EV turn signal questionnaire

[Ncdan]

A forum member has been working on 3D printing turn signal stems for the EV bikes.
He has advised me that he’s having issues with the rubberized material functioning satisfactorily in the 3D printer.
The question has arisen whether a more ABS type plastic may be suitable for the turn signal stem application.
Personally, I would not have an issue with a hard or semi hard replacement, as it would be more functional when attached to the plastic bracket, that it would be attaching to.
The replacement model would not have the brass hook molded into the stem as the OEM part has, therefore the semi hard material would attach more securely. A dab of bonding cement could be added to the installation process also, increasing the attachment integrity.

How about some thoughts from you folks who may be wanting replacements for your brittle or broken rubber signals stems?
Thanks in advance for your thoughts and opinions on this subject matter.

Dan

[Tom H]

I could be wrong on this. But I always thought they were a "bendable" material in case you banged one with your leg or had a tip over. This way they would not break or be bent out of shape like would happen with one with a metal mounting rod.

I was able to repair my originals by adding a small tube through the existing wiring hole. Quite rigid now.

When the rubber goes bad and starts peeling/chunking off I'll need to replace them. I would be fine with a fairly rigid material.

Tom

[pehayes]

There are lots of other manufacturers who provide 'flexible' mounting stems that flex quite easily and move quite a bit.  Alas, Guzzi chose a much more rigid material and cast some grooves into it to 'mimic' the accordion flex area of better manufacturers.  Looks nice.  Doesn't work.  The dynamics of driving on rough roads would make the signal device flex vertically more than horizontally.  The original design and installation was fine.  As long as the 'hook' was properly adjusted, the system bottomed out in its mounting recess and worked quite well.  Over time, that hook gradually opens and the device no longer seats flush in its recess.  Now ALL of the vibratory load gets transferred to the single mounting screw and it isn't long before the signals are on the ground.  The hook really is a critically important part of the mounting.  Absent that hook, I don't see any material holding up for long.

Patrick Hayes
Fremont CA

[Ncdan]

There are lots of other manufacturers who provide 'flexible' mounting stems that flex quite easily and move quite a bit.  Alas, Guzzi chose a much more rigid material and cast some grooves into it to 'mimic' the accordion flex area of better manufacturers.  Looks nice.  Doesn't work.  The dynamics of driving on rough roads would make the signal device flex vertically more than horizontally.  The original design and installation was fine.  As long as the 'hook' was properly adjusted, the system bottomed out in its mounting recess and worked quite well.  Over time, that hook gradually opens and the device no longer seats flush in its recess.  Now ALL of the vibratory load gets transferred to the single mounting screw and it isn't long before the signals are on the ground.  The hook really is a critically important part of the mounting.  Absent that hook, I don't see any material holding up for long.

Patrick Hayes
Fremont CA

I hear your point on the “hook” and agree that in theory it holds the unit on more stable.
That being acknowledged, one of my 4 stems  that I’ve replaced in the past 3 years I’ve had my 02 Stone was minus the hook. I put it on with just the one bolt and there has been no issues with it staying in place so far.
Like I said, a dab of contact can be applied and with the right stuff that alone would more than likely hold the unit on for possibly the life of the signal. I feel confident that the bolt alone will not allow the signal to simply fall off. JMHO.

[AJ Huff]

We're talking about these right? I don't want to assume the EV is the same as other Californias.since mine attach to the brake light "housing" not a "plastic bracket."

[s1120]

We're talking about these right? I don't want to assume the EV is the same as other Californias.since mine attach to the brake light "housing" not a "plastic bracket."

Looks like the same stalks, but what they are talking about as a plastic bracket, is the mount for the tail lights on the duel taillight models.

[kingoffleece]

I'd like to replace mine but don't think I'd go with anything rigid.  Vibrations and road bumps and such have a way with stuff that won't flex.

[Ncdan]

We're talking about these right? I don't want to assume the EV is the same as other Californias.since mine attach to the brake light "housing" not a "plastic bracket."

Yes AJ, same stem and light housing just different brackets. The bracket on my Stone is just a cheap plastic bolted to the fender.

[Ncdan]

I'd like to replace mine but don't think I'd go with anything rigid.  Vibrations and road bumps and such have a way with stuff that won't flex.

Read post #3, as that was addressed.

[Wayne Orwig]

I 3D printed mine. Put a rigid steel post through the center. Works for me. The originals didn't really flex on my California, or my EV.

[bigbikerrick]

Wow, that looks purty, Wayne! Did you paint them black, or were they molded, or, eh, "printed" in black plastic? Yours look smooth, not like some of the other 3d printed stuff I have seen with "layers" of the material visible on the finished product.
Rick.

[Ncdan]

Wow, that looks purty, Wayne! Did you paint them black, or were they molded, or, eh, "printed" in black plastic? Yours look smooth, not like some of the other 3d printed stuff I have seen with "layers" of the material visible on the finished product.
Rick.

Where did you get the hook for the end that bolts to the bracket? And how did you incorporate into the stem?
Are you going to offer them to members?

[Antietam Classic Cycle]

https://www.thingiverse.com/thing:5414558

[Wayne Orwig]

It is black material. The roughness, or resolution, depends on the printer. I sort of like it textured. It could be sanded and painted, or a better printer or material could be used.

I printed a slot in the plastic, then bend a simple piece of steel that I JB Welded into the plastic for the hook. Basically, that steel piece adds all of the strength, and the plastic adds very little to it.

[Bisbonian]

I've been working with NCDan on these for a little while now. I spent a lot of time trying to get a flexible version out of TPU to work but it always looked horrible and I hated it so much.

Dan convinced me that a rigid version would be sufficient, this works much nicer using ASA than it did in TPU.

I tried (and failed) to find a nice bit of commercially available metal that I could try to insert for the hook, I could try to print it with the hook as part of the body but that would greatly complicate things for my meager 3d modeling skills. I included a slot based on the example Dan provided me but have nothing to put in there. I was also hoping to find some good sized tubing to strengthen the bolt hole, I found the right size on Amazon but I'm trying to keep my own expenses down on this.

Here's a pic of the current finished product for the short version of the signal stalks. I had the long version on the printer last night but chose the wrong file and that was 8 hours of time wasted.

This is with the standard layer thickness, yes you can see the layer lines and I'm not sure there's much of anything I can do to get away from that. I ran the program to see how much time it would take at the smaller layer height and it took the short version, as shown, from 5 hours each to more than 8 hours each. The long ones go from 8 hours to more than 12 hours.

The long ones look pretty much like the ones in the picture below, just longer.

ASA is the material. I considered using ABS but I read an article which stated that ASA is far superior for outside applications and is quite strong. I don't have anything to test these out on and I'd be lying if I said I didn't have any concerns about longevity.

If you're interested then I'd be looking at $10 each to produce. We're talking about putting this up on the Swap Meet section but I'd like to see if there's really any demand, shoot me a PM if you're interested.




Here's a pic of the same file printed in TPU, this stuff is a bear and I have no interest in using it. Yes it has some flex, but the work needed after printing to make it anywhere close to acceptable is too much for me.

[Ncdan]

I think a member has achieved the task of reproducing an acceptable replacement stem for the EV bikes. I received one in the mail yesterday and it fit perfectly in the turn signal housing. The material is a durable harden plastic which will bolt to the bracket on the bike and due to the quality of the material can be securely attached to the bracket with the one bolt system. The hook will not be necessary as the bolt will hold it on with no issues.
The stem will be offered in the SWAP MEET after the maker is satisfied with the quality of his replacement stem.
Here is a couple pictures of the one I received.

[pehayes]

can be securely attached to the bracket with the one bolt system. The hook will not be necessary as the bolt will hold it on with no issues.

Playing Devil's Advocate.  I feel the metal hook is ultimately important.  Yes, the bolt will hold.  Yes, the newly printed mount will hold.  But it is all attached to the original threaded receiver inside the master lamp housing.  Might be different up front.  Might be different on other models.  But, on the 98EV (to which I am most familiar) all of the rear blinker load is carried by the interior threaded receiver.  Invariably, the screw loosens over time and vibration.  Eventually, as the hook bends open, the blinker delivers a lateral or angular stress load to the threaded receiver and the receiver snaps away inside the housing leaving the blinker to dangle by wires.

I reconstructed mine by lightly gluing the broken receiver piece in place and then creating a solid fill of epoxy to surround the receiver and greatly increase its load capacity.

I suspect that creating a strong mount without a hook may solve one problem while exacerbating another.  I hope I'm wrong.  Again, my concerns may be model and position specific.





I have two 98EVs at over 100K each.  I still reach down and flex each turn signal when I walk through the garage just to be sure the hooks haven't spread open.

Patrick Hayes
Fremont CA

[Ncdan]

Playing Devil's Advocate.  I feel the metal hook is ultimately important.  Yes, the bolt will hold.  Yes, the newly printed mount will hold.  But it is all attached to the original threaded receiver inside the master lamp housing.  Might be different up front.  Might be different on other models.  But, on the 98EV (to which I am most familiar) all of the rear blinker load is carried by the interior threaded receiver.  Invariably, the screw loosens over time and vibration.  Eventually, as the hook bends open, the blinker delivers a lateral or angular stress load to the threaded receiver and the receiver snaps away inside the housing leaving the blinker to dangle by wires.

I reconstructed mine by lightly gluing the broken receiver piece in place and then creating a solid fill of epoxy to surround the receiver and greatly increase its load capacity.

I suspect that creating a strong mount without a hook may solve one problem while exacerbating another.  I hope I'm wrong.  Again, my concerns may be model and position specific.





I have two 98EVs at over 100K each.  I still reach down and flex each turn signal when I walk through the garage just to be sure the hooks haven't spread open.

Patrick Hayes
Fremont CA

I would definitely agree it would be a better option if the hook was part of any of the reconstructed stems. However it comes down to what’s available if one is in need of replacing a dangling turn signal, which I’ve experienced 3 times, to date, with my 02 Stone.
I guess it comes down to using what’s available.
From what I can gather, adding the metal hook to the 3D printed model can’t be accomplished.
However it may be possible to add a hook mabe in the plastic while forming?
The 3D pros can address this issue.

[Wayne Orwig]

From what I can gather, adding the metal hook to the 3D printed model can’t be accomplished.

I JB Welded a simple hook into mine. Very strong. Just print a slot for it up though the center of the stem. Very easy to make.
I am convinced that the hook does the majority of the work and is required.

You may have to click on the image to get the full view.

[Antietam Classic Cycle]

From what I can gather, adding the metal hook to the 3D printed model can’t be accomplished.

From the thingiverse link I posted above:
I copied the original design, with a small change to give it a flat surface for easier printing. There is a slot where you will need to insert a metal piece. This is pretty easy to cut and bend. I ground some additional hooks and grooves for more grip (see the image). Then I got it hot in a flame and inserted it into the slot. By making it hot, the plastic will melt and form around the hooks in the metal, locking it in place.

[Ncdan]

Both good ideas Wayne and Charlie.
It looks like if the 3D model becomes available there are at least a couple methods one can add the necessary hook part of the stem.
We’ll see how this adventure develops. I’m sure an acceptable method will prevail, it is inevitable due to the experience available here👍

[Wayne Orwig]

I need to figure out how to get mine up on Thingiverse.

[AZach]

Hey all so I was made aware of this thread and figured I would chime in. I have also been working on the 1100 turnsignals. i modled mine in Fusion360 and am printing with my resin 3d printer. The one in the photos is done in a nylon like tough resin but I am about to order some supposedly flexible resin to see how the parts turn out. I hadn't mentioned the project to very many people because I too was trying to find a viable way to do the hook. I think it's need for the stability of the part. It keeps it from spinning I have also toyed around with a circular shaped plug on the bottom to go fit in the hole on the bike that the hook would normally go in.

I've been FDM printing (with thermo plastic) for about 6 years now and resin printing for about two, even if the flexible resin doesn't do what I am hoping I think might hold up better in the long run than FDM? I don't have any experience with the ASA that was talked about using so I can't speak to the durability but in my experience for functional parts layer adhesion has always been an issue, which isn't a problem in resin.

I also have several other original parts I have molded and have been making, if I have time I'll try and make a separate thread with pictures and info about those.

[Ncdan]

I need to figure out how to get mine up on Thingiverse.

See if you can figure out how to produce the stem with the metal hook in place 👍

[Wayne Orwig]

See if you can figure out how to produce the stem with the metal hook in place 👍

Simple. Print the stem, glue in a simple metal hook. It is working great so far and easy to make.

[Wayne Orwig]

See if I have this right.

https://www.thingiverse.com/thing:6237141

[AZach]

I got my first set put on a bike today. Used JB weld epoxy to glue in the hooks. I should have taken a picture of the hooks but forgot. Solid mount and fits perfectly.

[Ncdan]

Looks like we’re getting there, gentlemen. The days of dangling turn signals after hitting a pothole in the road may be over👍

[Chuck in Indiana]

Attaboy, Austin..

[averb]

Hi Dan
I have only just seen this topic but I think I am the person who you were originally talking to about the indicator stalks. I was happy to send some but being in Australia this would be an expensive operation because I was using the original metal hooks cut out of the failed parts.
As well as potting the hooks in with epoxy I also used 2 M4 x 8 button head screws to run through the ears on the hook, mainly because I printed the parts in Carbon Fibre loaded Nylon and I wasn't confident on how well the epoxy would bond to the plastic.



I have no idea how well they worked on the bike as I made them for my brother and I think he sold the bike soon afterwards.



If anyone is interested I can try and dig up the files, the only thing to note is that they are optimised for a Markforged printer and would probably need some fettling to achieve a snug fit into the indicator housing
Cheers
Steve