HPI Pro 4 – Assemble Tips


Tips are translated from Japanese to English, therefore some wording are hard to understand. Please try you best to read. (Have some guess!!) Thanks to HPI R&D Cafe Japan

TIPS 1
Please prepare the tape of 3M.
Pro4 has used the carbon mixture resin for the various parts. As for this carbon mixture resin there is a feature which rigidity calls high and light weight very. Because of that it is very hard the occasion where the screw is screwed in, operating efficiency becomes bad. Very it becomes easy to work by the fact that the tap of M3 is cut beforehand then. The point is not to cut the length all tap of the screw here. The length which cuts the tap when it makes 2/3 of length of the screw, screwing in the screw, becomes lastly hard and becomes also locking.

Pivot as for installation of mount prudently.
With Pro4 the suspension shaft is locked at pivot block the chassis. The occasion where this pivot block is installed in the chassis, paying attention to the movement of the suspension arm, please install. When the screw stopping pivot block securely, please verify that the left and right both suspension arm moves smoothly. When the suspension arm of one side does not move smoothly, pivot block has been installed slantedly. Loosening the screw of one time pivot block slightly, in order for pivot block not to tilt on left and right, while locking securely by the hand, it tightens the screw and densely is please be. If and it reaches the point where both suspension arm left and right moves smoothly, it is OK. As for this part when travelling when big crash is done even, please try checking.

Tips 2
First, we would like to explain concerning the bearing which belongs to Pro4.
The grease has not entered into the bearing which belongs to the Pro4 kit.
The oil whose viscosity is low in place of the grease is done just the small quantity note. Because, it is said well, as for “removal of fat” job as for the necessity to do it is not. Aiming toward light drive system, it has become the specification which adhered to also the kit standard bearing.

This time secret of the assembly of the gear box is introduced a little.

Bevel as for backlash of gear optimumly.
In order for the gear to drive, by all means backlash is necessary. If (to be tremendous high accuracy it is the gear, backlash is unnecessary, but that is when it is special. In the gear of the precision which is used for RC as for backlash it is necessary with any gear)
You took the backlash of the bevel gear and had entered with theory together reading the instruction manual of the annex, “Pro4 assembly guide” well, please adjust.
As for backlash with the notion that where, we would like to lighten driving by any means, there is a tendency which is taken more than usual, but when backlash is many above necessity, it becomes cause of the trouble such as the tooth being lacking and abnormal wear of the gear.
Backlash of the bevel gear the front according to explanation of the “Pro4 assembling guide”, equivalent of shim 1 restrictiveness is better than that, probably will be.

Bevel in gear just a little one coating.
The gear while sliding, transmits power. Huh! Perhaps, with the person who is thought it is many, but the gear one one tooth being connected, that continuing from to the next next, turns by the fact that it is connected, transmits power. It slides to being with something? ? With those where you think are proper thing. But, when it tries observing to just the process where one tooth is connected, driving side (the small bevel gear) with trailing side (the large bevel gear) one tooth starting being connected, until connection ends, being to slide it does the flank of the respective bevel gear. This continuing the connection which it slides, it does, being to be turning, it does.
Explanation became long, but while sliding, that if it transmits power decreasing resistance, when sliding, the gear means to be able to turn smoothly. The fact that and, sliding, means wears.
In order to decrease slide resistance Z158 super coating (fluorine combination dry type) it paints on the surface of the bevel gear. So when it does, it reaches the point where the bevel gear turns very smoothly. And the grease whose viscosity is low is painted in flank of the extremely little gear. Like this by the fact that it does, wear of the gear is prevented. Viscosity it is high this time, (it is hard) painting the grease, the large quantity painting the grease the stripe uninformed it meaning that revolution of the gear becomes heavy, please pay attention. (Presently, the optimum grease it is in the midst of developing)

Method of tightening the screw of gear box.
When the gear box the top and bottom is adjusted, the filter opening which is done has been less crowded. But, tightening the screw securely, when it assembles, there is no this opening. Because it has reached the point where fit of the bearing and the gear box becomes optimum in this state, as for processing please do not do to the gear box.
It attaches the gear box of the top and bottom with 4 these screws. 2 among those also the upper deck has become tightening. These 4 these screws the tube tighten the screw of the diagonal alternately and a little densely are please are. So, by the fact that it does, also the distortion of the gear box decreases, the upper deck, also twist of the chassis can prevent.

A little it became long, but because with shaft drive as for the gear box it becomes the most important element, settling, slowly please work.

Tips 3
It supplements a little with the assembly of the gear box.
Backlash of the bevel gear the front, seems that is many a thing where the filter backlash which we assume that it is according to the instruction manual, becomes overplentiful. The shim for backlash adjustment (Z892) in order for backlash to become restrictiveness, 2 please make sure to insert in bevel gear side.
In addition, several packing travelling, when the area of the section takes, opening the gear box, please verify the backlash of the bevel gear. When backlash has become more than the beginning this time, please adjust for the second time. So, it can make the trouble of the tooth being lacking evade and the like by the fact that it does.

As for the chassis there is no twist, the sea urchin.
The upper deck is installed, when screwing in the screw entirely, please verify whether the chassis has not curved. Especially it meaning that twist of the chassis is easy to occur, note is necessary.
When the chassis is twisted, the screw which locks the upper deck (12) please loosen slightly. And it tightens the screw little by little in diagonal line and it is with goes densely. When it tightens all screws and is dense it is being, when still the chassis has curved, densely it is the screw which is (8) 1/16 revolutions please tighten in the gear box and try loosening. While just little by little, verifying the twist of the chassis, please loosen the quantity which it loosens. If it does to here, when it is the majority, as for twist of the chassis it is the expectation which can be cancelled.
As for the screw please do not loosen 1/8 revolutions or more.
As for check of twist of the chassis after crashing even, we recommend that you verify.

Tips 4 – Ball Bearing

You are glad very much with the fact that as an ear Pro4 is sold and 1 week or more passes, has run the circuit of the every place in Japan already.
It seems that the trouble that occurs little among such, the bevel gear breaks.

We have recognized in order when high speed crash is done from the test result, for there to be a possibility the small bevel gear the front breaking. Of course, when Pro4 is sold, repeatedly the sufficient test it started concerning the strength of the bevel gear. Completely it meaning that cannot be some which, are not broken of course judging, that it has necessary sufficient strength from the result of the test, it sold.

But, as for extent of crash it is something which is influenced largely by the environment which can be sent, for we to grasp the everything of that, it is not possible regrettable.

Then, we would like to introduce Tips which it tries not to break the bevel gear.

1. Please adjust the backlash of the bevel gear appropriately.
Many times it explained this already, but backlash not to be the appropriateness (too multi, when be too little) is not, strength of the bevel gear decreases substantially.

2. Please boil the bevel gear at the hot water.
The material of the bevel gear has used the engineering plastic which designates the nylon resin as the base. Strength of the nylon resin receives big influence to humidity. The present way in the origin of the climate which is dried very there is a tendency which becomes brittle. In order to make the original strength of the bevel gear show, being to have the necessity giving the sufficient moisture to the bevel gear it does.
A) First, the hot water of the sufficient quantity is boiled. As for temperature of the hot water please make sure not to boil. About 80 degrees are good, probably will be. The bevel gear is shifted in your that hot water.

B) That temperature of the hot water does not rise too much, noting, approximately 20 – 30 minutes it does that way. When time passes, lowering the hot water from the fire, until the hot water cools down in normal temperature, it cools that way.

C) When the hot water cools down, very, please take the bevel gear and come out and dry the moisture sufficiently. This time without using the dryer and the like wiping off the moisture with the tissue, and the like it is good to dry that way naturally, probably will be.

D) Sort please assemble after the that usually.

3. Please be sure to paint the grease in the bevel gear. You are not concerned the grease at the extremely small quantity.

Presently, aiming toward further efficiency improvement, it is advancing the test of Pro4.
The high performance (high intensity & high accuracy, also sound is quiet) has tested the thing above now concerning the bevel gear. You think that with the good result would like to report to the cod and everyone.

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