niznai

Nope. You can't mould something with internal angles in one piece and then take it off the mould. It just doesn't happen. The pulleys you talk about have a side ring welded with ultrasound I suppose (it's a very neat way to weld plastics, but there are other ways) which is why it seems seamless. Take a closer look and you'll find one side of the pulley has a smaller internal diameter (measure the recessed part where you have the ball holes). That's because that is a ring attached there as I explained. There are plenty of pulleys that look like they are one piece (check out a Corally diff pulley) but none is.

That's why my idea is to machine it. It's more work, but better quality.

Offsetting the balls will save wear. Running nine/ten/twelve/sixteen balls in the same groove wears it down sooner. And you only need to offset the balls a fraction of a milimetre not any more.

bl4

iTrader: (5)

Hi Will there be any improvement by upgrading TA-51287 large ball differential plate and TA-53379 3mm lightweight differential ball set?

hermanchauw

Have you seen this: http://racingfactory.wordpress.com/2...l-trf415-diff/

Actually the original TA05 diff pulleys have two circles of 8 holes. I am a lazy guy so i just make use of all the holes and to get a 16-ball diff.

Haven't abused the car because i drift, no tour. So i can't comment how long it takes between rebuilds.

veecee

iTrader: (34)

That's because you're thinking of a simple open and shut tool that most manufacturers do. If you took an even closer look at the 416 one way pulley, you will see no fewer than 8 little parting lines around the circumference of the 2 pulley flanges. These parting lines happen to coincide with the 8 supporting ribs on both sides of the pulley. These parting lines indicate to me that they use sliders to form the peaks of the tooth. This overcomes the undercut problem you are thinking about. So in actual fact, it does happen - it's just a more complicated tool.

niznai

I am aware of the possibility of using a multi section die (mould). It would be so complicated (i.e. expensive to make) though that I don't think anyone would be able to make any profit from using it. But hey, you're right, it's not impossible.

As for the TRF pulley I suppose you're talikg about the 37 tooth pulley off the 501X? I am not sure if that's done with a one injection operation or not. I am looking at mine and I can not see how the sliders you envisage would operate. If they are on the side (i.e. slide across the edge to form the channels for the belt teeth), then it is a question how do they leave a rib raised above the hole on the belt face?

If on the other hand they slide along the radius, you do realise you need to have a die with 37 individual sliders and 37 individual separator sections between them. It can be done, but I am not sure anyone would even consider.

That being said, nothing changes. As I agreed, it can be done. I just think it's not feasible. I will keep looking at the pulleys and try to understand how they're made, though.

If that's not the pulley you're talking about, I have the TA05 one way pulley, but that's obviously made in two parts.

If that's not what you're talking about either, perhaps you can post a part number so I can check my collection?

I wasn't aware they did that (I don't have a 416). That is close, but not what I want. Doing it that way, they're still running 8 balls on the same track. I am down to three.

Grizzbob

iTrader: (2)

the lightweight diff balls MIGHT be a bit better, but the diff plates you mentioned should be just the same as came in the ver.2 kit. And if you build the diff as it's suggested on TryHard's site(which includes sanding the diff plates) they'll work just fine....

bl4

iTrader: (5)

Bro thks for the info. Which is the wed for this TryHard's thks.

Grizzbob

iTrader: (2)

Sorry, I was in a hurry earlier(about to head for the track) & for got, his website is at: www.thard.co.uk . That should give you a LOT of good stuff to read up on(it may mostly be for the 416, but there's still a LOT that works for all Tamiyas, I believe the diff building part is in the TRF416 - Things to know - Updated Mar'09 thread under the title Uber Diff......

bl4

iTrader: (5)

Thks alot!

slakr

iTrader: (36)

Is the internal ratio of this car 2.25?

Anyone have a suggestion for spur/pinion size to start off with? (Tekin RS 198/Trinity Duo 17.5 BL).

Also, what brand of 64P spurs work with this car?

Last question (for now )... just starting to build my kit, should I put any of the 1mm plastic shims under either the front or rear A/XA blocks?

Some pictures of the track I run on can be seen here... http://www.toytownhobbyshop.com/phpB...&t=733&start=0

Grizzbob

iTrader: (2)

No, the internal ratio of the ver.2 is the same as the 416, 2.055. And about gearing, it depends on the size of the track, but for an average to small track, I'd say start with about a 4.3:1 FDR on rubber tires(we're in that range at my local track, which is in the middling to small size, average laps with a 17.5 is around 9.5 sec.).
As for spurs, I'm happiest with Kimboroughs, & while it may be possible to use Xenons, when I tried one, it didn't seem right, I think it warped as I tightened the mounting screws(not sure why yet), & I'm hopeful that a PRS(I think that's the brand, it's one I tried at the last Novak race, spur was nice & flat, so maybe it could work) one will work, but I haven't yet had a chance to try one.....

P.S. Just saw the pics of your track, & it DEFINITELY looks quite a bit bigger than my local one, based on that, you might start with more like a 3.5:1 FDR with a 17.5 motor...

slakr

iTrader: (36)

Thanks for the reply Grizz. Fast guys turn around 13's at the track.

I don't know if I have got something together wrong or what, but on my rear diff, there is a lot of side to side play and I don't see any shims in the kit.

In the front I have the optional spool. It came with 6 shims and to be honest it could use a few more.

Any ideas or does anyone know where I can pick up some of those shims?

JimmyMac

iTrader: (2)

Tim, don't run 3.5 final, you'll fry your motor. Come talk to Timmie or myself at the track and we'll see what you got. When I ran 194 with a Duo, I ran 4.3 at RW with no motor timing and full timing boost on the Tekin. But ya gotta watch your motor temps.

slakr

iTrader: (36)

I won't... I will start out around 4.8 with v198 on the RS, 15 boost and middle timing hole on the Duo (that's what I have on the Photon right now).

By the way, do you know what the timing settings are on the Duo (original, not v2)?

JimmyMac

iTrader: (2)

I'm thinking 0/10/20 (suppose to be). But you can ask Tag on here on the other forum to be sure.