OldSchoolRC
12-09-2009, 06:58 PM
Thought I’d post up my mod for the TA chassis steering. The stock bellcranks are plastic and they ride on a stepped tapping screw, and after a few runs they start to wear and develop slop. When building up my TA based Hummer off a truck that was used hard, the slop was so bad the wheels flopped all over the place - no good! Replacing the z-bend is a no brainer, but here’s a way to fix up the pivot points on the bellcranks. Parts needed are a set of flanged Tamiya brass shock bushings, some 3/16 brass tubing, a 3/16 drill bit, X-acto knife, 2 tamiya 3mm washers, 2 3x15mm screws and a tubing cutter.
Note: I took some pics as I did the mod to my TA hummer which is heavily modded, so it’s a little different, but the same principle applies to all TA chassis (and FF01’s as well.) Sorry for the pics, my camera does not like close-ups. :(
First off drill out the bellcranks with the 3/16 bit. Try to keep it as parallel as possible, I used a drill press, but careful use of a regular drill would work here too. There's plenty of material around the pivot point - tamiya stuff is beefy.
http://i472.photobucket.com/albums/rr84/dschlegel/ta008_2sm.jpg
Take the 3/16 tubing and cut it down to just under the length of the shock bushing. There are 2 kinds of shock bushings, the thin flange and a thicker flange. For the standard TA chassis, use the thin flange (right) though since this is on a custom chassis, I’m using the thinker flange (left) for more clearance.
http://i472.photobucket.com/albums/rr84/dschlegel/ta009_2sm.jpg
Use an X-acto to remove the flashing from the cutter from the inside of the 3/16 tube and when you are done, it should slide right over the shock bushing. This is very important, the tubing should rotate freely on the bushing. When done, it should look like this. The bushing should be just slightly longer than the 3/16 tubing that was cut.
http://i472.photobucket.com/albums/rr84/dschlegel/ta010_2sm.jpg
Press fit the 3/16 tubing you just cut into the bellcranks. Should fit snug and not rotate. If it rotates a bit, a drop of CA will hold it in place.
http://i472.photobucket.com/albums/rr84/dschlegel/ta011_2sm.jpg
Put a little oil or light grease onto the shock bushing and mount to the chassis flange side down, then slide the bellcrank over it. Use a washer on top to keep the bellcrank from sliding up, and cinch it down with the 3x15mm screws – the finer threads help keep it tight compared to the tapping screws. The bellcranks should rotate freely with no slop! Sometimes I had had to do a little filing on the top of the bellcranks to clear the washer as they bound a little, but mostly it’s a perfect fit. Here’s the final set-up on my TA based hummer.
http://i472.photobucket.com/albums/rr84/dschlegel/ta013_2sm.jpg
Have run this set up with touring cars, trucks and buggies and it definitely tightens up the steering and stays tight.
Note: I took some pics as I did the mod to my TA hummer which is heavily modded, so it’s a little different, but the same principle applies to all TA chassis (and FF01’s as well.) Sorry for the pics, my camera does not like close-ups. :(
First off drill out the bellcranks with the 3/16 bit. Try to keep it as parallel as possible, I used a drill press, but careful use of a regular drill would work here too. There's plenty of material around the pivot point - tamiya stuff is beefy.
http://i472.photobucket.com/albums/rr84/dschlegel/ta008_2sm.jpg
Take the 3/16 tubing and cut it down to just under the length of the shock bushing. There are 2 kinds of shock bushings, the thin flange and a thicker flange. For the standard TA chassis, use the thin flange (right) though since this is on a custom chassis, I’m using the thinker flange (left) for more clearance.
http://i472.photobucket.com/albums/rr84/dschlegel/ta009_2sm.jpg
Use an X-acto to remove the flashing from the cutter from the inside of the 3/16 tube and when you are done, it should slide right over the shock bushing. This is very important, the tubing should rotate freely on the bushing. When done, it should look like this. The bushing should be just slightly longer than the 3/16 tubing that was cut.
http://i472.photobucket.com/albums/rr84/dschlegel/ta010_2sm.jpg
Press fit the 3/16 tubing you just cut into the bellcranks. Should fit snug and not rotate. If it rotates a bit, a drop of CA will hold it in place.
http://i472.photobucket.com/albums/rr84/dschlegel/ta011_2sm.jpg
Put a little oil or light grease onto the shock bushing and mount to the chassis flange side down, then slide the bellcrank over it. Use a washer on top to keep the bellcrank from sliding up, and cinch it down with the 3x15mm screws – the finer threads help keep it tight compared to the tapping screws. The bellcranks should rotate freely with no slop! Sometimes I had had to do a little filing on the top of the bellcranks to clear the washer as they bound a little, but mostly it’s a perfect fit. Here’s the final set-up on my TA based hummer.
http://i472.photobucket.com/albums/rr84/dschlegel/ta013_2sm.jpg
Have run this set up with touring cars, trucks and buggies and it definitely tightens up the steering and stays tight.