for those not on Facebook... injection molded parts rolling out

[rctenracer]

Why is there a Hex Hole in the caster blocks.

[TRX-1-3]

Why is there a Hex Hole in the caster blocks.

Dude, nice eye-spy!

Would that align the pin better? Fewer contact points/less friction? Oversight or just plain "mistake"?

[GoMachV]

He answered this on his post by saying it reduces friction but i personally don't like it. It seems intentional since the pins used for the mold would be more of a hassle to make in a hex form than in a standard round pin. It's weird.

[MarkyDents]

Looking at the pic with all the parts in it together it looks like it’s all based on a rere worlds, correct ?

[JosephS]

I've got a set on the way. I'll post up pics and impressions when they arrive.


Or I'll be warning everyone about getting scammed. It'll be one of those.

[mikea96]

I had bought some of there first yokomo molded parts and they were great!

[JosephS]

I had bought some of there first yokomo molded parts and they were great!

Were they similar to the original molded nylon or did they have a different feel?

[mikea96]

They felt very similar to me and very nicely done.

[morrisey0]

Or I'll be warning everyone about getting scammed.

The seller has a pretty solid reputation on the FB page. He has been selling there for awhile. I don't think getting scammed is going to be an issue.

[JosephS]

Or I'll be warning everyone about getting scammed.

The seller has a pretty solid reputation on the FB page. He has been selling there for awhile. I don't think getting scammed is going to be an issue.

I wasn't really worried about getting ripped off. I am mostly curious about the parts and materials used.

[jcwrks]

Interesting how a small scale individual can release affordable injected molded parts, but both AE and RPM claim that it's way to expensive. What gives?

[mikea96]

Interesting how a small scale individual can release affordable injected molded parts, but both AE and RPM claim that it's way to expensive. What gives?

I was thinking the exact same thing.

[GoMachV]

my understanding is (from RPM anyway) that it isnt that they cant run the old parts, it is that they cant afford to stop making new parts long enough to make the old parts. Their machines are busy, and pumping out new modern product makes them more money than pumping out a few hundred old parts and sitting on them. I heard the last time they ran RC10 buggy arms they sat on the product for quite a while.

People only want stuff when they cant have it. If AE dropped 1500 rere classics tomorrow, 95% of the people would wait till they were sold out and then complain about it.

[JosephS]

Interesting how a small scale individual can release affordable injected molded parts, but both AE and RPM claim that it's way to expensive. What gives?

I was thinking the exact same thing.

It depends on how the molding tools are made.
RPM is set up to make very long lasting molds (tools) through a multistep process. They gave me a tour and explained some of what they did.

The tooling material is tool steel and can make 100k's to millions of impressions. As well it can withstand the pressure to make large parts and detailed of alternate nylon compositions. Tool steel is basically not machinable.

To put the pattern in the steel an electrode is made via cnc in carbon. From there the electrode and a tool steel blank are placed in an EDM machine. The machine basically uses electric current to evaporate parts of the tool steel. Details on this can be exacting. Basically air(gas) relief channels can be made in the material so thin that gases can escape, but no nylon material will. So there will not be air bubbles, bit as well no extra material.

After that the tool are sent somewhere else for the letter engravings to be added, basically the RPM logo.

The process is expensive and time consuming. It sounded like their cost would be in the 20+k range per tool. But they can make nearly millions of parts with out the risk deformation.

It was described to be the kind of presses that RPM have utilize such a large amount of pressure that only hard grade steel can survive. Aluminum would blow apart. It's many tons per square inch over the sizes that fit in their machines. The high pressure makes perfect, void free, parts over and over.

Basically tools never 'break' but they begin to produce parts that are not geometrically correct. Hence why tools have a listed life. The harder the material the longer it lasts.

What I am assuming that the process that these current parts are being made by is a low volume injection molding tooling. Depending on the size of the tool it can be made of steel or aluminum. The tool can be directly formed by a CNC machine. Parts are injected with a much lower pressure.
Tools like this can only be of smaller size, larger details and not especially complex.

You can only make a few hundred to many thousand parts per tool, with more parts possible where tolerances can be lesser. Stuff like suspension arms and mounts can likely be pretty far out before they become unacceptable. If you own the CNC mill it's likely easy enough to just make a new tool when complaints get to numerous.

I have feeling this is why none of these places are making transmission cases. The tolerances required for that would make it so only a limited number of successful cases could be made from low volume tooling before the tolerances would make them bind. If the press injection pressure isn't high enough it could be impossible to make a case that is ever close enough.

Given the limited run of the AE RE-RE the factory likely used a lesser steel for the stealth cases, ran the presses at a lower pressure to make the tooling last longer and ran the tooling longer than they should have for QC purposes. As much as everyone says they want AE to make more parts, RE-RE stealth cases are avoided by most here because the quality wasn't high enough. AE likely figured out that the cost to make proper tooling, even at the reduced quality, wouldn't make enough profit.

I was looking into low volume injection molding PA6/6 for RC10 parts to do my own run. Now that there are 2 sources for parts I am very glad I I didn't.

If we really want RPM to make parts we can flat out commission them to do so. We can pool money and pay upfront and they will make most parts.

[JosephS]

my understanding is (from RPM anyway) that it isnt that they cant run the old parts, it is that they cant afford to stop making new parts long enough to make the old parts. Their machines are busy, and pumping out new modern product makes them more money than pumping out a few hundred old parts and sitting on them. I heard the last time they ran RC10 buggy arms they sat on the product for quite a while.

People only want stuff when they cant have it. If AE dropped 1500 rere classics tomorrow, 95% of the people would wait till they were sold out and then complain about it.

I'd really like to see if we could start a kickstarter for RPM parts. Pre-sell the parts in prices and quantity so that it's known it'll be worth the time. If the project doesn't sell enough it closes down without any risk on the RPM side.