7 replies to this topic

[Mudhen]

On a JK chassis, do you want the guide flag to have any play in it at all, or only side to side. As per usual, any and all help is always appreciated.

 

Richard Marnhout

[Dave_12]

The guide should self centre. If it doesn't. it's either too tight or the leadwires are not installed correctly.

[Bill Seitz]

On any chassis, the guide should turn through its complete side-to-side travel without binding or sticking and with minimum play. Usually the guide will turn freely without any noticeable play, but occasionally its practically impossible to eliminate all play without some binding/sticking. So, the least play possible without binding/sticking.

 

The type guide nut used has some influence as well as metal-to-metal mating surfaces. Nuts designed with a wide supporting surface will make it easier to eliminate play/wobble vs a narrow/small nut. I also always place a Teflon guide washer in a metal-to-metal joint, like a metal guide nut against the metal guide tongue. Lube oil is probably enough, but the Teflon washer further reduces the friction in the joint to allow tightening a bit further to remove the last bit of play/wobble.

 

In addition to the guide not binding, guide self-centering is dependent on the lead wires and how they're dressed. Very supple lead wires may not exert sufficient lead wire pressure to center the guide when not in the slot. The primary purpose for self-centering is to assist in marshaling the car on a de-slot. If the guide returns to "straight" rather than being turned to one side, the guide will find the slot faster when placed back over the slot and get the car underway again faster.  The car's cornering ability is more effected by the guide not turning freely than having it self-center which is mostly a nuisance on a de-slot.

[Mark Onofri]

If you are referring to up & down, no. Do your self a favour and buy a tech block for the braid depth.

[mreibman]

Wait, did I hear "metal to metal" surfaces? That's what Teflon guide washers are for, one above and one below the chassis.

As for your guide, it should move freely side to side, and pretty much not at all up and down. no wobbling.

 

The spring action to re-center the guide comes from the lead wires being done up properly to act as the spring, but if you don't have the guide moving freely before you start, you've already lost that battle. Personally, I use earring backs and 20 or 22 ga silicone wire... on a flexi type car, I might go as big as 18 gauge just because I have it. but always you want the spring action regardless. Silicone wire in this case is a great friend.

If I have a chance, I can take pictures, but not sure that I'll have time for this week.

Ok Slot Car Sages, who's got a nice picture for Frank?

[Mudhen]

If you are referring to up & down, no. Do your self a favour and buy a tech block for the braid depth.

 

Since the braid on the track is not even, and has some bumps and tiny peaks and valleys as it goes around, I wondered if having just the tiniest amount of up and down play would act as a shock absorber, but as I think more about it, perhaps the braid on the car serves the same purpose. 

 

Aaaand.... While we're on the subject of guide flags, what do you guys think about using extra-long guides. My best handling car has a Slick 7 guide on it that is not long at all, but the prow angles up and back, maybe 15-20 degrees. 

[Cheater]

Let me make two points.

The variability of the braid depth is why you have to test on the track. Sure, you can use a tech block to set guide depth, but what really matters is what guide position gives the lowest lap times.

 

Second, teflon washers exhibit a property called 'cold flow.' They get thinner over time under pressure.

 

My preference was Koford bronze guide washers.

[Mr. M]

He might be asking about play if you hold the guide and rock the chassis right up left down left up right down looking from the guide front. None is too little and when it flops so much it deslots on the fast turns too much. Tuning of guide nut tightness on inside and outer lanes is needed. It does seem to help to let the car rock a bit, but not too much.