap and don´t last long, they do give some sort of plus in the weight-saving department, which is ver important to R/C cars.

What are you thoughts?

[SJoerD]

The theoretical gain in weigth by using plastic bushings is insignificant compared to the known advantages of ball bearings... 'Relative insignificance' are the key words here.

[mud4fun]

I would say from experience that the reduction in rolling resistance is worth more than the weight saving for a few reasons:

---

1) The bearings give much longer run times, this is well proven. So even if your car is marginally faster due to reduced weight the bearing equipped car will run for longer and in the end that is more important and potentially race winning!

---

2)The reduction in resistance means your motor is under less strain, therefore consuming less power and is more free revving. It will also suffer less from overheating.

---

3) The plastic bearings wear out in a very short time if used with powerful motors, my daughters Mad Bull wore out a set of gearbox plastic bearings in just 20 minutes use with a technigold. This then means you have to strip the car and replace them all. Not easy in some modern Tamiya such as TL01 where almost the entire car must be taken apart to replace the bearings. Not to mention the addition wear and tear on shafts etc that could result - very expensive damage.

---

4) Plastic bearings used in the front wheels of a 2wd or axles on a 4WD will wear and cause poor steering and potentially erratic behaviour at speed.

---

So basically there is no advantage that I can see in running plastic bearings other than cost which is just a short term solution as long term running costs will be higher. Also worth noting that the difference even in weight is pretty small and again insignificant compared to the weight of Motor, Battery and Electronics. NiMH batteries are for example much heavier than the equivalent NiCD and I run 8.4v (7 cell) packs which are even heavier again yet the overall gain in performance is significant better even with the extra weight.

[madman]

u took the words right out of my mouth mud4fun lol

[WillyChang]

quote:

Originally posted by El Mexican

What are you thoughts?

---

id="quote">id="quote">

When Lord Surikarn runs bushings, so will I. [][8D]

[El Mexican]

Excellent answers for a little doubt I had in my mind.

Willy:

Just out of curiosity, does Surikarn use teflon (ceramic?) or the legendary blue shielded bearings from Tamiya?

[mymonsterbeetleisbroken]

i think the nail has been hit right on the head[8D]

metal bearings are far superior to plastic ones, making any weight saving totally insignificant.

i like to put things into a silly over the top context, so here i go[]

rather like saving weight to make your lambo go faster, by replacing the v10 engine or wateva it has with a 800 cc bedford rescal van engine[)]