Couple of spur gear questions

[Alex5]

I am just finishing up putting my new truck together, I have the 17t vented clutch bell and the 'thin' 47t steel spur which I believe are those supplied with the X SS kit (my truck is a scratch build and I have had parts from all over).

I have a few questions!

First up, from searching on here, plastic spur seems to be favoured. I can understand it's better to have a cheap weak point and it makes you set a good mesh. So why are HPI supplying steel spurs now with the X SS and XL? Is it just to help with noobs destroying spurs or are they required for more powerful engines available now?

Which brings me on to my next question - is it not advisable to run a hardened clutch bell with steel spur gears? The clutch bell HPI are supplying with these steel spurs are AFAIK just standard vented bells. I mean, I'm sure HPI know what they are doing and all but it seems a little odd in the face of all the advice I have seen?

Finally, having fitted said steel spur for into my truck I notice there is a certain amount of play/wobble as it rotates. I took it all off, it's not the gearbox shaft but seems due to the slipper spring not actually being square on the flatted ends. I had a look and it's the same thing with my old Savage. Spur/clutch still mesh good but it's one of those thing that doesn't seem right. Anybody had anything similar?

Thanks for any advice regarding this combo. Don't really want to spend more on parts unless I have to!

 

[Crash]

I am just finishing up putting my new truck together, I have the 17t vented clutch bell and the 'thin' 47t steel spur which I believe are those supplied with the X SS kit (my truck is a scratch build and I have had parts from all over).

I have a few questions!

First up, from searching on here, plastic spur seems to be favoured. I can understand it's better to have a cheap weak point and it makes you set a good mesh. So why are HPI supplying steel spurs now with the X SS and XL? Is it just to help with noobs destroying spurs or are they required for more powerful engines available now?

your probably rite, HPI is tried to fix the stripped spur issues. The plastic one is fine.

Which brings me on to my next question - is it not advisable to run a hardened clutch bell with steel spur gears? The clutch bell HPI are supplying with these steel spurs are AFAIK just standard vented bells. I mean, I'm sure HPI know what they are doing and all but it seems a little odd in the face of all the advice I have seen?

If the spur is hardened then you want a hardened cb

Finally, having fitted said steel spur for into my truck I notice there is a certain amount of play/wobble as it rotates. I took it all off, it's not the gearbox shaft but seems due to the slipper spring not actually being square on the flatted ends. I had a look and it's the same thing with my old Savage. Spur/clutch still mesh good but it's one of those thing that doesn't seem right. Anybody had anything similar?

really shouldnt wobble much, curious about that one. Make sure your not over tightening it

Thanks for any advice regarding this combo. Don't really want to spend more on parts unless I have to!

..................................

 

[Alex5]

Thanks Crash

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=190254590731&ssPageName=STRK:MEWA:IT&ih=009

This is the combo I have although it came from different places.

I shouldn't really be worried about running this setup it as it's factory but I don't think that cb is hardened. I have a hardened Robinson on the other Savage and it looks like bare metal.

As you can see the spur gear is very thin compared to the plastic or other metal ones, I suppose this is to keep weight down.

The one I have mounted has only a small amount of forward back play in the rotation, maybe .5mm either way max. Like I say it seems to be due to the spring in the slipper, and I have the same thing on both trucks (both with different setups). I'd be surprised if I'm the only person who has encountered this, if it's normal I'd let it go.

 

[Bankrupter]

The steel spur is a good spur in my opinion I have several gallons with no issues.

The HPI vented racing bell is stronger than the HD Bell. It is the right cb to run with that spur.

As far as play or that could be from the pad you stuck to it...

I run mine cranked all the way down with no slip and other than ring gears from on throttle landings it has not taking out any other parts... I have stopped trying to correct attitude with in a few inches of the ground. Since I have stuck to the NO throttle rule on landings I have hurt nothing. I will let it cart wheel b4 I land on the go juice...

 

[Alex5]

Thanks Bank that helps with my fears, I'll stick with what I have for now then!

As far as the wnder goes, I have tried re-seating the spring and making sure it stayed straight whilst tightening up the nut, helps a lot. I'm surprised that worked but it did. Good point on the slipper pad too - mine was actually stuck hard to the slipper plate when I took the thing off the shaft. I did get it on straight when I stuck it down, but it is very slightly larger than the relief on the spur. Perhaps I should give it a very light sanding.
Overall I think it's a combination of spring and nut not being perfectly straight, you just have to line them up right to get it running true.

Good news though, glad someone has experience of this setup, I hope it all plays nicely for me.

Now if only somebody in the UK had a Spektrum DX3.0 in stock I'd be all set :nono: :duh:

 

[xtremsavage]

Alex, if your concerned about the wobble have an effect on anything, don't worry. Mine does the same thing and haven't had any issues with it. I'm also runnin the vented CB and steel spur except my spur is different than yours. The one I'm using is the one with the purple alum. hub and changeable ring gear. I even asked the owner of the LHS I goto and he said all the spurs he's seen have wobbled, T-Maxx's do the same thing. So, after a few runs and it does start to wobble again, don't worry about. And welcome to the forum.

 

[Alex5]

Thanks for the reply. Bit of a matter of knowing what's 'normal' I guess. Savage is a bit larger scale than anything I've had before, tolerances are a bit more noticeable.

Well, that and I'm a bit anal/paranoid about these things, lol. It'll take me a while to bash this thing hard, put it that way. Mind you I didn't spend the money for it to look pretty on a shelf either!

 

[xtremsavage]

Trust me, after a few "minor" jumps, you'll be goin bigger within a few min. once you realize how fun it is and looks. I was the same way, tried taking it easy until I got used to it, but that never happened.