Resin Choice to Simulate Aluminum 6061 Bike Clamp Prototype


#1

Hi I’m working on a clamp design for a mountain bike part. And I’m wondering what Resin will get me closest to the mechanical properties of 6061 Aluminum. Any suggestions? Rigid 4K or Tough 2000? I’ve used Tough 2K in the past but it’s strong enough but is a little too flexy.

Thanks!


#2

My wife is an avid cycler. Road and off-road bikes. I would not use any resin-printed part for a load-bearing component on a bike. If you’re clamping a bell to the handlebars, resin is fine. If it’s holding the seatpost, probably not a good idea.

If you wouldn’t use injection molded plastic for the part, IMO you don’t want to use a resin-printed part. Resins approximate plastics not metals.

But you can get the part prototyped in resin for “dry fit” purposes, and then send the model to Shapeways to get it printed in actual T6061 for a functional prototype.


#3

Thanks Randy, Yeah the actual manufactured part would be aluminum but for iterating on the prototype I need to have a material that gets me close. The clamp is only holding a grip to the bar so the forces are not that harsh. Tough 2k has worked for the first version but flexes too much so I’m not getting a good feel for how the part is truly functioning. So I’m thinking Rigid 4k might get me close to aluminum in that its more rigid. But hopefully wont snap as soon as I torque down a bolt into it. (within reason). Once I get the design close to final I will order a Shapeways Aluminum part.

Which brings me to another question: Is the 3D printed “aluminum” at Shapeways as strong as something CNC’d? I imagine not but if that gets me closer than resin prototypes that would be awesome!

Thanks!


#4

The last time I looked at Shapeways printed metal parts. It would say not for functional use.


#5

I’m pretty sure Shapeways can print functional metal parts, but you’ll have to check. There’s no way they’d warranty such a thing, of course. They have no capability to evaluate the integrity of your print. All they can tell is “will it print?”.

But printed metal parts can be as strong as molded, though it depends on the printing process. I’ve been seeing more and more stories about 3D printed functional parts being used in rocket engines, aircraft and automobiles. So clearly, someone’s got it figured out.

I have a small CNC (and laser cutter) for making parts that printing can’t handle. I hog a lot out of ABS, but also Aluminum and once, Steel (I have no coolant so I had to hand oil it and it was painfully slow and incredibly loud and I wrecked a couple of end mills).


#6

Randy is correct, there is no formlabs resin that can simulate a CNC machined aluminum or forged aluminum bicycle handlebar component. Such a plastic part will fail as soon as you apply normal forces. I have a full CNC machine shop and make parts out of titanium, steel and aluminum mostly. I had an invention consulting business for many years and over the years I have made many of my own bicycle parts. My advice is, for this application, forget about 3D prints all together and that includes Shapeways. Just get with a friendly local machine shop and have them machine the part you need out of 6061. It is the only way you will be able to test this parts actual functionality. Many local machine shops can make the part from CAD files or better yet drawings. This is a great option because often the machinist can offer up improvements. However if you prefer to work with somebody online, many of the 3D printing houses like 3D Hubs can take your drawing and give you a quote for a CNC machined part. They farm out that kind of work every day:

https://www.3dhubs.com/cnc-machining/cnc-milling-service/

Cheers Dave


#7

A few years ago I worked with a client to produce his product, a machined aluminum clamp for biking shoe, kind of cleat, with 3D printed Nylon. This material (Nylon) got the strength and flexibility needed for the design.

Now, you cannot print Nylon with SLA, for that you meed a FDM (filament) ñrinter. There are other very sturdy materials (e.g. carbon fiber and PTF) that you could use as well with an FDM. Here is where the FUSE is needed :slight_smile:


#8

MJF and SLS print Nylon, and these printing processes result in an isotropic print, unlike FDM. I haven’t checked, but I suspect that Shapeways can do Nylon SLS. And of course, Formlabs has their own SLS printer, the Fuse1, which I’m pretty sure is Nylon or a similar plastic…


#9

Laser sintering stainless steel.

I can take care of this if you need it.

Made in house from NYC.


#10

Thanks everyone for the excellent ideas/suggestions. I think I’d prefer to support a shop vs the big prototype companies if possible. I think the part is relatively simple. Ashtree I may hit you up for some estimates once i get the design more dialed. Hopefully the Rigid 4K gets me close.


#11

It really depends what your goal is. None of the resins are even close to simulating the various properties of 6061.

Rigid 10K is the stiffest material, but if you look at the datasheet values, it’s still like 6x or 7x less stiff than 6061.

Elongation and impact strength will be substantially worse.

In this type of scenario, you really should be just using any resin to test fit, and then moving to CNC the part out of 6061 for functional testing.

I’m assuming the geometry is simple since it’s a bike clamp. Also, I wouldn’t consider metal 3d printing unless you have wild geometry…its almost always more expensive than CNCing a simple part.


#12

Let us know how it works! For what it’s worth, I’ve successfully tightened fasteners onto Rigid (aka Rigid 4K). Didn’t use a torque wrench or anything precise, but I hand-tightened to nearly the same tightness I would use when screwing or bolting a steel bracket onto wood. They were fairly beefy parts, though. I really do love the material. Although it’s more brittle than the Tough variants, the glass-infused pieces “feel stronger” (though of course not equivalent to aluminum and I agree with the cautionary remarks above).


#13

Also, to those talking about SLS Nylon…nylon is a very tough material but entirely different than aluminum.

In most cases where you need metal parts, you need stiffness. Nylon is extremely flexible and thus is the opposite of what you want.


#14

Like every material, depending on the specific composition you can get different levels of stiffness. For my client, taulman Nylon and PETT (Taulman T-glass) provided the required stiffnes for the bike clamps. So much that he ditched aluminum in facir of 3D printed parts. Also,

Of course, it all depends on the specific needs and application. I would never replace extrusion aluminum for a 3D printed one (-:

Here a brief description of the taulman versions (not a taulman sales rep or so, I’m just a happy customer, same as a happy Formlabs one )


#15

Have you tried PEEK (SLS or FDM)?
Among printable polymers it has closest properties of Aluminum, except weight (less density). Its used in industry as great replacement of aluminum.


#16

No I have not tried PEEK although Form Labs says their Rigid 4k is close to PEEK. Not sure how close. I am just trying to get a feel for part fit and how they interact with each other. (All I mean by “interact” is do the parts function as intended and to get a good feel for that the resin has to be stiff. Stiffer than Tough at least. Once I have a certain level of confidence that the parts will function as intended from a mechanical point of view. I will spring for a CNC prototype.

There is another part in this mechanism that will be extruded aluminum. Does anyone know of a place that offers Extrusion Prototypes? (I dont think the shape is well suited for CNC)