Newbie with Tamiya DT-03 Racing Fighter Hop Up

[ChuChu]

Hi,

I decided to create this topic, because I still have too many questions and do not want to create more and more topics...

I am total newbie but with some mechanical knowledge and skills, mainly from cycling. I spent last 9 years on stripping down every bike part to undestand how it works.

I started with Racing Fighter kit but read a lot and decided to go with some Hop Ups. I have luck that Tamiya distributor in my country has shop 10 minutes from my home.

Kit was supplied with Torque Tuned engine, CVA dampers and ESC. I bought:

- Aluminium Bridges
- Sway Bars
- Aluminium Servo Mount
- High Torque Servo Saver
- Ball Bearings ( Tamiya + 1$ generic)
- CVA dampers... Shop told me that there are friction shock in kit, so I bought CVA...
- Hard suspension oil
- Aluminium Cover for Servo Saver
- Aluminium M4 wheels bolts
- Aluminium M3 for Servo Saver
- 12 Aluminium Hex for rear wheels
- 0.1 0.2 0.3 0.5 shims

Some of them just for "bling", some because I read a lot reccomendations.

Today I ordered light gearbox shaft but I will install them next time. I do not want to strip down gearbox again.

Progress photos:

Shims in suspension. I tried to leave around 0.1 mm of play. I used wax on shafts to reduce friction. All parts are sanded down on contact surfaces.

Plan is to buy all Hop Ups I want to install them now and not to disassembly model each month to put something new.

Of course as newbie I did few mistakes. Nothing big, but still. I diff I used M3 screws instead of M2.6. Works fine so no big deal. Worse is that I installed bottom rear wishbones shafts from wrong side. It works fine but I do not have access to them. Upper shafts are installed correctly but on the same side. So in the end to do something with wishbones I have to remove gearbox.

I wanted few more things like stainless steel suspensions shafts but unfortunately they are not available in my country. I also wanted metal drivetrains shafts but again, not all parts are available.

Questions time!

Can I use both holes to install shocks ( front and rear) or should I stick to manual?

I have also problem with Servo Saver but I will do photos tommorow when light be better...

 

[bill_delong]

those holes on the lower suspension arm are for tuning purposes.... basically the outer hole will take away droop which also takes away grip, the inner hole will increase the droop and increase grip so you can tune front/rear accordingly to what you need the car to do, more info here on pages 2 and 8:

https://www.teknorc.com/wp-content/uploads/2014/06/Set_Up_Guide.pdf

 

[ChuChu]

Thank you! I understand purpose but I was not sure if I can use them. I know Tamiya from scale models. Quality is excellent. I am little surprised that they did not mention this in manual.

I forgot about one upgrade. I bought 19T steel pinion too.

As I wrote above I bought some generic cheap bearings. Waste of money. They are so poor quality that they spun on gearbox shafts... Not precise inner diameter and friction caused that they act like plastic bushings. Inner race did not spun and polished shafts... I bought Tamiya and everything works perfect.

I used Ball Diff Tamiya grease on plastic gears in gearbox. Local shop sold me it as suitable. I read a lot and was scared that I did stupid mistake and should use something else. I run engine for a while and surprisingly everything inside looks perfect. There is light coat of grease. Gearbox runs perfectly smooth and very quiet. On next service I will probably use recommended Ceramic Grease but it is good to know, that Silicone Grease will work fine too.

I have to say that I have real fun with build of this model. It is simple but there are so many things to tune and upgrade. Unfortunately it is little annoying that some parts sold as compatible ( like High Torque Servo Saver) are not Plug and Play.

 

[ChuChu]

Servo Saver issue.

Servo + standard Servo Saver + mount with 1.5 mm shims

High Torque Servo Saver

Standard servo with 1.5 mm shims in chassis

High Torque in chassis. As you can see it is pretty low. Nut will hit chassis edge.

High Torque without 1.5 mm shims visible on first photo

I did some math and without shims servo will not be exposed too much above chasis. Tamiya recommends max 29 mm servo height measured from mount to bottom. My servo has 26.5 mm so if I remove 1.5 mm shims it will be still 28 mm.

I wonder if ball joints position with High Torque is correct. It seems quite high compared to standard.

Some additional info. Aqroshot manual, so the same chassis and the same HT servo saver.

Racing Fighter Black Edition, so the same model as mine but with included HT Servo Saver in kit.

As you can see there are no nuts but screws. I assume they are smaller in diameter and does not hit chassis.

 

[bill_delong]

not sure why you need the spacers in the first place?

probably wouldn't hurt to dremel where the nuts will bind into the chassis to get more steering throw, though I wouldn't go too crazy by only removing just enough plastic so the nuts don't rub on the chassis when the servo is at full lock left/right

 

[ChuChu]

I just wanted to follow manual. Reason below.

On left standard plastic part. On left aluminium Hop Up. As you can see in standard shims are integral part. Tamiya wanted to create Hop Up part the same.

I will install servo at the end of build with shocks attached, just to be 100% that sterring rods will not hit chassis.

 

[bill_delong]

kinda looks like the part on the left was designed for those raised plastic nipples to fit inside the opening of the servo flange, but most servo trays in modern designs are like the part on the right to allow a wider range of servo flange designs to be used.

 

[ChuChu]

Quick update.

I polished rear shock shafts, because stock were black ( not problem) and very harsh ( problem).

I used abrasive cloths and at the end Autosol.

I do not know exactly why, but area where I polished the most turned little orange. I think:

1. I removed second (?) coat

2. Too much heat

To be honest, I do not know. I polished many things, including screws, they were hot but did not change colour.

Does not matter. If something bad will happen, I have second set of shocks. Most important that shafts are very smooth now.