HPI Sprint 2 Mods
#91
Judgement Day
Monday, August 20th, was judgement day at The Track @ Harbor Hobbies.
Except for two snapped C blocks, a few dents 'n dings in the front end and some side scars, the Silk Purse survived my retro rookie skills and drove well (up to the part where I hit the barrier one time too many and the C block(s) broke).
With some more practice I hope to run with the big dogs this carpet season.
The NOVAK CLUB SYSTEM perfomed flawlessly.
Kudos to NOVAK for making it and to RobK for approving it for USVTA use.
The $40 I saved over purchasing the Edge 2S / Ballistic Brushless 25.5T VTA System will buy me more C blocks.
OBTW: The C block mod I've been working on has now been track tested. Results: I found out how not to do it.
My heartfelt thanks to Eric Whiteside from The Track @ Harbor Hobbies for working with me, sharing his knowledge and helping me with some of the finer tuning adjustments.
THANKS ERIC!
Eric mentioned that switching over to the HPI Pro 4 steering system has worked out for other Sprint owners. So, that's a definite option for me in the future.
Last edited by Marv; 09-27-2012 at 06:33 PM.
#92
Tech Rookie
#93
Suspended
Nice work man!
#94
The voodoo I was working on: #1 - pinning the flange tubes in the C block with set screws. This kept the tubes from flopping around in the C block. #2 - Entailed using 1/4" delrin plugs to replace the flange tubes and pinning them in with set screws. This eliminated the flange tube to C block slop as well as the slop between the ball stud and lower screw in the flange pipes. = Both were structurally unsound and after a few smacks to the barrier busted up at the screw holes. Even if nothing got smacked they would eventually fail anyway just from the stress of use alone.
Making replacement flange pipes with tighter tolerances is the trick - However, that requires a good lathe & the skills to run the lathe. I have neither.
Can't have things too tight = the car will be like chasing a bear with a sore ass.
Some slop is needed (another valuable tip from Eric).
Another option, if you're just street bashing, is to just go with aluminum C blocks - These have an 8° camber - http://www.ebay.com/sch/m.html?_nkw=...T&_ssn=rc_mall
I chose not to persue the Pro 4 upgrade at this time. So, I don't know which parts are needed or what, if anything else, needs to be done.
It wouldn't hurt to PM Eric and ask him which parts you'll need.
I have not failed. I've just found 10,000 ways that won't work. - Thomas A. Edison
Last edited by Marv; 09-27-2012 at 06:25 PM.
#95
Suspended
Who has the sore ass, you or the bear?
#97
Servo Buzz
I forgot to add this earlier:
I had some servo buzz - very slight and not always, but sometimes. In GOOGLING the issue, I came up with two probable causes = 1) The servo is ng or 2) Something is binding in the linkage. Mine was #2.
I removed all of the linkage ball studs, chucked each one up in a Dremel and polished each one with 500 grit silicon carbide paper to removed the factory black coating and then reinstalled = no more buzz.
Last edited by Marv; 09-05-2012 at 11:49 AM.
#98
Tech Rookie
Figured it would be a good place to ask, but what are the benefits of the front 1 way differential, and the ball differential? I've seen on numerous posts on other forums/threads that people suggest them as a good upgrade... but why?
#99
DIFF Voodoo
That's a great question.
The following links can answer your question much better than I can.
http://www.rctech.net/forum/electric...y-vs-diff.html
And
http://www.rctech.net/forum/rookie-z...way-spool.html
And
http://www.rctech.net/forum/electric...-benefits.html
And
http://www.rctech.net/forum/electric...s-explain.html
Last edited by Marv; 09-05-2012 at 11:49 AM.
#100
Where exactly do you get the carbon fiber shock tower? Which company makes them? I cant find them anywhere
#101
Here ya go -
FRONT
http://www.philshobbyshop.com/catalo...106&q=HPI73106
REAR
http://www.philshobbyshop.com/catalo...aphite_sprint2
BUT:
Be advised, these guys are SLOW on shipping and don't always update their web site with the current inventory (ask me how I know this...).
On one occassion my order sat in the Fort Wayne Post Office for FIVE days!
IMO -Your best bet is to call them, verify the parts are in stock and place the order over the phone.
Personally, I advocate buying from the LHS, but there are occassions when they just can't get what you need/want when you need/want it OR their suppliers are out of stock.
Last edited by Marv; 09-05-2012 at 11:51 AM.
#102
Tech Regular
iTrader: (4)
I got mine from Tower Hobbies. http://www3.towerhobbies.com/cgi-bin...?&I=LXLLN2&P=X and http://www3.towerhobbies.com/cgi-bin...?&I=LXMCS5&P=X
They ship pretty quick.
They ship pretty quick.
#103
Radio Grip Upgrade
I wasn't liking the feel of the OEM foam grip on my HPI TF-40 Tx.
I found a great replacement.
This grip fits my HPI TF-40 2.4GHz Radio PERFECTLY!
No need for tommy tape, glue or any other adhesive solutions.
The grip hugs the wheel like it was it's mama!
I like the way it feels - WAY MUCH better than the OEM foam!
reptile does a great job on these grips!
EXCELLENT COMMUNICATIONS! SUPER FAST SHIPPING! GREAT GRIP!
THANKS Steve!!!
Here's his link on R/C Tech - http://www.rctech.net/forum/r-c-item...-grips-54.html
04.19.2013 Update:
The thread has been removed by the admins.
Last edited by Marv; 06-05-2017 at 03:29 PM.
#104
Customized Pit Boards from Genesis
I recently purchased my very 1st pitboard.
After Googling for quite some time and getting tired of seeing out of stock on many web sites, including Integy - I found a link to Brandon Skewes - Genesis R/C Products right here on R/C Tech.
I thought to myself, "Hm... racing products for the racer by a racer! That's TIGHT!" (You younger greybeards will know what that means).
I emailed Brandon, explained what I wanted and included a mock up.
After several revisions (due to my indecisiveness) my board was in the works.
From the final revision go ahead until the package was delivered was only 3 days (UPS)!
That's FAST!!! REAL FAST!!!
The board was very well wrapped in packing paper and the working surface had a paper protective coating.
The board measures 290mmx425mm = that's about 11 1/2" x 16 3/4" for us global non-conformists and it's 3/8" thick.
Custom sizes ARE available. Just ask.
And as you can see in the picture above - custom text is also an option.
Communications with Brandon were excellent, his work is impeccable, the product is of the HIGHEST quality and Brandon provides SUPER FAST SERVICE!!!
I couldn't be happier.
Well, I could, but neither Eva Longoria nor Selma Hyek have answered my emails...
Here's some recent posts - Customized Pit Boards from Genesis
Brandon makes other nice stuff - GENESIS PRODUCTS PDF
Here's a page from the product catalog[/B]
Acrylic Pitboards & LED light up option.
Check out the information on Brandon's website at: http://www.genesisrcraceway.com/grc.html
OR
Call or email with questions!
507-828-8697 or [email protected]
Thanks
__________________
Brandon J. Skewes
RCAMERICA - XRAY USA - HUDY USA - MAX Power - VP Power Masters
Trinity ReVTech - TEAM GENESIS R/C - SRC Tires
genesisrcraceway.com - skewesjewelry.com - race-rewards.com
Last edited by Marv; 06-05-2017 at 03:33 PM.
#105
Ball Cup/Link Measurements -
20/20 Hindsight voodoo
For those of you that may have forgotten to take and write down the measurements of your ball cup/link assemblies before you swapped over to the RPM Ball Cups - this may help...
From my notes before I took mine apart.
These are center to center - measured at the center of the cups - for each link.
Measured in INCHES.
The sign " following a number/numbers denotes INCH/INCHES.
The sign ' following a number/numbers denotes foot/feet.
They probably haven't taught this in schools for quite some time.
Measured center to center either inside or outside of the cups.
TOE LINKS: 1.40"
FRONT CAMBER LINKS: 1.585"
REAR CAMBER LINKS: 1.5"
SERVO LINK: 1.82"
ACKERMAN LINK: 1.915" - I reccommend that you LEAVE THIS ONE ALONE - Leave the OEM cups on this one = It gives you some slop that is acceptable (IMO) after you do the zip lock bag shim fix to tighten these balls cups found in post #16 of this thread.
Last edited by Marv; 10-16-2012 at 07:33 PM.