TL-01 Ultimate Rebuild

[Bazyli 39]

First things first: I bought a set of long aluminum control arms and aluminum hubs in a kit that was designed for the GF01 (see here).  Kudos to @svenb @Juls1@ThunderDragonCy@TwistedxSlayer for their information in this thread from which I knew to get the kit.  Here's a picture of the hardware test mounted to the new chassis plastic (no upper arms/tie rods attached yet).

Despite advice given, I was still not 100% sure when ordering this kit that the components would fit, or that the track and wheelbase would remain unchanged (call me paranoid if you will).  I have now verified to myself, based on my own measurements, that these parts fit perfectly and that track, wheelbase, and wheel positioning forwards/backwards has not changed even 1 mm.  I measured the old arms on the old chassis and the new arms on the new chassis in the following places and got the same numbers for both (I estimate +/- 0.5 mm margin of error in my measurements):

• rear chassis centre to outer edge of wheel shaft bearing: 76 mm
• front chassis centre to outer edge of wheel shaft bearing: 76 mm
• rear flat edge of chassis to wheel shaft centre: 20.5 mm
• wheelbase rear shaft centre to front shaft centre: 257 mm

I am certainly convinced the wheel positions have not changed!

Next, I wanted to compare the weight of the stock control arms and hubs to the new aluminum hardware.  Unfortunately, the aluminum is noticeably heavier (about 1.5x the weight of the stock components).  The stock plastic control arms use 2 screws each to join 2 plastic halves.  I used titanium screws in the plastic control arms to give a best case comparison.  I did not include any upper control arms/tie rods in this comparison as weight differences there are hopefully marginal (the new arms will use longer upper arms/rods so there is some extra weight there but hopefully its negligible).  The final numbers are:

• old arms: 29 g (per half of car so 58 g total)
• new arms: 43 g (per half of car so 86 g total)

So that's a 28 g (86 - 58) penalty I am paying now for using the aluminum suspension components : (  Hopefully the handling is worth it.  I don't think I'm inspired enough to attempt to construct my own arms or hubs : P

[Bazyli 39]

Next up, I took the running car apart again and inspected the drivetrain components.  Sadly, the propeller shaft is showing signs of wear now at both ends where the cross pin goes through.  Now, as @WillyChang mentioned, it would have been best if I went over the drilled face/edge in the carbon graphite with CA glue to seal and join the fibres, and I did not do this.  I'm sure that would have helped, but I'm not convinced this would completely solve the problem of those cross pin holes wearing out... So now I'm conflicted.  Do I try again the carbon graphite shaft and drill holes but this time seal them proper?  Or do I try aluminum or brass now?  Or, maybe, I'll just epoxy the end gears onto the propeller shaft (bearings on first!)...  The last solution is a bit ghetto I know; but I don't know how much time I want to spend engineering this prop shaft!  Pics of wear and tear below (not super visible - the shaft has expanded at the location of the drill holes.  It is noticeable when sliding bearings on/off the shaft):

 

[Bazyli 39]

The other item of consideration is the differentials I built.  It seems the caulking I layed down around the outer edges held just fine, but the grease has been working its way out along the out shafts (more significantly on one diff than the other, and I don't know if it was the front or rear because I mixed them up right away).  Also, I checked the limited slip action after some heavy driving and it was below mediocre in my opinion.  So, I hope the Tamiya grease I ordered will turn out to be significantly thicker than this automotive grease.  Otherwise, I will have to keep searching for some thicker grease that wont leak out of the diff and that won't soften up so much under use.

[ThunderDragonCy 7881]

Interesting to see that aluminium set on a car. The performance should be great, but i think it's a shame they don't offer it with plastic arms and aluminium ecerything else. I think that would be the perfect weight/durability balance. 

For the prop shaft i have seen 5mm diameter metal ends bonded into 7mm OD/5mm ID carbon tube. If you are confident of keeping things concentric that might be you best bet? 

Diffs-wise, i used a hot glue gun to drop three blobs of hot glue in the front diff and left the rear diff pretty much open. Just a dab of grease on the bevels for lubrication. 

[Tizer 606]

Probably if you factor in the heavy screwpin kingpins of the original suspension vs. the thinner and lighter kingpins on the aluminium arms the total weight difference will be less. Also you gain a lot of handling performance from the altered suspension geometry which will be much more than you lose from adding a few grams of weight

[Bazyli 39]

21 hours ago, ThunderDragonCy said:

For the prop shaft i have seen 5mm diameter metal ends bonded into 7mm OD/5mm ID carbon tube. If you are confident of keeping things concentric that might be you best bet?

Sounds beyond me.  Plus the shafts the hobby store sells don't even seem to have the hollow part centred hahaha.  I'm going to give it one more shot using the carbon fibre rod and this time:

• drill more accurately sized holes
• seal exposed faces with CA glue
• use a stronger epoxy for the fill around the pin holes

If the above still fails then I am going to try aluminium next.  I have an idea for how to strengthen the pin holes on an aluminum prop shaft...

21 hours ago, Tizer said:

Probably if you factor in the heavy screwpin kingpins of the original suspension vs. the thinner and lighter kingpins on the aluminium arms the total weight difference will be less. Also you gain a lot of handling performance from the altered suspension geometry which will be much more than you lose from adding a few grams of weight

Yes, hopefully the handling is improved!  We shall see, though I am likely not even skilled enough of an RC driver to notice : P

[Bazyli 39]

Got my new dampers and motor ready:

The dampers are Yeah Racing Shock Gear.  They came with 2 kinds of cores: i) normal bound/normal rebound damping and ii) faster bound/normal rebound damping.  I went with the normal bound/normal rebound since having faster bound seems to me like just a trick to keep the suspension packed down.  Not sure what would be the benefit of that and sounds like you could get pretty inconsistent behaviour that way depending on the surface.  Maybe someone with suspension tuning experience can chime in here.

For the motor I kept the wires short to reduce weight and I soldered on 2x 0.001 uF capacitors (1 on each side of the motor spanning across the +/- poles).  Now reading up on it (yes, after I did the work lol) it sounds like 0.001 uF might be too small : \  Interestingly, I connected both my new 23 turn motor and my old paradox 27 turn motor directly to my battery just to see which one spins faster.  By ear it sounds like the 27 turn spins faster!!!  Maybe my ear is not a great measuring instrument... The real test will be when I run the car.

I noticed that the new motor (and I think the old one as well) allows me to rotate the cap +/- ~15 degrees... I'm guessing this adjusts the timing on when the brushes switch the flow of current?  And if so, I'm guessing that turning it one way gives me better top end torque and turning it the other way gives me better low end torque?

[WillyChang 1814]

To Advance timing, turn endbell Into the direction of Rotation... ie Clockwise when looking from the endbell end.

 

Paradox should be "stock racing" with fixed timing I thought. Doesn't the can have flats on side? 

[Bazyli 39]

1 hour ago, WillyChang said:

Paradox should be "stock racing" with fixed timing I thought. Doesn't the can have flats on side? 

Just tried it now and yes, you are accurate - the endbell cannot be rotated on the paradox motor.  I had falsely assumed it could be rotated when I saw a groove in the plastic which looked like the one in my other motor - the groove/channel that limits rotation to a given range.  The flat sides to indeed prevent rotation if nothing else does hahaha.

[Bazyli 39]

More parts arrived today.

[Bazyli 39]

Rims and tires are ready.  I ordered and used the Tamiya brand tire glue.  It might just be regular CA glue, but it comes in a metal tube that is perfect for squeezing a small amount of glue out and it comes with a very nice applicator tip.  The tip is really fine and long, like the beak of a humming bird; it slides right into the gap between tire and rim easily.  It was not the most expert application by me, but the tires are firmly glued all around.

I went with these rims and tires to match the Lancer for a tarmac setup (these look similar to the kind of tires I've seen run on tarmac in rally).  I am really surprised by how grippy these tires feel in my hands.  I suspect they will wear out super quickly.

The rims are not a perfect match for the Lancer (the original kit came with five spoke rims, and the body shell comes with stickers designed for those rims), but I think they will look good.

[Bazyli 39]

I built the new diffs (stock parts) using the Tamiya Diff Plate Grease.  This stuff is super sticky, just as I hoped.  No idea how this compares to the badhorsie grease I originally wanted.

The grease has a consistency that reminds me of semi-dried maple syrup, or a melted jolly rancher.  It is really sticky and tacky.  I foolishly applied it using my bare hands and it was both a pain in the butt to clean and I ended up getting it all over the outside of the diff as a result of my sticky fingers.  Automotive brake cleaner did a great job removing the grease I needed to clean up.

I used about twice as much grease in one diff than the other, hoping that diff will be tougher to turn.  In the end they are both pretty similar to each other.  The built diffs are really tough to turn.  Feels about 3x to 5x tougher to turn than the automotive grease packed diffs I built back on page 1.  This time I didn't seal the diffs using caulking because I don't think the "grease" will work its way out.  I'll give an update on that when/if I take the chassis apart again in the future.

[Bazyli 39]

New problems: I assembled the rear gear assembly and something is binding against the differential housing gear.  I thought maybe it was part of the chassis due to poor casting or mould design. Upon closer inspection though, I suspect now the diff gear is binding against the gear that drives it.  The binding occurs during the diff rotation points where the 3 screws are located in the diff to hold on the cover. I could not source the correctly sized screws here so I went with something a bit oversized and I think the diff is swollen due to the overly large screws.  I will swap with the screws in the other diffs I built and see if the binding is resolved.

[lowspot 299]

I would change the diffs to ball differentials from the TA03 chassis. They are working perfect with less resistance internally.

Have done it on mine, that's a huge improvement in terms of handling as well.

 

[WillyChang 1814]

6 hours ago, Bazyli said:

New problems: I assembled the rear gear assembly and something is binding against the differential housing gear.  I thought maybe it was part of the chassis due to poor casting or mould design. Upon closer inspection though, I suspect now the diff gear is binding against the gear that drives it.  The binding occurs during the diff rotation points where the 3 screws are located in the diff to hold on the cover. I could not source the correctly sized screws here so I went with something a bit oversized and I think the diff is swollen due to the overly large screws.  I will swap with the screws in the other diffs I built and see if the binding is resolved.

yeah I think the proper screws are M2.6 or thereabout; they're an odd size I've never found anywhere other than T screw bags so that's all that can be used 

[Quailane 33]

3 hours ago, WillyChang said:

yeah I think the proper screws are M2.6 or thereabout; they're an odd size I've never found anywhere other than T screw bags so that's all that can be used 

I’ve never found M2.6 self-tapping screws either, but when I have fresh plastic I try to use M2.5 machine screws. Works fine.

[WillyChang 1814]

yeah M2.6 self tappers were also provided as an option for servosaver fitment in most kits, but only 1 in each kit... does T still do it?  

[Bazyli 39]

15 hours ago, lowspot said:

I would change the diffs to ball differentials from the TA03 chassis. They are working perfect with less resistance internally.

Have done it on mine, that's a huge improvement in terms of handling as well.

 

I will give that a try thanks : ) will be interesting to compare the ball diffs to what I have now.

switching the screws back to the stock ones did indeed solve the binding problem. The screws are 2x8mm tapping screws - not that odd a size but the 2 hobby stores I went to did not carry them, nor did rcmart.

[Bazyli 39]

Assembling the rear gear housing with the Tamiya high speed gear set.  You can see the new final drive ratios I will have.  I'm going with a 19 tooth pinion for now on a 23 turn motor.

Using high strength output shafts from the diff because I noticed the old ones had a lot of play in them.  Hopefully these last longer.

[Bazyli 39]

Putting in the new driveshaft; carbon driveshaft version 2.0.  This time I used a harder epoxy to fill the shaft ends, drilled the pin holes more accurately, and sealed exposed faces with CA glue.  If/when this one blows up I'm switching to aluminium and brass.

Check out the titanium screws.  I think they look so good.  Wish I could replace all the metal bits with titanium!

[Bazyli 39]

Tamiya pinion (left) vs. yeah racing (right).  Not a heavy part, but they are the same price and the yeah racing looks plenty strong, so that is what I will be purchasing in the future.

[Bazyli 39]

Old servo (left) vs. new high speed servo (right).  The new servo is significantly heavier.  Not sure if this is normal for high speed servos?  This one was fairly cheap at $15 so I think I will look for something better/lighter.

[Bazyli 39]

10 regular screws (left) vs. 10 titanium screws (right).  Not a huge difference but it all adds up!  I think i have used 36 of these across the whole car, so maybe about 10 g in savings?

[Bazyli 39]

Hop up servo savers.  3 Racing on the left, Tamiya on the right.  The 3 racing one was really cheap so I bought it just to compare.  The plastic and metal bits feel very cheap, but the design otherwise seems identical to Tamiya.  I went with the Tamiya one.

I am worried about the steering head in this servo saver being shorter than the stock one.  Not sure if the stock one was tuned for its particular length or not, but assuming it was, the ackerman is going to be way off now with the shorter head.  Maybe I can glue the old head to this new one somehow.

[lowspot 299]

FYI: You can use up to a 26T pinion by using the smaller gear of your high speed gear set, the one that is further away from your motor and is a bit smaller. Mine was running with a 11x2 super modified motor and hit 84kph.