I boiled some CRT.5 arms as a test... -
03.14.2008, 01:21 PM
I mostly drive an indoor track with high traction clay. With this kind of surface and the right tires you can pull some amazing speed through the corners. Of course the negative is that if things get loose you hit the walls really hard. Because I'm more of an overdriver than an underdriver I've broken a few front lower arms on the crt.5. Because I only break fronts I've accumulated 6 extra rear arms. So, I decided to do some test boiling last night.
I kept 1 arm stock, boiled 1 arm for 10 min, and boiled a 2nd arm for 20 min. For your typical 10th scale plastic arms even 10 min would probably be too long, but due to the crt.5s very stiff and thick arms I went for some longer times.
The results:
10min arm - this arm does have more flex than the stock arm and is till quite a bit stiffer than a typical 10th scale plastic arm
20min arm - this arm has even a bit more flex than the 10min arm, but still does not seem too flexy for good handling use.
I wish I had some way to measure the increase in flex of the arms, but if I had to guess I'd say the 10min arm is about 10% softer and the 20min arm is about 15% softer. I think you would have to go 45 - 60min to make them too soft. These are really stiff arms.
To do some sort of a test I labeled one side of the arms and had a couple of friends put them in order of stiffest to softest. The stock arm was easy to tell, but the difference between the 10min & 20min was a bit tougher.
I'm hoping to drive the clay track tomorrow. I'll post any handling differences I notice.
Awesome, I'll be waiting for the results. I definitely favor durability with some loss in precision versus a precise setup that could break on a hard landing.
OK, last night I still wasn't satisfied that I had boiled an arm long enough to the point that it was too flexy. So, I tossed in another spare rear arm for 30 min. Again it got a bit softer than the 20min arm, but was still not overly soft IMO. So, I took all 4 arms off my crt.5 and boiled them for 20min. I'll be doing some test driving at the local backyard track today, but its pretty supercross style with all bowl turns, so any lose in handling probably won't be noticed. Next week I'll get over to the clay track and get some real feedback.
Went to the clay track today. Managed to throw the crt.5 into a huge cartwheel trying to jump the quad (30ft out of a corner). I broke a front C-hub and bearings in the steering knuckle. The front arm survived great. This is only the 2nd time I've broken a C-hub and I've broken at least 6 front arms in that time. So, I think the 20min boil helped save the arm. I did not notice any odd handling issues, but I also did not get to drive it as much as I wanted. Hopefully, I'll test it some more this week.
I just wanted to add that if you boil parts just boil the parts you want softer. I recently made the mistake of boiling almost all of the plastic parts including steering knuckles, and was disappointed to find that the steering is now a little sloppier. It appears to be because of the two knuckles that connect the steering together (they point foward). I was pleasantly suprised at the durability of all the rest of the parts especially the wing mount, a-arms, and main steering knuckle. They had just enough flex. Everything boiled for 25 minutes.
Any new info about the 20 min. arms? Still holding?
I have been having much better luck with the boiled arms. Not sure if 20 min is required. 15 may be enough to take the edge off the brittlness and still be pretty stiff.