Super Falcon

[BuggyDad 4405]

'Tis perhaps a strange idea but I'm going with it. I had a Falcon as a kid. Like everyone else's, the front bulkhead mounting to the chassis broke the tub, the tub got drilled through for long bolts and nuts which was better but ultimately not enough better. Judicious application of Araldite helped a little. But only a little. The dogbones fell out so the back got shimmed, or what passed for that by 12 year old me in a farm workshop. That half worked. Other things I've forgotten about broke. Motor upgrade was inevitably part of the cause. 

But, it was mine. I loved it. It's why I'm back into RC now. So I'm planning a tribute to it.

The starting point is a Blitzer Beetle new kit, because chassis tub is the same, so layout is close enough, it should fit the Falcon shell well, and it largely solves the major issues of the day (especially once I add 3d printed braces). And it adds double wishbone rear suspension which i think is a nice slant on it. I hope also to be able to adjust width, ride height, angles etc for a more modern performing buggy. 

So it's a tribute not an attempt to recreate one. Some aspects of the original's character I will try to recreate, others I will heartlessly throw in the bin. 

My initial unknowns are:

What shall I call it? Super Falcon, Fake Falcon, Fake-on, Falcon Evo, Phony Phalcon. The options are many. Hit me with inspiration! 

Yellow stuff. Yellow bits are important. They won't be quite the right bits but they're still essential. Can I dye white to a passably accurate shade? Help please! 

Shocks. Old ebay CVAs look like the only way to get the requisite yellowness here. But they're not often found in good nick, or at least I'm a liitle unsure about old plastic here on a runner, so I'd love it if something else was available. Colour is important. Roughly CVA level performance is important. Other precise details on appearance/brand perhaps less so. 

Grasshopper 2 wheels and tyres look right. They might even be identical to originals but for the hex. If I can dye a set of them they could be the answer. But small diameter may make the buggy look off given the other changes to it (wider stance) and won't perform as well as 2.2. Really this build should be 2.2, yellow and broadly in keeping style wise. Dyeing JCR's Fox ones is another option. Hmmm. 

[Andreas W 1543]

This is a superb project and will be interesting tofollow. The idea of JC Fox wheels is good. They look the business and you get to use good tyres. You will not be happy with the Grasshopper II tyres, believe me. 

 

As for shocks I think I found yellow bodys (part trees and konvolut) on Tamico last week. Check out the Terra Scorcher and Monster Beetle .

[BuggyDad 4405]

1 hour ago, Andreas W said:

As for shocks I think I found yellow bodys (part trees and konvolut) on Tamico last week. Check out the Terra Scorcher and Monster Beetle .

Ah! A medal for that man! They have the yellow plastic trees. Blitzer uses V&W for the front and X&Y for the rear, and the same lettered trees are used for those other models so I'm working on the basis they're just the same but yellow. They come out at similar lengths and I think there's only 2 diameters of buggy piston so a very good chance it all fits together. And I'll have a full set of internals and springs in the Blitzer kit. If that works it's a right royal result! Now I just have to work out how to get it to me from Tamico. I do have an idea... 

Another wheel option is star dish. Wrong, a bit, but yellow. I'll probably grab some because it'll go through wheels anyway. 

[BuggyDad 4405]

Can anyone confirm the suspension shaft lengths required for the Blitzer? 

I see a bit of conflicting info on the subject (well, of which part sets to buy). 

This would be for lower arms, inner and outer shafts, and kingpins. I don't think the upper arms use them anyway (step screws as stock?) but regardless I'll use turnbuckles and ball joints.

[Falcon#5 594]

Good to see someone taking on this project. It has been something i have wanted to do for a long time now. I even bought all the front end parts a number of years ago to build a Falcon Hawk, but have yet to get motivated...

Two Blitzer Beetles & a Stadium Blitzer are sitting in my man cave awaiting me to do something with. (Along with a Bear Hawk & 5 or 6 Falcons...) So I am following this thread with interest.

Have you checked out TamiyaBase? There is info for all 3 models including manuals which can be downloaded.

Blitzer Beetle link & Blitzer Beetle Manual link.

The screw pin lengths are slightly different to the width of the suspension arms & C hubs.

These are all lower arm.

                            Screw Pin    Arm Width

Front Inside        46mm           45.8mm

Front Outside     32mm           30.5mm

Rear Inside         46mm           44.5mm

Rear Outside      38mm           35.8mm

 

                           Screw Pin     C Hub Length

Kingpin               22mm             21mm

 

[BuggyDad 4405]

12 hours ago, Falcon#5 said:

Good to see someone taking on this project. It has been something i have wanted to do for a long time now. I even bought all the front end parts a number of years ago to build a Falcon Hawk, but have yet to get motivated...

Two Blitzer Beetles & a Stadium Blitzer are sitting in my man cave awaiting me to do something with. (Along with a Bear Hawk & 5 or 6 Falcons...) So I am following this thread with interest.

Have you checked out TamiyaBase? There is info for all 3 models including manuals which can be downloaded.

Blitzer Beetle link & Blitzer Beetle Manual link.

The screw pin lengths are slightly different to the width of the suspension arms & C hubs.

These are all lower arm.

                            Screw Pin    Arm Width

Front Inside        46mm           45.8mm

Front Outside     32mm           30.5mm

Rear Inside         46mm           44.5mm

Rear Outside      38mm           35.8mm

 

                           Screw Pin     C Hub Length

Kingpin               22mm             21mm

 

Ah thanks so much for the measurements. It looks to me like the TL-01 set plus some 22-25mm options I have in stock should do reasonably well for all bar the front outside pins. Those will either need me to stumble upon a part I've yet to identify or load up with a slightly unsightly number of spacers. We shall see. I do also have transparent and black plastic spacers might work. 

I hope to begin the project in the next couple of days, although my yellow shock plastics are some weeks away still. 

[BuggyDad 4405]

And so it begins. 

I decided my main aim today was to assemble sufficient chassis to start working on body fitment. So I skipped a lot along the way. This in part because I'm lacking a few bits, in part because I think I'll want to 3d print body mounts/posts and in part because I might want to lay out servo and electronics differently anyway. 

Along the way I've found a few issues to mull over. But I also found I had loads of parts bin parts to fit - eg uprights and all recommended suspension shafts. 

1. First issue is steering. The standard mod to reduce the bad bump steer of the Blitzer is to flip the uprights. But doing that looks to me like it would severely limit the steering:

So, I've fitted mine as per the manual for now. Mine are DT-03 uprights but they're identical except for axle length. For those that have flipped theirs on Blitzers - what am I missing? 

So I am now even more tempted to go a bit crazy and fit a bellcrank steering arrangement, which could bring the tie rods to about the right angles and lengths. 

A positive I did notice though is that I reckon the c hubs give more clearance than DT-03 ones, so I do wonder whether some rotating axle uprights, like my Cougar ones for example, might fit without hunting around for different C hubs. I don't have my DT-03 with me though to confirm. That'd be nice for hex wheel fitment but not help bump steer. 

2. Second issue is suspension shafts. Inner ones are perfect (front) or so near as makes no difference (1mm spacer rear). King pins also only required 1.5mm spacers.

Outers though, my 37mm fronts would require 4mm of spacers in the front and shaving about 2mm off the arms in the rear. So I'm going to keep searching for better ones. I also have set 53301 coming, but I believe it's the same ones. 

3. I fitted DF-02 Universals. They look shorter than ideal to me

This is having shimmed 0.6mm at the wheel end. It might be fine, but I'm not sure. Would be interested to know others' thoughts? 

4. The shock towers feel flimsy to me and I am exposing them where the Blitzer bodies don't. I'm going to mull over whether I can improve with some CF sheet or some other method. 

5. The body wing sides are cut up the sides at the back rather than being left to curve around for more structure. I know this is the Falcon way, and I'll probably just do it, but I think it is a bit of a shame in a way too, and will let dirt in. The back wheels would foul it, but not by a huge amount. It makes me wonder about a slightly leftfield solution to multiple small issues, to design new arms that place the wheels a few mm further back and/or out, with the side benefits that I could hopefully design them to take a known common CVD and I think with a rear motor buggy like this it might do some good to weight balance. It sounds a bit nuts and I probably won't do it but food for thought. Or maybe DT-03 arms and rear uprights would fit. Or some other. Hmmm. 

Anyway, I'm getting somewhere. 

Looks a bit Falcon-like. Sorta. I fitted the wheels just for a bit of yellow - I haven't got the other bits with me and I couldn't photograph it without any yellow. The shocks are nicked out the DT-03 spares just for dimensions. And nobody say "DT-02". It doesn't look like one of those. At all. Wash your mouth out. 

[Grumpy pants 4446]

I’m pretty sure you can dye CVA shocks - so white to yellow will work - Rite Dye 👍

I don’t think Grasshopper wheels will dye - wrong type of plastic, however Holiday buggy wheels will dye well.

Yep, the shock towers are a weak point, they split where the step screw goes in to secure the shock.

 I’m pretty sure Falcon rear shocks are 90mm eye to eye. I have a pair I can check for you, if that helps at all. 

I’m pretty sure when you flip the uprights you move the ball stud to the other side from memory.

I’m sure you’ve got this all covered ⬆️

Looks like a great project for a retro Falcon 👏

 

[ThunderDragonCy 7873]

Good start. You could dial in some rear toe in if you do arms

[BuggyDad 4405]

5 minutes ago, Grumpy pants said:

I’m pretty sure you can dye CVA shocks - so white to yellow will work - Rite Dye 👍

I don’t think Grasshopper wheels will dye - wrong type of plastic, however Holiday buggy wheels will dye well.

Yep, the shock towers are a weak point, they split where the step screw goes in to secure the shock.

 I’m pretty sure Falcon rear shocks are 90mm eye to eye. I have a pair I can check for you, if that helps at all. 

I’m pretty sure when you flip the uprights you move the ball stud to the other side from memory.

I’m sure you’ve got this all covered ⬆️

Looks like a great project for a retro Falcon 👏

 

I should soon be sorted on yellow shocks - I found that you can buy the yellow plastics which I'm 80% sure are otherwise the same trees as in the Blitzer, so I have those coming from Tamico (fingers crossed - complicated logistics via a mate in Germany!). I note also that these DT-03 ones seem a reasonable fit - I suspect they might be exactly the same. 

I decided against grasshopper wheels because of diameter anyway. I'm guessing the yellow ones I have are off a Holiday Buggy? I also intend to try dyeing some repro Fox ones from JC Racing, which, although they aren't like the Falcon ones, I like and think they suit in a period sort of way. 

[BuggyDad 4405]

Born to be Wild? 

Well, Born at least... 

Not great cutting, a bit trial and error. I have a second shell I may do once everything else has settled down. The further forward than Falcon placement of the Blitzer front shock tower is a bit troublesome. 

Another mod I'll do from the off is to drill the holes where the front attaches to the tub and use 40mm screws and nuts to clamp top all the way through to bottom. I can't not do this - it was the first modification of an RC car I ever came up with, in about 1988!

Also considering a CF brace from those top holes all the way to somewhere on the rear tower. The chassis flexes like spaghetti and I might not fit much of the other internal stuff because layout ideas. 

The body should give some protection for the rear tower. Not total, but some. 

[BuggyDad 4405]

An option for bracing on the top is to go all the way to the back rather than to the mid chassis mount points. Work in progress:

As well as being stronger than a 3d printed brace to the middle, this would better enable me to alter servo position, required for a bellcrank steering option I'm hoping I can make work. Touch and go whether it'll get in the way of body fitment. Also it might be self-defeating if I remove bulkhead material to retain that thick section of carbon. I might need that option to fit steering parts, but if I don't I'll cut back a load of carbon to keep the bulkhead to chassis mount intact, which would be stronger.

Underneath, I might try to make a brace out of some steel sheet. Agricultural, but it's weight where the car wants more weight. I'm also not sure whether a lower brace is required. So will mull that over. Or maybe I go carbon and countersink the screws, more rigid, might be easier and I have a suitable piece. 

On a side note if weight distribution is a focus, this brushless motor is quite a bit heavier than a Superstock BZ I have. The higher RPM of brushless appeals though - this thing is geared for big wheels. I'll probably give both a try in this car. 

Other hairbrained ideas I'm toying with are:

- tilting the whole rear assembly back a shade for some anti-squat. 

- mounting the battery front to back if it helps weight distribution significantly, but I don't think it does really. 

- mounting the wing direct to the chassis to avoid tearing the back off the shell in a crash. 

[BuggyDad 4405]

Today, ladies and gentlemen, the FrankenFalcon received its first* piece of real life bona fide yellow Tamiya Falcon. 

Its fate is seald. 

*quite possibly only, I fully accept! 

It wasn't quite so simple though. The good folk of Tamiya designed even this piece to be different on the Blitzers. 

So I had to cut and space it. 

It may therefore, I admit, now be a little less, er, seald, than it might otherwise have been. No matter. Onward and upward. 

To the arms. I had an idea to try DT-03 arms (requiring only ~1mm filing away at the inner mount) and a pair of @ThunderDragonCy's toed in DT uprights, because I have both in stock. If it works it'll give me the toe-in but also take the rear wheels about 5mm backwards, which to my simple mind could be a useful addition to this rear weight biased chassis. I didn't really like how the CVDs I have fit in the stock parts either, so although I had a hunch my new arms might make this worse rather than better, I was already thinking I might need to shop for different length CVDs. I also wasn't sure how the shocks would like their now slightly out of plane mounting although a slightly raked forward shock would look more Falcon. But I did know I have perfect fitting hinge pins for these arms, so there's at least one problem my idea solves rather than creates 😁. 

Fitting the parts a few things come up:

- it turns out, contrary to my expectation, my CVDs are now a shade too long rather than short. They spin OK but they won't take any negative camber without limiting suspension travel. Perhaps I could cut the bearing recess in the upright a tiny bit deeper, if I find the right drill bit, or find a way to bring the outdrives in a shade (they have ~2mm of exposed shaft outside the gearbox case). Or if none of these things is a goer and I can't find fractionally shorter CVDs I could design slightly different uprights or arms for 3d print. Also this situation must mean I've narrowed rear track a little, which isn't desirable. 

- these uprights just foul the star dish wheels, but they don't the Fox ones which have a lot more offset. Thing is though, I really like the Fox ones (assuming I can dye them OK) and I don't really care for the star dish ones. Also, I've room for wider hexes and 1mm more would do. And, if the car wants wider track then more offset is good. 

- shock bottom shock mount does now sit a bit rearward of top mount but I don't think it's enough to matter, although I'm not certain. 

 

[BuggyDad 4405]

Painted and stickered the shell tonight. 

 

 

 

I messed up the wing, so I'm going to save the wing decals this time. I have a second shell and set of decals. I'll do one stock wing and use a different one for a second setup. Maybe do black with red sides (or vice versa) on a Revive RC one mounted a little further back on a custom mount. 

Anyway, although there are some issues with this shell it serves as a successful test for the next one. PS-2 red is very translucent isn't it? I backed with bright gun metal after plenty of coats of red and it's gone very dark. So proper Falcon colours have to be unbacked I reckon. Which is fine. Or maybe I back with another more solid red. Or white? 

What else? The big side decals have some black lexan behind them because I cut the shell way longer than the line, even though I moved the sticker back a bit (to accommodate my post holes). So I need to decide whether to cut the shell forward to the sticker or leave as is. Cutting it further forward exposes black chassis bits, so clean black shell there isn't so bad. Alternatively I could paint this section red on the next one but I doubt it'd match the sticker colour very well. 

Also I raised the rear of the shell a little on the posts. If I decide that's the way to go I can cut the next shell quite differently. 

[jonboy1 2943]

On 6/5/2023 at 10:27 PM, BuggyDad said:

- it turns out, contrary to my expectation, my CVDs are now a shade too long rather than short. They spin OK but they won't take any negative camber without limiting suspension travel. Perhaps I could cut the bearing recess in the upright a tiny bit deeper, if I find the right drill bit, or find a way to bring the outdrives in a shade (they have ~2mm of exposed shaft outside the gearbox case). Or if none of these things is a goer and I can't find fractionally shorter CVDs I could design slightly different uprights or arms for 3d print. Also this situation must mean I've narrowed rear track a little, which isn't desirable. 

what size bearings are there in the outer hubs? I remember this being an issue when fitting CVDs to the Astute, and you get around it by fitting thinner bearings (3mm thick instead of 4mm) 

https://www.tamiya.com/english/products/42379/index.htm

 

[BuggyDad 4405]

25 minutes ago, jonboy1 said:

what size bearings are there in the outer hubs? I remember this being an issue when fitting CVDs to the Astute, and you get around it by fitting thinner bearings (3mm thick instead of 4mm) 

https://www.tamiya.com/english/products/42379/index.htm

 

Good point. They're 1150. 5x11x4. So if I could find a well sealed 5x11x3 bearing that would also solve the problem. I'm not sure such a thing exists though? Or have you sleeved the 1050 out to 11mm?

Another (rather more convoluted) solution that tempts me is to design my own arms. These could take a longer CVD to widen the track and be sized to fit the gearbox end perfectly as well as adjust the shock mount forward a little. They could also either toe in the standard uprights or (more likely) take DT-03 ones. One for the future though. I don't fancy my chances of cutting into the uprights accurately enough for a deeper bearing recess.

On that note I was looking at the available CVD lengths. It seems to me in the ballpark from Tamiya we have:

54016 DB-01 64mm (which I intend to use in TD4 rear with DB-01 arms and XV-01 uprights) 

53791 DF-02 70mm (which are coming up either a little short as direct replacements in the Blitzer or a little long in the Blitzer with DT-03 arms and uprights) 

22028 TD4 73mm

So, I'm tempted to design new arms to use with TD4 CVDs and otherwise all the same parts I've got fitted currently (and a longer turnbuckle). If that's 2mm extra wriggle room and a +3mm shaft it's +5mm either side. Worth a try I think. 

[Falcon#5 594]

2 hours ago, BuggyDad said:

Good point. They're 1150. 5x11x4. So if I could find a well  5x11x3 bearing that would also solve the problem.

Problem sorted.

[OldSchoolRC1 982]

Looks fantastic! So much better than the "Neo Falcon" we got on the DT02 chassis a few years back. 

[BuggyDad 4405]

22 minutes ago, OldSchoolRC1 said:

Looks fantastic! So much better than the "Neo Falcon" we got on the DT02 chassis a few years back. 

Thanks! 

That Neo Falcon thing is an abomination. Good name though, shame it's taken. 

[BuggyDad 4405]

A tiny update to this - I found I already have in stock (because they may be required to fit longer rear axles to either XV-01 or TT-02, which I didn't get around to doing) a pack of the 5x11x3 bearings as suggested by @jonboy1, so I have fitted those to solve the binding CVDs. At the extreme of full compression they do begin to affect rotation but that is well beyond chassis bottom-out with buggy wheels fitted, so I can easily space the shock shaft to prevent that. As currently built the arm angle at full compression is also far greater than at full droop, so there may be an argument for longer shocks or switching to the inner lower mounting holes, but I won't consider that til I've completed and run the chassis. Meantime, I now have nicely moving rear suspension, even the stardish wheels clearing the uprights, a slightly rearward extended wheelbase and rear toe in. 

Otherwise I am awaiting M-05 steering parts, which are on a long lead time. I plan to experiment with a bell crank setup based on those parts, inspired by @ThunderDragonCy's hotshot bellcrank steering using same/similar to clear what look like similar chassis side constraints. So I am hoping the curved bellcrank arms will enable that. I will probably make steering posts that fix top and bottom. If I can build that steering setup in, then I should be pretty close to a first runner. 

[BuggyDad 4405]

Finally received my M-05 steering parts and I had a bit of time this evening so I mocked up the bell crank steering with the M-05 arms and scrap materials for a bridge (because I thought it worth starting with it sized to take exactly the same length tie rods as the suspension arms) and a base to fix things to (to enable test positioning before drilling the chassis). 

As you'd expect, this eliminates bump steer but with these uprights there's no Ackerman (direct mount to servo does provide some, which is probably why Tamiya spec these ball directly behind kingpin uprights with direct mount steering cars). Throw lock to lock L-R is just over 20mm. Feels just about enough although I'm not certain. I may be able to eak a little more out with a dremel once fitted. Or perhaps I could alter the pivot positions a fraction. 

I don't know how I'd introduce Ackerman without changing uprights here. I'm minded not to worry about that, build it in its current configuration as my first runner and go from there. Then source different uprights if I want to change that.

It all looks like it'll work otherwise, once I work out the right hardware for posts and pivots, which all need to be a good fit. Bridge will have to be CF to be stiff enough and I'll most likely drill the cranks to take 4mm OD Tamiya bushes. I'll most likely try M3 threaded internal, 5mm OD spacer/sleeve aluminium for posts, which I can see on ebay. One small concern is that the bridge overhangs the cranks a long way. I think that'll ask a bit more of the material. However as well as using CF I could deepen it if needs be. 

What Tamiya bell crank steering 2wd buggies should I look at to research alternative uprights? 

[BuggyDad 4405]

I had a whole evening to myself so I made and fitted a mount for my steering posts. 

 

I just need hardwear to make steering posts and pivots. I hope to make the posts themselves by tapping the inside of some 5mm OD spacers. And I'll make a CF steering bridge to replace the aluminium placeholder. Crank to bridge pivots I'll try stock 4mm tamiya top hat bushings over m3 screws. An alternative is the YR aluminium M-05 steering set which would get me what I need for both posts and bridge pivots but I'll try my homemade approach first. The only YR posts I've used before are sloppy anyway (TT-02).

I mounted the servo to the underside of the stock electronics platform. 

Then ESC on top and receiver in front.

I thought I'd have to drill and cut the tub for both servo placement and steering posts but I found ways around both so have avoided what I feared would be compromises to its strength, which I'm pleased about. 

Blitzer manual ESC placement seems a bit odd anyway so I'm not sure I've made that any worse, although mines's a bit high and the body only just fits over it. 

So we're getting there. 

I also like its lowered, bigger wheeled look compared to an original Falcon. Dog is, as usual, wary of the little wheeled monster.

Still quite a lot to do: finish my CF chassis brace (and I'm not certain about battery access under it, or that my hole drilling is accurate enough - rookie error - I should've started with a plastic template), consider an under-chassis brace (Ampro), sort switch placement (wire too short for stock position - I might extend it), build and fit yellow shocks and set them up, other yellow parts TBC, dye the Fox wheels, start again on a new body, consider different geometry front knuckles. Oh, and I need to do something about how the nuts atop my steering posts fit with the ribs over the bulkhead. Either cut down the outer ribs (prefer not to) or build up material between, to take the nut. 

[Grumpy pants 4446]

This is the nicest Falcon I’ve seen, the DT02 wheels and lower stance work perfectly. 
 

[kontemax 1725]

On 7/3/2023 at 12:08 AM, BuggyDad said:

Finally received my M-05 steering parts and I had a bit of time this evening so I mocked up the bell crank steering with the M-05 arms and scrap materials for a bridge (because I thought it worth starting with it sized to take exactly the same length tie rods as the suspension arms) and a base to fix things to (to enable test positioning before drilling the chassis). 

As you'd expect, this eliminates bump steer but with these uprights there's no Ackerman

You can have Ackermann.
Drill the inner holes on the steering yoke closest to each other.
I had the Ackermann angle on my Egress for example.

Max

[BuggyDad 4405]

2 hours ago, kontemax said:

You can have Ackermann.
Drill the inner holes on the steering yoke closest to each other.
I had the Ackermann angle on my Egress for example.

Max

AH! Yes, I see how that would. Thank you. That is a great call. 

I think I will need to experiment with a mockup or two, to see where I get clearance issues when it moves around at the resulting angles. But I think some positive change will be possible. I may then have to bring the outer holes forward for clearance, but I suspect this would negate some of the effect so will start by keeping them all in line. I will start by bringing each hole in only about 1mm I think. If I have this right from the sketching and headscratching that passes for analysis in my kitchen, a very small dimensional change will cause quite an angular change in the bridge at full lock, so I will soon hit clearance issues but hopefully some good effect before I do. 

Edit: mocked up the first one. Inner holes each 1mm inwards. Unfortunately too much slop in my unfinished suspension (crank bearings are not properly located on the posts until I get a suitable 5mm post/spacer, so slop is massive, this car at the moment is really only assembled to check fitment of various parts) to understand/measure the effect properly, so this'll have to wait until I sort that other stuff. Hmm, maybe I'll pillage my TT-02 to borrow its steering posts. 

Meantime, I think I'll make a -2mm version too.