Impress Formula 1 build thread

[Lavigna]

Great thread. I am not familiar with these cars at all, but have always liked how they look, and their relative simplicity to many other RCs. Keep it coming!

[EvolutionRevolution]

Just received some more stuff:

The car is mostly stock has has a home-repaired top deck, but includes the optional chromed wheels.

[tintin74]

Digging out this old thread, as I just bought a Kyosho Impress myself and I am trying to restore it... without the manual

Awesome thread you have done here. Thanks for the detailed pictures, it is all starting to get clearer in my mind as I now know there was two different models of this F1 car, the early version and the impress version.

Turns out I have the impress version, which is a good thing by the looks of it. I was just wondering if the impress all had the ball diff standard...

I'll post pictures of my car later on.

I hope, you can show us the end product of your impress with all these great options!!!

[EvolutionRevolution]

Later this week I will be continuing my original build, but I just wanted to show another parts car I bought some time ago:

This is an Impress with the suspension kit front end installed, plus almost all other options (alloy diff, carbon chassis, alloy shock, alloy t-bar mount, carbon rear axle), and a few aftermarket parts: alloy body mounts, delrin adjustable friction damper, and some very cool aftermarket alloy pod parts:

...and a 16x4 modified motor.

Going by the servo saver, and the noise it makes when moved, the servo might be a good model, too.

[EvolutionRevolution]

So continuing the build of the old car where I left it...over four years ago.

First, I decided to reinstall the front uprights. So I got the ones that were on the car out of the bag of parts:

These are quite dirty and one of the steering links is bent. I will replace that link with one from another parts car later on, when I have a suitable servo. The kingpins used are those from the optional kingpin set.

However, I will be using this Cross set instead:

These include slightly longer kingpins and shorter springs:

All so they add an adjustment option to the car:

...adjustable ride height, either through the spacers shown here, or by limiting the suspension travel through a collar that is attached to the bottom of each kingpin. However, the latter choice uses very small set screws in an aluminium collar, and I'm afraid of losing them while running. So I chose the spacers.

[EvolutionRevolution]

The Cross set comes with three spring rates, soft, medium, and hard, with the medium set being as hard as the hard set from Kyosho. After taking the front arms apart and then bolting the front end back together, I went to have a look at the friction damper. Sorry, I forgot to take a picture of the assembled front end...

The friction damper consists of a spring loaded lower plate, a middle plate that attaches to the rear pod, and a spring loaded top plate. I put some teflon tape on all of the mating surfaces to protect the plastic from wear.

First, a look at the top plate and the original 'damper', which is no more than a spring on a screw:

As I will be using an oil shock, I need to remove the spring damper's mounting point from the top plate:

This required quite a bit of force to snip off.

The parts required for assembly:

Putting the central plate in place was a pain in the behind because the axle that goes through the front of the pod was hard to correctly insert into the holes, and then it was also hard to fully slide it through the pod. If there had been a motor installed I wouldn't have succeeded...

Mounting the top plate failed initially because the plastic collar onto which the ball for the shock mounts broke when I tried to tighten down the ball. So I swapped it with a TF-2 alloy collar:

After assembly:

I used some medium Tamiya friction damper grease on all of the plates. The friction damper is non-adjustable.

The simple spring damper will be replaced by Kyosho's FJW-7 Formula oil shock option:

However, I won't be using this new shock, as one of the parts cars came with this shock. I still have to figure out which grade of oil I should use, since Kyosho gives no indication on what to use.

[EvolutionRevolution]

So I managed to get the used formula shock apart (pics will follow later this week). It's a fairly conventional shock except for the spring, which fits over the shock shaft instead of the shock body.

I've also discovered the optional ball diff has a design issue: it can't be properly tightened because the nut bottoms out too early I figured there was some kind of issue when I saw the instructions helpfully suggested shimming the diff on the axle side if it couldn't be properly tightened... Of course, only a single shim is provided. I was already planning on getting ceramic diff balls for it, so I will add the correct size of shim to the order.

Another issue I need to solve is that the carbon axle I want to use is a bit worn and tightening down the set screw in the diff hub won't lock the diff hub to the axle...

[EvolutionRevolution]

First the pictures of the front end I forgot last time I worked on the car:

I'm not sure I can salvage this set of front tires, they're quite dried out:

Anyone know a solution beyond glueing the cracks with superglue?

[EvolutionRevolution]

Then I installed ball bearings in the ball diff and reassembled it:

When mounting it to the car I discovered the aforementioned problem with adjusting it, so I've temporarily removed it (and the whole rear axle assembly) again.

I then attached the top deck:

The second-hand shock was mostly taken apart, except for the bottom cartridge, which was stuck:

But it still seals well, so that isn't really a problem. Parts layout:

The bottom cartridge contains two o-rings.

I cleaned the shock before filling it again with 45 wt oil and reassembling it, and then mounted it to the car:

I've also managed to straighten the bent steering linkage.

[Diamond Dave]

Very nice car, looks great so far. I have not missed an F1 race this year.

[EvolutionRevolution]

Thanks. The latest controversy that led to the stewards taking a ridiculous amount of time to penalize some drivers was actually the reason I though I'd do something F-1 related not related to the current season

So, after getting some new superglue I fixed up the carbon axle, flipped it 180 degrees, and installed the left wheel mount on one end:

I then turned my attention to the gear diff that was installed on one of the parts cars. It was really dirty and had been filled with way too much grease. After a lot of cleaning I ended up with this:

Note how the small gears are rather chewed up. Probably the excess grease and dirt is partially to blame, but the parts car was only run with a 540-class motor ...so the small gears can't handle even the weakest motors . I still decided to rebuild the diff.

First, a modification:

I drilled a hole in one of the diff hubs so I could properly tighten the diff shaft to the rear shaft without having to take the whole diff apart.

I then installed ball bearings in the other diff hub, and put the worn gears in the spur, only lightly greasing them this time:

I then assembled the whole diff and applied a little bit of blue loctite to the nut keeping everything together so the diff can't loosen while running:

Surprisingly, it is quite smooth despite the damage to the gears.

Then it was installed on the car:

I then put on the wheels and took some picture without and with the body:

The body will need some improvements, but that's for later. I also will have to source electronics for it, but that can wait a bit since it's winter here now and very wet, and F1s can't run in the wet.