Jump to content
Sign in to follow this  
ThunderDragonCy

Boomerang wreck to Boomerwig runner

Recommended Posts

Thought i would do a little thread on this, mainly as somewhere to ask for help! So I low balled an ebay auction the other week and won this

20190507_115808

Right old mess. Mismatched wheels, missing parts, a few bodges. Still i got it so cheap that even with some refreshed plastics it won't owe me much. The big win is that it comes with the supershot front suspension conversion complete with shocks. As it needs a new c parts tree (blue bits) anyway i thought i would do the big wig front suspension conversion.

  • Like 4

Share this post


Link to post
Share on other sites

Some of the parts have come in. I ordered new C parts, D parts (due to missing battery door) Big Wig F parts (front arms). E parts are on their way as i am missing the battery door closure too. Pulled apart the rear gearbox to see what is up. 

Tamiya Boomerang restoration by CTE RC Tamiya Boomerang restoration by CTE RC

First thing is that there are a LOT of plastic bushings in here! Pretty old grease but all the gears seem in really good condition. I dug out as many spare 850 and 1150 bearings. Some are used, but all still run smooth. Two 850s meant i could get bearings in everything here. 

Tamiya Boomerang restoration by CTE RC

This is quite different (and a lot more fiddly) than the Thundershot series transmissions i am used to. Nastiest find was twisted on wire holding the outdrives instead of e clips. Ewww! Luckily u had some 4mm e clipsin the bit box so bearings installed and outdrives propwrly secured. Gave everything a quick clean with nail varnish remover on sone kitchen roll.

Tamiya Boomerang restoration by CTE RC

Going over the manual it seems i ammissing more plastic than i thought with a lot if the E parts missing. The tree is already on order for the vattery door closure, but looks like i will end up needing most of the sprue. 

As i can't reclose the gearbox without the E parts, i mounted the bearings in the new uprights, cut a spare urethane pink outsrive stopper half to hold the centre outsrive pin in place, and remiunted the rear arms with the new uprights. Looks better already! 

Tamiya Boomerang restoration by CTE RC

I put the screwlins in from the front into fresh plastic as the rear sides of the arms were looking a bit ratty and possibly cracked. We'll see. 

Ordered some more 850 bearings and a handful of 1150 to make sure i have enough. Once those and the e parts arrive i can have a go at the front end. 

  • Like 1

Share this post


Link to post
Share on other sites

I loved my old boomerang. Sold it last year for reasons i still dont understand. Sold the spares with it, but i do have a set of used wheels if they are any use to you. Depends where your going to take this.

Share this post


Link to post
Share on other sites

By the way, these split the arms where the hinge pins screw in. New arms and e clipped pins would be a good idea.

Is that gear with the holes stock? Been a while since ive been inside a boomerang gearbox but i dont remember a gear that looked like that.

Share this post


Link to post
Share on other sites
6 minutes ago, graemevw said:

By the way, these split the arms where the hinge pins screw in. New arms and e clipped pins would be a good idea.

Is that gear with the holes stock? Been a while since ive been inside a boomerang gearbox but i dont remember a gear that looked like that.

Shafts and new arms would be the ultimate solution, but i don't want to go mental on this. Plan is to build a runner and see if i like it. 

I think the gears are stock. I wouldn't know but everything seems very tamiya. 

Share this post


Link to post
Share on other sites

 I think what you identified as twisted on wire might have the old C clips used in the original hotshot series gearboxes. If you use the E clips you've got on there at the moment I suspect that the gearbox will bind when you close it up as the C clips are a lot thinner. Have a look at an original hotshot / boomerang manual on the main site if you can. The re-re boomerang / hotshot, etc use E clips, but the gearbox moulding is different and not compatible with the original release gearbox. Might be worth closing the gearbox with just the rear diff fitted, tighten up the gearbox and see if the diff rotates smoothly or not. I suspect it wont :(.

 

 

  • Thanks 1

Share this post


Link to post
Share on other sites
10 minutes ago, ThunderDragonCy said:

Shafts and new arms would be the ultimate solution, but i don't want to go mental on this. Plan is to build a runner and see if i like it. 

I think the gears are stock. I wouldn't know but everything seems very tamiya. 

I remember it being great to drive, even with a 17t in it. I had/have 3 schumacher cougar 2000 shocks (i think, they are posh schumacher ones) i had on mine, really sorted it out. Still have them but i have no 3 shock cars to put them on.

If you wanted the wheels there yours. They arent mint, but im pretty sure they are runner quality.

Share this post


Link to post
Share on other sites

Did yours come with thrust bearings?  

Knowing how precise you are, I just wanted to make you panic.  lol... (in good jest, of course)  

 

xrSz6Sk.jpg

 

They are cheap and easy to find, if you don't have them.  I think I got 1150 size, 4.5mm thick, and that was too thick.  Fortunately, these are loose (unlike Tamiya), so I just swapped one race-washer with a thinner vintage plain washer.  That was perfect thickness to provide good mesh between gears.  

https://www.ebay.com/itm/5-50pcs-Axial-Ball-Thrust-Bearing-F2-6M-to-F12-23M-Mini-Plane-Bearing-3-Parts-/401576500186?var=&hash=item5d7fd31bda

 

Share this post


Link to post
Share on other sites
3 hours ago, Juggular said:

Did yours come with thrust bearings?  

Knowing how precise you are, I just wanted to make you panic.  lol... (in good jest, of course)  

 

xrSz6Sk.jpg

 

They are cheap and easy to find, if you don't have them.  I think I got 1150 size, 4.5mm thick, and that was too thick.  Fortunately, these are loose (unlike Tamiya), so I just swapped one race-washer with a thinner vintage plain washer.  That was perfect thickness to provide good mesh between gears.  

https://www.ebay.com/itm/5-50pcs-Axial-Ball-Thrust-Bearing-F2-6M-to-F12-23M-Mini-Plane-Bearing-3-Parts-/401576500186?var=&hash=item5d7fd31bda

 

Yes, it came with thrust bearings fitted and it seems to spin freely. Only thing i replaced on the prop ebds are the regular 1150 on the outside and the 850 on the inside. 

 

10 hours ago, MadInventor said:

 I think what you identified as twisted on wire might have the old C clips used in the original hotshot series gearboxes. If you use the E clips you've got on there at the moment I suspect that the gearbox will bind when you close it up as the C clips are a lot thinner. Have a look at an original hotshot / boomerang manual on the main site if you can. The re-re boomerang / hotshot, etc use E clips, but the gearbox moulding is different and not compatible with the original release gearbox. Might be worth closing the gearbox with just the rear diff fitted, tighten up the gearbox and see if the diff rotates smoothly or not. I suspect it wont :(.

 

 

Don't suppose someone with a vintage manual could photograph and post the page could you? 

 

  • Like 1

Share this post


Link to post
Share on other sites

@MadInventor Thanks. Looks like i definitely have the vintage gearbox and it did use c clips. It doesn't go together with the e rings. This car also came with 850 sized bronze bushings where it says the A5 part should be, but surely these will just cause drag? Maybe i could install an 850 bearing instead? The rere has no spacers there at all. 

Share this post


Link to post
Share on other sites
3 hours ago, ThunderDragonCy said:

@MadInventor Thanks. Looks like i definitely have the vintage gearbox and it did use c clips. It doesn't go together with the e rings. This car also came with 850 sized bronze bushings where it says the A5 part should be, but surely these will just cause drag? Maybe i could install an 850 bearing instead? The rere has no spacers there at all. 

A5? That's the right hand anti-roll bar mount according to the manual ?:blink:

 

Share this post


Link to post
Share on other sites
25 minutes ago, MadInventor said:

A5? That's the right hand anti-roll bar mount according to the manual ?:blink:

 

Sorry, i was looking at the Bigwig manual to see how the bearings worked. I have out it back together without anything in there and it seems steady enough. 

  • Haha 1

Share this post


Link to post
Share on other sites

Got some more done today, but also found a few roadblocks 

20190514_115702

Front gearbox apart. More c clips so this is definitely a vintage boomer. Replaced all the bushings with bearings, cleaned and greased the diff and put it all back together. 

Then onto the front suspension... 

20190514_122021

All pretty yuck to be honest. Screwpins are stripped in the upper arms, hubs are brittle and cracked. Good job most of this is going in the recycling anyway! 

New hubs and guide rings from the Bigwig F parts tree. There are also some on the Boomerang E parts tree if you aren't Bigwigging the front end. Used the hubs off the c parts tree. As this is vintage they are the direct replacement so they should work. The rere had different hubs and driveshafts i think. Only carry over is the metal parts. 

20190514_133916

And with all the bigwig front arms fitted.

2019-05-14_01-53-45

One of the bits of yuck was the countersink screws were all mangled on the heads. I didn't have any spare 8mm screws to replace them so i ordered some stainless screws. 

Finally, i took the shocks apart. Guess what? More yuck! 

2019-05-14_05-52-32

So we have warped guide rings due to being stuffed in with the sprue tags still on. And we have an example of all 3 different piston options across 4 shocks (thumbs!). I tried the cva pistons i have spare but they are really loose between the e clips, and i don't have enough shims to take the slop out. I have some vintage pistons but they are 4 hole. It wouldn't be my first choice, but having matching pistons all round is better than not and i have shock oil up to 800cst, so i can go heavy on the oil. Given the general state of these i decided to splash out the £3.50 on some red o rings for when i rebuild them. 

Finally, i also found my spare thunder dragon prop shaft joint doesn't fit as the flat section isn't long enough, so that's another thing ordered. Whilst i was at it i got some new rear arms. For the sake of £6 once i was ordering the other bits it seemed silly not to refresh them given they are beginning to crack. So far its still only plastics i have bought, and i have put up the supershot front suspension mounts for sale now i don't need them so if shouls still end up owing me less than a £100, which ain't bad! 

  • Like 1

Share this post


Link to post
Share on other sites

Vintage boomerang , hotshot , super shot , super sabre , Hotshot 2 , big wig all use C-clips .

RERE boomerang , super ( hot) shot , hotshot , bigwig use E-clips .  

You can use re re gearbox's on vintage 4WD and use the vintage out drives , BUT must use E-clips on rere gearboxs .

You can use rere out drives , dogbones , axles on vintage G-box's with the C-clip . 

  • Thanks 1

Share this post


Link to post
Share on other sites

Few bits turned up which allowed me to get the chassis together

20190516_121359

Extra bearings so put 850s onto the gearbox outdrives as welk as the 1150s in the gearbox itself. Feels nice and solid now. More new 1150s for the front knuckles, and the prop shaft outdrive arrived, so added the plastic shroud from my e parts tree and used the prop shaft that used to be in my Thunder Dragon. All fits nicely. Bigwig arms and shock towers on, and gearboxes mounted with spare 3x15 self tappers i have left over from other builds to make sure there is a bit of fresh cut threads on those gearbox to tub joints. Beginning to look like a buggy now! Just need the shims and e clips to arrive tomorrow so i can build the shocks. 

  • Like 4

Share this post


Link to post
Share on other sites

Got a bit done on the shocks. First up, trimmed the rod guides and cleaned the damper bodies, then re-assemble with nice soft red o rings. A squirt of 3000cst diff oil to keep them sticky. 

20190516_123115

Tried the 2 hole pistons, filled with 600cst oil and tried the front damper. First thing that occurs is that the supplied spring is too long so you end up eith tonnes of preload even with no collars installed. Dug out some stiff Schumacher rear springs out of the spares and they fit splendidly. 4lb rate which is in the ball park of the DF03 53927 front springs. 

20190516_125554

Second thing is that the damping is VERY light. And the mount on the arm is quite inboard so lots of leverage. Time for a re-think. Scrounged together 1 hole pistons (didn't think i had enough as i run 1 hole in all my cva2 dampers). Allied to some cheap 3mm x 0.3 shims off ebay (3 quid for 50) and we have tight piston install. 3 shims needed on each piston

20190517_153937

Rebuilt with 800cst oil. Much slower. Hopefully more like what is needed. Away for the weekend now so the rest of these will keep until next week. 

 

  • Like 3

Share this post


Link to post
Share on other sites

Back from my trip, so finished the dampers. Took a few goes. Schumacher spring still felt too soft so i put the hardest silver DF03 spring on. 

20190519_202721

After feeling how slow the fronts felt i decided to put 600cst oil back in the rears, just with the 1 hole piston instead of two. Once installed i noticed two things. 1) Even with the 800 oil and stiff springs the front still feels very much lighter sprung and faster damped 'at the wheel' compared to the rear, when compressing the suspension and letting it go from the hubs. 2) Even though the manual calls for full length Long rear dampers, the downstops on the arms prevent the arms drooping enough for the full shock length, so the shocks have preload built in. They are about 7mm too long. 

So, rebuilding the shocks AGAIN I put a 6mm spacer off a black front cva sprue and an o ring under the piston and rebuilt, then used the rear hard silver DF03 spring which are a little shorter than the kit long springs. 

20190519_202750

As a brief aside, whilst i was mucking aboit with rear shocks i replaced the rear arms as the new R parts turned up yesterday. The screwpins feel nice and solid now. 

The suspension still seems harder and slower damped than the front though. I think the leverage of the front arms is really mismatching the shock performance front to rear. Normally on front arms the shock mounts 2/3-3/4 of the way out to the wheel, reducing the leverage and mechanical advantage over the front shock. The bigwig arms mount the shock barely halfway out, which means the shock is being compressed with potentially 20-30% more load than on most other buggies, hence the soft, fast feel. I will give it a drive, but i suspect i will need to go down to 300-400cst and much softer spring on the rear shocks to balance out the car. Having the stiffer rear end is going to make turn-in really fast and tend to oversteer. We'll see how it drives. 

Here it is with all the shocks on

20190519_202732

I also popped the electronics in. The spare cheap esc that came with another car, flysky RX, silvercan motor and 14t pinion i used to run in my Thunder Dragon. 

20190519_202740

Installed the redundent MSC tray to cover the prop shaft and hold the power cables off it. 

Anyone got a bigwig have any setup tips? 

Share this post


Link to post
Share on other sites

Annnnd running! 

20190520_210705

Got a screaming deal on a full set of new Mooncraft wheels which look great. I fitted some schumacher mini spikes on the rear and some CAT blocks on the front from the spares box. Also picked up a cheap 21t stock motor as well. 

20190520_210715

Shell came with the original wreck. It's a very poorly painted and cut repro shell. I have tidied it up around the edges and added a few layers of double sided foam tape and some velcro to hold the front down now there is no anti roll bar.

20190520_210742

Gotta love that classic profile!

As i don't know if this is a keeper, for now it stays. I have ordered some decals from MCI in a non-box art scheme to see if i can give it a lift. 

It ran pretty well, but i think the ESC is a little weak. It's fun to drive though. Nice to get it going. 

 

  • Like 4

Share this post


Link to post
Share on other sites

Stickers turned up courtesy MCI Racing. You know me; never knowingly box art! 

Tamita Boomerwig by CTE RC Tamita Boomerwig by CTE RC

They have really helped tidy up this otherwise pretty rough repro shell. Will do nicely for a runner. 

Also changed the front dampers back to the yellow cva 1 hole pistons. Even with 800cst oil, with the black cva2 1 hole pistons the damping was just far too light. The holes in the cva2 pistons are a fair bit larger than the original cva. Combined with the leverage of the inboard shock mounting and there just wasn't enough damping. I put 700cst in with the yellow pistons and the damping feels much more controlled. Its just quicker than the rear dampers with the black 1 hole pistons and 600cst oil. As i don't have any other pair of yellow pistons (the buggy came with 3 different pistons) i need to put lighter oil in these. I'll try 300 and see how that goes. If you have a bigwig i would strongly suggest putting the 1 hole pistons in the front and 2 hole in the rear to even out the damping. 

Got a hobbywing 1060 esc to go in to make the most of the 21t motor, so hopefully will have the handling and running sorted very soon. 

  • Like 3

Share this post


Link to post
Share on other sites

I popped some 300cst oil in the rear shocks and installed the 1060 esc this evening. Took it to the park to find freshly mowed grass. Grass cutting rooster tails for days! Also some pics of the decals in sunlight. 

Tamiya Boomerang 'Boomerwig' Conversion by CTE RC Tamiya Boomerang 'Boomerwig' Conversion by CTE RC

The steering is still a bit loose and wayward, but overall its a lovely runner. Really nice to drive, not too quick so the chassis isn't being over powered. Just really nice. Couple of flips claimed the vintage wing mount. Hopefully there is a metal option as ev3n if new it seems pretty flimsy. 

  • Like 3

Share this post


Link to post
Share on other sites

Those wing mounts should be mega flexi. I dont think they would snap even if folded in half. Your vintage one must have gone brittle.

Share this post


Link to post
Share on other sites
8 hours ago, graemevw said:

Those wing mounts should be mega flexi. I dont think they would snap even if folded in half. Your vintage one must have gone brittle.

Yeah, i thinks that's it. Its very faded compared to the new plastics so looks like it had a lot of sunlight and is probably 30 years old. I replaced the shock towers and rear uprights because they were in a similar state but at least they all came on the same sprue. I have ordered the A parts sprue just for the wing mount as the general feedback is same as yours - a new one should last for years. 

Share this post


Link to post
Share on other sites

Yep , will last a long time . 

Now on the colour . I have vintage A parts Sprues and the colour shading of the Blue is so different , Of the A parts trees i have in vintage . 

Not sure if it was done like that to show Year of new parts trees ??? Or if they here made on a friday arvo and didn't

put in enough colour :lol: .  

Now the re re A parts tree is dark blue . 

Share this post


Link to post
Share on other sites

@matman The original blue plastics weren't just a different colour, they were definitely faded too. If you look in the very first picture, the wing plate is new but the wing mount is not. Yoy can see the difference in colour. 

 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×
×
  • Create New...