Playing mantis gears

[keven]

All I think I have left of a playing mantis is a top plate with rear gear set:

16D243BD-73CB-45F9-8F51-3A888730927C.jpg

notice the size of the pinion gear: (same 14-tooth as the drive gear)
brass and delrin are shown for comparison…



Removed the gear to create a cannibal car…

note that the shaft was splined on the drive gear side

mite try the splined shaft with a new delrin drive gear and remove the playing mantis pinion to install from the top.
then it mite be a bit tricky to add a pinion gear (especially a 9-tooth pinion) .
l do have a hammer and cutting board.

or if I use the 14-tooth delrin as the pinion, I guess I could try my wheel puller to “pull” it onto the shaft.

another option that may be easier to do would be to “hammer”/press fit the spline end of the shaft into the pinion gear and press fit thru the gear plate into the rear gear.
of course the the shaft would extend above the top plate gear

shaving down the crown gear to mesh with a 14-tooth pinion is another project….

[RichD]

Playing Mantis was the parent company of Johnny Lightning, the company was eventually sold but the new owner was really only interested in the diecast part of the business. Eventually the original owner bought back the slot racing part and started a new company called Round 2. The slot cars are now sold under the Auto World name. Back in the day all of my Aurora T-Jet cars had the 9 tooth drive pinion replaced with a 14 tooth armature pinion. The hub of the crown gear had to be shaved to get a good mesh. A weak point of the JL/AW cars is that the cluster gear shaft is too short. Often the lower end of the shaft does not fit into the hole in the tub part of the chassis causing a poor mesh between the drive pinion and the crown gear as well as between the driven and idler gears. That problem can often be fixed by repositioning the cluster gear shaft. You have to be careful not the get the splined part of the shaft into the hole in the gear plate. Some people prefer to replace the splined cluster gear shaft with a longer plain one. If I recall correctly the JL/AW gear plate is not a good fit in an original Aurora T-Jet tub.

[model murdering]

I forgot how nice they were, not. The alternative is to punt on 4th and 27.

Hike a new shaft up, so the vertical alignment between the chassis and the gear plate isnt a factor.

The trick is perfecting the clearance on what you have left after shortening the shaft. It's a fine line, so straight, new parts are really a big help. Will it be perfect? Likely not, but it's waaaaay better than having a canted shaft bound and doodling around with too much clearance.

Be sure to check that the pinion height relates to the crown, before you trim the shaft and press it all together; so you're not needlessly pressing and repressing plastic gears.

Good luck!

Note that Aurora eliminated this extra friction, as well as the alignment issue; when they introduced AFX and Magna. Their redeaux of the pinion cluster was actually a nifty bit of work. The crown is free to mesh on the tall "Xellerator" style pinion where ever it lines up.

[keven]

If I recall correctly the JL/AW gear plate is not a good fit in an original Aurora T-Jet tub.

not using the gear plate, maybe just try the 14 gear pinion for a drag car using a dash gear plate and a Lincoln chassis.
thought the splined shaft was a great way to make sure that a plastic gear won’t slip under load…