P4/EM wheel quartering advice sort

[Marc Dobson]

Having moved from 7mm to 4mm it has come as a bit of a shock to find that 4mm divers aren't, on the whole, self quartering. I'm currently finishing of a LYR pug, with a highlevel chassis,that I got second hand. Luckily for me it came with two sets of wheels one self quartering and one not. So you can probably guess which ones I used as I don't have a quartering jig. So being new to quartering is there a guide to quartering and can you do it without a jig? Also how do you quarter if the wheels are in the chassis?

 

[ullypug]

Hi Marc
You can quarter wheels without a jig and also in the chassis.
Set one of the driven wheels on an axle.
Assemble through axle boxes, adding spacing washers, gear box, gear and spacing washer.
Put other wheel half on axle. I countersink back of wheel and make sure axle has no burr beforehand and secure with loctite.
Set wheel to required lead.
Push home to gauge
Set one wheel on other axle
Insert through axle boxes etc
Again put remaining wheel half on
Set lead to match driven axle by eye. Easier if you have spokes but a pug doesn’t obviously.
Try to fit coupling rods. I secure temporarily with stripped sleeve of wire surround.
It’s then a case of pushing along and making small tweaks twisting one wheel.
Watching the relationship between coupling rod and crank pin hole will tell you when it’s dead centre, though things should roll under gravity if it’s all true.
Apply loctite to remaining wheel and push home to gauge.

Sounds complicated but really it’s just practice.

 

[Bob Essex]

Just to add that in most cases the right hand leads. Easy to change if you get it wrong wth self-quartering but best to keep in the back of your mind when DIY with push fit locked onto the axle with adhesive of some type.

Bob

 

[Rob R]

If the frames and rods are of the same centres and the wheels all have the same crank throw, then quartering just follows on.
Most quartering issues are actually due to other bits being not as they should be.

 

[Tim V]

I believe only some 7mm wheels are self quartering, there are some one has to quarter oneself. EG the AGH wheels.

The crucial thing in 4mm, as in 7mm is absolute correlation between rod length and wheelbase. If they are spot on, minor differences in quartering do not affect the running.