DrJB

Flex System replacement - Any viable alternative?

Recommended Posts

I tought so to. But as i am not have any of the old builds, i mailt it to @Rudivdk he is going to test it. When he is ready with that, he will post the results here. I only know if it really works afther it is been tested..

Share this post


Link to post
Share on other sites

All, I received the package from @JDL1967, will try to post some initial testresults this weekend on barcode scanner truck.

Thanx Jesse for the very complete package, I can certainly work with this:thumbup:

Share this post


Link to post
Share on other sites

Making the indentations isn't too difficult, i've done it successfully to create custom length cables and to turn broken ones into smaller sizes. Use a small cutting bit on a rotary tool (dremel) to cut the indentation. It helps to meanwhile mount the cable in a drill and have it rotate around slowly so you get an even cut. The indentation doesn't have to be perfect, or even down to as small diameter as the original cables for the ends to snap on. Simply cutting a semi-circle profile (as opposed to square profile as per factory) seems to work just fine.

Edited by nbTMM

Share this post


Link to post
Share on other sites
1 hour ago, Rudivdk said:

All, I received the package from @JDL1967, will try to post some initial testresults this weekend on barcode scanner truck.

Thanx Jesse for the very complete package, I can certainly work with this:thumbup:

It is great to see that members can work together, to get something done..

Share this post


Link to post
Share on other sites

Hello, I was wondering how the proposed solution with the fish cable worked? (I'm working on the 8485 set)

Would you have an online link where I could buy such cable?

 

Thx,

 

Share this post


Link to post
Share on other sites

So I am bumping a 3year old thread, but with reason. I have finally tested the steel cable solution shown by @JDL1967, after being reminded of this action because of a question posted by @Josephiah.

I have hooked up one side of my Barcode Scanner Truck's arm with two steel cables instead of the flex plastic ones (1x 12L, 1x 20L).

The 12L is fixed and just there to keep together the arm (which is built from connectors and axles). Because the steel cable is much smaller in diameter compared to the original LEGO cable, there is much more slack and I don't think it will completely keep the arm attached if put under weird stress. But it could be fixed by slightly shortening the cable length perhaps (putting it under tension by maybe making it 11,5L).

The 20L has a crucial role in the grabber ánd arms movement. I shot a video of how that works (my original motor died, so I use the good old hand motor...):

 

Conclusion: works fine for light to medium force applications, as long as the steel cable is only slightly exposed outside of the outer pipe. With larger force or large amounts of movement (= great length of cable exposed out of pipe) this system is too weak. This was tested with a very thin cable, maybe if there are thicker cables it could work better.

On 8/4/2017 at 1:05 AM, RohanBeckett said:

I'd be more worried about the steel slowly cutting through the plastic outer piping - if the mechanism is operated with too much force! :)

I shared this worry, so I slid a sleeve into the outer pipe on both ends, making sure it stayed put by slightly deforming it into an oval. It sits snug inside the outer pipe, and it can still be removed later on to keep your parts original. Or if you do not want to keep your pipes compatible to the original flex cables, you can glue them into the outer pipe as well:

800x600.jpg

800x600.jpg

@ChrisVandeVoorde, sorry to dissapoint, but I do not know the address where JDL1967 got the cables etc. He mentioned that any professional fishing equipment store should have this stuff.

 

Share this post


Link to post
Share on other sites

Thanks @Rudivdk, appreciate the effort. I hadn't thought of the issue of the cable just buckling in compression - I guess the plastic ones have enough stiffness to prevent them from doing this over the short distance they protrude from the sleeve.

Share this post


Link to post
Share on other sites
On 7/30/2017 at 3:29 PM, AttentionSpanner said:

Maybe someone can create some 3D model and try to 3D print them? 

Years later I decided that it's time to restore my old LEGO Technic models. Of course all that tiny cables had gone missing or broken so I started to search for solutions.

I used the model found here to create printable stl files in the lengths needes in model 8839. I printed them from durable ASA without any special optimization using a PRUSA. The result is of course not perfect, but it seems to work.

 

 

 

flexCablesPrintedFromASA2.jpg

Share this post


Link to post
Share on other sites

Thanks for this. I've been following this topic for a little while and it's nice to see some movement. All of mine have also snapped thanks to my son getting into Lego, but also they probably would have snapped regardless. I will try to print some and reply to this topic for my progress. I want to rebuild my old Whirlwind Rescue 8856

Share this post


Link to post
Share on other sites

I use these a fair bit, I haven’t yet broken any but I think it’s only a matter of time. I’d be interested in getting my hands on viable Lego-ish alternatives.

Share this post


Link to post
Share on other sites

Very unique bricks! I have seen them on Bricklink before, but never got what they are used for.

I won't be using them tho. No wonder those break, they went out of production before I was even born :oh3:

Share this post


Link to post
Share on other sites
2 hours ago, Bartybum said:

Man I'm so bummed we don't have a new version of these, they have so much potential

Especially if they were metal (which I had supposed they were!). Just the front assembly of the Barcode truck looks so much cleaner rather than if it were made with levers or axles, not to mention the flexibility :poke: of the system. 

The 3D printed alternative seems like a great solution, perhaps it would be possible even to use the filament itself, making some notches on the ends for the clamps? (Although I'm not sure about the inner diameter of the LEGO tubes, the filament comes in standard 1'75 and 2'85mm)

Share this post


Link to post
Share on other sites

I think they are fine as plastic, just not a brittle plastic. 
they really enable compact solutions to be made. I was delighted when I saw them after my dark ages, I had, prior to that, used the version for radio controlled models as a third party component and really got on with them.

 

Share this post


Link to post
Share on other sites
On 9/14/2021 at 10:20 AM, syclone said:

The 3D printed alternative seems like a great solution, perhaps it would be possible even to use the filament itself, making some notches on the ends for the clamps? (Although I'm not sure about the inner diameter of the LEGO tubes, the filament comes in standard 1'75 and 2'85mm)

Well, I read this thread quite a while ago, but I guess this comment stuck in my mind...

I'm working on a MOC right now where flex system parts could be invaluable, but while I have a handful of the ends, I only have two cables, so I decided to try @syclone's idea and make flex system cables out of 3D printer filament. I'm using 1.75mm black PLA filament, which is a perfect size. My .1mm resolution digital calipers can't tell the difference between the original and the filament, and neither can I in practice. The only tricky part was cutting the notches. Originally I tried a fancy solution involving a drill and Dremel tool (as I realize someone suggested on here, as I reread it), but I had no success. In the end, I just took my small, sharp Swiss Army Knife and started carving away, going around the diameter, and was surprised to find it worked great! I've just made an 8L one so far for testing, but it seems like it should be easy and dirt cheap to make ones of any length I need now! (Well, apparently 335 meters is about the limit of a single 1kg spool, but I can't see applications for anything that long!). Since I already have plenty of filament, it costs me about nothing, but if any of you who aren't into 3D printing are interested in trying to make some yourself, you can get really tiny spools (designed for 3D pens) dirt cheap, like this $2 one here: https://www.amazon.com/Basage-Filament-Temperature-Printing-Supplies/dp/B085Y61WKJ/ref=sr_1_2?crid=1A0X42Y0WY8TD&keywords=1.75+pla+filament&qid=1662516001&sprefix=1.75%2Caps%2C170&sr=8-2

Here are some pictures of what I got:

800x600.jpg

800x600.jpg

EDIT: I was just playing with mine, and it turns out that if you twist it too much, it'll break, so maybe don't use it in any applications that require a ton of twisting.

Edited by 2GodBDGlory

Share this post


Link to post
Share on other sites

Good work. It never occurred to me to try raw filament, as I'd assumed that the diameter was too large to fit the sleeve, and had never got round to measuring.

I guess we just need a reliable way to notch the ends... (goes off to design a tiny mould to squish a warmed filament end into... 😉)

Share this post


Link to post
Share on other sites
8 minutes ago, Josephiah said:

Good work. It never occurred to me to try raw filament, as I'd assumed that the diameter was too large to fit the sleeve, and had never got round to measuring.

I guess we just need a reliable way to notch the ends... (goes off to design a tiny mould to squish a warmed filament end into... 😉)

Huh, that's a thought! My first plan was to design a jig to reliably notch it with the Dremel tool, but it didn't seem to work great for me. It would be nice to come up with a reliable, automated way to do it.

Share this post


Link to post
Share on other sites

It´s a real shame that TLG doesn´t offer spares in any color and lengths available. They would be so cheap to produce. So others have to do that in the future.

Share this post


Link to post
Share on other sites

My gut says heating either the filament or a mould and squeezing the ends into shape would be more reliable than cutting, but making an appropriate mould is probably a metalworking challenge rather than a 3d printing one.

Share this post


Link to post
Share on other sites
42 minutes ago, pleegwat said:

My gut says heating either the filament or a mould and squeezing the ends into shape would be more reliable than cutting, but making an appropriate mould is probably a metalworking challenge rather than a 3d printing one.

It wouldn't be hard to make such a mould from aluminium for example, but of course you'd need the right tools for that, which I don't think many people have.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.