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Re: Optima Mid Runner Budget Build to LWB conversion

Posted: Tue Jul 17, 2018 10:02 am
by XLR8
So, while Kyosho went with four-pack on the left, aftermarket went with four on the right. I think Schumacher also went with four on the left. Interesting.
Off-road in North America race clockwise (most turns are right), was this also true in Europe and Asia?

Re: Optima Mid Runner Budget Build to LWB conversion

Posted: Wed Jul 18, 2018 5:42 pm
by XLR8
Attaching the servo to the new main plate using the original mounting blocks will require a couple new screw holes (I don’t want to mount it with tape). Placing the servo and marking the holes isn’t too difficult but I guess there’s some risk of drilling the holes in the wrong spot. I have this cad model that I made a while back so, I reckon, why not use it.
Kyosho Optima Mid LWB servo mount 1.jpg
BTW, I think the ESC fits very well on the right side, the cables will reach the motor okay, etc. I plan to extend the switch wires so it can be mounted back near the wing mount for easy access.
Kyosho Optima Mid LWB ESC mount.jpg
If I were to simply mirror the servo’s location to the left side (as shown here), this won’t provide much space for the RX. In fact, it’s really crowded in this model.
Kyosho Optima Mid LWB Rx mount.jpg
Simply moving the servo forward could cause it to collide with the bell crank and/or the undertray. There is ample space for the Rx on the right side ahead of the ESC. However, I remember back in the good ‘ole days of AM, I would never attempt to place these two components so near each other due to radio interference. With a modern 2.4ghz systems, would this still be a problem?

Re: Optima Mid Runner Budget Build to LWB conversion

Posted: Wed Jul 18, 2018 6:04 pm
by GoMachV
:shock: nice work on the cad model :shock:

Pretty sure you will have no interference issues with modern. Heck, they don’t even run caps anymore haha

Re: Optima Mid Runner Budget Build to LWB conversion

Posted: Wed Jul 18, 2018 10:59 pm
by XLR8
Thanks Jeff.
I think I'll switch to a Futaba 6g Rx. It's a little narrower and will fit easily in either location.
Kyosho Optima Mid LWB Rx mount 1.jpg
Kyosho Optima Mid LWB Rx mount 2.jpg
Anyway, I've updated the template to include my servo screw hole locations.

FW Mid LWB chassis mods.jpg
I'm ready to print the template and head to the drill press. :D

Re: Optima Mid Runner Budget Build to LWB conversion

Posted: Thu Jul 19, 2018 6:51 am
by matt1ptkn
GoMachV wrote: Wed Jul 18, 2018 6:04 pm :shock: nice work on the cad model :shock:
What he said! :!:

Re: Optima Mid Runner Budget Build to LWB conversion

Posted: Fri Jul 20, 2018 2:25 pm
by XLR8
Thanks Matt.

I don't know why Kyosho didn't add 2.84 mm and a threaded hole to the steering rack's pivot posts so they can also be secured to the upper deck. It seems that this could reduce or maybe even completely eliminate all deflection in the steering system and make steering inputs more precise. Anyway, I think I will go ahead and do this while I'm building the car. Also, I think I'll add a band (probably a tie strap) to the servo saver's plastic *spring* to further tighten things up.

Re: Optima Mid Runner Budget Build to LWB conversion

Posted: Sat Jul 28, 2018 12:55 pm
by mikea96
Any updates?

Re: Optima Mid Runner Budget Build to LWB conversion

Posted: Sat Jul 28, 2018 2:13 pm
by XLR8
Hi Mike,
I was about to ask you the same question. :lol:
Most of the chassis work is completed. I have the body, undertray and wing trimmed and painted white. I need to finish the body with black window paint and the matte black accent on the exterior at the back and apply decals like boxart. I didn't choose to do the sunroof so it won't be a perfect copy of boxart.
I also need to trim the belt covers then it will be ready to assemble.
At the moment, however, I want to progress the design work on the 91 Stealth car so I can order chassis materials. I have it drawn up but just discovered that it's too short so I'm trying to sort that out. :roll: Anyway, once those materials are on order, I can return to the LWB Mid project.
Where have you gotten to on your Mid projects?

Re: Optima Mid Runner Budget Build to LWB conversion

Posted: Sat Jul 28, 2018 2:21 pm
by mikea96
Still waiting on some parts most importantly a custom topshaft to run a b4 slipper. I am also working on 91 chassis and actually have already ordered a carbon panel with 30degree kickup.

Re: Optima Mid Runner Budget Build to LWB conversion

Posted: Sat Jul 28, 2018 4:33 pm
by XLR8
Cool. You are way ahead of me.

Re: Optima Mid Runner Budget Build to LWB conversion

Posted: Mon Aug 06, 2018 5:47 pm
by XLR8
Some progress....
P1010077 (2).JPG
P1010075.JPG
P1010077.JPG
P1010078.JPG
P1010079.JPG
I went ahead and fitted the re-release Optima/Javelin rear hub carriers and installed the 1 degree inserts. The inserts that are included with the carriers are zero, one and two degrees. You won't be able to see it in the photo but some small modifications to the arms are necessary at the carrier's slot to provide clearance for the new carriers.
P1010081.JPG

Re: Optima Mid Runner Budget Build to LWB conversion

Posted: Thu Aug 09, 2018 4:11 pm
by XLR8
A previous owner removed (or probably broke off) the original wing mounting points from the tranny cases so I'll need to fabricate some replacements.
Some posterboard mockups. First attempt with the wing in factory location revealed that the wing will need to be removed before the body can come off. No good.
P1010076.JPG
P1010075.JPG


Second attempt with wing moved aft 20mm. It looks like the body will clear easily. Actually, maybe 15mm would have been far enough.
P1010079.JPG
P1010078.JPG

Re: Optima Mid Runner Budget Build to LWB conversion

Posted: Sun Aug 12, 2018 3:33 pm
by XLR8
Finished the wing mount today. Wing Stays are Kydex. Made some aluminum Wing Washers and Spacer Collars on the lathe.
P1010090.JPG
P1010085.JPG
P1010086.JPG
P1010087.JPG

Re: Optima Mid Runner Budget Build to LWB conversion

Posted: Fri Aug 17, 2018 12:57 am
by Lavigna
Very cool build. Just to play devils advocate (looking at your previous layout drawing) what about swapping the esc and servo? It looks from your your layout, that the steering servo would be at a near perfect 90 degree angle to the steering arms if placed on the right hand side. And by moving the esc to the left side, you would have a shorter and cleaner run for your wires to the motor.

I am assuming there are reasons I don't know of for choosing the sides you have, but I just figured I would share what I see.

Keep it up!

Re: Optima Mid Runner Budget Build to LWB conversion

Posted: Fri Aug 17, 2018 2:19 pm
by XLR8
Thanks, I think the car will be a hoot when it's finished.
I agree that the locations for servo and ESC probably should be switched but the main chassis is slotted for individual cells and one of those slots coincides with where the rear servo mount would need to go. Also, the right side upper deck post would need to be moved to accommodate the servo. Ultimately, I've just accepted that the chassis was made for the servo to be located on the left.
The car is ready for electronics and the body and wing are ready for the decal set so it won't be long now.
Thanks for following the build. :D