Spring tester

I like to play with my suspension.  A lot.  With the Slash, I was looking for some third-party springs because I didn’t like the GTR springs.  Well, the tricky part is that every manufacturer uses different published measurements for their spring rates, so it’s hard to figure out if something is stiffer or lighter than another brand’s spring.

G-Force makes a spring measurement tool, but it costs $100 so I was looking for a cheaper alternative.  It turns out that a friend of mine had a Dremel Workstation that he hadn’t used and was selling it for cheap ($20).  This looked like something that might work as a spring tester, so I bought it from him and tried it out.

It works really well.  I have a Protek scale that fits perfectly on the base, and the Dremel has a nice adjustable throw so you can set it to a particular distance.  With some calipers I set the throw to 1 inch, and with the Workstation I can measure lbs./inch really easily.  You just set the spring uncompressed, turn on the scale, and then move the handle 1 inch.

If you already have a scale, this is a fairly cheap way to make yourself a spring tester.  New, the Workstation costs $40 on Amazon.

B5M setup changes

I got some practice time in Thursday and Friday and ended up working on my B5M Factory Lite a bit.  I was struggling with a little bit of front end push and decided to mess around with battery placement and actually found I liked the battery forward a bit.  I’m not sure why, but most everyone runs the battery all the way back and I just assumed that was correct.

But for me, I ended up with the battery placed about in the middle.  That allowed me to carry a little more corner speed and add some front end steering.  I’ve never really had much problem with rear end grip on this car, and I still have tons of rear traction, so I’m liking the change.  Looking through some pro setups, I noticed they also placed the battery in the middle for high-grip indoor clay, so it sounds like I’m on the right track.

That plus 1 mm less in ride height (23/23) led to a 0.5s drop in laptimes which was nice to see.  I’m still doing mid-high Sportsman times, but not bad considering I haven’t driven my buggy much and it’s still pretty much stock out of the box.

Car charger

I’m the kind of guy that forgets to get all his batteries ready before he goes to the track, so I was looking for a way to be able to charge my batteries in the car on the way to the track.

My SUV has an AC plug, so I was able to plug my Duratrax Onyx 245 dual charger into it and charge on the way to the track, but I could only do one battery at a time.  It would reset itself every time I tried to charge two batteries (5A each).

It seemed inefficient to convert the car’s DC output to AC (through the car’s inverter) and then back again from AC->DC in the car charger, so I looked for a way to get straight DC output.

The cigarette lighter supports up to 120W on my car and I found this neat little adapter for banana plugs at my local Fry’s electronics store for $5.  The DC input on my charger used alligator clips, but I chopped them off and put on Protek 4mm banana plugs from amain.com.

This works out well and now I have a really nice and clean DC->DC charge on the way to the track and can get two batteries ready in about 30 min.  It’s the simple things in life…

Slash 4x4 setup sheet for 4/10/16.  Made a few more changes, car is driving pretty well, can keep it close with some of the 1/8 scale buggies.
Only comment missing is that I’m using a rear Slash shock tower in the front.

Using fuel tubing as a shock limiter

There are a lot of guys on Youtube, the RC forums, etc. suggesting using nitro fuel tubing as a shock limiter inside your shocks.  Don’t do it!

I was experiencing some weird jumping characteristics where my car would randomly and inconsistently takeoff and roll a bit and what not, and it was really strange.

I tore apart my rear shocks and found the fuel tubing completely ripped in one shock and partially torn in the other.  I’m sure this was contributing to my weird takeoff behavior as the shocks were extending to different lengths.

So use proper shock limiters – plastic spacers that don’t break down.  Fuel tubing is for hacks…

I recently took a photo of all my Slash 4x4 tires.  Didn’t realize I had so many, but they all serve a purpose:
- Traxxas S1 BF Goodrich (street)
- Pro-line Caliber (loose dirt)
- AKA Wishbone (hardpacked dirt)
- AKA Chainlink (dusty indoor clay)
- AKA Handlebar (near slicks)
- Jconcepts Smoothies (damp clay)

Sanwa update

Those of you who have been following RC news the last couple of days have probably heard that Airtronics is going under.  I didn’t know exactly who they were, but they were basically the US brand of Sanwa, and that name is going away.

So I guess I own a Sanwa MX-V and Sanwa MT-4S.

I’ve been using the MX-V a bit more lately, it’s the radio I usually pair with my TLR 22T2.0.  I find the wheel overly stiff, but other than that it is a fantastic radio and I have to give it the nod over the Futaba 3PL.  Even if I were just bashing, I’d go with the Sanwa for the better precision and fit and finish.  I still use the Futaba with my Slash, but am seriously thinking of converting it over to the MX-V also.  We’ll see…  at this point I am quite a Sanwa fan.

Slash steering slop

There was a cool new thread on the Traxxas forums a week ago that piqued my interest.  Those of you who have a Slash 4x4 have noticed the excessive steering slop.  New plastics help, but most of the slop comes from the shoulder screws in the C-blocks and the steering linkage, and a smart guy on the forums had a fix.

Here’s the thread:

https://traxxas.com/forums/showthread.php?9056238-Steering-slop-reduction-mod

I took it a bit further and expanded on his ideas.  The main mod is to use 3x6x2.5 bearings everywhere there are shoulder screws, and then replace the shoulder screw with an M3 screw.  For the steering linkage, I’m using flanged 3x6x2.5 bearings I got from Avid RC, and some 3x5x4mm Serpent spacers to take up the excess space.

For the C-hubs I’m using the same flanged bearings with an additional 3x6x2.5 bearing in the bottom and a 3x5x2mm spacer on the top.

Check out the thread for more pictures and a more detailed description of the mod.  Overall, I’d say this cut out about 80% of the excess steering slop I had and cost less than $20 in parts!