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ThunderDragonCy

Project Ultra Hornet

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I still feel like an idiot about this. I'm not really running buggies that much at the moment, and I'm more into onroad vintage racing. I was all set to buy a Mardave Mini to race indoor at the club, and then this idea just got stuck in my head. Totally, completely, can't-get-rid-of-this stuck. I don't even like having cars that are close together in layout or use value, so this makes no sense at all. So this is Project Ultra Hornet, the sister car to my Grasshopper 2 Ultra G. A transmission swap, 4 wheel independent suspension, buggy.

It all starts with the Super Hornet. I am an absolute sucker for the bodies around this time. I mean, just LOOK at it. What a thing!

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However, the old swing axle chassis leave a lot to be desired IMO, even in hopped up, CVA equipped Super Hornet form. And unfortunately for me the Super Hornet was very unpopular over here in the UK so they're rare, and they haven't been rere'd unlike the Grasshopper 2, so getting one to base the build on was a non-starter. However, I remembered watching the AMPRO Engineering episodes on the Rising Fighter, and how he called it the Hornet III. With his Hornet style paint job I realised the Rising Fighter has almost the same body as the Super Hornet from the wing forward, and it uses the GH2 tub, so a plan formed for the body. And a nice NIP Rising Fighter popped up on ebay for very little money.

Project Ultra Hornet

As you can see, the body is a pretty good match. It will be sanded, primed and painted gloss black, and I found some repro Super Hornet stickers on ebay for a good price. So, that's the plan for the body.

Before I did Ultra G, my first effort to improve the front of these cars used DT02/3 front arms, the geometry of which was much better than the Thundershot arms I used on Ultra G for vintage look/matchiness with the Thundershot transmission. Despite the fact that Ultra G is completely brilliant, I always had this little germ of a thought of what a version would be like with more modern geometry suspension. So, I pulled the transmission off Ultra G and off my DT03 to see if they would look like marrying up in any way, but the spur gear on the DT03 transmission is very tall and hits the tub. Then I realised I had quite a few bits of TA02/DF01 transmission lying around from various FF01 and TA02 adventures, and found that the Top Force/Manta Ray B Parts tree conveniently has all the rear end exterior plastics including a shock tower. So I grabbed the trans off my TA02 and this looked much more promising for a nice fit. A lot of measuring, checking and paper outline printouts later, I had this:

1720026802_UltraHornetDF01TransmissionSwapV1.thumb.JPG.aec690c4eb10f27c0e2247969fdd5e5b.JPG

Forgive the incorrect shock tower. It's my FF01 carbon tower, but the mounting points are all the same so it helped me line everything up. The transparent grey block on the left is the space envelope of the GH2 tub. The white part on the side are 3D printed parts which bolt onto the swing axle mounting locations on the side of the tub. These have mounting holes for the carbon base plate being made by Fibre Lyte for me. There's a transmission bulkhead just in front of the motor, and the orangey part on the top sits on top of the gearcase, and I use that as a drill guide to drill through the back of the tub and bolt three M3 bolts through as a top mount. A nice little win is that the DT03 rear arms fit the DF01 mounting bosses, so it will get DT03 rear arms, and my own 3 deg toe in 3D printed rear uprights I designed years ago during my DT03 build. I have ordered the DT03 turnbuckle set for all the camber and steering links. 

The front get an updated version of my arm mounting block with more kick up

1030856110_RisingFighterGH2SuperHornetFrontWishboneMountV4.thumb.JPG.2b289327788c91cc5fc9662ee66e5d29.JPG

And I've ordered the 3D printed and carbon parts I need to include the linkage steering I put on Ultra G last year:

Although for this I've made a mirror image part for the link to keep the connecting rod on the right. It's a tight fit with the driver head on Ultra G.

It's going to run CVA shocks, and I'm getting some JC Racing Products Wild One 2.2" wheels in orange to complete the look. I'm going brushed on the motor to compliment the low gearing of the DF01 transmission. I have a used Reedy Rage Type R 27t stock racing motor from ebay on the way. Hopefully that will be fun, but if not I'll just get something hotter. 

A few bits arrived today, and plenty more on the way

Project Ultra Hornet Project Ultra Hornet

I'm going to run a ball diff for the full old school experience, but knowing what I do about Ultra G, I'm hoping for big things. Despite it being a bag of vintage design bits held together with some 3D printed parts, it's fundamental layout is a three gear mid-motor transmission with a good longitudinal battery location. As Ultra G is a 2 gear (the motor rotates the opposite way to this one), it will be interesting to see how they compare. 

 

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Sounds like a great project, good luck & looking forward to it 👍🏻

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1 hour ago, ThunderDragonCy said:

 I mean, just LOOK at it. What a thing

 

Someone has been watching WAY too much Tamiya Legends on You Tube lol

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1 minute ago, Snappy1 said:

Someone has been watching WAY too much Tamiya Legends on You Tube lol

I actually don't watch any of those, but might be influenced by car journos I watch. 

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I do stare longingly at the Grasshoppers at the local hobby shop lately. Do you follow many of the japanese guys that chop these up? There's quite a few on instagram. Looking forward to watching this unfold :) 

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9 minutes ago, slydar said:

I do stare longingly at the Grasshoppers at the local hobby shop lately. Do you follow many of the japanese guys that chop these up? There's quite a few on instagram. Looking forward to watching this unfold :) 

I haven't seen anything recently, but the Grahoo Grasshopper did inspire me to push on with Ultra G initially. I know there's some 3D printed trailing arm designs knocking about on Thingiverse too. Feel free to share some others. Always interested in ideas.

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6 minutes ago, ThunderDragonCy said:

I haven't seen anything recently, but the Grahoo Grasshopper did inspire me to push on with Ultra G initially. I know there's some 3D printed trailing arm designs knocking about on Thingiverse too. Feel free to share some others. Always interested in ideas.

this guy has a hopper, hornet, and a new frp chassis DT based project.

https://www.instagram.com/sorarin.nana/

these guys are worth checking out too https://www.instagram.com/street_rc_association/

 

 

 

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Started painting the shell and wing today. Rubbed down after washing. I had forgotten how quickly and beautifully automotive paint covers. It's so good. Managed to drop a wet shell off the hanger though didn't I? Idiot. Anyway, automotive plastic bumper primer is on in two coats. Will rub down tonight after it's dry and hopefully rescue the bits that touched the floor when I dropped it. Another coat tomorrow then throw the black on. I'm not getting too hung up on perfect finish. This will be a runner. It'll get some black, then stickers, then clearcoat over everything. 

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Postie just arrived! 

Project Ultra Hornet

Fibre Lyte turned things around in double quick time! That's the transmission base plate on the right. The shock tower is actually for Ultra G because I snapped the shock towers off are the last Tamiya Junkies track day, but the parts underneath that are the tower mount base plates which will also hold the camber link balls. There's an extra one of those for Ultra Hornet. On the left are two carbon base plates for the linkage steering conversion - again, one for each of the Ultra's - because Ultra G still has the test 3D printed base plate which is a bit flexy.

Motor is an ebay special Reedy Rage Type R 24 deg advance timing 27t stock buggy racing motor. Wheels are JC Racing Products 2.2" Wild One style in fluro orange. RC bearings is self explanatory, although I've bought an 1150 thrust bearing to see if it will fit in the ball diff.

Now the long wait for 3D printed parts and the bits I had to order from the Far East.

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Awesome mate! This looks like it's going to be badassB)

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Few first steps this morning. Got the camber link mount plate on. Mounts at the front with the body mount screw. 

Project Tamiya Ultra Hornet

Use the holes in the part as a drill guide, then bolt in place. Also used the dremmel cutting disc and a round file to open out the steering aperture

Project Tamiya Ultra Hornet

Checked the fit up of the transmission plate. Width is perfect, and the gap I left for the battery door seems OK too. 

Project Tamiya Ultra Hornet

 

 

 

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Another small step. I couldn't source the gear shafts for sensible money so I bought so 5mm carbon fibre tube off ebay for £4. 

Project Tamiya Ultra Hornet

Measure up, bit of tape to mark, dremmel abrasive cutting disc went through like butter and hey presto! Lightweight gear shafts for not much money

Project Tamiya Ultra Hornet

They are a very tight fit on the bearings, but is does go with a bit of pressure. All smooth and free running. Made another for the spur gear too

Project Tamiya Ultra Hornet

Little smear of tamiya grease on the teeth then cut threads and buttoned it all up with machine screws. Not, no prop shaft bevel or drive. No need. 

Also finally found the ball diff gear I thought I had, so ordered some drive cups and pressure plates to complete the diff without having to rob anything else. 

Also saw the shop with the drive cups had the top force FRP tower for a cheeky 6 quid, so that got ordered too. Nice. 

 

 

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Aaannnnnnd.....with stickers 

Project Tamiya Ultra Hornet

 

Project Tamiya Ultra Hornet

The stickers were good value compared to MCI, but they are quite thick with a top clear vinyl layer. I was going to clear coat them, but I think for now I'll just run it and then see if I want to get some better stickers later on. 

 

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Rcjaz delivery! 

20220308_122544.thumb.jpg.b895c5a1de548ab43a2fdfdb07d61ca8.jpg

Just waiting for diff outdrives which should arrive this week and I can build the rest of the gearbox and I can start on the shocks. Then it's waiting on 3D printed parts. 

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@ThunderDragonCy  Wow!  Very cool.  

 

Man, everyone is designing custom parts and cars left and right.

Why was I born so dumb?!   ..not fair!  :angry:

 

 

 

 

 

:lol:  GL with your project!!  

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@Willy iine Thank you, you ard very kind, but don't put yourself down. I have a set of skills for my job that modern technology allows me to apply to my hobby. I am in awe of people who scratch build things, I am terrible at painting, to name a bunch of things just in this hobby I am no good at. I am sure there are plenty of things you are good at that I suck at. 

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Couple of little steps forward this morning. All the parts arrived to build the ball diff. Nothing unusual in the build. I just scuffed up the surfaces on the diff plates with some sandpaper then built as per the manual. The 1150 size thrust bearing I got from RC bearings was perfect fit, all metal and only £2.16, so about a quarter of the price of the official tamiya metal thrust bearing. 

Tamiya Project Ultra Hornet

DT03 rear arms fitted no problem. Needed 0.5-0.7mm of shims to take up the slack on the inner pivots.

I fitted the Top Force shock tower with all the ball nuts. 

Tamiya Project Ultra Hornet

Because the DT03 arms mount the shocks on the front, the ball nuts are mounted flipped compared to the Top Force, so the camber links will fit on the outside read face, and the shocks inside front. I used some 10mm drone standoffs I got off ebay to space the shock top mounts forward enough to line up with the arms

Tamiya Project Ultra Hornet

 

 

 

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Is that a TA-03 ball diff fitted in there?

I am really enjoying this thread  

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30 minutes ago, Snappy1 said:

Is that a TA-03 ball diff fitted in there?

I am really enjoying this thread  

It's the TA03 diff pressure plates with all the regular TA01/2/Top Force other parts. The pressure plates are interchangeable and it so happened the TA03 plates were cheaper and easier to get for this.

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Just stumbled on this tread and love what you are trying to do! I have all these aspirations but lack the technical ability to do this. Instead I will enjoy watching your progress.

Thanks for sharing 👍🏻🙌🏻

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Rather unexpectedly lots of 3D printed stuff turned up! 

Tamiya Project Ultra Hornet

I have a busy few days of family stuff ahead so I spent lunch time doing the fit up of the transmission as this was most prone to mismeasurement in the design phase. Side mounts went on perfectly, but I was fairly confident in these as they are a variation on the proven Ultra G design

Tamiya Project Ultra Hornet

Transmission bulkhead lined up perfectly. 

Tamiya Project Ultra Hornet

 

And with the tub mount added. 

Tamiya Project Ultra Hornet

The top mount has come out a little higher than I hoped, but that's what you get for having to measure and work off the original parts. There isn't a lot of scope to lower the holes, and the gap is 1.5mm (I had hoped it would butt up), but it's wrong in the right direction, if you know what I mean? So everything can still fit. 

Tamiya Project Ultra Hornet

 

I measured this from bottom surface of the plate to top of the tub mount at 53.5mm. I reassembled without the transmission and it came out at 51mm. So I added some spacers that added up to 2.5mm difference and bolted it all back together without the transmission so I could use the tub mount as a drill guide. That face of the tub up there got three holes. I have ordered some 1.5mm spacers so I can bolt it together. 

Here's a little video of it so can see what's going on. 

 

 

 

 

 

 

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