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DeBruce

My Original Astute Rebuild

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Hi all,

So I bought an original Astute some time ago because I always wanted one, but before I really knew much about them. I have subsequently discovered that my model had been modified with the Madcap lower arms and c-hubs, which whilst making it more robust wasn't really what I was after. Below are the before shots of the model before my restoration.

image_zpscp01oyft.jpeg

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If thats the quality of the start point, I can't wait to see what the end result is - subscribed !

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First thing required was a new chassis plate. The old one was okay but scratched and I want to create the best model I can. The idea is to try to improve on the original but stick to its basic design. So I want to use almost all Tamiya parts, not aftermarket and use original Astute chassis parts, arms, etc, all in their over-engineered glory. But I want to make the car more durable. It'll be a shelf model when finished but I want to use it occasionally indoors just to experience it.

So I bought this chassis plate below. It looks different to all the others I've seen? The weave is much more visible - all previous plates I've had have been almost black. Can anyone comment on it?

image_zpssnxl9mfp.jpeg

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In terms of dampers, the original has the yellow CVAs of course which are a little tatty and in need of a rebuild. I could rebuild these but I have another idea. I don't want to go for Hi-Caps because I want to stick with the originals but the yellow doesn't work with my proposed new colour scheme which is Red and Black (more on that later).

So my ideal is this... Sticks with the original CVA theme but upgrades them and gets me shiny new dampers that work as smooth as silk. Yes I know it's not quite original and I did debate the grey versions from the Super Astute but I think I want black.

IMAG1862_zpscw1tcxpr.jpg

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Wow, this will be an interesting thread, looking forward to see your progress and end result. (If you ever want to part with the madcap parts, let me know :P )

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I stripped down the front end from the original car and removed the CVA 1's. I'll restore these for some other project at a later date. The CVA 2's were really easy to build and they seem to be lovely and smooth in operation. I've built them up with the included damper oil and springs to start with so that I can use this as a base from which to tune the handling (if I run it that much!). They bolted back up to the original damper mounting plate using the original upper fixing.

This gives a nice smooth operation and looks good as a starter! I'm leaving the original larger upper arm that comes with the original Astute as I like that it's thicker and stronger than normal upper arms. I also like the use of bushings in all the moving joints (more about this later too!). I've left the anti-roll bar in place from the original car.

image_zpstge6vkbm.jpeg

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Pleased to see this emerge as a build thread and really looking forward to seeing your progress. The weave on the chassis plate does look a bit lighter, but normal I think. I have some original Egress shock towers that have the same lighter appearance.

If you have not already started bolting it together, it's a good idea to use the bare chassis plate as a template for drilling the holes in the undercowl. Assuming you are going to use a replica undercowl, sometimes the dimples don't quite match the actual chassis.

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Pleased to see this emerge as a build thread and really looking forward to seeing your progress. The weave on the chassis plate does look a bit lighter, but normal I think. I have some original Egress shock towers that have the same lighter appearance.

If you have not already started bolting it together, it's a good idea to use the bare chassis plate as a template for drilling the holes in the undercowl. Assuming you are going to use a replica undercowl, sometimes the dimples don't quite match the actual chassis.

One of my favorite cars I had as a kid. That front bulkhead I broke about 5 times lol

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Pleased to see this emerge as a build thread and really looking forward to seeing your progress. The weave on the chassis plate does look a bit lighter, but normal I think. I have some original Egress shock towers that have the same lighter appearance.

If you have not already started bolting it together, it's a good idea to use the bare chassis plate as a template for drilling the holes in the undercowl. Assuming you are going to use a replica undercowl, sometimes the dimples don't quite match the actual chassis.

The weave is a lot lighter than on my other chassis plates, both of which look like they have been sort of painted black by Tamiya whereas this plate effectively looks untreated.

Yep got a full replica body and that's a really good tip, thanks. However in this case I've already painted the body as I did that first. Really like how it turned out to be honest - agonised over colour choices for a long time (it's not that radical a colour but I'm very picky about things looking exactly how I want them to).

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If you have not already started bolting it together, it's a good idea to use the bare chassis plate as a template for drilling the holes in the undercowl. Assuming you are going to use a replica undercowl, sometimes the dimples don't quite match the actual chassis.

Great tip Thommo :)

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I should preface this thread with a thank you to t3garrett and thommo for help with some of the harder parts to find.

I managed to get two sets of brand new B-parts trees for the original front and rear lower arms. The intention is to restore the original suspension back to the car. I know these arms are much more flexible than some of the other options but I want originality and I like how the front line of the arms blend with the bumper in a neat curve.

I also purchased replacement C Hubs which, thanks to a handy tip, turned out to be the same as the Super Astute parts. However the front uprights have so far proved impossible to source. However one of my aims with this project was to maintain the original wheelbase and the original Astute uprights set the wheels back about 5mm behind the pivot point.

I wanted to get new parts and keep things black where possible (the current Mapcap upright is white like the super astute arm) and maintain the geometry to the steering arm. One suggestion was to use the F103 parts which have very similar arm geometry and are made of black carbon reinforced plastic.

There are two versions of these arms... The hop up part 53259 has a 3.5mm reward offset which is the closest I could find to the original part but not actually what I want. However there is an alternative F103 part 54154 has zero offset for the wheel which was perfect. This part is shorter than the original Astute part so I used two 0.8mm black nylon washers (3x8x0.8) to remove the slack.

For the bushings I decided to do something different, based on some advice and good posts across various forums but I'll add that later.

image_zpsuopgxdpl.jpeg

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Have you checked Shapeways for 3d printed parts ?

I'm not sure there are any available yet, but there are quite a lot of the hard to find Top Force J parts on there. Maybe TC members simensays or pintopower could model something ?

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One slight problem that I should mention - when I came to remove the gearbox assembly from the original car, the fixings for the rear aluminium hex spacers had corroded together and I completely stripped the heads trying to remove them. I wasn't sure what I was going to do but found a suggestion to drill the heads until they broke off which worked perfectly and I was able to get the gearbox off the original car, although I did I have buy replacement hex spacers.

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Have you checked Shapeways for 3d printed parts ?

I'm not sure there are any available yet, but there are quite a lot of the hard to find Top Force J parts on there. Maybe TC members simensays or pintopower could model something ?

Actually I've given a friend one of each of all the C Parts and they are going to create 3D models of them for me. A colleague at work has a sample part that was 3D printed in a metal (I think something like aluminium) and I'd like to see if I can get the key weak parts printed in a stronger material, retaining the original design ideas but making them more durable.

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Fantastic! I have an Astute sitting here that I intend to rebuild as well. It has Hi Caps but other than that I'd like to keep it as original as possible. Maybe strengthen it here and there but keep the fundamentals of the Astute alive. I will run mine. Keep up the good work.

Chris.

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Wow, looks like you got the reinforced rear arms too ! They were a change during the production run. These arms have extra plastic compared with early run Astute's and are quite rare I think.

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Wow, looks like you got the reinforced rear arms too ! They were a change during the production run. These arms have extra plastic compared with early run Astute's and are quite rare I think.

I do? What were the differences? I'll do a bit of research and see if I can find some comparable pics!

Found and you're right! I bought the two trees of front and rear arms separately so it was completely by accident that they are both the reinforced type!

astute_modifications_03.jpg

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Okay here is a close up picture of the front hub assembly showing the F103 part with 0.8mm spacers.

IMAG1895_zpss68koydq.jpg

And this image from the front shows my solution for the bushes. I've read that the metal bushes in the Astute were Tamiyas idea to improve tolerances in their plastics mouldings and were not specifically intended to improve friction of the joint. Thus changing the bushings for bearings is a mistake because the bearings do not withstand the pounding that these joints take on the track. However the bushings are heavy. So I searched for a set of Nylon bushes which I was unable to find. I have however managed to find a 3x7x3 plastic bush used on the Carisma M14 and I have used these in all the bushing locations. These are lighter than the original metal bushes but have good fit and tolerance. My intention is to glue them into place to remove the variability between the bearing and the arm, etc, as per original intent. As a happy coincidence they continue the black theme.

IMAG1897_zpsh3rvhn9d.jpg

The blue 6mm adjusters are annoying - these are going to be replaced with black parts asap.

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And here is a gratuitous shot of the rear hub assembly. Not much to say here except I've used the same black plastic bushings and that I made the toe in adjustment link from Hotbodies turnbuckles to allow easier toe in adjustment.

I added new metal shielded bearings into the hubs for the drive shafts, but I intend to upgrade to Tamiya blue rubber shielded bearings when I get them. And I replaced the rubber o-rings inside the drive shaft joints.

Both hubs I managed to get were cracked at the lower mounting point so I will stay on the lookout for good new ones and if I can get a 3D model this is an area I will look to strengthen.

IMAG1898_zpsig2k8b8g.jpg

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Ooh, I do love a good Astute thread!! Will be watching with baited breath.

The reinforced arms were news to me, I had no idea the Mk1 arms had been a weak point and that the Mk2 even existed. I cannot imagine mine will ever get abused sufficiently for this to be an issue. Mine are all Mk1. ;)

Thanks for the outer link bushes/bearing situation, it had never occurred to me that the bushes would deal with it better, I guess I am always thinking about the friction and not the likely abuse they would be subjected to under use. Once again the light use mine will get will probably make it less essential, something for my next rebuild.

I have been trying to get some modified rear hubs out of my head for years now as mine are both cracked as yours are. I have a carbon fiber aluminium arrangement in mind. Have tried 3D modeling it a few times now, sadly a bit too complicated for my CAD skills. I need to find someone with the skills who also an RC junkie who will work on it for the love of it, or for food or something. :D

I look forward to seeing where you take this.

C..

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Ooh, I do love a good Astute thread!! Will be watching with baited breath.

C..

I'm still waiting to see yours too....... not even in your showroom, what gives ? :D

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In terms of dampers, the original has the yellow CVAs of course which are a little tatty and in need of a rebuild. I could rebuild these but I have another idea. I don't want to go for Hi-Caps because I want to stick with the originals but the yellow doesn't work with my proposed new colour scheme which is Red and Black (more on that later).

So my ideal is this... Sticks with the original CVA theme but upgrades them and gets me shiny new dampers that work as smooth as silk. Yes I know it's not quite original and I did debate the grey versions from the Super Astute but I think I want black.

Well done M8!

I did the same with my SA.

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The reinforced arms were news to me, I had no idea the Mk1 arms had been a weak point and that the Mk2 even existed. I cannot imagine mine will ever get abused sufficiently for this to be an issue. Mine are all Mk1. ;)

Me neither - he great thing about this forum, yo find out something new every day - and I have Mk1 arms on my Astute, and it won't be an issue for my lack of use either ;)

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When I dismantled the original car I found that a number of the screws were in a very poor condition. Titanium is a fantastic metal because it's very light but it's also quite soft which makes it quite easy to strip and destroy screw heads. I did try to purchase some direct titanium replacements however they are hard to come by so I decided to go in a different direction. Instead of going with titanium, since I was being pushed in the direction of steel, I've gone for 10.9 grade steel for high strength. The idea being if I have to sacrifice some weight then I might as well get a high tensile strength component out of it. The plan is to replace all the fixings with black 10.9 grade coated (for corrosion) steel where I can.

In this picture you can again see the very visible weave of the chassis plate.

IMAG1901_zpsyzclgank.jpg

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Kontemax's like of my above post ref. the Astute modified arms reminded me that I should credit his articles on the Astute for the picture. One of the best sources of information for modifying Astute that I am aware of!

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