Yet another Customised Optima Mid Custom Special

[alcyon]

I just got my own designed ball bearing POM C hubs. Those are standard unmodified ZX-5 knuckles part number LA219-4.





The steering is now super smooth.
I also cut out my Kamtec Lazer ZX-S body and fit it on.

[Coelacanth]

Nice work on the C-hubs. How were they made?

[alcyon]

Nice work on the C-hubs. How were they made?

I drew it on solidworks, making sure everything fits properly, then made a drawing, asked my plastics machinist to make 2 sets for me, one for my Lazer and the other for this car. The material is P.O.M

[HKS_TRD]

Thanks for posting the pics of the ZX-S shell install, I am planning on putting a ZX-S shell on my 21st Century Mid

I also have an idea for the gear cover, more details when I get to make it a reality

[rccars4sal]

Im curious to see how well the plastic c hubs hold up in racing. Very nice work!

[Coelacanth]

Im curious to see how well the plastic c hubs hold up in racing. Very nice work!

The only part that concerns me is the upper part where the top kingpin is mounted...it might be a bit thin there. On the plus side, it is ballraced and should be held securely in place by the camber link.

[alcyon]

Im curious to see how well the plastic c hubs hold up in racing. Very nice work!

The only part that concerns me is the upper part where the top kingpin is mounted...it might be a bit thin there. On the plus side, it is ballraced and should be held securely in place by the camber link.

Me too, but I had no choice, after thinking out so many scenarios, I deduce that since I kept the ballstud area thick and radius the edge coming down to the thinner section, plus the strength of the material this should hold up. I will test this at the rough track near my home, hopefully this coming sunday, if it does not rain. hmm, I see you used the word ballraced, that's soo british !

[Optimusprime]

Cool stuff acyon. Just realized this was your buggy. Did you get your lipo location figured out? What type of track are you running this at ? I took my old zx-5 on an indoor off road clay track last month and I broke every single plastic piece on it lol. I had a second parts car and at and of 2 weeks I had no second parts car. Then I broke down and got a brand new b44.2 with a 9.5 and its holding up allot better. I have been working on a long wheelbase optima mid on and off for the track that i'm trying to bullet proof. Hopefully it will fare a little better than the made of glass zx-5.

[alcyon]

Cool stuff acyon. Just realized this was your buggy. Did you get your lipo location figured out? What type of track are you running this at ? I took my old zx-5 on an indoor off road clay track last month and I broke every single plastic piece on it lol. I had a second parts car and at and of 2 weeks I had no second parts car. Then I broke down and got a brand new b44.2 with a 9.5 and its holding up allot better. I have been working on a long wheelbase optima mid on and off for the track that i'm trying to bullet proof. Hopefully it will fare a little better than the made of glass zx-5.

Hi Optimus. Yes this is my LWB Mid, besides the SWB I am building up. I had this car running since 2011. I do have some tips on how to bulletproof this car. I had problems initially with the front arms breaking, but to be fair they weren't kyoshos but from speed model. I also snapped a rear fibrelyte shock tower, bent an original optima mid and Lazer ZX rear tower, which I promptly straightened back with a hammer. I will be working on designing a strong Lazer ZX graphite rear tower with more material at the weakspots. The only other problems I face are the ball cups popping off, other than that seems to hold up better than the B4's and durangos I see over here. I run this car on an outdoor 1/8 dirt track that is very rutty and bumpy, and the high ground clearance, together with the Lazer suspension and Kyosho big bores really helps this car keep its composure on this track. Look also for my method of securing the shock tower and front gearbox which will prevent your front gearbox from breaking and your front tower from coming off. I can tell you its been a frustrating but rewarding journey to drive a car that I really wanna drive. And working on the improvements myself has really given me a sense of accomplishment. I feel all this hard work is worth it.

[alcyon]

Finally tested my car against a dingo, a RC10 T4.1 ,and a thunder tiger 1/8 EP.
I also brought my friends Lazer ZXR Mk2 for testing. I ran the ZXR first and I was amazed that it handle the bumps by soaking all of them up without losing composure. And the shocks weren't even big bores or kyoshos. The car did however, understeer horribly, which could explain why it tracked straight so well. It could be because it had proline M3 at the rear and the fronts were bald kyoshos. The track condition was damp. After a crash which threw off the main steering tie rod, I retired this car, happy with its stability and performance. I then tried my Custom special with gear diffs, it was oversteering !
There could be 2 possibilities, one is damp sand which clogs up my Jconcepts flipout's spikes, causing it to work like slicks. The other was the geardiff unloading too easily, especially the rear one. However, I encountered no serious durability issues with the C hub I designed, except where the ball stud area was screwed on. a Ballstud went out of position after a hard collision, and I surmise its because the material at that area did not offer enough support to the M3 ball stud, I will extend that area a bit to offer full support in my revised design. When I loosened the B4 clutch, the car was s lot more easier to drive, there was no more on power oversteer, however the clutch isn't consistent and loosens by itself if its set too loose, something a lot of B4 guys know about, I heard the VTS and Avid ones does not suffer from this inconsistency.
So I tightened up the clutch a bit more while still allowing slippage and the car oversteered slightly, so I had to be careful with throttle from almost a dead stop. After the Durango guy went home, I was basically king, easily hounding and beating the thunder tiger 1/8 and one SC10 4x4 and T4.1.
I finally managed to get a hang of the cars nimbleness and used it to my advantage. The lack of traction caused my CS to have not enough speed to clear the huge jump several times, most of the time the rear shock and rear upper links pop a joint. Finally what did me in was I broke a front right ZX arm.

So I went home and changed to my custom made white POM ZX arms.

It looks tough and feels tough, only way to tell is to test it.

oh yeah, a guy recorded a video of my battle with the dingo. The dingo guy seems to think he buried me in this video. I think I did not do bad at all. Well the war isn't over yet, the revenge of the OMCS will come ..
http://www.youtube.com/watch?v=sJtPhz_k3b4
this video is incomplete but the good thing is the poster zoomed up the video so you can see my mid taking the huge jump.

http://www.youtube.com/watch?v=1VTnzIfZCRM
this is the full version of the video, you can see my Mid putting up a better fight at the end. Traction was the main problem.Should have changed to ZXR tyres.

[GoMachV]

Finally what did me in was I broke a front right ZX arm..

Oh no...now the "nylon isn't as good as fiber reinforced stock arms" gang is gonna have to stomp ya!

Looks great, and nice job on the custom pieces! (I'm not in that gang )

[mikea96]

I was thinking the same thing!

[Seabass]

Good ole Delrin...

[rccars4sal]

WOW, thats a big ole jump yo.

[EvolutionRevolution]

Finally what did me in was I broke a front right ZX arm..

Oh no...now the "nylon isn't as good as fiber reinforced stock arms" gang is gonna have to stomp ya!

It's all the fault of that hinge pin! Evil little B*****d, sneaking out of the arm like that!