Tamiya RC models

[JhnBssll]

I've got a couple of new 3D printers arriving over the next few weeks so will be able to print bigger bits. I decided a new chassis tub for the Clod Buster would be a good plan so I'm in the process of designing one I've got the basic layout sorted, along with cooling channels, just need to consider how to hold the battery in and where to run the wires now

The yellow block represents a 3 cell LiPo battery pack and the blue blocks underneath are the brushless speed controllers

 

[classic33]

I've got a couple of new 3D printers arriving over the next few weeks so will be able to print bigger bits. I decided a new chassis tub for the Clod Buster would be a good plan so I'm in the process of designing one I've got the basic layout sorted, along with cooling channels, just need to consider how to hold the battery in and where to run the wires now

The yellow block represents a 3 cell LiPo battery pack and the blue blocks underneath are the brushless speed controllers

View attachment 565733

What will that cost to print do you know.

 

[JhnBssll]

What will that cost to print do you know.

If I use the FDM it'll be no more than a couple of quid in filament I would imagine. The LCD resin printer is a little more expensive to run, but even then I'd be surprised if it used £5 of resin 🤷‍♂️ The main problem is build time - on the FDM it'll probably take 12hrs to print and about half that on the LCD resin.

 

[classic33]

£25 and up on ebay, and that's second hand.

Thought it'd cost more to print one.

 

[JhnBssll]

The materials are generally pretty cheap. Obviously theres the outlay for the printers too, but the main cost of printed parts is labour. If you want to use exotic materials with enhanced properties (super tough resins for example) they cost a lot more but I doubt they'll be required for this part 😊 Once the printers show up and I've had a chance to get them set up and running properly I'll find out I guess

 

[JhnBssll]

I finally got round to printing the chassis tub 😊 It took 23 hours on the FDM printer, I've printed it in black ABS so it should be fairly robust. I'll try and assemble it tomorrow, hopefully I've measured right but there's always something that needs tweaking If needed I'll print it again over the weekend but we shall see 😊

Here it is being printed...

And this is the finished part with the support structure removed from around the edges - it's only needed to allow the overhangs to be printed and then breaks away when it's finished

The two motor controllers will sit in the bottom at either end with the radio gear in between, and the battery sits along the top. I'm planning on fastening it down with large black rubber bands but will see what happens

 

[classic33]

I finally got round to printing the chassis tub 😊 It took 23 hours on the FDM printer, I've printed it in black ABS so it should be fairly robust. I'll try and assemble it tomorrow, hopefully I've measured right but there's always something that needs tweaking If needed I'll print it again over the weekend but we shall see 😊

Here it is being printed...

View attachment 580584

And this is the finished part with the support structure removed from around the edges - it's only needed to allow the overhangs to be printed and then breaks away when it's finished

View attachment 580585

The two motor controllers will sit in the bottom at either end with the radio gear in between, and the battery sits along the top. I'm planning on fastening it down with large black rubber bands but will see what happens

For finish, how does it compare to an injection moulded one?
Flashing, thin spots, that sort of thing.

 

[JhnBssll]

For finish, how does it compare to an injection moulded one?
Flashing, thin spots, that sort of thing.

An FDM print fresh off the printer will never be as nice as an injection moulded part. The top and sides have actually come out pretty nicely on this print, I'm really pleased with it. The bottom is generally the worst, especially where it has had to be supported during printing. This is a close up of one of the corners:

This was printed with a 0.2mm layer height - I can go down to 0.12mm which would make the steps finer and less noticeable but it would nearly double the build time so isn't really worth it in this case

With ABS prints you can dramatically improve the finish with post-processing - putting them in a sealed container with a small amount of acetone and a fan to circulate the fumes basically melts the surface of the plastic and gives it a glassy finish. I have some acetone on the way to give this a try at some point, but again isn't really worth it for this print. The acetone also slightly weakens the plastic, so there is a tradeoff for the improved aesthetics.

 

[JhnBssll]

I test fitted the chassis tub today, it fits a treat

Unfortunately the motor controllers don't fit at all I don't know what I was thinking when I did the CAD, the gap is about 4mm too narrow Oh well... At least the radio gear fits in its little pocket

I've now fixed the dodgy dimension and have taken the opportunity to make a few other improvements. One of these is to add pockets at the top to hold the switches in place 😊

It's now 2 hours in to printing so I should have the mk2 part to test tomorrow

 

[JhnBssll]

The new tub finished printing this afternoon

I'm happy to say the motor speed controllers now fit in their designated spots along with the radio gear - I'll be fixing them in with adhesive velcro strips shortly.

The switches also sit neatly in their little retaining features, so a pretty good result all round Here it is with the battery connected up and held in with rubber bands 😊

I had my first brief play with it earlier, crikey it has some power I'm excited to get it out on some open ground and have a play, it certainly pulls away pretty quickly So much so in fact that one of the old original tyres has torn I might look to print some new wheels and replace the old tyres with new

 

[JhnBssll]

I bought new wheels and tyres, fitted them this evening I don't know what kind of anarchist designed these new wheels but 1 nut and 12 tiny screws per wheel seems excessive, my fingers still hurt from tightening them all

Since the rolling chassis is now in pretty good shape I've started to think about replacing the rather beaten up shell so will look in to options. I'll probably repair the old one too so I can use it to mess around without fear of smashing it further

 

[HMS_Dave]

Just today i was digging through my shed and i found my old RC cars. A thunder tiger MTA4 monster truck is one of them. Last time i used it was probably 2007 ish. Still has the old crystal radio gear. It has a seized gearbox by the feels of it, engine is free... Will have to investigate. I doubt parts are easy to come by. I may have the itch again...

 

[classic33]

Just today i was digging through my shed and i found my old RC cars. A thunder tiger MTA4 monster truck is one of them. Last time i used it was probably 2007 ish. Still has the old crystal radio gear. It has a seized gearbox by the feels of it, engine is free... Will have to investigate. I doubt parts are easy to come by. I may have the itch again...

Wonderlandmodels!
https://www.wonderlandmodels.com/radio-control/rc-spares/thunder-tiger/

 

[HMS_Dave]

Wonderlandmodels!
https://www.wonderlandmodels.com/radio-control/rc-spares/thunder-tiger/

Ive been doing some research on it. It seems Thunder Tiger did a few continuation models after it. S28 and S50 which seems exactly the same apart from body paint and engine displacement. Mine is the old .21 engine. So it seems spares are possible. I may get it going again.

 

[HMS_Dave]

I've been looking about at random RC related stuff on Ebay and i have to say, times have changed since i had any involvement in the hobby

Look at the size of this!? 50cm's!? Or is the fellow rather small?

A 1:1 scale must be a sight to behold...