Optima Mid Modern Race Build

[jwscab]

is the belt width OK from SDP-SI? I can trim them if need be.

[Seabass]

It is going to be a 6mm belt so it needs trimmed. I know you made a jig on your lathe to trim belts. I was going to do the same with my lathe. Do you happen to have any pics of what you did. I have a idea in my head but some of the pics of your jug could help. I have a Yoke belt you trimmed and it looks fantastic.

Jake

[jwscab]

the only pics I have taken were in the thread about it, take a look and if there are any more questions, just let me know. The important part is a nice fresh razor blade. I made a small bracket that attaches to the toolpost to hold the blade, the main pulley in the lathe chuck I cut a small recess the exact size of the belt so it wouldn't shift around. The idler isn't too important, I originally wanted to spring load it, but I wanted to cut the belts more than make new tools.

http://www.rc10talk.com/viewtopic.php?f=29&t=22335&hilit=belt+lathe&start=15

[Seabass]

Sweet thanks for the link, I will be making my jig this weekend.

I also found out why my belt is too long. I guess there was a LWB Bullet chassis made for the Optima Mid and I bought a belt for that chassis. The chassis is longer then the LWB chassis. Luckily the guy is willing to provide a refund upon return of the belt.

Thanks for the help guys.

Jake

[Seabass]

Got a ton of work done this weekend. Machined new wings mounts, wing buttons, a chassis brace, and LIPO cradles.

I didn't like the OEM wing mount so i decided to make a coupld changes to the rear. Since I plan to run this car I had to put something in the car that would secure a LIPO saddle pack. I don't have a knurling tool so I didn't get a chance to knurl the the fastener for the battery straps. The cradles, battery strap and upper brace was machined from 1/16 G10.

Jake

[j0pp3]

Wonderful work Jake!

I have a suggestion for you. Have you thought about making new suspension shafts so you can make rid of the C-clips design?



/j0pp3

[kaiser]

mad skillz YO!

[isobarik]

I use the 65.5 new cvd in front of my lazer zxr and zxs and yes they work i have also tested the 68 and it worked to on the other side in the rear i use the 62.5 bone and the axle from the 65.5,68 since they are shorter then the one that are on the UM510 and LA245.

works perfectly

I had my arms machined by www.dynotech-racing.com



Regarding the wheels the 2.0 wheels have same offset front and rear the 2.2s from kyosho have the same ofset in the rear but use an more shallow ofset in the front.

Hpi 2.2s had the same offset front and rear


mvh isobarik

[j0pp3]

I got the tranny tore apart and freshened up. I was actually happy to find it in really good shape. Bearings were in super condition, new grease in the diff, and decided to machine a new part for the car.

I was doing some research and came across a guy who came up with a way to put a B4 slipper assy on the Optima Mid. I have done this before with other cars so I machined a new top shaft from stainless steel. It came out pretty good and I am happy. I cleaned everything up and put the tranny together. Once my long belt comes in I will need to take the tranny apart to get it in there but I am calling this part done for now.

Hopefully if time permits I can get the front done today as well.

Jake

I just want to add how the shaft looks together with vented slipper hubs and V2 spring. Thanks Jake!

[Seabass]

Looking nice, thanks for the pics.

[Seabass]

I got my new swing shafts in and here is the final verdict.

The 68mm is perfect for the front of this car with these arms. The 62.5 bones are perfect for the rear. The only issue is just as Isobarik mentioned, a short wheel shaft has to be used with the 62.5 swing shaft. I also got my belt from SDPSI and the 127 tooth, XL pitch belt fits perfect. I had to slice the belt into two since the width was 6mm. I have the belt on the car and a spare in the event it is needed.

The last part of this build is machining the arms which will be completed during Jul 4th. The ZX5 wheels also fit perfect so I can use the newer wheels with the different offset. Hopefully I can get this car finished in the next couple weeks and get it on the track.

Thanks for the help so far guys.

Jake

[Seabass]

Looks like I need to change a couple more things to the front. After taking some measurements, the rear track is approximately 1/2 inch wider then the front. I made some adjustments to my front arm measurements to extend the front to the correct width. Of course this means a new set of swing shafts will be needed. I also had to order the 73mm swing shafts to fit on the front. At least I will be able to run the ZX5 wheels as originally planned.

I should have the arms machined in the next day or so. Look for new pics very soon. Almost done with this one, and good thing too becuase this car is hurting the wallet for sure.

Jake

[DennisM]

Really looking forward to seing the arms.

[Seabass]

Arms are cut, and turned out awesome. I am running a few extra sets of these long arms since I have the material as well as a couple sets of the shorter Optima Mid arms which I drew.

Pics over the weekend since I left the cam at the house in AL.

[Seabass]

Huge thanks to Aaron and Jason for helping me with parts for this car. It would not have happened without you guys.

Big progress last week. I finally was able to machine the arms and get the remainder of the parts in to finish the build. I wanted to run the newer ZX5 wheels so i had to make a couple adjustments to the drawings on the arms. I ended up machining the front arms 1/4 wider then the factory ZXR arms, which made up the difference in the different wheel offset. I also ended up running 73mm swing shafts in the front and 62.5mm swing shafdts in the rear.

The factory Kyosho steering was cracked so I needed to figure out a way to make the car steer. After looking at the RC10 Worlds car steering I had at the house, I went ahead and machined new posts so i could have the ball bearing steering in this car. Works great but I am not getting full lock on the outside tire when turning. I may need to find some different bellcranks.

I fired the car up today and it runs really well. The B4 slipper works flawless and I am surprised how quiet this car runs. I need to take the car aprt and clean everything for the final assembly. There are a handful of things I am going to replace but nothing major.

Parts Used:
ZX5 Wheels Front and Rear
ZX5 Rear Hubs
ZX5 Front steering arms and Castor Blocks
73mm Swing Shaft (Front)
62.5mm Swing Shafts (Rear)
RC10 Worlds ball Bearing Bell Cranks
Machined LIPO Cradles
Machined Arms
Machined Top Brace
LWB Chassis
SDPSI Belt
Repro Body and Undertray

Jake