I can't offer advice but I will say that part looks cool whatever it is. So what is it or what is it used for?

 

I would bet you will ruin it in short order if you try to braze or solder it. If the maker cheaped out and did not do a proper inert gas purge before firing up the laser it will be a filthy mess. What does the maker recommend?

Where are you located? There are plenty of folks around with the competency to weld delicate alum parts. I could weld it for you but you would be responsible to blend down the welds.

 

@ giz - aluminum casting. Slick. Was the assembly casted via DMLS direct metal laser sintering? The LM9 [En 43100] parent metal combination recommends 4043/4047 filler. The literature states the alloy is non heat-treatable with good weldability and high ductility. Furthermore, industry recommends a preheat between 200-550F followed by a "slow cool".

What's the function of the assembly? Design loads? Tension, shear, moments?

 

crazy glue.....

 

Looks like the body of a real expensive RC car.

 

The print was done by Concept Laser on one of their M2 machines. It is a DMLS machine and the process is done in an inert environment.

Post print, the part was bead blasted, hand polished, and heat treated at 240C for 6 hours.

I didn't ask too many questions about welding because i was leaning towards the other processes. I will definitely check back with Concept Laser re: filler.

My understanding is that the AlSi10Mg material is similar to 4046.

I am located in Salt Lake City, UT. I thought about contacting MikeGyver, he is the one member I know who is local and very skilled. But part of me wants to finish this out on my own.

Brooklyn nailed it, this is an 1:10 RC car chassis I designed.

Sent from my XT1049 using Tapatalk

 

Brooklyn nailed it, this is an 1:10 RC car chassis I designed.

My parents owned a hobby shop for many many years :cool2:

 

Neat design. Amazing what they can do with lasers these days.

I expect it may pretzel if not welded very carefully. I'd think a weld fixture would be required. I'd expect it may need to be straightened and re-heat treated post weld. I imagine you have a bundle into this part... not something to experiment on unless they gave you a second one to mess with.

What are you planning for a finish? Paint or anodizing? If your anodizing then a filler selection will be important, or you'll need to dowel pin the parts together leaving the seam visible.

If your painting then pin the parts and use body filler. Alternatively you could use aluminum solder to fill the seam if your leaving it raw aluminum color. I doubt solder would work on the butt joint by itself because it requires a scrapping action with the filler to wet out and won't wick due to the oxide on the aluminum.

I'd think re-thinking the joint design would be the best option on the next part you have printed. It may work to run screws in from one end to pull the halves together. Or even have the aliment pins/pockets increased and epoxy the halves. Or milled a dovetail and slid the two halves together.

 

If you need help welding it I live in Roy and welded aluminum all the time at my past job before.

 

That sounds like a great opportunity. Will message you.

 

From someone who used to run off-road R/C cars and still operates farm equipment:

That seam will be the source of never-ending trouble.

If this is a prototype that will never see use in the field, consider it a lesson learned.

If I was involved in the project, I would move the seam in the outer arms (nerf bars? rock sliders?) further aft and include the weld as part of the junction there.

That should reduce the load on the seam in the "floor pan" by a huge factor. Consider a Z-shaped seam (see how truck frames are repaired).

This is free advice. If you don't like it, you are entitled to a 100% money back guarantee!

 

Yeah,

I'm guessing that that seam is there in the first place due to size limitations of the 3D printer.

But I hope this thread will show the outcome of it welded. I'll bet it would do fine, maybe by pinning it down well and including some heat sinking action on some points too.

...That seam will be the source of never-ending trouble... I would move the seam in the outer arms (nerf bars? rock sliders?) further aft and include the weld as part of the junction there.

 

Watch how the Germans build. Add, subrtract, and cut via solid state lasers. Tony Stark technology is here....

https://youtu.be/ndx-amkf4qU

 

@ giz - rolling assembly your design? Personally, would have designed subassembly A to integrate to Subassembly B via mechanical fasteners. Specifically, button head cap screws. Welding thise two halves together now requires $kill and dollar$.

Know if that sintered Al alloy "accepts" drill n threading processes? The locator pins are nice, but believe a 'scab' (sleeve) to conect the halves would be dakine. Obviously, you would need to neck down the interfaces on the half-sections.

You aren't by chance adding a RamCat turbine on the roller? Electric? Internal Combustion?

 

FWIW, my son had a part 3D printed out of steel alloy that needed to have threads tapped into it. He broke 4 taps using lub and correct technique due to how hard the metal was. Finally had to have it 3D printed again with the threads that time!

I could not believe how hard that metal was.

 

^ was expecting the OP to state this. Good feedback. As anticipated, the sintering process binds these metallic powders like the hammers of h3ll. Cool.

 

Thanks for all the comments guys, it is an interesting topic.

Regarding the split... it was due to the size limitations on the machine. I had about an hour to design the split and send off before jumping on a plane. I basically placed it in a position that would make welding simplest and appropriately size the halves.

I need to drill and tap many M3x0.5 holes. Luckily the material is not very hard. I overlooked two holes that were not accessible to a drill/tap. I tried threading an M2 machine screw into the pilot hole I printed and it worked. The part was heated treated at 240C for 6 hours, will have to look up how that would effect the hardness in aluminum.

I made this chassis to be completely compatible with the low cg Traxxas Slash chassis. I have the Slash VXL brushless motor paired with a LiPo battery.

This is a one-off showpiece that will never be raced hard. I designed this chassis to highlight 3d scanning, topology optimization, CAD, and 3D printing tools we sell.

I met up with a local member tonight and he welded the seem with some 4043 filler on the recommendation of the 3DP vendor. The metal was very clean and welded ok, but the puddle didn't want to wet out. We didn't have the equipment to pre-heat, and it would have helped. Designing a bevel into the print would have been a good idea as well.

I'm going to smooth out the welds tomorrow and will post some photos.

Sent from my XT1049 using Tapatalk

 

Hey,

Cool, photos.

Can the 3D scanner communicate with the printer directly, or does it go through a computer?

How about some photos of the equipment too?

... I designed this chassis to highlight 3d scanning, topology optimization, CAD, and 3D printing tools we sell... I'm going to smooth out the welds tomorrow and will post some photos.

 

If it were me, I'd design the joint so I could rivet it together with solid, aluminum rivets. But, that's just me...and what I do.

KDub

 

This is what I would use. It would never break no matter how hard you ran it.

http://www.belzona.com/en/products/1000/1111.aspx

Sent from my SM-G900V using Tapatalk

 

Apologies for the late photos, was on vacation all last week. Here are some shots of the weld, post-grinding, and the assembled car. There is some slight porosity in the weld but it's good enough for my purposes.

 

Beautiful design Giz. That's one expensive chassis but very nice and great to see you were able to get it welded together. I would be so nervous after receiving that from the printers. Anyways, as always 3D printing amazes me. Have you shared this on social media at all? Id love to share it on my page. Drop me a line if possible. Cheers.

Chris,

 

Way cool!

 

@ giz - beautiful! Think Predator meets Ironman meets Xmen.

 

@ giz - have used older school CMM systems in the past. That metrology-grade fiber based system is THE cat's meow. What the juice on that rig? Prob $50k+ ? Impre$$ive

 

Good guess - that particular scanner runs about $55k for the hardware. It's an awesome piece of technology, and I've been lucky enough to scan some amazing parts with it.

 

You know, since it is a hollow frame, you could have fashioned a slug to slide inside the frame to reinforce that joint before you welded it.

 

This is sick.
i was wondering if you had a 3d file of the chassis or if its private due to it being a work thing?