Pylon80 2445 Posted September 28, 2022 https://www.tamiya.com/english/products/22047/index.htm Thank you Tamiya! It took you about 10 years but there's finally a nice spool compatible with the TT-02 (I am aware there's been a diff locking block forever; it's not nearly as nice as this). 2 Share this post Link to post Share on other sites
Superluminal 3730 Posted September 28, 2022 Shame its hidden as its a nice looking bit of kit 1 Share this post Link to post Share on other sites
Pylon80 2445 Posted September 28, 2022 5 minutes ago, Superluminal said: Shame its hidden as its a nice looking bit of kit It gives you an excuse to do maintenance on the car though 🙂 Share this post Link to post Share on other sites
toyolien 4508 Posted September 28, 2022 You'll also need new shorter universal shafts too. Â 3 Share this post Link to post Share on other sites
Pylon80 2445 Posted September 28, 2022 53 minutes ago, toyolien said: You'll also need new shorter universal shafts too. Â I think you would be able to use it with normal swing shafts on a type S though, arms are about 1.5mm wider than standard TT-02 if I recall. I have had similar length issues with the older TT-02 oil filled gear diff. Had a set of Eagle Racing 38mm swing shafts knocking around and I was able to use that to make Frankenstein Universals! Share this post Link to post Share on other sites
Raman36 1647 Posted September 29, 2022 Yikes… I have these on order for my TTs. On the RR I have dcjs which were a bit of work to make fit. I’m not aware of DCJs under 39 mm… maybe they will release them for XV02 Share this post Link to post Share on other sites
Pylon80 2445 Posted September 29, 2022 16 minutes ago, Raman36 said: Yikes… I have these on order for my TTs. On the RR I have dcjs which were a bit of work to make fit. I’m not aware of DCJs under 39 mm… maybe they will release them for XV02 That's right, the M chassis ones are 33 and then there's nothing until 39. There is always the trick of using a slim bearing that buys you 1mm extra margin. Not sure if that will be enough. Share this post Link to post Share on other sites
toyolien 4508 Posted September 29, 2022 @Raman36 Tamiya have released them. https://www.tamiya.com/english/products/22054/index.htm 1 Share this post Link to post Share on other sites
Raman36 1647 Posted September 29, 2022 7 hours ago, toyolien said: @Raman36 Tamiya have released them. https://www.tamiya.com/english/products/22054/index.htm Thank you.  I check and I couldn't believe my eyes.... Tamiya USA has them on stock. I am going to press my luck and buy a lottery ticket today.. 😜 Share this post Link to post Share on other sites
Pylon80 2445 Posted September 29, 2022 8 hours ago, toyolien said: @Raman36 Tamiya have released them. https://www.tamiya.com/english/products/22054/index.htm This is a historical moment. The TT-02 (standard, non type S) now has DCJ's. That means you can spend the cost of your chassis once over with only one hop-up 🤣 2 3 Share this post Link to post Share on other sites
qatmix 794 Posted September 29, 2022 If running a spool it’s worth every penny Although on a stock TT02 I think putty in the std diff makes it handle better. Just a little bit of give protects the drive train and helps it into the apex.  Also no chatter with universals.     1 Share this post Link to post Share on other sites
kontemax 1723 Posted October 3, 2022 Somebody could explain me, please, the need of a spool in the front end? Thanks Max Share this post Link to post Share on other sites
Juhunio 6828 Posted October 3, 2022 On 9/28/2022 at 8:51 PM, Pylon80 said: I think you would be able to use it with normal swing shafts on a type S though, arms are about 1.5mm wider than standard TT-02 if I recall. I have had similar length issues with the older TT-02 oil filled gear diff. Had a set of Eagle Racing 38mm swing shafts knocking around and I was able to use that to make Frankenstein Universals! So, just following the logic through.... When installing the spool on a 'standard' TT02, recommendation from Tamiya is to use shorter 37mm universal shafts instead of 'standard' 39mm shafts When considering the Type S, the manual (published long before the spool was released) recommends the XV-01 front assembly, which has a 42mm shaft So to use the spool in the Type S would need a shorter shaft, so the 'standard' 39mm shaft or XV-02 rear assembly? Is that right? Share this post Link to post Share on other sites
Pylon80 2445 Posted October 3, 2022 58 minutes ago, kontemax said: Somebody could explain me, please, the need of a spool in the front end? Thanks Max Touring Cars will need a very stiff front diff or even a spool at the front to prevent the inside wheel from spinning ("diffing out"). This happens when power is applied while the car is still leaning into a corner, offloading the inside wheel. The opposite wheel just stops providing any traction. Some 1:1 scale cars have Torsen diffs which provide full differential action: they can't spin a wheel on one side. We RC hobbyist do not have access to miniature Torsens  We use "open diffs". So the simple solution is, as often, a compromise: we slow down the diff or even replacing it with a spool. That makes the tires slip a little in any turn, but at least you avoid one wheel spinning while the opposite wheel stops. This is really required for racing and generally speaking when using higher power and when the track has the grip required to allow leaning aggressively into the corners. You don't need that for parking lot fun but you need it on any but the most novice classes at the track. Share this post Link to post Share on other sites
Pylon80 2445 Posted October 3, 2022 2 minutes ago, Juhunio said: So, just following the logic through.... When installing the spool on a 'standard' TT02, recommendation from Tamiya is to use shorter 37mm universal shafts instead of 'standard' 39mm shafts When considering the Type S, the manual (published long before the spool was released) recommends the XV-01 front assembly, which has a 42mm shaft So to use the spool in the Type S would need a shorter shaft, so the 'standard' 39mm shaft or XV-02 rear assembly? Is that right? The part just came out so I doubt many people have tried it on a TT-02 type S. On the Tamiya picture, the 37mm shaft, on a standard TT-02, looks awfully close to binding... From my own measurements the Type S was 1.5mm wider per side. That might not leave enough clearance with 39's. Share this post Link to post Share on other sites
kontemax 1723 Posted October 4, 2022 On 10/3/2022 at 11:02 PM, Pylon80 said: Touring Cars will need a very stiff front diff or even a spool at the front to prevent the inside wheel from spinning ("diffing out"). This happens when power is applied while the car is still leaning into a corner, offloading the inside wheel. The opposite wheel just stops providing any traction. Some 1:1 scale cars have Torsen diffs which provide full differential action: they can't spin a wheel on one side. We RC hobbyist do not have access to miniature Torsens  We use "open diffs". So the simple solution is, as often, a compromise: we slow down the diff or even replacing it with a spool. That makes the tires slip a little in any turn, but at least you avoid one wheel spinning while the opposite wheel stops. This is really required for racing and generally speaking when using higher power and when the track has the grip required to allow leaning aggressively into the corners. You don't need that for parking lot fun but you need it on any but the most novice classes at the track. I suppose you are speaking about 4WD touring models, right? I remember we used the front one way and, eventually, the rear spool. Max  Share this post Link to post Share on other sites
wilysloth 22 Posted October 5, 2022 How does a spool compare to a diff locker (e.g. Tamiya TT-02 Diff Lock Block 54649)? They appear to fulfil the same function but, seeing as both exist, it seems likely there is a subtle difference. My guess is that the spool is simpler, with fewer moving parts, so is more reliable, has less slop, and less rotating mass to accelerate. Share this post Link to post Share on other sites
Pylon80 2445 Posted October 5, 2022 26 minutes ago, wilysloth said: How does a spool compare to a diff locker (e.g. Tamiya TT-02 Diff Lock Block 54649)? They appear to fulfil the same function but, seeing as both exist, it seems likely there is a subtle difference. My guess is that the spool is simpler, with fewer moving parts, so is more reliable, has less slop, and less rotating mass to accelerate. Agree. The diff locking block allows you to lock and unlock the stock diff quickly without changing anything else on the car (out drives, drive axles etc) but it does have some slop. Also, if you are using the large diameter drive axles it is your only option (short of dropping epoxy glue inside the diff 😅). The spool on the other end is from the XV-02 and would replace an oil-filled gear diff since they come as standard. When used on the TT-02 it will be a much fancier part than the diff locking block, similar to what high end TC cars would use. Probably lighter and certainly with much less slop (or no slop at all) as you mentioned. Share this post Link to post Share on other sites