Archive for July, 2012

TRF417X Build – Part 5

July 19, 2012 1 comment

Time to finish the build. I now turn to the shocks, just like Jilles says I put a 0.1mm shim under the piston to take out the slop. The slop here is amplified at the wheels, without the shim it means your arms have a bit of movement without the oil doing anything – BAD!

I like to pre-thread the shock ends, it just makes it easier to screw down

I forgot to take a photo of the completed shock, sorry! I fill it with oil, pump out the air, and seal. Make sure all your shocks are the same length with veriers, I make mine 61.5mm. Like the diff I write the oil on in sharpie, these are filled with muchmore 400

Now I put the servo in. Like the bulkheads, I tighten this in stages. First I put the mounts on the servo loosely, then I attach them to the chassis, then I tighten everything up. This will help keep the car tweak free.

I don’t normally use the servo saver – I find the springs wear out fast and make your car wander, so normally I just use a servo horn. This cars’ first outing however is on a track with boards so I’m using the saver. The servo horn goes on a slight angle to make it 90 degrees to the link.

I also attached the top deck before taking the last photo. Again in stages, 1, put all the screws in, 2. tighten all till they pinch, 3. then finally tighten.

Now the sways go on. I use a drop of threadlock on all the grub screws in the collars. No tricks here, just make sure everything moves freely with minimal play.

To get the sways even, I first set the droop and then flip the car upside with the shocks detached. I hold one arm against the droop screw and let the other hang, noting how far it drops before the sway bar stops it. Then I hold the other arm against the droop screw and check how far the other arm falls, then adjust the links until how far each arm can drop is even.

It’s a bit hard to explain, and it’s impossible to photograph without a 3rd hand! Once that’s done I use a droop gauge to confirm it’s even, edgeing it in on the arm until the opposite arm moves, then check the other side. I’m using tamiya springs because I’m racing on carpet this weekend.

Bumper on, the car is now finished, time for the electronics. I’m using the HW v3 speedo for modified, sanwa SRG BLS Type R servo, Sanwa 451R receiver, and Reedy sonic 4.5 and Reedy batteries, so my electronics are all blacked out.

To get nice curled wires wrap them around a screwdriver and heat them with a hair dryer

That is it, my ride is now ready. I will post a parts list for what I have used for the whole build in the next day or two.

I hope you have enjoyed reading my build. Feel free to leave a comment if you have any questions.

Categories: Tips & Tricks

TRF417X Build – Part 4

July 7, 2012 Leave a comment

I had a little time after dinner so I built the turnbuckles and bolted the corners on the car. I built the rear unis the same as the front so no need for pics, just 0.2mm spacing on the inside for these guys.

I hate doing turnbuckles, but this way is pretty painless. Make sure you have a turnbuckle wrench because the tamiya ones are made of cheese and scratch easily. The only turnbuckles I measure are the steering ones, this helps you get the steering link right – we’ll get to that, but just make sure the steering turnbuckles are exactly the same length. All the other turnbuckles I just get started and finish once they are on the car. For all the turnbuckles I cut the top of the balls of so you can get a wrench into them. You can use a drill or reamer but I find this way leaves the least flashings on the inside that can cause the joint to bind.

Now I can put the c-hubs and uprights onto the car. Normally the c-hubs fit well and can go straight in, but check for any binding that might impede the movement. The rear uprights often need a little sanding to ensure free movement, this is going to be really important when we de-tweak the sway bars.

Now I can put the turnbuckles on and tighten them up. I like to point all the turnbuckles in the same direction on one end of the car and the other direction on the other end. That way I don’t need to think about which way to screw the turnbuckle, I just know that if I turn the turnbuckle away from me it tightens it and if I turn it towards from me it loosens it. If I turn the car around to work on the back then its the same, away tighter towards loser.

If the weather holds tomorrow I will head to the track and practice, if the weather doesn’t hold then I will put the servo in and build the shocks 🙂

Categories: Tips & Tricks

TRF417X Build – Part 3

July 7, 2012 Leave a comment

Being a rainy saturday I decided to knock off a bit more of the build.

I’ve previously posted my diff build so no surprises here. I’m trying 900 oil in this one, and I always write the oil weight on the case with a sharpie.

Next up is getting the eccentric holders to fit right, if you put the bearings in you will see the bulkhead clamps rock because the holders are slightly too large. If you leave them this size, when you tighten the clamps they will squash the bearings and reduce their life.

I like to sand them by hand to make sure I don’t overdo it, but if you’re good with a dremel then there’s no reason why you couldn’t use one.

This trick is from Viktor, a sharpie line across the top so you can see if you have the eccentric holders equal. Don’t forget it’s DOT up ARROW down. I also assembled the centre shaft, use shims to take out any play – I used 0.3mm plus the 1mm spacer.

Not too tight on the belt, but remember they will stretch a bit in the first few runs.

Put the steering rack in, no tricks here but don’t forget to put the front belt underneath (like I’m about to). I use flourine coated screws throughout for extra smoothness.

Now time for the spool, these 3 screws are the only ones I threadlock in the whole car. Make sure you use the 9.8mm pins here too, not the 10mm ones! I always use steel spool cups too.

Again loose belt for a smooth drivetrain. It’s sometimes good to have the front belt tighter than the rear if your car is taily on power.

DCJs for the front. Kiyo told me to put the pins the same way in the uni’s, not have them crossed. I assemble the uni then use spray lube. The lube I use is for motorcycle chains and it’s designed not to attract dirt.

Time to shim the driveshafts. The kit calls for 0.1mm on the outside, but I also chock up the inside with shims to reduce play. You’ll notice your camber is hard to measure accurately when you have too much play, it also makes your car inconsistent on track.

Every car is different but I ended up with 0.3mm inside and 0.1mm outside. There is basically no slop now, which is OK because there are crush tubes between the bearings to prevent them breaking.

Time to assemble the c-hubs. Make sure you have the 0.7mm spacers and you can tell the difference between the top-hat washers. You can see the difference here and also an 0.7mm compared to an 0.5mm. If in doubt, verniers are your friend.

Make sure you get the c-hubs around the right way!

Next up is rear uprights then turnbuckles (ugh) and shocks, then it’ll be time to put it all together.

Categories: Tips & Tricks

TRF417X Build – Part 2

July 4, 2012 Leave a comment

Time to start assembling, first I’m going to put the arms and blocks on. For this setup I’m running C/B XA/E with inboard split blocks and 0.5mm shims under all blocks

Use 0.75mm shims instead of 1mm on the hinge pins to ensure free movement

A lot of people still mess this up. Hole 1 is the most outside, hole 2 is the next most outside. For the front use hole 1, for the rear hole 2

Now time for the suspension blocks to go on. Tighten them up then check for any binding. The right rear was sticking a bit on mine, so I give it a couple taps with the handle of my driver. It seems ok but I’ll probably lightly sand the arm to make sure it doesn’t start binding again

Next it’s time for the bulkheads. It’s important to get this right because it will affect how the car tweaks (or rather doesn’t) in crashes. I start by attaching all the lower bulkheads but not tightening the screws fully, then I put the top deck, bulkhead clamps and shock towers. None of the screws are tight at this point everything can be wobbled.

Finally I tighten up the screws. I do this in 3 stages, first I screw everything in but leave it loose, then I tighten until the screws pinch, and then I do the final tightening. For each stage I start with the lower bulkhead screws, then the top deck and bulkhead clamps, and finally the shock towers. Remember the top deck and bulkhead clamps are coming straight off so they don’t need to be super tight.

Stay tuned for the rest of the build…

Categories: Tips & Tricks

TRF417X Build – Part 1

July 4, 2012 1 comment

OK, so time to build a new car. I thought it was a good idea to have two so I could have different setups on them plus my other 417 is due for a refresh. There are plenty of good build articles about, Viktor has a good one on his blog and Jilles pro tips videos are where I got most of my tips from. Nonetheless, lets do this

Start with a clean area

Just the essentials

I used to take time to glue chassis edges and get them looking nice but now I just take the sharp edges off with a bit of sandpaper. Wet the sandpaper to catch the dust because it doesn’t mix well with lungs. Keep the sandpaper handy

At this point I also sand the top deck to make it a little shorter. Often the top decks can touch the bulkhead clamps when assembled so I take about half a millimetre off each end

Categories: Tips & Tricks