Top Force Evo build questions

[BuggyDad]

A few basic setup questions if I may.... 

1. I was advised a while ago to use plumbers grease in off road ball diffs to stiffen them up, while sticking with tamiya ball diff grease on road. I have both. So I'm tempted to do the same again. What say you? 

2. I use x rings in place of red o-rings in CVAs and see them as a good upgrade. I'm tempted to do the same in the TFE hi caps, but I know the shocks are already well regarded. What do you think? 

3. The pistons are on a sprue, so they won't be as accurate as the posh ones, but how much does it matter in this case? Are you running the kit ones or have you upgraded? If running the kit ones have you stuck with the three hole ones? 

As an aside, they're 12mm. I hadn't realised they were so big a bore. It has to be a good thing. 

4. Tamiya yellow soft oil is quoted in the manual as "400". I tend to shun this stuff for Core RC silicone oil, simply because I can go up or down from a known starting point with oils I have in stock. I also have a (strong) feeling that Tamiya 400 is not the same as my Core RC 400, but I can't remember in which direction. My usual starting point is Core RC 300. What oil are you running?

5. Are you happy with the kit springs? I believe the big bore set are the same size.

Edit: 6. Right, I've put the diffs together. I used the plumbers grease. Pretty much had to do them right up to pass the "push on the carpet" test. They might be a little on the stiff side, not sure. 

Another aside - all my ball diffs have the same feeling of slight, but consistent, roughness. I'm pretty sure the reason is my sanding and that if I had some say 1000 or more grit paper they'd feel a lot smoother. I've gone to 500. I don't think it's a problem but it's notable they all feel just the same in this regard. I noticed when cleaning the plates in my hand that just rubbing two together gives a similar feeling which is what made me realise I should probably sand finer.

[ThunderDragonCy]

@BuggyDad My ball diffs always have a tiny bit of roughness, but always seem fine. I use either tamiya or core rc ball diff grease in my ball diffs. Seems fine.

No experience with hi caps, but if they are 12mm bore then you can use big bore aeration pistons

[BuggyDad]

17 minutes ago, ThunderDragonCy said:

No experience with hi caps, but if they are 12mm bore then you can use big bore aeration pistons

Yeah, I have Hi Hopes for the Hi Caps 😉

Big bore, simple design, nicely made (the walls are amazingly thin), most likely I'll go "Hi Caps Max" with x rings and, if I've got some suitably holed, big bore pistons. Maybe this'll be my buggy most often dropped admiringly on the workbench for its cat-like landing. 

[Howards]

If you’ve got time / energy you should fit better pistons to the hi-caps. Not sure what difference the x-rings would make but why not give them a go too. 

As they are big bore but without a collar adjuster thread it’s tricky to find any springs that work with them as they come from the kit.  Normal big bore springs do not fit without some modification, don’t assume the Tamiya big bore springs will fit. 
 

350 rear 300 front is a good starting point.

[BuggyDad]

7 hours ago, Howards said:

As they are big bore but without a collar adjuster thread it’s tricky to find any springs that work with them as they come from the kit.  Normal big bore springs do not fit without some modification, don’t assume the Tamiya big bore springs will fit. 

Is it diameter or length that's different? 3d printing could make decent collars/preload clips, maybe cups too, if it's just dimension changes in the plastics required to make them fit. 

[Howards]

3 hours ago, BuggyDad said:

Is it diameter or length that's different?

Both but it’s the OD that makes things tricky. 
 

The OD is somewhere in between contemporary BB shocks and regular bore shocks. The cap OD is < than the ID of a BB spring. To fit BB springs you need a collar with a narrow ID and a BB OD. 

The ‘clever’ stock spring rest reduces the length of spring required,  and because the stock spring ‘s ID matches the shock body OD, is too small to work with BB springs. 

To sum up you need a custom collar and a new spring rest if you want to fit a contemporary BB spring

Or bodge fit Schumacher stuff like I did

[naturbo2000]

7 minutes ago, Howards said:

Both but it’s the OD that makes things tricky. 
 

The OD is somewhere in between contemporary BB shocks and regular bore shocks. The cap OD is < than the ID of a BB spring. To fit BB springs you need a collar with a narrow ID and a BB OD. 

The ‘clever’ stock spring rest reduces the length of spring required,  and because the stock spring ‘s ID matches the shock body OD, is too small to work with BB springs. 

To sum up you need a custom collar and a new spring rest if you want to fit a contemporary BB spring

Or bodge fit Schumacher stuff like I did

I was of the understanding that the rere Evo springs are actually the same as the Tamiya Aeration Big Bores, and that you can just use the tamiya tuning springs as required.

I can go check if wanted. Whilst my Evo is now on Tamiya Big Bores, I moved the originals to the Super Madtute.

[Twinfan]

35 minutes ago, naturbo2000 said:

I was of the understanding that the rere Evo springs are actually the same as the Tamiya Aeration Big Bores, and that you can just use the tamiya tuning springs as required.

I can go check if wanted. Whilst my Evo is now on Tamiya Big Bores, I moved the originals to the Super Madtute.

That's correct as per part numbers in the manual.  I don't know if the Evo kit comes with soft, medium or hard springs for the front and rear though.

[Howards]

38 minutes ago, naturbo2000 said:

the rere Evo springs are actually the same as the Tamiya Aeration Big Bores

Cool if so - it would mean they revised the plastics to fit them. 
 

Would be good info to add to the buggy damper thread.

[ruebiracer]

I think the Evo just uses lower spring seat and ball collar from the Big bore dampers part tree, so the spring is guided well in the lower end. Upper end sleeve still has some kind of radial play, as there was no special new part created, sadly. Correct me, if I´m wrong. I checked last year the Evo manual, as I also want to use Big bore springs on High caps...

[ThunderDragonCy]

I am a big fan of the Schumacher/Core RC springs for CVA2 rears and they really hold into the spring platform. 

[naturbo2000]

11 hours ago, Howards said:

Cool if so - it would mean they revised the plastics to fit them. 
 

Would be good info to add to the buggy damper thread.

Pretty sure i originally found out from that thread.  I'll see if I can find the link to the post. 

Was just about to go check on my Super Madtute and saw that I'm already using Big Bore yellow springs on the rear and kit white springs on the front. I can confirm the play at the top shock collar as mentioned,  hence two photos of the front shock. Does not seem to matter particularly - this play is in the stock Evo configuration (shock,  spring,  collar) and it's the same using kit or big bore springs. 

 

[ruebiracer]

2 hours ago, naturbo2000 said:

Pretty sure i originally found out from that thread.  I'll see if I can find the link to the post. 

Was just about to go check on my Super Madtute and saw that I'm already using Big Bore yellow springs on the rear and kit white springs on the front. I can confirm the play at the top shock collar as mentioned,  hence two photos of the front shock. Does not seem to matter particularly - this play is in the stock Evo configuration (shock,  spring,  collar) and it's the same using kit or big bore springs. 

 

With this Hicap setup it didn´t work for me. The big bore springs were jumping over the lower spring seat of the Hicaps.

[naturbo2000]

2 minutes ago, ruebiracer said:

With this Hicap setup it didn´t work for me. The big bore springs were jumping over the lower spring seat of the Hicaps.

I'm using the "silver" spring seat per the Top Force Evo kit. It's a larger diameter seat to match the big bore springs.

[BuggyDad]

14 hours ago, ruebiracer said:

I think the Evo just uses lower spring seat and ball collar from the Big bore dampers part tree, so the spring is guided well in the lower end. Upper end sleeve still has some kind of radial play, as there was no special new part created, sadly. Correct me, if I´m wrong. I checked last year the Evo manual, as I also want to use Big bore springs on High caps...

As it happens, I have the parts trees from both the Big Bores and the 2021 TFE here.

BB left, TFE right. 

They have the same numbers on A906792/84421 and year of 2006 but they differ slightly. BB has cups to take springs of ID 13 or 14MM. TFE 13 or 16.5mm. However. The BBs also come with aluminium cups of course. 

All the springs are ID 16.5mm.

[Howards]

Hmmm. I should buy a TFE. 

[BuggyDad]

Big bore pistons won't fit the Hi Cap shafts which are sized for thinner pistons, however the kit pistons are a nice fit so I don't think anything's lost there. 

[BuggyDad]

So I assembled the shocks essentially stock except I used Core RC 300 oil in place of the Tamiya yellow "400". They feel "in the ballpark" - a loosely acceptable starting point in so far as I can tell with the car incomplete. As an aside, making the same choice on the Saint Dragon CVAs (to use kit parts but replace the Tamiya yellow oil with Core RC 3OO) leaves those feeling way underdamped - I will await a fully assembled car before adjusting but am likely to replace with the fancy pistons on that one before then adjusting oil.

[BuggyDad]

I have a second round of TFE questions for you good folk... 

1. What are the real glaring weak points and what are the usual options in solving those? My understanding is it's gearbox casing and tower mount (which are related) - mainly in the rear - and arms and hubs/knuckles which top the list. 

2. I saw somewhere that folk replace the aluminium idler gear for plastic - what's the story there? How necessary is this and what part do you recommend? I see one option is Xtra speed:

https://www.rcmart.com/xtra-speed-delrin-gearbox-gear-for-tamiya-ta01-ta02-top-force-xs-ta29163-00129457

On Q1, we have of course @Concorde's excellent thread

 

and interesting 3d printed solutions but in order to make my own choices I'd like also to get abreast of the other solutions people have used and the aftermarket. What's good? What's most necessary? 

One fairly good looking option I can think of is to:

- buy the @Concorde rear reinforcement kit (notable that I think that'd work too on a home printer)

- possibly buy an aluminium front diff cover - there does seem pretty clear consensus this is a decent call

- look for aftermarket front knuckles and c hubs which I could keep in reserve until I break the kit ones (but I question whether aluminium is the right option here, and that's what I've seen) 

- and keep a watching brief over rear hubs which I should be able to design myself in one iteration if that becomes necessary. I could also work on c hubs for commercial printing, having had good success before in that area, but they (and the front knuckles and rear hubs) aren't a thing for home printing. 

[ThunderDragonCy]

@BuggyDad In answer to question 2, the aluminium idler against plastic gear eventually does the same thing as sift aluminium pinion and chews it all up. For keeping kit gearing you need the 50529 touring car gearset. If you are running brushless I would suggest getting the TA02 high speed gearset to not only replace the metal bits, but get smaller spur gears. Even if you have already bought a 21t pinion, the 69t spur in the high speed kit will fit.

Can't comment on the other bits really, apart from to say the DF01 rear trans in Ultra Hornet has seen a lot of track running with no issues, but I am running old school fast brushed, so not much torque.

[BuggyDad]

1 hour ago, ThunderDragonCy said:

@BuggyDad In answer to question 2, the aluminium idler against plastic gear eventually does the same thing as sift aluminium pinion and chews it all up. For keeping kit gearing you need the 50529 touring car gearset. If you are running brushless I would suggest getting the TA02 high speed gearset to not only replace the metal bits, but get smaller spur gears. Even if you have already bought a 21t pinion, the 69t spur in the high speed kit will fit.

Can't comment on the other bits really, apart from to say the DF01 rear trans in Ultra Hornet has seen a lot of track running with no issues, but I am running old school fast brushed, so not much torque.

Thanks. I can see 47393 TA02 High Speed Gear Set, but curiously I see "NOTE: Cannot be used with Manta Ray and Top Force models"

https://www.modelsport.co.uk/product/tamiya-ta02-high-speed-gear-set-435441

So I wonder whether that's a fundamental incompatibility or them just referencing the change in spur size which would result, of course, in the pinion size labels on the motor mount being out by however many teeth different we are. 

Have I got the right part? 

[Saito2]

You know, even the standard 50529 touring car gearset has a note in the instructions about not being compatible with "1/10th RC off-road buggies" and no one that I'm aware of has ever had an issue with using them in DF01s. I've had them in a Dirt Thrasher, Top Force and Manta Ray for years without issue.

[BuggyDad]

5 hours ago, Saito2 said:

You know, even the standard 50529 touring car gearset has a note in the instructions about not being compatible with "1/10th RC off-road buggies" and no one that I'm aware of has ever had an issue with using them in DF01s. I've had them in a Dirt Thrasher, Top Force and Manta Ray for years without issue.

Ah ok. Fair point. Good to know. Thank you. 

[naturbo2000]

Weak points: I crash a lot (getting better) and rip the OG front diff cover to shreds when an arm goes. I swapped to an alloy cover which completely resolves that issue,  but transfers all of the load into the front gearbox which splits open instead. That said,  I've got better driving since then and would still prefer the alloy cover route,  just for mean time between failures.

I've never broken an arm or hub,  but switched out to alloy just in case.  I don't deem it to be necessary.  Beware that the OG rear hubs have toe in and some replacements do not.

I have broken the chassis mounted steering arms and would consider this a must replace to alloy, if only because the short one is effectively impossible to replace at a race meet.

I have not broken any towers or supports. My rear gearbox is suffering from lifting under torque from a quick 13.5T. I always hear one of the gears jump a tooth from launch. I should brace it before failure...

I've also bent steering turnbuckles, but that's easy to replace as and when.

[BuggyDad]

TFE completed except electronics and stickers. 

What an absolute beauty this is. 

 

Currently box stock except stainless hex screws throughout.

My shopping list is growing but I don't think it'll be huge. 

TA02 gear set and one of the aftermarket motor mounts. 

Probably Xtra speed aluminium front diff cover.

Maybe their front knuckles as well but I think probably not the c hubs at this point - looking to avoid too much hard aluminium in that area. Or I could just pick up spare Tamiya plastic ones, which are less than half the price. Nice that they're not sided so this is perhaps a rationale to keep them as the most likely breaking part. 

I think I'll buy @Concorde's rear strengthening set and his stick lipo holder. They look like very good solutions and I like to support someone in the community. I had been looking at how best to design a stick lipo holder in already and his design looks excellent, much better than I'd come up with as a first go, for absolutely certain. 

One thing I might consider, but not now, is to incorporate into the lipo holder a pair of inboard screws to both the chassis lower and upper decks (for which I'd cut my own modified versions), because I read the chassis is regarded as torsionally too flexible and this should change that in one hit. It doesn't feel flexty to me though, I'm the owner two Blitzer chassis 😂. 

The rear suspension mounts have almost perfect space in front and behind the arms for simple CF left to right braces, so I will design and cut a pair. I think this is a contributing factor, even if not a huge one, to rear gearbox failure, since some have highlighted the suspension mount bosses as part of that failure, plus I've seen loads of failures in this design in other models. It's entirely solvable with a new pair of longer shafts and two small parts cut on the CNC. Can't do any harm. I could extend the rear one such that the one CF plate takes in all four screws of the diff cover as well, if the failure mode there is linked to the strength of that it would help there.