84 replies to this topic

[Phil Hackett]

Alright... I've been monitoring this thread and have been staying away...

There are various methods of making gears but gears used in slot cars are mainly created by: hobbing; shaping; drawn wire (and finish machining); molding (plastics) and stamping.

Pinions: Sonic pinions are hobbed out of a pre-hardened stainless steel. We have made hardened steel pinions in the past and they would outlast *you* BUT (there's always that word) they needed a very aggressive, industrial-level flux and proper technique to get them to solder properly. They also would rust easily and, well, you're more likely to lose them than wear them out. They could not be used for press-on pinions: they'd crack.

We also have made OEM pinions for those who need a basic pinion from pinion wire. These are usually brass or a easily machined steel and they are not as accurate as hobbed gears but they are considerably less expensive. These are not sold as a product under the Sonic label but to others to market under their own label(s)/products.

The pinion **should** wear faster than the crown/spur. The reason is that the pinion is engaging more teeth per revolution of the axle than the crown/spur. For instance, a 8/39 ratio, each pinion tooth sees 4.875 crown/spur teeth for each axle revolution. Multiply than by tens of thousands of times and you can see where the wear comes from.

Plastic can be very abrasive, sometimes worse than metals, so depending on what plastic is being used you can see pinion wear. Plastics that have glass reinforcement for strength are among the worse. Remember, they cut diamonds with diamonds. Erosion is slow but sure.

[One_Track_Mind]

'MSwiss', on 17 Nov 2011 - 12:26 AM, said:

Or maybe one of the frequent posters from Ohio, Brian M or Mike P?

I'm the guilty party of trying to use the green and red crown gears for the heavy cars I build and they simply didn't hold up!

From my understanding they were made for 1/32 application.

Don't recall now if they were used as a hypoid or not? I would say Not! As we where still in the learning stages at that point of Retro building.

[Phil Smith]

Very interesting post, Phil!

[MSwiss]

'Ron Hershman', on 17 Nov 2011 - 02:13 AM, said:

There could also be some differences between the plastic they use for the gears as well.

But I see more wear on pinions than crowns of late.

I wouldn't be surprised if this is the case (the plastic on the crowns being a little bit tougher).

[Gator Bob]

Phil... and Ron, explanation.

How are the ARP tapered pinions made, they do show wear pretty fast with Parma pinks in hypoid.

Even faster then the Parma plated brass in non-hypoid with the same pink crown.

Pinks all out...

[HarV Wallbanger III]

All I got to say is you "have" to order "Wednesday" pinions... Mondays are hard for Foamy!

[Bryan Warmack]

I think much of this slot car stuff is just meticulous attention to detail and IMO the two most important details are... as LOW as possible and as WIDE as possible.

With the hypoid setup the CG is just a LITTLE bit lower. Probably doesn't show up on the stop watch with any consistency but since I have NEVER had a problem with the tapered pinions and the almost-indestructible pink Parma gears, I chose the lower CG over any possible gear drag issues.

I have always run hypoid setups and have often switched between TSR and Falcon 7 motors and often used the SAME gear for both rotations. Never any problems if everything is set up correctly.

[slotcarone]

I have built many cars with hypoid set ups and used straight GT1 pinions and they were usually the smoothest and quietest ones on the track. I agree 100% with what Bryan said!!

[MSwiss]

'Bryan Warmack', on 18 Nov 2011 - 06:19 AM, said:

I think much of this slot car stuff is just meticulous attention to detail

I agree.

I think more noisy gear meshes are the result of the wrong amount of lash, or in some cases,
a poorly sleeved crown gear.

IMO. getting an optimum gear mesh is the most important thing in Retro, and unfortunately, not super easy.

Also, IMO, some guys settle for "close enough" where the time should always be taken to shoot for "perfect, or real close to perfect".

[Russell Sheldon]

Hi Guys. Interesting discussion. Could someone please explain the benefit of using tapered pinions with an inline set-up?

Many thanks,

Russell

[MSwiss]

They just happen to mesh up real well with the Parma King Crown tooth profile.

If you felt how smooth the mesh is, and how quiet they are, especially in the straight mode, there isn't a reason to run anything else. Also, I've never seen an ARP straight, but the tapered ARP has a boss on the end to help keep solder out of the teeth.

[MSwiss]

Also, IIRC, when Retro started up, there wasn't a high quality straight 48P pinion.

[Ramcatlarry]

The only thing that is logical is that an angled pinion will have less contact surface and therefore less friction than a straight cut pinion....and it will blend a hypoid mesh better for the same reasons. A smaller pinion also has less flywheel mass than a larger pinion. Dragracers usually use a larger straight-cut pinion to ensure the maximum power transfer, although they usually use an axle gear that will wear out quicker.

[Howie Ursaner]

I have had cars with hypoid setup that i just can't get a good mesh with and i move the motor up a little and like magic i have a perfect gear mesh. Whatever works!!

[Mark Wampler]

I'm going to be a hypocrite for a try at a very mild offset on this next bracket. Between 3 and 4 thou offset and see what happens. One dead giveaway on a hypoid is the grinding sound during braking. I SUPER dislike that. I agree, whatever works, but quiet gears take priority.

[MantaRay]

Sometimes a Fast Car may not be a Quiet Car..........

[Noose]

I have been running hypoids almost exclusively and do not have the poor gear mesh or noise problems. Now, you do need to realize that inlines are of course noiser than anglewinders. I have also noticed that different bodies make the car sound differently. As a test, try a GT body vs. a Can-Am and you will probably hear a difference.

[Ron Hershman]

'MantaRay', on 30 Nov 2011 - 6:56 PM, said:

Sometimes a Fast Car may not be a Quiet Car..........

OH so true......LOL Sano Dave told me last weekend if I could get my car to be quieter it would probably go a 10th faster.

[Ron Hershman]

'Bob Israelite', on 17 Nov 2011 - 11:52 PM, said:

Phil... and Ron, explanation.

How are the ARP tapered pinions made, they do show wear pretty fast with Parma pinks in hypoid.

Even faster then the Parma plated brass in non-hypoid with the same pink crown.

Pinks all out...

Well the APR pinions are made from Stainless steel or once was...... the plated brass pinion works pretty well and not sure if that brass is or could actually be a bit harder than the stainless steel that may be used in a APR pinion.

My guess of "steel" pinions are wearing out before plated brass pinions.... the brass must be harder and if my memory serves me correct..... the pinions ( plated brass ones here ) made in China actually have a slightly different "pitch or tooth profile" from the pinions made here.

[MantaRay]

Maybe it's time for a POLL! I have seen a lot of cars and pics and do not see very many plated or otherwise straight pinions.
I did not know 48p Straight APR pinions were available..........

[Rick]

'Ron Hershman', on 30 Nov 2011 - 9:22 PM, said:

Well the APR pinions are made from Stainless steel or once was...... the plated brass pinion works pretty well and not sure if that brass is or could actually be a bit harder than the stainless steel that may be used in a APR pinion.

My guess of "steel" pinions are wearing out before plated brass pinions.... the brass must be harder and if my memory serves me correct..... the pinions ( plated brass ones here ) made in China actually have a slightly different "pitch or tooth profile" from the pinions made here.

If it's chrome plating, chrome is VERY hard...............if it's nickle plating nickle wears very well................

When I had my portable track and took it the dirt tracks, the atmosphere was harsh with all the dust. One night, on a rain delay and a lot of runs on the track, the cars I had with me completely wore out the pinions while the plastic spurs were perfect. After that I switched to the Champion steel solder-on pinions(the brown ones) and they lasted better.

[Ron Hershman]

'MantaRay', on 30 Nov 2011 - 9:50 PM, said:

I did not know 48p Straight APR pinions were available..........

ARP-4807-A 7 tooth 48 pitch ultra low friction steel pinion gears with 6 degree angle,
ARP-4807-S 7 tooth 48 pitch ultra low friction steel pinion gears,
ARP-4808-A 8 tooth 48 pitch ultra low friction steel pinion gears with 6 degree angle,
ARP-4808-S 8 tooth 48 pitch ultra low friction steel pinion gears,
ARP-4809-A 9 tooth 48 pitch ultra low friction steel pinion gears with 6 degree angle,

'Rick', on 30 Nov 2011 - 9:53 PM, said:

After that I switched to the Champion steel solder-on pinions(the brown ones) and they lasted better.

Those Champion pinons were "cut off" from pinion "wire" then hardened.... that's why they were hard to solder on shafts.....lol

Again those pinions made from "wire" have a different "pitch/pressure angle" than most "machined" pinions.

[MantaRay]

Ron, have You or Rande used the straight ones?

[Ron Hershman]

Ray.... we have used the straight plated brass pinions on FK motors in the inline retro races with great success.

Getting ready to try the straight ones in F1 and Can-Am soon.

I am thinking we may get double life out of the straight ones as depending on how long they may be..... they could be moved on the shaft or maybe reversed as they wear out.

[MantaRay]

Thanks Ron...............