Impress Formula 1 build thread

[EvolutionRevolution]

The next update will likely take a while, because almost everything on this car mounts to the chassis (which is in the mail).

I didn't find the alloy t-bar mounts ,

I've dug through close to a dozen boxes until now, including some pretty huge ones, and am starting to think that I won't be able to find the one part that always made me wonder whether I should try a build of this car or not (ironically). I'm pretty sure I didn't sell the part, but it's not in the obvious places where I remember storing it (with the other F-1 bits) and also not in quite some other places. Still four boxes to dig through tomorrow. Also can't find a transmitter I know I should have...

But at least all of the boxes I had a look at are now labeled.

[EvolutionRevolution]

Found the missing transmitter, no go on the alloy t-bar mounts I either lost the parts bag or sold it. Sigh. One more thing to buy.

Did find this though:

Carbon fiber version of the lower pod plate in the FJW-20 suspension kit. No number on the header card, no manufacturer, only "Impress" in Japanese and something else I don't recognise (guessing: "R chassis/plate (carbon)" - can't really read Japanese). There's a price on it though, so it must have been sold somewhere...

I also received the diff joint for the original Kyosho F-1 rear axle, so there will be a small build update today anyway.

The diff joint fixes something Tamiya never got right until fairly recently: it's possible to adjust the diff independently of swapping wheels. However, the nut provided is not a locknut, so I guess I'll have to use blue locktite instead.

The Impress should be able to use Tamiya wheels, as the hex portion of the axle is the same size:

Parts required to assembled rear axle minus diff and rear axle:

The setscrews were pulled out of my Tamiya F-1 parts box, as they are not provided with the diff joint. The ball bearings come from the Impress box.

Temporary fit with a Tamiya steel axle:

The flat parts of the Tamiya axle unfortunately do not align with the Kyosho parts (on either side). I thought I could use an aftermarket carbon axle for a Tamiya car that was lacking the flat spots instead, but although the axle fits into the diff joint parts it doesn't fit into the ball bearings. That axle is just a fraction too thick. Guess I'll have to get the Kyosho one...

[EvolutionRevolution]

Scratch that, new new list:

- FJW-1 carbon chassis
- FJW-2 carbon axle (might need to check whether I can use a Tamiya carbon axle)
- FJW-22 optional diff rings
- body

So, slight changes to this. FJW-22 can't be used with the alloy diff set due to tabs on the diff rings (I'll show this later), so I can leave that one out. Instead of the FJW-2 carbon axle, I've bought a steel axle for the old F-1 car (FJ-13) - less chance of breakage and some more weight to keep the rear planted. I've just bought a new FJW-4 alloy t-bar set, since I can't find my old one . I have a carbon chassis in the mail that I hope will arrive - it entered Holland a week ago and hasn't been moving since then (don't know what is up with the Dutch Postal services right now, last year they seemed to have improved a lot, yet this year they've been pretty crappy and under par compared to previous years...I blame idiots who think shareholders are more important than service... ).

[EvolutionRevolution]

And...

The chassis has turned up today. It was stuck in customs, and for some reason the international tracking was updated with the wrong information (AGAIN . I can feel a complaint brewing... ).

FJW-1 carbon chassis...wait, wait, wait? Carbon?

Nope:

Graphite.

Same part number as optional carbon chassis, but different.

Comparison of fiberglass Impress chassis (left), FJW-1 carbon chassis (middle; pay no attention to non-factory holes), and FJW-1 graphite chassis (right):

The graphite chassis has the additional holes of the Impress fiberglass chassis that are not present in the carbon chassis. It is also much thicker (top chassis) than both the fiberglass (bottom) and carbon chassis (middle):

The bag and header card are not entirely standard:

So this looks like a part made in Japan for Kyosho's US importer, Hobbico.

On the other hand, I also have a carbon pod plate besides the graphite one included with the suspension kit. Maybe the suspension kit also exists with a carbon pod plate in the box? And the graphite parts are later upgrade parts when it turned out the carbon parts didn't cut it? It's all a bit of a mystery...

[EvolutionRevolution]

FJW-4 received, this time without customs shenanigans:

[Dadio]

Don't you just love those little packages arriving ! Keep up the good work , I'm looking forward to seeing the finished car .

[EvolutionRevolution]

One more little package, received a while back:

Might have found a good place to get a original Kyosho body (and a original Kyosho F1 chassis with a load of options).

[AscotConversion]

Somewhat random question: Do you think the rear axle parts fit Tamiya cars? Just asking as the Kyosho gear diff parts may be cheaper than buying a Fenix gear diff (over $100) http://www.teamcrc.com/crc/modules.php?name=Shopping_Cart&file=product&c_op=viewprod&prodID=7719754

[EvolutionRevolution]

Somewhat random question: Do you think the rear axle parts fit Tamiya cars? Just asking as the Kyosho gear diff parts may be cheaper than buying a Fenix gear diff (over $100) http://www.teamcrc.com/crc/modules.php?name=Shopping_Cart&file=product&c_op=viewprod&prodID=7719754

They could possibly fit, but I haven't compared the dimensions of the diff joints yet - seeing my experience with the rear axle I won't be surprised if Kyosho's dimensions are off by just a little bit.
Another problem is that the Kyosho gear diff is made from fairly hard plastic that is not fiber reinforced, and the small gears don't have metal shafts but use molded on nubs to rotate on. I wouldn't run the Kyosho gear diff with a brushless, it'll probably won't be able to withstand the torque of such a motor and might melt due to the friction generated.

[AscotConversion]

Thanks for the info. 25.5 motors are not incredibly powerful, so I would not be that worried, especially if it's 48p or the metric equivalent (0.6??). Getting it on the car is a bigger concern to me.

The Kyosho F1 cars are cool, just don't get the love Tamiyas do....

[EvolutionRevolution]

Today the Kyosho F1 chassis with a load op options (and a body) turned up - after being stuck in customs for way longer than necessary (because of the ongoing IT mess at the Dutch postal services I guess...tracking never updated and the customer service was impossible to reach...).

So this one is the pre-Impress F1 that is mostly compatible with the Impress:

[ChisaiKuso]

This is a great thread! Thank you for taking the time to put it together with so many detailed pictures.

What is it about these old school F1 cars that is just so dang cool? I personally have an obsession with the HPI F1 cars, but perhaps I need to add an Impress to my collection as well.

[EvolutionRevolution]

This is a great thread! Thank you for taking the time to put it together with so many detailed pictures.

What is it about these old school F1 cars that is just so dang cool? I personally have an obsession with the HPI F1 cars, but perhaps I need to add an Impress to my collection as well.

In the case of the Kyosho, I would say its relative lack of success despite being technically more advanced than Tamiya's offerings.

Anyway, I realised that I basically have a almost full-options pre-Impress F1, so I figure I'd take a little detour and show that car's reconstruction with all options installed.

First, a few comparison pictures between the Impress chassis kit parts and the original Kyosho direct drive F1 chassis. Impress at the top, original F1 below.

Forward top deck:

Basically, the only things that are the same are the holes for accessing the tweak screws, the antenna tube location, and the two most forward holes. Everything else is different. On Kyosho's original F1 the servo gets doublesided to the chassis.

Battery top deck:

Again, many changes, including the location of the multidirectional friction damper. What's interesting is that the top deck on the original F1 is reversible, allowing a forward and rearward battery location. It's also a bit flexible.

The old carbon chassis, this time without additional holes:

On the old F1, the front arms have fixed camber and caster, and screw together like on all old Tamiya F1 cars up to the F103:

They attach to the chassis using 4 mm screws:

However, the front wing attaches with 3 mm screws, meaning that although it looks Tamiya-compatible in general shape it actually isn't (Tamiyas use 4 mm screws):

I do think that the Kyosho suspension arm geometry looks more realistic than on Tamiya's F1 cars.

[EvolutionRevolution]

Let's continue a bit.

The only difference between the Impress chassis kit rear pod and the one from the older F1 is one screw hole, which on the Impress serves to mount the multidirectional friction damper's central post.

On the older F1, this central post attaches to the top deck, with the multidirectional friction damper's flat middle section attaching to the rear pod instead (basically the inverse situation of all more modern F1 cars), using a hinge of which the shaft fits into the upper screw holes of the front pod section:

(very practical for maintenance )

The t-bars have the same shape, with the Impress' t-bar made from somewhat stiffer white fiberglass:

Anyway, since the t-bar is the only suspension option on the old F1, I'll attach it to the pod:

Theoretically, at least, it should be possible to use the rear link parts of the Impress link suspension kit on the old F1 chassis, as all of the screw holes used are the same, but because the top deck is different the additional tuning options provided by that kit can't be installed. This would mean there would be no option for roll control.

On the old F1 kit (and also standard Impress kit), the t-bar attaches to the chassis using two plastic parts (the classic o-ring suspension):

The front part has holes for installing tweak screws, but no tweak screws are provided. Looks like they need to be quite long, 5-10 mm. However, the plastic parts apparently cause a problem that is sometimes also seen on very abused second hand Tamiya F1 cars with badly tightened top deck: bent screws. Too much play in the screw holes?

So instead I will be using option FJW-4, Special Mechanic Post:

This replaces the plastic parts with machined alloy bridges and screw-on alloy posts, and it also includes fresh screws.

(Note that the FJW-4 instruction sheet shows the awful original plastic chassis, to be avoided at all costs. Just replace it with the carbon chassis)

So:

That looks better.

Then I added the rear body mounts to the top deck (use short screws), and installed it onto the car:

The top deck is placed in such way that the battery will be located to the back of the centerline of the top deck.

[EvolutionRevolution]

I also attached the rear wing to the rear pod:

I then installed the center post for the multidirectional friction damper, followed by attaching the rear pod to the rest of the car:

That will be it for the moment, as I wait for some stuff I need to complete this car.