Monthly Archives: September 2006
Painted two Mazda 6’s for Micke @ RacingFactory.fi yesterday.
Did not go smoothly at all but they look decent I guess. Never paint when you’re in a hurry…
Got a few new batterypacks from Digipeak a few weeks ago.
Below a few photos of them in the car as I received them as I was building the MRE. Numbers are certainly impressive and there labels even match the MRE! 🙂 Super performance!
Digipeak Process has developed a robotized unit to test and assemble refillable elements. The process increases tension of the elements in order to provide a greater output power and decreases internal resistance in order to support punch. Digipeak’s procedures of measurement and sorting uses a 100 % computerized solution making it possible to have each second a reserve of homogeneous power specifies between all the cells of same label.
Each cell from Digipeak Process is cycled out of the machine before testing in order to guarantee stabilization of the values. Several hundreds of measurements are recorded during the tests of load and discharge for each cell. A data-processing unit compares all these values stored to generate the assemblies. This process ensures a perfect homogeneity between cells allowing a balancing in load and one made optimal of the power in discharge.
At the end of the tests, each cell is reloaded to 30 % of its capacity to compensate for the auto-discharge. The cells receive a label with actual values measured in the machine. Digipeak Process does not compose of assembly by reading values on labels. Digipeak preserves the measurements of each assembly. The identity of the assembly is represented by a code of production written on the label.
An application PC allows each user to graphically visualize the homogeneity of the assembly and the power available. The application and data can always be retrieved.
Just the last few parts left now.
When fastening the shock towers do not fully tighten the screws until all four screws are in place. Then gently push the tower down while tightening the screws.
Follow the same procedure when tightening the screws for the upper deck.
Instead of using the supplied bumper I run Square’s STM-10MS bumper.
TRF Damper Assembly
The Tamiya TRF dampers have been the standard by which all TC dampers are measured for a long time already, and for a reason. With the MR edition you get the blue fluorine coated TRF dampers with titanium nitride shafts, 2 hole teflon pistons etc.
1. 3×0,1mm shims
2. Extra o-rings for rebound
3. Associated Green Slime
4. Associated 60wt oil
Start off with leaving the o-rings in their plastic bag and put a few drops shock oil in the bag. You can also put a bit of green slime in there and move around the o-rings inside the plastic bag to make sure they are covered with oil (and green slime).
Use the 3×0,1mm (or if needed 3×0,2mm) shims under the piston to remove any play between the piston and e-clips on the shaft. be careful not to damage the pistons.
Clean out the damper cylinders with motor spray and let dry. With the cylinder upside down put a drop of oil where the o-ring goes before you place the o-ring.
If you have not used green slime in step one you can put a little bit of green slime on the o-ring now before you insert the damper spacer and rod guide.
Before you put the piston rod through the damper cylinder and o-ring put a bit of green slime on the threads and spread it over the threads to save the soft o-ring from getting damaged.
Using the Losi Shock Matching Tool (sponsored by Jupe :yes: ) i check that the left and right dampers are equal length and that the friction without oil is the same.
Fill the dampers with shock oil and move the piston slowly up and down 2 times. Then leave them for a few minuted to let any air bubbles out. You could alternatively use a Ride Air Remover if you have one.
Put the bladder on top and carefully push it down so it sits straight on the top of the damper cylinder. Then I put one Tamiya transparent o-ring on top of the bladder, then the damper top and the cylinder cap. Gently tighten the cap.
The result should be a perfectly working damper.
For the front driveshafts use the same tips as for the rear.
When assembling the steering spindles I also used the same tips as for the rear hubs to remove some play.
Use the included 3×0,1mm shims to remove play between the spindle and caster block.
You can use a drop of light oil here as well to take away any excess friction.
The front caster block – steering spindle – driveshafts assembled. I use the rear holes in the steering spindles to start with. Since the steering geometry has changed totally from the MSX this will be the first thing to check when I start running the car.
On the front I adjust the droop screws for 6,5mm droop with the Yokomo droop gauge.
Remember to drill out the holes in the caster blocks.
On the end of the driveshafts use a good amount of AW grease before you insert them into the spool outdrives and fasten the assembly to the suspension arm.
Front spool and upper bulkheads
On the three screws you use to fasten the belt pulley to the spool use thread lock. Do not fully tighten the screws until you have all three srews in place to make sure you don’t warp the pulley.
The spool has been improved with the addition of the saver rings. These will make it much harder to break a spool outdrive in a crash. I left the outer edge on the outdrives although you’re instructed to cut it off in the manual. This will make it harder to remove the savers but will also make sure they stay where they are. Check with a driveshaft that it can move freely inside the outdrive after you’ve installed the saver collars.
When assembling the front upper bulkheads again make sure that they do not bind the spool and that it can spin freely. I also sanded the bearing holders for the front like on the rear. I also put the front bearing holders 1 step looser than the manual says.
Under the camber link ball connector I used 3,5mm of shims for a lower front roll centre, something I also run last winter on carpet.
Now to the front suspension and bulkheads.
On the front I use the included suspension blocks – 1 A (bridge) and 1 B – for 0,5 degrees of inboard “toe out” or arm sweep. I use 0,5mm washers under the rear block for a bit of anti-dive, again something I have found to work well for a spool setup indoors. I do not use the lexan shims here as they could interfere with the front belt.
On the arms I again use the normal included arms and the middle hole of the three for the damper mounting. On the hingepins I put 3mm in front of the arm and 1,5mm behind the arm. This will give a shorter wheelbase and more weight on the front.
The new steering is very impressive, both in looks and function. I built it fully according to the instructions without any special tips. You can use thread lock on 3x10mm set screws again here to ease future ackerman adjustments with spacers.
The end result of the new steering system with regards to smoothness and (lack of) play is very good.
Like with the rear bulkheads and suspension blocks try to make sure the front ones sit straight before you tighten the screws.
Time for the drivetrain assembly.
Start with fastening the rear bulkheads to the chassis. Try to make sure everything is seated straight before you tighten the screws.
Before I put the bearings in the bearing holders and these on-to the diff I slightly sand the outer edges of the bearing holders with 400 grid sandpaper. The reason being that any unevenness could cause the bearings to bind when everything is assembled and tightened.
Attach the diff to the bulkheads and secure with the upper bulkheads. For the rear belt tightness I used 1 step looser than in the manual to start with. Make sure that the diff spin freely when in the bulkheads and if necessary check that the lower and upper bulkheads are straight and do not bind the drivetrain.
On the MSX one of the few misses in the design was that the ball mount for the camber link on the rear upper bulkhead was very hard to tighten or adjust. This has been corrected with the use of the new 53906 5x5mm Ball Connectors. I use a 1mm spacer under this.
The driveshafts have been updated for the MR edition with new hardened aluminium wheel axles. These are super light and cuts quite a few grams of unsprung weight. Hopefully they will be durable enough as well.
When assembling the driveshafts put a bit of thread-lock on the small set screws to make sure they don’t come loose. Use AW grease again on the cross joints, the shaft and on the end of the swing shaft.
The centre shaft has been redesigned totally from the MSX and is now all aluminium with plastic pulleys. This is a much better design although a possible future centre oneway will require a different centre shaft. The bearing holders are now aluminium and are offset so you can change the height of the centre shaft. This is useful especially with the latest high-power brushless motors that require a very short gearing, i.e. big spur gear.
When assembling the rear hubs you can use some thread lock on the 3×12 screw. This will make it easier when you want to add or remove spacers under the ball connector. I use a 1mm spacer when building my car.
Unfortunately there is still a bit too much play in the rear hubs with the MR just like the MSX. I took away a lot of it by putting a bit of CA glue on a cotton swab and putting a very thin layer of CA on the inside of the hubs where the bearings go. In addition I used two 5 x 0,1mm shims instead of the single one shown in the manual.
Regarding the bearings I did not do anything to any of the bearings. Obviously you can clean out the grease with motor spray and use light oil for an even more friction free drivetrain. On my MSX I did not do this either and found that the bearings freed up nicely after some time with the bonus of longer bearing life.
Part 3 and it’s time to build the rear differential.
Already on the MSX Tamiya had improved the differential by including hardened aluminium outdrives with plastic blades. For the MR edition there are a few small changes as well with the new white low friction pulley. For the diff the improvements are better precision with the new pulley as well as now using 9 diff balls instead of 8 to better hold up for the extreme power the latest batteries provide.
For the diff I don’t use the included steel diff balls. Instead I use Tamiya’s 53124 3mm Tungsten-carbide diff ball set.
I start off by cleaning the diff rings, diff balls and thrust bearing using motorspray.
For the assembly of the diff I use Associated Black Grease and Stealth Diff Lube.
I try to cover the diff rings with grease and also put grease in the diff pulley before you insert the diff balls. Try to pack the thrust bearing with black grease and finally wipe off the excess.
Compress the diff spring with a pair of pliers before assembling the diff. Then I put a small washer either side of the spring when assembling for an even smoother diff.
When assembling the diff I always keep it vertical. Then as you tighthen the diff screw you should rotate the diff every 2 turns on the diff screw. This will help get the diff balls seated. Tighten until you feel some resistance and then continue to tighten just a bit further in very small increments. Once fully tighten, I back off the diff screw 1/4 of a turn.
Something I have used since my first 415 is the Atlas Diff Protect Seal. This has worked very well both indoors and outdoors. With the way the new diff pulley’s designed it might not make such a big difference as previously but it will always help.
For the MR you need to use the Atlas parts for the TA-05, Atlas MH7-633 Diff Protection Seal.
Using these tips I usually get a very smooth diff that last very long.