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XR311 restoration 11 years 3 months ago #16428

Now I've got my bench clear of various electrical & Grasshopper bits, it's much easier to work on stuff, so I've spent the past few days tidying up that XR311 I won cheap on Ebay recently, some of you might remember it...

Here's what turned up for around 40 quid





I was pretty pleased with it considering the gamble on a poor listing/description, it looked pretty complete bar a couple of torsion bars, but horrors did lurk beneath, & this is their story...

As always, pull it to bits & see what's up with it, to generate shopping & making lists.





Still impressed, looks like a fairly early one, going by the fitted motor. All the original fasteners are there, virtually no wear on the bearings, shafts, gears etc, only minor scuffing on the suspension arms.



Then I found the first problem. Despite the rest of it looking like it had been carefully put together & looked after for the past 35 years, it would appear that some div got hold of it, bodged some radio in & ran it (I guess until the torsion bars broke, say 20 seconds?). To bodge the radio in, said div has flattened out the front portion of the chassis, for whatever reason. I just know this will cause me problems, it's unlikely to bend back without breaking. No idea what the balsa wood residue is about either.



The wheels had matt green paint on them & I didn't really want painted wheels so I stipped them for a soak in brake fluid.
Whilst dismantling them, I noticed that most of the spokes were cracked at the rims. Further looking revealed that the cracking had been caused by the wheels having been mounted back-to-front. Shame, I'm guessing XR311 wheels with NO curbing marks must be fairly rare!



Wheels had been soaking for about 30 minutes, so I decided to give them a quick toothbrush scrub, just to give me a clue as to how obstinate the paint was going to be, at which point the job turned from ok to horrific! I couldn't believe it, the wheels literally just disintegrated! Not only in a state of shock at this point, but I think I might also have been mourning. Felt really bad that the parts had survived this long only to die in my hands, but also angry at whoever had done whatever they did to an otherwise perfect set of wheels, to make them so fragile. Was it the paint? Had they already been restored & subjected to something plastic unfriendly? Could it just be the plastic's age? The other plastic parts seemed to be fine...



I tried gluing them back together, but it just wasn't happening - there were just too many tiny bits & the styrene cement wasn't bonding the plastic. Tried CA but that wouldn't stick it either.
I had a spare set of wheels, but these are chewed/damaged & I didn't really want to be putting damaged parts on an otherwise fairly unscathed vintage car. So, plan was to do other stuff first & wait to see if any came up on the bay for sensible money (Which obviously didn't happen whilst I was looking!)

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Re: XR311 restoration 11 years 3 months ago #16430

Moved on & cleaned the paint off the bumper, & washed the pile of bits ready for re-assembly



then put some of the bits back together (Making use of the time whilst trying to avoid going out in the shed!)



I cleaned the goop off the chassis, then took a deep breath & tried to straighten its bent bit - absolutely no resistance whatsoever, it just fell off in my hand....
Kinda expected it, but that didn't prevent more anger!
I did attempt to weld it back on, but obviously being so thin it was never going to go well. Yeah the bit's stuck back on, but it really isn't tidy, & certainly not good enough for this resto. I have another home for it... Fortunately I had a good spare chassis in the box of XR311/Cheetah bits Mr Jonny sent me (I love you...) so I'll use that.

Torsion bars... I'll let slip now that I've got another XR311 project I'm half-thinking about, & having this fairly complete one was taken as an opportunity to copy some bits for use on the other. That's why there's other XR311 bits in the next pic, they're bits I've made for the other car, using the originals from this one to copy - it's easier to do it now whilst its in bits, than take it apart again later for copy-age.
So, below is a pair of torsion bars I made from uPVC bar, using some originals to copy. I've since fitted them & have to say, they're far better/stronger/stiffer than the originals! Still plastic crap though, but I want to keep the cars as original as I can, so no upgrades on this one.



As I've said on another topic, I always fancied converting my old Cheetah to run on dry-cells, ie as it's supposed to be without the NiCd upgrade. Thought now I have 2x these chassis, it would be worth the effort to do something about it. Apologies if you've already seen this...
Chopped up some baked-bean tins for material, scaled the manual pics for dimensions, then made some battery contacts. I already had the plastic backplates & 1x smaller contact courtesy of Mr Retro (Ta, ta, ta) so they were a big help in getting it right.
I machined up a punch for doing the dimples on the smaller contacts, to make things easier & get them all looking the same.







Passed some more time in the warm doing twiddly body bits. It came with 1x mirror stem, so I decided to have mirrors on it... Machined up some uPVC mirror heads, & copied the original stay from an old wire relay clip (1mm spring steel).





Also made a tow hitch (That was missing), which as far as I can tell, leaves only the 4x mudflaps, internal rear view mirror & the pedal assembly, missing from the body. Haven't got anything to copy for these parts, so they're going to have to stay missing for the mo.

Then I'd sort of run out of things to do to avoid thinking about wheels...

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Re: XR311 restoration 11 years 3 months ago #16432

Wheels... Ok, I'm going to actually need 8x outer rims really (Ideally need 4x for the other car at some point, so may as well sort that now).
1x of the busted originals was in sensible few enough pieces to tack back together as a suitable pattern for a mould, so I decided to go that route. I have an aversion to paying 20 quid for 2-off plastic re-re rims, I'd rather put some effort in & say "I made these".
Somewhat typically, I opened the box of moulding silicone I bought ages ago, only to find it had "gone off", & for some reason the catalyst bottle was upside-down & empty... Can't afford more at the mo, so I had to make do with the dregs of some high-temperature stuff I had left. Horrible stuff to work with, it's a total nuisance for trapped air & loss of detail...

Anyway, after some messing about, a usable mould was born & some rim outer blanks thereafter



After several hours tidying them up, I gave them a coat of Holts automotive satin black paint (Which has a finish uncannily similar to the black plastic parts on the XR311/Cheetah) as a dark base coat to whack some Halfords auto "green camoflage" paint on.
I tend to use auto paint on cast resin bits as I've had problems with reactions & stickiness in the past. Post curing it helps, but that comes with its own problems, so it's just easier to use cellulose based paint.



Whilst waiting for paint to dry, I cobbled together some radio/electrics to install. Yeah I know it's not period gear, the bits aren't even from the same set... they're left-overs & they'll do for now!
Made up a steering link out of a big paperclip, messed about for hours with left under-travel & right over-travel of the steering (Due to the pivots being out of line) & eventually found a setting that allowed some steering without wrenching the servo off its mount. Nice bit of early poor design there Mr Tamiya, I see you started at an early age...

Nice to see the MSC was original & complete, unworn & working! I have to say though, why so complicated for a 2-stage speed controller?!

Anyway, wheels on, tighten the torsion bars (& hope they don't break!), discover UM2 batteries aren't the same thing as HP2/D-cells (Of which I have loads & no use for them) so I'll have to buy some C-cells (Looks like that's what's supposed to fit) before I can run it.







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Re: XR311 restoration 11 years 3 months ago #16433

Nice work, great skill to be able to manufacture your own replacement parts :)
If you can't fix it with a hammer, you've got an electrical problem mate :)
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Re: XR311 restoration 11 years 3 months ago #16436

...
it would appear that some div got hold of it, bodged some radio in & ran it (I guess until the torsion bars broke, say 20 seconds?). To bodge the radio in, said div has flattened out the front portion of the chassis, for whatever reason. ...


The answer seems to be in your first photo - have they _really_ taken the front end apart, bent the chassis, rebuilt it & fitted the servo ninety degrees out, rather than find another paperclip to bend for the steering servo link? ... As it's not my car I think I can be impressed by the combination of laziness and stupidity involved there :blink: :pinch:

...
...



Nice work on the wheels BTW :y:

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Re: XR311 restoration 11 years 3 months ago #16438

Great work there Eddrick! :y:
I have no clou what they were thinking with that chassis :whistle: but the body work and driver seem to be nicely done!

Cheers, Bram
Restoring Countach 58005
Restoring 58015 RR
Restoring 58098 F40
Restoring King Cab and Monsterracer
Restoring Audi Quattro rally
Restoring Mk.1 Sand Scorcher
Restoring Porsche 936
The following user(s) Liked this: eddrick

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Re: XR311 restoration 11 years 3 months ago #16442

Still quite amazed at some of your skills and the final quality of the parts. :huh: :y:
Sorry, no extra builder award rank available.

:silly:
The following user(s) Liked this: eddrick

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Re: XR311 restoration 11 years 3 months ago #16448

Cheers peeps!

Jonny, going by the fact that the screws holding the front of the chassis on were M3 CSK ones (The only non-original fasteners), I'd say the front of the chassis might already have been off, or extra stupidity in losing all 4x original screws whilst he was doing the mod. As for why, I can only think it was an attempt to get a different battery in, perhaps a lead-acid, given the screw block connector thingies. Mind you, putting the servo in that way around kinda defeats the space-gaining object!

Incidentally, not having the proper screws for the front of the chassis meant I had to make those too (Forgot about that...) - Started with M3 cheese heads, re-cut the threads 1/8" whitworth (Apparently I haven't got a 4-40 UNC die, but whit is close enough, just a different thread angle, 55deg vs 60deg), then domed the heads in the lathe. The Tamiya 4-40 brass nuts are an oddball A/F size, so they had to be scratch-made too, starting with round brass bar & having to cut their hex on the mill to be the same as the originals... proper mental keen!

Yes Bram, I didn't touch the paint/body as like you say, it's been really nicely done. The model was all nicely built. It really annoyed me that somebody could wreck a nice model like this for the sake of trying to run it briefly. Thankfully the torsion bars are crap enough to stop matey before he did any serious crash damage!
The mod was a fairly recent one, as the fitted steering servo isn't hugely old, whereas the MSC one is proper ancient & likely to be what was originally fitted in '77. To think the model was obviously someone's pride & joy, & that it had survived intact for so long before being brutalised, annoys me immensely.

Just looked back at the "how it arrived" pics - there's the clue to the wheel damage - as I suspected, the wheels had been mounted back-to-front, the domed outers would have cracked when the wheel screws were tightened. Still no clue as to why they had gone so brittle & un-bondable though.

I bought some C-size dry cells today & gave it a run tonight to see what performance is like.
1st thing to note was the battery terminal & securing method is total rubbish, it's nigh impossible to keep the batteries in, & the suggested rubber band in the manual isn't in the right place to keep the cells in. I gave up fighting the wiring, aerial wire, being careful with the body, then taking it all apart again cos the batteries fell out... I ended up running it without the body (Probably just as well).

Not what I was expecting, I have to say! I fitted the low gear set, for use with dry cells, as per the manual - it's incredibly slow! Due to the gearing, not the batteries though, the motor is revving out as it would with a NiCd, there's plenty of torque too. Managed lots of wheelspin on the kitchen tiles, managed to climb a doormat propped up against the sofa too (About 40 degrees I'd say). Drove over my feet lots of times. I got bored after about 25 minutes, but the batteries were still ok. The 2-stage MSC wasn't as much as a nuisance as I was expecting either, it's a perfect match for this slow, torquey setup, in fact I'd say you'd get away with just a single-speed

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Re: XR311 restoration 11 years 3 months ago #16449

I was looking forward to this one!
Once again, I am in awe!
The following user(s) Liked this: eddrick

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Re: XR311 restoration 11 years 3 months ago #16450

...I can only think it was an attempt to get a different battery in ....


I didn't think of that ... maybe to get a stick pack in?

I've seen the same lack of sense on the Pajero wheelie chassis tub - which is the only bit on the whole car you can't get a replacement for :S ... luckily the "find it in a garage, bodge it up, lose interest, sell it on ebay" thing doesn't seem to happen that often - but the older cars that aren't stick pack compatible definitely suffer more often :pinch: :cry:

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Last edit: by Jonny Retro.
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