Door Handle Lever Printed (LMTV)

[Cave Johnson]

With how many of these things break, I dont see a reason to reflect on how long a printed version will last. But at least it's not 200 dollars.

I didnt have the exactly correct bolt length, but once that gets in, proof testing time in the truck.

 

[INFChief]

With how many of these things break, I dont see a reason to reflect on how long a printed version will last. But at least it's not 200 dollars.

I didnt have the exactly correct bolt length, but once that gets in, proof testing time in the truck.

View attachment 866201

View attachment 866202

Pretty slick.

 

[Cave Johnson]

Pretty slick.

There are a number of low/no ash filaments now that can be run through a conventional 3d pringer for people who really want to do an investment casting of something because they dont like plastic. Wax filaments if you want to go jewelry grade.

Im fairly happy with "test run" right now just to get my door handle working again for a while.

 

[Cave Johnson]

#4-40 x 3/4" bolt w nylon lock nut (so it doesnt need to be torqued down to hold and risk cracking the seat).

Seems to work just fine. Fit in place in the truck, opens the door fine.

You could use a #6, but you would need to tap the bottom part of the seat.

 

[Cave Johnson]

Its installed and works just fine.

So I guess time will tell for how long. I printed the final unit out of solid PLA. I'm being positive minded here and hoping the increased flexibility and quality (versus the brittle and porous nature of pot metal) will give this guy a lifespan long enough to make it worth the trouble to install. Which frankly, now that I figured out the tricks on that, is trivial.

 

[HDN]

Have you tried printing this in ABS? That'll do a lot for durability.

I also suggest printing it in a different orientation. The way the layers are printed make the handle more vulnerable to shearing apart along the layer lines at the screw hole and what looks like a catch at the tip of your part.

 

[Cave Johnson]

Have you tried printing this in ABS? That'll do a lot for durability.

I also suggest printing it in a different orientation. The way the layers are printed make the handle more vulnerable to shearing apart along the layer lines at the screw hole and what looks like a catch at the tip of your part.

The image is a little misleading on the layer question. Its got full length grain, for lack of a better term. It hasnt failed yet, but I dont use the passenger door all that much anyhow. Ill post if and when it does for sure though.

 

[Cave Johnson]

Still works. Been abusing it, but I dont have an ISO standard salt spray test or whatever for equivalent. Just texas summer and use.

I would file it under "this is an excellent option for anyone who isnt an originalist.

Anyhow, been busy arranging a 1082 to be it's buddy for a song and a whistle. That thing has no need for printed parts at all though.

 

[INFChief]

Still works. Been abusing it, but I dont have an ISO standard salt spray test or whatever for equivalent. Just texas summer and use.

I would file it under "this is an excellent option for anyone who isnt an originalist.

Anyhow, been busy arranging a 1082 to be it's buddy for a song and a whistle. That thing has no need for printed parts at all though.

Song & a whistle. Nice!

 

[SrqRyan]

Do you have any plans for sharing the file?

 

[aw113sgte]

My truck came with 3d printed handles, broke the third time I used it. Truck latches also needed lube so there was extra stress. I replaced them with aluminum ones and lubed latches.

I wouldn't use 3d printed parts for this situation. Considering potential high loads, it's not their ideal use case.

 

[Icesythe7]

I'd suggest just uploading the model to like pcbway or the likes and having it cnc machined, it is usually pretty cheap

 

[JoeHUMvee]

With how many of these things break, I dont see a reason to reflect on how long a printed version will last. But at least it's not 200 dollars.

I didnt have the exactly correct bolt length, but once that gets in, proof testing time in the truck.

View attachment 866201

View attachment 866202

There are some fairly strong plans out but I plan on machining most mechanical parts from aluminum. Not high temp printers can print very strong thermoplastics like PEEK (poly_ether_ether_ketone.)

 

[JoeHUMvee]

The 1st plan should have been "pla's".

 

[HDN]

I don't think I'll ever go back to PLA as a regular printing material. ABS is physically tougher and has excellent temperature resistance. It also costs less per kg than PLA and can be smoothed out with acetone.

It does, however, have a steeper learning curve in that it will warp without enough bed adhesion or high enough ambient printing temperature. A heated enclosure is also needed. I built mine out of PVC, sheets of plastic cut from rolls (the thick stuff painters use to cover rooms), and a couple bed comforters I bought at Goodwill. The print bed heated at 100 C for at least 15 minutes after reaching temperature will heat the enclosure on its own to at least 40 C, which is the threshold at which ABS won't be as likely to warp during the printing process.

I also print 2 mm-thick walls at a minimum where the design allows. Print strength is heavily dependent on wall thickness.

 

[JoeHUMvee]

Do you have a filament printer? The only issue I see is it will have poor torque strength. I tried a test piece earlier and even using higher temp and very fine layers I had a hard time getting it to stand up to the twist. Although I must say the handles on mine do take a fair amount to close all the way.

 

[HDN]

Do you have a filament printer? The only issue I see is it will have poor torque strength. I tried a test piece earlier and even using higher temp and very fine layers I had a hard time getting it to stand up to the twist. Although I must say the handles on mine do take a fair amount to close all the way.

Yep, I run a Creality Ender 5 Plus which is an FDM 3D printer - a bigger version of Creality's Ender 5. Lower layer height does also increase strength. Unfortunately the nature of a 3D print's creation still renders them 50%-70% weaker than injection molded parts made from the same material.

For something like a part that acts like a lever, its print orientation is going to be the most important. The part needs to be printed such that its axis that is most likely to split or shear is printed parallel to the print bed.

For those of you who aren't familiar with this, I'll use a Transformers figure weapon for an example (Earthrise Optimus Prime's Ion Rifle):



With this weapon, the area of greatest concern is the 5 mm post at which the figure will hold it. The post's layer lines are across its smallest cross-section, the 5 mm post diameter, all the way up to where the post meets the rest of the weapon. Plastic layered like this is nowhere near as robust as a continuous layer of plastic. As a result, the weapon stands a greater chance of shearing somewhere along a layer in the post, especially where it meets the rest of the weapon. There's nothing like shearing a 5 mm post inside a mounting hole in a Transformer - ask me how I know

To prevent that shearing break at the post from happening at all, I print the weapon like this:



By printing the weapon in this orientation, the post's layer lines are across a wider cross section and directly connect to the weapon because of the way the printer lays the plastic.

Here's a view of inside the print to better show how the post connects to the rest of the weapon:



See how the post is made of continuous lines of plastic going to the rest of the weapon?

So there's two things at play here:

• Size of layer cross-section - the bigger the better
  • This is also a consideration for structural steel design where it's referred to as the "area moment of inertia", in which the orientation of a W-shape (a modern "I"-beam design) really makes a difference in how the beam can handle a load.
• Continuous lines of plastic are always stronger than the bond between layers of plastic

In the case of the OP's door handle lever, I would've printed it as it lays in the posts pictures with the screw hole's length perpendicular to the bed to maximize strength around both the hole and the length of the handle.

 

[aw113sgte]

I purchased my aluminum door handle with rubber covers on eBay for $8 each, I have an FDM printer but there's no way it makes sense at that price and durability level.

 

[HDN]

I purchased my aluminum door handle with rubber covers on eBay for $8 each, I have an FDM printer but there's no way it makes sense at that price and durability level.

That's valid too. There are many parts that are less expensive than a 3D print or a custom-machined part and more durable in construction. Whenever I print an oddball thing for myself, I do some research to determine whether I can just buy it for less than it costs to print.

Where I think the technology is most valuable is when it comes to parts made of unobtanium or original parts that are more expensive to buy than to have someone make. I think the best part about it is that there's more flexibility in production run sizes to recoup design costs than if special tooling or molds had to be developed.

 

[niferous]

Would making this thing beefier be an option? I have a sheet laser I could cut this out with. However, to compensate for the bend and some of the holes, it would be a good bit thicker than what I see above. The advantage to that is it would be much stronger. I could cut it out of thick carbon or stainless.