Somebody help me understand aluminum.

[Kowalski86]

I've been trying to wrap my head around aluminum hop-ups, not just for Tamiya but all RCs and some of the tools (setup stations and such)

It does look nice, and it is good to have in important areas (hubs, castor blocks, motor mounts, shocks). I understand it's usefulness and how important it can be.

My question is, why is it quite expensive most of the time? Other than profit. Is it expensive to make? Is anodizing expensive?, Or do most RC companies use a nicer grade of aluminum as they do plastic?

To elaborate, when I think of aluminum, I think of things like soda cans, foil, largely disposable things for the recycle bin. I don't see it as this expensive, high end "exotic" material.

Carbon I completely understand, I can't go buy a cheap 12-pack of cans made out of carbon fiber (as cool as that might sound!). Better plastics are always welcome too.

[LongRat]

Once you have the moulds set up, the actual production time for a plastic sprue of parts is very low.  You can get thousands of parts per hour (have a look at Lego factories).  That makes plastic parts cheap.  The RC hop ups you are talking about are almost always machined, that's a comparatively slow and expensive process.  Plus, it requires multiple post-processes such as deburring, surface finishing, cleaning, anodising and some of those are almost as slow as the machining step.  Whilst the volume of material is also more costly than plastic, it's the time they take to produce that drives the cost mainly.

[BuggyDad]

Also, in something like a can the amount of material is very small and the manufacturing relatively easy. And, it'll be remade into future cans many times over. So which material is the cheapest depends on the application. 

Sometimes I wonder about aluminium as an upgrade over plastic in RC. It's presumably generally heavier and more prone to a permanent bend. Plastic more likely to spring back or break. Broken plastic is usually no worse than bent Al because either way the part is knackered. And if the plastic giving then springing back prevented something else from breaking then probably fewer breakages overall. 

[Wooders28]

Aluminium is fairly cheap (stock Aluminium, compared to carbon etc) is a soft metal, so it's easy to machine (although a nightmare to tap a hole...😳) , lightweight, and pretty. 

You can add alloys added to aluminium, and make it stronger (some chassis), but then it gets expensive.

All the top race cars ,don't use aluminium for suspension arms, towers etc, as if they're too rigid, they snap.

I'm not great fan of aluminium hop ups just because, I've have bought them for better their cooling, and gearbox casing, if I've gone for hotter motors.

[Kowalski86]

24 minutes ago, BuggyDad said:

 Sometimes I wonder about aluminium as an upgrade over plastic in RC. It's presumably generally heavier and more prone to a permanent bend. Plastic more likely to spring back or break. Broken plastic is usually no worse than bent Al because either way the part is knackered. And if the plastic giving then springing back prevented something else from breaking then probably fewer breakages overall. 

In my experience aluminium is heavier, but that can be useful if you want to add weight to a specific area of your RC.

7 minutes ago, Wooders28 said:

I'm not great fan of aluminium hop ups just because, I've have bought them for better their cooling, and gearbox casing, if I've gone for hotter motors.

That's where I'm currently at, plastics bendy, cheap to replace, and lighter. Aluminium has its use but the price (at least Tamiyas) can get silly.

[Pylon80]

Aluminum is better because it's blue. 

Seriously, now. There are many hop-ups that could very well be made out of plastic instead. Ball raced steering sets, or toe-in rear uprights with various angles could be made out of plastic for cheaper.

In terms of cost, as other posters have said the initial investment for plastic molds is huge but then plastic parts can be practically mass produced.

Aluminum when machined is expensive because 90% or more of the initial blank ends up in chips and only 10% is your final part. Then parts need shot peening or at least media blasting of sort and anodizing.

Some cheap parts are available on eBay and the such for suspension arms, these are to avoid as they will get immediately scratched and will bend out of shape in any crash. Plastic is the better choice. All the modern high end racing cars use plastic for the arms and even shock towers these days. Shock bodies must be made out of aluminum to be mirror finished and resist swelling as the shock compresses and pressure builds up on one side of the piston.

[Gebbly]

The most important rule in business is always "charge what the market will bare". There is a perception amongst the general public in the RC hobby rightly or wrongly that aluminium parts are premium parts. A lot of people will pay a premium price for that perceived premium part. If experience shows that customers will willingly pay X for a part then it would be a foolish company that would charge less.

I suspect one of the reasons why a lot of the parts are all anodized is to help with the premium look that entices customers to pay more.

[Wooders28]

Just a side note, 

In our club, there seems to be alot of people now jumping on the 'stainless screw set' band wagon.

Yes , stainless won't rust (as easy, depands on the stainless quality) ,  but it reacts with aluminium,  (Galvanic corrosion), and welds itself in the aluminium hole...

[skom25]

5 hours ago, Wooders28 said:

Just a side note, 

In our club, there seems to be alot of people now jumping on the 'stainless screw set' band wagon.

Yes , stainless won't rust (as easy, depands on the stainless quality) ,  but it reacts with aluminium,  (Galvanic corrosion), and welds itself in the aluminium hole...

It happens only after long time without touching it. Thin layer of grease solves that issue.

15 hours ago, Kowalski86 said:

I've been trying to wrap my head around aluminum hop-ups, not just for Tamiya but all RCs and some of the tools (setup stations and such)

It does look nice, and it is good to have in important areas (hubs, castor blocks, motor mounts, shocks). I understand it's usefulness and how important it can be.

My question is, why is it quite expensive most of the time? Other than profit. Is it expensive to make? Is anodizing expensive?, Or do most RC companies use a nicer grade of aluminum as they do plastic?

To elaborate, when I think of aluminum, I think of things like soda cans, foil, largely disposable things for the recycle bin. I don't see it as this expensive, high end "exotic" material.

Carbon I completely understand, I can't go buy a cheap 12-pack of cans made out of carbon fiber (as cool as that might sound!). Better plastics are always welcome too.

You have to remeber one thing: in most cases, you pay for knowledge and time spent on research, not cost of material. Of course, Tamiya is expensive as a brand, so you pay much more for the same from other brands.

To understand this, think about drugs for very, very rare disease. It is only one pill but sometimes costs hundred thousands euros/ dollars. Why? Because research was so long.

Of course it is edge case but clearly shows, how it works.

Other thing is fact, that hobby was always good place to make a lot of money, because you can just tell people that they need that alu parts.

[Honza]

Aluminium parts are typically made by CNC machining and that alone makes them expensive. There are exceptions though - flat parts can be stamped out of sheet metal and such parts are typically included in kits - motor mounts for example. There was also time when Tamiya manufactured some parts by die-casting, which is much cheaper, but those were plain gray - I guess they cannot be anonised, so they wouldn't be as attractive as option parts. Also, tools for that process are more expensive than plastic molds, so they need to run on larger scale.

[Wooders28]

3 hours ago, Honza said:

Aluminium parts are typically made by CNC machining and that alone makes them expensive

Having worked as a CNC programmer/operator, most of the parts could be rattled off in seconds, so production cost per unit, is fairly low tbh. What you pay for, is set up costs. If its a decent run (1000+), it's pence per unit.

[ad456]

I think another point may be that as a company your not going to sell as many hop-ups as you would the full car kits, especially when it comes to more expensive or less popular kits so returning the investment, be it for true R&D or just getting the in-house CAD guy to “do one of these in alloy”, is passed on to the customer.

Personally I avoid alloy whenever possible because, as stated above, it does not bend back.

[neo2001]

I think what also makes it more expensive is the precision and repeatability of the same. Better brands need to make sure the parts fit, which includes quality control and setup times and some rejected parts.

Cheap Chinese parts look identical at first, but unfortunately are often not fitting as good as they should be. But this also depends on the individual parts.

But, of course, some simple parts are just really expensive because people seem to be willing to pay the price. There’s this simple round pin with a hole at the end, that locks the battery in the DT-03 chassis and costs about 10 bucks. For this price you can probably make a few dozen ones from cheap aluminum rods. Or simply keep using the plastic one.

 

[skom25]

If you think that battery holder for DT-03 is expensive, check Heat Sink. It costs around 30 Dollars/ Euros and it is more than twice more expensive than rest of Heat Sinks from Tamiya. At the same time it is super tiny and probably smallest from all. It has only additional plate, to separate motor from gearbox. Magic...

[Kowalski86]

3 hours ago, skom25 said:

If you think that battery holder for DT-03 is expensive, check Heat Sink. It costs around 30 Dollars/ Euros and it is more than twice more expensive than rest of Heat Sinks from Tamiya.

That's in line with Tamiyas aluminum motor mounts, the TT02 mount costs $20 while providing minimal benefit (it doesn't cool nor provide anymore adjustability).

On 10/25/2023 at 4:11 AM, neo2001 said:

I think what also makes it more expensive is the precision and repeatability of the same. Better brands need to make sure the parts fit, which includes quality control and setup times and some rejected parts.

Cheap Chinese parts look identical at first, but unfortunately are often not fitting as good as they should be. But this also depends on the individual parts.

You are correct there, there's a really good build thread that goes into detail comparing a TT-02 built with Tamiya Hop ups, and another built with cheaper parts.

I think I should've rephrased my question, I get the use, need, and desire for a good number of aluminum parts. I'm more confused as to the "let's chuck a bunch of money at hopping up cheap junk" vs "let's buy something good with the upgrades included".

[bRIBEGuy]

On 10/21/2023 at 3:31 PM, Kowalski86 said:

I've been trying to wrap my head around aluminum hop-ups, not just for Tamiya but all RCs and some of the tools (setup stations and such)

It does look nice, and it is good to have in important areas (hubs, castor blocks, motor mounts, shocks). I understand it's usefulness and how important it can be.

My question is, why is it quite expensive most of the time? Other than profit. Is it expensive to make? Is anodizing expensive?, Or do most RC companies use a nicer grade of aluminum as they do plastic?

To elaborate, when I think of aluminum, I think of things like soda cans, foil, largely disposable things for the recycle bin. I don't see it as this expensive, high end "exotic" material.

Carbon I completely understand, I can't go buy a cheap 12-pack of cans made out of carbon fiber (as cool as that might sound!). Better plastics are always welcome too.

Aluminum costs are hard to define with one quick answer as there are so many factors that play into it.  What bugs me the most with aluminum hop-ups, is that people view them all equally, despite the fact that "aluminum" is just a catch all phrase describing a family of alloys, the same way "plastic" is used to describe hundreds of different materials.  That in and of itself defines the first part of my reply here... that not all aluminum is equal, as sometimes the cost reflects that.

SO...... factors of the above:

1. Material cost.  In general, aluminum (6061) is priced the same, to slightly more expensive than basic ABS (or similar) plastic.  As the Aluminum gets "better", the price goes up.  7075 is significantly more expensive than 6061.
2. Manufacturing.  Almost all (RC) plastic products are injection molded.  This is expensive to tool up for, but is extremely cheap to produce afterwards.  There is almost no waste material, the parts can be made in seconds to minutes, and the process can run almost indefinitely without humans needed.  A parts sprue might cost pennies to make, and you may be able to produce over 1000/day. 
   Aluminum parts are typically CNC'd. You are paying for more material than present in the part, as it's a subtractive manufacturing method with a lot of waste.  It requires more setup work (as mentioned previously in this thread), takes longer to machine, and almost certainly requires human interaction between parts.
3. Secondary Processes. The biggest cost adder in manufacturing is additional steps required.  When a plastic part comes out of an injection mold, it is typically finished.  It gets packaged, and shipped.  When a CNC aluminum part comes off the mill, that is typically not the case.  At the very least, it will require anodizing, which isn't hugely pricey in and of itself, but requires time, human interaction, and moving the part someplace else (which is expensive).  It may also require re-fixturing for machining on alternate sides, deburring, tumbling, or heat treating.  Each of those incurs a cost, bost for the process, and for the labor.  If an employee is paid $20/hr, then you need to be billing out that work for $40/hr.  $40/hr is $0.67/minute... which sounds cheap, until you realize that is probably less than it cost to make an injection molded sprue in it's entirety.
4. Perception: While your comment on cans and stuff is likely bang on to a large extent, it doesn't translate to hobbies.  Here people buy with their eyes, and blingy blue shiny bits look cooler than black plastic ones.  It's the same in the bicycle industry, the 1:1 car world, etc.  And cool costs $$$.

To put it in perspective, here are some real world numbers from a project I have worked on recently for (what will become) a large injection molded product.  To CNC a prototype (single) was $1800 in ABS.  6061 aluminum was the same price.  7075 was about 50% more.  That price dropped to $450each for a small production run.  That was all with zero additional processes. 

Now, the same part, but injection molded will be $9.  Ya.

 

40 minutes ago, Kowalski86 said:

I think I should've rephrased my question, I get the use, need, and desire for a good number of aluminum parts. I'm more confused as to the "let's chuck a bunch of money at hopping up cheap junk" vs "let's buy something good with the upgrades included".

I think this is largely just human psychology:

• Upgrading what I have will make it better than it was
• Why spend $500 on a new kit when I can spend $100 on hop ups?
• High end kits are over priced and over rated

None of these points are necessarily correct IMO, but it's easy for people to believe them.  Plus you can differ costs, and convince yourself you're not spending as much.  Why buy a $50k car when I can buy a $10k car and slowly put $60k into it making it better?   

Confirmation bias factors in as well, where people don't want to admit (to themselves, or to the internets) that they may have bought the "wrong" kit, and will try anything to "fix" it before inevitably buying the correct kit.  Why pick up an Associated RC10B6 for racing when you could put $500 into the DT03 you picked up instead?

Just my 2 cents...

[SlideWRX]

An Aluminum can for drinking costs so little because the machine that produces them can pump out thousands a day.

https://www.theworldcounts.com/challenges/consumption/foods-and-beverages/aluminium-cans-facts

We use ~180 Billion aluminum cans per year, 6700 cans per second.    At that scale, you make multiple custom machines to produce the parts. Even if it costs millions, the cost of the machine and employees per unit part produced is tiny.  The base cost of the aluminum is also lower, as they can buy in bulk direct from the source, are a repeat customer, and any scrap is recycled back into the source sheets.

Each change in magnitude of production volume comes with a different production process, from ~1000 parts to ~10,000 to 100,000 etc.  

1 hour ago, Kowalski86 said:

"let's chuck a bunch of money at hopping up cheap junk" vs "let's buy something good with the upgrades included".

I won't learn why the parts are upgraded if they already are...    It's all about learning... yeah... 

Also, a lot of "upgrades" are either visual not performance, or performance not visual.  People have different ideas as to what is a cost effective upgrade.

[Kowalski86]

@bRIBEGuy

Thank you for the in-depth response, the different aluminum types are a good point. I'm all too familiar with plastic quality now having seen different nylons, all grades and brittleness of ABS, etc.

I guess hop-up/money dump makes sense when you spread it out, vs buying a "nicer" model up front. Plus, as far as on-road goes, you wouldn't hammer a TRF 9999X like a TT02.

[Honza]

I found nice example from Tamiya themselves. TB03 had ugly, gray aluminium motor mount #5405047 out of the box. It was likely die-cast, since it was a large volume production. Spare has MSRP of $12, the actual production cost is probably even lower.

Then there was an optional anodized mount, #54150, made with CNC. This shape probably produced a lot of waste - MSRP is $55.

Source:

https://www.tamiyausa.com/shop/7-digit-spare-parts/rc-motor-mount-58409/

https://www.tamiyausa.com/shop/option-parts/rc-tb03-aluminum-motor-mount/

 

[Pylon80]

13 hours ago, Honza said:

I found nice example from Tamiya themselves. TB03 had ugly, gray aluminium motor mount #5405047 out of the box. It was likely die-cast, since it was a large volume production. Spare has MSRP of $12, the actual production cost is probably even lower.

Then there was an optional anodized mount, #54150, made with CNC. This shape probably produced a lot of waste - MSRP is $55.

Source:

https://www.tamiyausa.com/shop/7-digit-spare-parts/rc-motor-mount-58409/

https://www.tamiyausa.com/shop/option-parts/rc-tb03-aluminum-motor-mount/

 

...and they are both invisible once installed! 

[Kowalski86]

13 hours ago, Honza said:

I found nice example from Tamiya themselves. TB03 had ugly, gray aluminium motor mount #5405047 out of the box. It was likely die-cast, since it was a large volume production. Spare has MSRP of $12, the actual production cost is probably even lower.

Then there was an optional anodized mount, #54150, made with CNC. This shape probably produced a lot of waste - MSRP is $55.

I'd happily take the "ugly gray" mount, partly because that $43 can buy some nice hop-ups, and partly because I'm not a fan of generating extra waste just for an RC part.

[Honza]

10 hours ago, Pylon80 said:

...and they are both invisible once installed! 

TBF, there's a little bit visible around the driveshaft 😀

9 hours ago, Kowalski86 said:

I'd happily take the "ugly gray" mount, partly because that $43 can buy some nice hop-ups

I don't mind it either, I was joking a bit. Use of die cast parts in the basic kit is another reason why I think that TB-03/TA-05/DB-01 was the golden era of Tamiya midrange chassis.