markkat

It's been a bit. That crash revealed a few Frogtima weaknesses. The first that I remedied was the rear arm linkage. Previously I had the stock Optima pins sticking into holes in a rectangular piece of aluminum spanning the back. As in the original, these pins were held in by friction applied by screws coming in from the sides under the motor. One pin popped out in the crash. To prevent that, I swapped the pins for some long M3 screws, ran them through a plate, and fastened them with nylon insert nuts. The next order of business was the shocks. As much as I loved the look and dual spring action of my Team Raffee's, they were quite leaky and I broke a rear one. Despite over 30 years having passed, my original Turbo Optima Kyosho Golds were still full of clean oil! Replacing the lower front arm coupling was all it took to get them to fit attaching to the arm rather than the c-hub. I like the more vertical look. Speaking of the c-hub, I replaced the broken Ultima one, and swapped in aluminum knuckles. If the c-hub breaks again, I'll get aluminum ones, if I can find them. The next update was driven more by style than performance. I found some 95mm and 90mm crawler tires that have a nice looking tread and wheels. I also like that they aren't low-profile. Not racing tires by any means, but the Frogtima wasn't ever to be a competitive buggy. I'll be off to the track soon to put these updates to the test. Until then, cheers!

5 minutes into the first run at the track. oooohhh nooooo That broke the front C-hub, the rear arm connection, and a rear shock all at once! Also you can see a good amount of paint flake off the wing. I got it driving again in about 15 minutes and took it easy after that. This week I am repairing and hardening the Frogtima. More to come...

Driver is done. Thanks for the suggestion, Dakratfink! Ready to hit the track!

Thanks! Just good paint. Winsor & Newton oil paint. The undercoat was black, so it produced some nice variation.

I split the difference. The long arms of the multipurpose driver wouldn't fit, so I went with the multipurpose head, and the Tamiya Frog driver body. He's going to sport the sunglasses once he dries. The Frogtima is a mutt in every way.

Yes, I hear that. The Frogtima deserves a driver with a bit of attitude too. Purchased and on its way. 🙂

Thanks for the suggestion! MCIracing has scalable helmets, and I was thinking about taking a similar approach. https://mciracing.ca/collections/introducing-red-wagon-rc-bodies-and-parts/products/helmet-8

Ok, I am pretty proud of this little mod... I created a cross over sleeve (instead of a cross over ring), for the rear dual spring shocks. After waxing on this a bit, I decided that some large heat shrink tubing might do the trick. Cut and shrunk: It fits nicely under the spring, but stops the collar: Uncompressed: Stopping the collar: And the bottom spring compressing only: Genuine dual spring rate action! Also, the heat shrink sleeve slides down if needed, so I can still use the top adjustment screw to tighten or loosen the shock. Now I just need to do the other shock, and add them to the Frogtima!

Thanks, all! Video forthcoming. The snow has been a mess, but we are in the 40's this week. A couple of little tweaks... I still had remnant Optima decals, so I added "Kyosho Racing" to more clearly display the Frogtima's heritage. Also, I recently read this article about dual rate springs: https://shocktherapyst.com/the-truth-about-dual-rate-springs/ I went with the dual spring shocks for looks, and because it was my intuition that two spring rates would improve handling (soft springs for less travel on small bumps, hard springs for more travel on jumps). However, according to the article, you need either binding (full compression) of one spring, or a cross over ring to limit travel of the spring divider to get the benefit of dual springs. This from an ORV: The Team Raffee double springs I installed have the divider, but no cross over ring. Using short soft springs for the top of the front shocks, I am able to get binding when the springs are about half compressed: This results in genuine dual spring rate, which you can feel. I don't have long enough lower stiff springs to achieve binding of the top rear springs, unfortunately. I am now going to see if I can get longer springs, or create a cross over ring for them.

I found an interesting way to simplify the top of the Optima gearbox/Frog chassis connection. Some time back, I ran some bars between the shock mounts and the rollcage: However, I still had some roughly cut carbon fiber panel pieces spanning the Optima gearbox to the Frog chassis. It wasn't elegant, I didn't like it, and became a bit less necessary with the mount/rollcage connection. Adding the wing mount created an opportunity to replace them. I had a bit of angled black aluminum tubing with a M3 thread. With a headless M3 screw, I capped the tubing with a steering link that fit snug around the rear aluminum cross bar. I then threaded the screw running through the wing mount into the other end of the angled tubing. It was a perfect fit. I was able to remove the panel connections, and it stabilized the wing mount to boot. I also completed the decals. Except for the numbers, which are from the GMade R1, I went with Frog decals from MCI. I gave the Frogtima the number 210 as an homage to its Optima roots.

A couple more updates... The lexan body that I hacked up for the Frogtima came with a spoiler. After some deliberation, I decided to channel The Frog a bit more and go for it. After some searching around, I ordered an Associated B64D Wing Mount, and realized I could couple it with this optional chassis piece from my original Frog (I added the aluminum spacer): Those two pieces fit nicely against the rear Optima shock mount, fastened with a long M3 screw: It looked like it was meant to be. I then cut and painted the spoiler, and attached it: Voila! I prefer the look with a spoiler. It's less traditional Funco, but imo the proportions are better this way, and it looks more bratty. You might have noticed that I also swapped the aluminum Scorpion top for one I cut out of spare lexan. Some stress cracks are apparent after the heatgun bending, but I don't mind much. I am sure there will be more to come. One bonus of adding the spoiler was the ability to sport the Frog's "No Guts, No Glory!" motto : More decals to come, mostly from the Frog, I think. If we didn't have 7 inches of snow on the ground, I'd take a video of a run. The Frogtima is a beast.

Thanks! It's been a ton of fun. A few more tweaks left. Also, I am pleasantly surprised by the performance. Much better than my actual Frog (which I love no less)... I'll post a video of the Frogtima soon.

More Frogtima progress! My time to work on this project has been sporadic, but it has been a lot of fun. I replaced the servo head with an aluminum one, and used angled links to bring the arms towards perpendicular. I also shaved the top mount on the servo to make room for the body. Next step was a roll cage. I decide that I wanted an actual roll cage rather then the lexan shell, and I went with one from the Kyosho Scorpion. The Scorpion's rollcage is more angled than I wanted, however, so using a vice and a heatgun, I brought the angle more vertical: I found an interesting way to connect the rear bars to some spacers jutting out of the rear shock mount plate. The next step was the body. As mentioned above, I tried to create one using a heat gun and a sheet of lexan. That proved far too difficult. The arduous process was leading to something that looked ok, but I could tell that I wouldn't be crazy with the end product. Instead, I decided to chop up a preformed body that was closer to what I was going for. I found this in a BOKI Racing Aftermarket RC10 Protech 2 on Ebay. Here's the original "fit" which gave me a lot of material to work with: Slowly trimming away, I brought it down over the chassis: And then I trimmed a bit more: While I was working to get the body on the chassis, I decided that the roll cage coud use some more work. To add some more form to it, and to better secure the back end, I ran some spacers between the rear shock mounts to the roll cage (I also reversed the vertical bar): I might not be done with the roll cage just yet. And then the paint: And some headlamps: I have some decals on order from MCI Racing, and a few more tweaks that I would like to make. I've added oil to the shocks, and greased the gearbox. I have also added an ESC and a receiver. Next up, finishing the roll cage (I'd like some bars running across the back), adding decals, and taking it for a spin. ATM I have my old Kyosho 240S in there. I'll post that shortly. I think it also might need a driver. I have my Frog driver, but because the wheelbase is pushing the limits of 1/10, he looks a bit small. Are there any places where I might find a 1/9 driver?

The Frogtima project continues! I've lapsed a bit with taking photos of the process. Since last update, I have added shocks (Team Raffee double spring) on the front and back, and decided to use the Optima mounts. The rear mount was reversed with the gearbox, but it had little impact on the placement. I also used the Optima sway bars, although the back sway bars needed some trimming due to the gearbox flip. I mounted the front shocks to the arms rather than the hubs to make them more vertical than horizontal. I also added wheels and tires. The fronts are Proline Hoosier's (I rubbed the logo paint off), and the rear are some generics I got off ebay. As mentioned, I'd like to get a 70's Funco look to the buggy, so I'll probably replace the rears with a different tread. The biggest challenge thus far was the steering servo. I finally went with a AGFrc 8.5kg coreless servo that was both small enough yet provided enough torque. Mounting was a bit tricky, but I eventually got a setup that worked. There's no servo-saver, but direct was good enough for the Frog, so it's good enough for the Frogtima. We'll see how that works out. I'll likely trim the top mounts off to make room for the body. I'd like to get the hood as low profile as possible. I have some bent ball links coming that will bring the steering links more perpendicular rather than sweeping back, which will reduce the impact of vertical wheel travel on the alignment. The Frogtima has a healthy amount of ground-clearance. In the future I might get some shorter stocks for a lower optional stance. I am happy with the look. My next steps are a bit of a rear roll cage, as well as a driver roll cage. After that, I am going to attempt to create a body with a flat piece of lexan and a heat gun. That should be interesting...

The journey continues! Some time on vacation and bashing about with my proper Frog, led me to consider more options for the Frogtima. I came back and did a 180, literally: I turned the Optima gearbox around and went for a mid-motor setup. I also painted the Frog chassis black. I tried Rit dye, but it didn't take very well, except for the spots where I cut and sanded it. I used a plastic-bonding primer. I'm sure it will scratch over time, but I can live with it. I think it looks pretty sharp. To make room for the motor, I needed to extend the bottom plate, taking the wheelbase from 268mm to 290mm. It's still within ROAR's 292mm for 1/10 scale, but just barely. It's not going to be the lightest buggy, but I think it will be well-balanced. I decided to go with the stock rear shock mount, and I am waiting for a replacement to arrive since I hacked up the original. Next step is the steering.

More Frogtima Buggy! My first step was staring a this for a while and trying to figure out how to join the two: I cut off the top of front Optima gearbox, but left the lower swing arm portion. However, it didn't make sense to keep the Optima knuckles and axles, so I ordered some Ultima SC6 knuckles, and was pleased to find that I could add them with just the addition of an aluminum spacer. I also did some cutting into the Frog chassis, and finally figured our how the Optima front could be attached. The front was a bit too pitched up, and it took some working to get it right. However, once I had it figured out, I extended the bottom aluminum plate to fasten to the front assembly, and ran some aluminum bands from the chassis to the top. It is solid as a rock, and lighter than it looks. I think a black Frog chassis would look so good, that I am tempted to replace it with the black version. However, I have some black Rit DyeMore, and I will see what effect that has. Any advice would be appreciated. You might have noticed that the wheelbase is significantly longer than that of the humble Frog. The Frog has a 250mm wheelbase, whereas the Frogtima's is currently about 268mm. According to the ROAR Rulebook, the max for an off road 1/10 buggy is 292mm, so no issues there. I can actually extend it to 270mm by moving that spacer, and I might just do that. An odd beast. I'm really starting to like this Frogtima. The next step is figuring out how I am going to get a servo into the front end. I am going to look into some smaller servos. If anyone has a recommendation for a micro servo with enough torque, I am all ears. After that I am going to figure out the shocks. I decided against using the Optima Golds. Both for aesthetics, and because there is enough Optima in this thing already. I can use the front shock mounts as is, but am going to have to get creative with the rear shock mounts as I don't have any upper options atm. To be continued...!

Thanks everyone! It worked. I did about 3 min on mi NiMH charger, then switched to the lipo charger, and it recognized it. No swelling, no heat. No explosions. I’ll take it for a spin tomorrow.

No. This is the setup. I am flying blind... O_o I do have an old meter though. I'll try it first.

Thanks, @mtbkym01 and @matman. The Frogtima Buggy project continues. The next step was to attach the dog bone axles and the upper rear arms. As I had previously chopped up the Optima mount that holds the upper rear arms (and rear shocks), I had to create a new solution. I found the placement for the arm mount attachment could be matched by extending some aluminum spacers from the Frog chassis. I drilled some holes: and attached the spacers on M3 screws coming from the inside. Slightly hacky, but not terrible. The ball mounts for the arms screw nicely into the spacers: Thus the rear arm was mounted. The arm doesn't take a lot of force, but I wasn't crazy about the leverage it had on that spacer, so I added some screws (and aluminum tube sheathing) coming from the gearbox into the spacers. This firmed up the mount, and also increased the strength of the Frog/Optima connection. Not too shabby. The next step it to figure out how I am going to mount the shocks. I have the Optima Gold shocks on hand, so I might start with those, and replace them for style if I can find something more suitable. If anyone has suggestions on for good performance shocks, I'd appreciate it. Extra points if I can find some that are white. I'm starting to dig the Frogtima!

All right. It sounds dangerous. I'll try it on the driveway! Thanks, @Mad Ax! @Wooders28 stand by. I need to dig out my reader.

I have a relatively new 2S 5000mAh lipo and accidentally left it plugged to the ESC for a few days. I believe it fully discharged, and doesn’t seem to be taking a charge. Is there any hope for it at all? I has no damage or swelling.

I have a lot of spare parts for two 1/10 RC cars: the Kyosho Turbo Optima, and the Tamiya Frog. My quest is to build a performant 2WD buggy that looks good, relying heavily upon the parts I have. My goal is to have something that looks like a late 70’s Funco buggy: This will likely be some time in the making, but I'll post my progress here along the way. The Optima has great motor placement compared to the Frog: low, rear, and centered. I only needed to seal the gearbox where the chain/belt feeds out, as I will be forgoing 4WD. My first requirement for this buggy is that the battery is as low as possible and centered. With a new bottom, the Frog chassis accommodates a lipo lying flat right down the middle. I bent and cut some aluminum sheet for a bottom plate to arrive at this setup: The Frog chassis already has much of the shape I want, but I shaved off some protruding parts, including the side mounts for the antenna. I’ll probably dye the plastic later in the process. The way that the Optima rear arms attach provided a simple opportunity. The arms swing on pins that insert from the rear of the gearbox. All that was missing was holes to support the front of those pins. To both join the Frog bottom plate to the Optima gear box, and to provide holes for the rear arm pins, I cut a piece of square aluminum rod, and drilled holes for the pins and the screws coming in from the sides: Aw yeah. Frogtima!: The next step was to solidify the hybrid connection. To do this, I trimmed some of the Frog’s upper body mounts back and cut some aluminum strips to create a bridge to the top of the gear box. I used a threaded aluminum spacer, and put it together: The connection has no wiggle in it at all. It’s almost as if it were meant to be. 😊 My next goal is going to be getting the rear dog bone axles inserted, and the upper connectors for the rear arms installed. After that, I’ll be adding the rear suspension. I still have the Turbo Optima gold shocks, but I will probably get some that look more appropriate for the 70’s style I am after. To be continued…

Thanks, RichieRich. I totally agree. There's just something about the Frog. What it lacks in performance, it makes up in character.

After improving upon the Frog's balance, my quest has become to do something about the front suspension. I think the stock suspension is genius, but it would be great to add some dampening. I did some research, but all of the damper modifications to the front suspension really detract from the look of the Frog, IMHO, and I wasn't about to cut the body to allow for mounts. Currently, I am halfway to a solution. First, I cut some aluminum from my scrap Optima, and created a small front mount that didn't require cutting the body, or look out of scale. Next, I measured the distances a damper would travel, and arrived at 38-45mm. I searched shocks and dampers with those dimensions, but that were also a small diameter. There aren't many, and I settled upon these "The Ultimate Mini Scale Shocks": They are internal spring, not oil, but I am determined to change that. Here's what they look like mounted: I pulled the internal springs, so they aren't functional yet, but the travel is there and smooth. The lower chamber of the shock can be opened, and I am hopeful that a very small and flat o-ring/soft-washer will enable it to hold oil and still glide. Any suggestions are appreciated.

Putting the steering servo and receiver in-line presented a re-balancing opportunity. My Lipo (and new motor) arrived, and voila: The Frog is almost completely balanced on the center line, and the center of gravity has been moved forward by nearly an inch. More to come...