3D laser metal parts

[busaf4]

Has anyone used a turn key service to produce metal parts such as heads, rocker arms which are plan unavailable. The service would have to scan the part for dimensional information , use metal that will be similar composition and physical the properties of part and perform any after working for cleaning part for use. Also if someone had this done what the total cost range.

 

Art

[edinmass]

Yes, and no.

 

There is no one stop shop from start to finish for design, Cad-cam, Prototyping , manufacturing......and finishing from start to finish that I am aware. If available it would be ten times more than you are willing to pay. 3D printing in metal, scanning, design, and program from pc to CNC are available at huge numbers. Simply put, if you can’t do 2/3 of it with after hours guys working for cash off the books......the formula doesn’t lead itself to working for us old car guys.......YET. I think it’s still ten years out before the supply and numbers work. Post a photo of the parts you want to make.........water jetting sometimes can make complicated parts half way and then you can finish them by hand.

[Terry Harper]

Art,

 

There is a lot to those questions. 3D printed parts, like any other type of fabrication process, is not always appropriate for the application at hand. For example there are often times where CNC machining a part from solid is far more costly and wasteful than starting with a casting and vise a versa. Same with 3D printing. I look at a 3D printed part - whether metal or otherwise, as esentially the same state as a casting. In otherwords it still needs machining in order to meet the design intent. The degree of work to produce the 3D model, calculate the fits and tolerances and produce the shop drawings (a must!) can vary widely from part to part and that of course affects the cost far more than the actual printing which is rather cheap in comparison.

 

Here is an example. Awhile back we reverse engineered a radiator cover. Our original intent was to have it cast so we 3D printed the patterns. However, due to time constraints and foundry availability we had to forego that desired method. Then we were offered the opportunity to have it 3D printed in metal. However, because of concerns with warpage etc. due to the geometry we coudn't go that route either so we decided to CNC machine out of solid. However, we did have the locking knob 3D printed. The CAM work, machine time and wastage added considerably to the cost. While it was a pro bono project we estimated that that one cover would have cost well over $10,000.00 if we had billed for the full time and materials. 

 

3D scanning is a wonderful tool and time saver (when applied to the correct application) but it still requires a considerable degree of work to transfer the raw, scanned model into a finished 3D model free of blemishes etc. and again meets design intent and required tolerances. If your paying someone to do this work than its going to be costly. Like any other service, before you jump do your research. There are many people out there offering these types of services. However, the quality can be patchy to say the least. They have to have a solid understanding of your expectations and likewise, you of thier expectations and capabilities. Unless you can do the work yourself its not simply a matter of having a part scanned and simply printed. They have to be capable of determining the design intent (i.e. how the part interfaces with other components) determining the type and class fit and calculate the appropriate tolerances etc. and again, provide proper shop drawing complete with all GD&T. If they cannot or unwilling to meet these basic requirements than you need to look elsewhere.

 

None of this is intended to discourage but to help to focus expectations. Especially when we are frequently told that 3D printing and scanning is the "be all to end all."

 

 

 

 

 

 

 

Edited December 26, 2021 by Terry Harper (see edit history)

[busaf4]

Ed

 

Thanks for the thoughtful reply. The head I mentioned is for a 1926 Pierce Model 80 (aluminum head) which is in rough condition. THe are a rare as the holy grail.

 

The rocker arms are for a Franklin Series 10

 

Art

[busaf4]

Terry

 

Thanks for the also very thoughtful reply and the practical information on applying the technology

 

Art

[Terry Harper]

1 hour ago, busaf4 said:

The rocker arms are for a Franklin Series 10

Art,

Do you have some photos of the rocker arms? Also, you mentioned a head  - I know the series 10 used a non-detachable head so I am thinking its for something else?  Regardless, such an application as a head would be nearly perfect for reverse engineering, developing a 3D model and using 3D printed foundry moulds and cores. These are only good for one casting but are usually far more cost effective than a traditional pattern and core box unless you are having a sizeable run made. 

 

Best regards,

 

Terry

Edited December 26, 2021 by Terry Harper (see edit history)

[Terry Harper]

Art,

 

I just found the photo you posted over on the Franklin Forum. 

 

My first thought is to go with castings. I suspect the originals were forged. Dakota Foundry ( https://dakotafoundry.com/ ) does ductile iron castings and can use an original rocker arm as the pattern. They also welcome small projects such as this. Is there a bronze bushing for the rocker shaft? Since they are subject to impact forces from the valve and the push rod I think I would shy away from grey cast iron.

 

CNC machining from solid could be done but would be pricy with some challenging setups, high machine time and lots of waste.

 

As for 3D metal printing I would contact these folks: https://autotiv.com/ one of my former students is an engineer with them.

 

Edited December 26, 2021 by Terry Harper (see edit history)

[ryan95]

As long as it can be made from flat parts, I use sendcutsend.com. You still need to do the CAD work yourself, but it's as simple as uploading your part, picking a material, and giving them some money. Parts show up nicely packaged in a few days. I look forward to the day that the same can be done affordably with CNC machining.

[2carb40]

On 12/26/2021 at 1:04 PM, busaf4 said:

Has anyone used a turn key service to produce metal parts such as heads, rocker arms which are plan unavailable. The service would have to scan the part for dimensional information , use metal that will be similar composition and physical the properties of part and perform any after working for cleaning part for use. Also if someone had this done what the total cost range.

 

Art

Hold on to your anticipation. I just ran this by my oldest offspring. Free app available to take images and create whats called a cloud point image. Picture you spilling baking flour on the part to duplicate, that's what the free app was described to me to be able to do with a smart phone. Next step is to use software to 'clean Up' the cloud point image and give it to someone who has equipment to 3d print in metal. I will be replicating a 1941 Buick right side chrome diecast circular 'disc' labeled, I believe selector or station selector. I've located an original with a willing owner to allow photos with the app. Documenting the process, as this may be a way to replicate other 'unobtainium', at least small items. Another friend has 'spray chrome' equipment and advises as long as not often exposed to sunlight should hold it's 'Chrome' look. Details to follow as things progress.

Edited December 29, 2021 by 2carb40 (see edit history)

[Gary_Ash]

While scanning and creating a "point cloud" may be a good start for many objects, like a room or a building, there is still a lot of work to turn it into a useable 3D file.  For something as small and simple as a part for a radio knob, it's easier, faster, and more accurate to just measure the part, make a crude sketch on paper, and draw it in CAD (Computer Aided Design), especially when it has a precision hole in the middle.  Photos with a ruler in place help to define details, like placement of lettering.  The "station selector" dial can be recreated in CAD in about an hour, including the raised or recessed letters.  Companies like Shapeways.com can 3D print direct-to-metal using sintered 420 stainless steel infused with bronze, barrel polish it, and electroless nickel plate it to give an acceptable, if not perfect, part.  For most people, not knowing how to do CAD is the biggest hurdle.

 

But, for the Franklin rocker arms, casting in ductile iron using an original for the pattern, as suggested by Terry, sounds like the right approach in order to get the strength and impact resistance needed without having to create a CAD model.  I think a 3D printed part in stainless steel/bronze would work, but I would have to cross my fingers and take no responsibility for its life in use.  

 

[Gary_Ash]

OK, here's my 1-ish hour attempt at the knob.  I did find some photos of the Buick Super Sonomatic radio knobs that were posted on the AACA Forum back in 2019 and sold on Ebay.  Still, I didn't have any real dimensions but assumed the knob to be about 1 inch diameter.  Shapeways quoted $32 to 3D print it in stainless steel/bronze, polished and nickel plated.  Let us know when you get the model done from scanning with a cell phone. 

 

Rendering of 3D model in TurboCAD Pro Platinum.

 

Actual knobs from 1941 Buick Super Sonomatic radio.  Those radios apparently had 5 bands, AM plus short-wave.  In 1941, you could probably listen to BBC radio from England to get war news.

[Terry Harper]

7 hours ago, Gary_Ash said:

I think a 3D printed part in stainless steel/bronze would work, but I would have to cross my fingers and take no responsibility for its life in use.

My thoughts exactly. Also when making the 3D model, whether scanned or from measurements, adjustments have to be made to accommodate machining (machining allowance) for such processes as milling surfaces, boring holes etc. to tolerances to maintain fit and function. Again, for something like the rocker arms look at the 3D print as a rough casting that needs to be machined to function properly and interface with other components. Even the most advanced 3D metal printer cannot hold the tolerances required or finishes required to make that rocker arm a "drop-in" part.

 

As for scanning... you get what you pay for. Would a point cloud scan from my phone work? for some applications yes. For many? No. (been there done that) At the moment I have a scanner for our lab spec'd and quoted and waiting for the funding to be in place. At $67,000.00 its not cheap! Even at that price the accuracy is +/- .0009" For most applications we encounter it will work just fine but again.... to produce a precision part from even a scan of that quality takes some work in a 3D modeling program such as Soildworks or Inventor - its not scan and forget!

 

All that may sound discouraging but don't take it that way. As Gary pointed out its the 3D modeling that trips people up. Unless you can do it yourself it gets very expensive fast! AutoDesk offers Fusion 360 free for hobby and home use. Granted, its stripped down compared to the version offered on subscription but has enough capabilities to satisfy most home and hobby users and its rather easy to learn with a ton of tutorials available on Youtube. We use SolidWorks but we use Fusion 360 for it's CAM capabilities.

 

Here is a project we did awhile back. We needed to convert a modern push/pull magneto switch into  a faux-American-Bosch magneto switch. We used our CNC milling machine but other than the engraving on the knob it would have been a great candidate for 3D metal printing. The nickel plating was done with a homemade setup on the kitchen counter so its not perfect!

 

 

 

Art, we are always looking for interesting projects and the Franklin rocker arm fits right in. If your interested, send me a PM and we can discuss.

 

 

Best regards,

 

Terry

 

 

 

 

 

 

 

 

 

 

 

 

Edited December 29, 2021 by Terry Harper (see edit history)

[edinmass]

The  magic of 3D printing hasn’t come full circle yet. The scan and go directly to metal printing  item doesn’t exist. It takes a talented draftsman and engineer to make things come out right. Gary was very generous to help me out several times, and I actually took time to see if I could get a set up and try to be able to do it in house. Fact is even if I learned to do cad-cam and scanning;  without an engineering background there are just way too many variables that take education and YEARS of experience to get things to come out correctly. Understanding how the original part was manufactured, how 3D printing works, 3D printing a pattern for lost wax castings, understanding shrinkage and draft on patterns........all of this takes talent, experience, and education. Fact is, if it were easy, everyone would be doing it. With time and luck I think the future in this field will work out to be a great benefit to the hobby.........and I expect it will be another ten years where we get better access to it at cost curves that make sense.

Edited December 29, 2021 by edinmass (see edit history)

[Gary_Ash]

Here is the Buick Super Sonomatic radio knob printed in silver metallic PLA plastic.  Print time was 1 hr 9 minutes, materials cost 7.2 cents.  Even in plastic, it's strong enough to work the band selector switch on the radio, close enough in color to the stainless ruler it is sitting on.  The letters aren't resolved quite as well as one might hope, but swapping the print nozzle with a 0.4 mm hole for a 0.2 mm size would improve things, though double the print time.  I've never tried the smaller nozzles to get finer details, but I just bought 24 nozzles of assorted sizes for $0.38 each on Amazon.

 

Unfortunately, there is almost nothing to listen to on the 16-31 meter AM broadcast bands offered on the Super Sonomatic these days.  Most of the old national radio stations shut down when the Internet took over, though China and a few countries still transmit.  So, it's unlikely that a band selector switch will get much use, will just stay on the 540-1600 KHz AM band, I predict - and there is little enough to listen to there.  Oh, where are Guy Lombardo, radio soap operas, "The Shadow", and the one my sister hated, "Your Treasury Men in Action", with the sound of machine guns as part of the opening?  Incidentally, we just had the 100th anniversary of trans-Atlantic shortwave radio communications.  My little 100 watt amateur radio transmitter easily reaches across the Atlantic on many HF bands, partly because my antenna is 265 ft long and is 40 ft above ground.

 

Now, what happened to @2carb40 who posted about wanting the knob?

 

Edited January 7, 2022 by Gary_Ash (see edit history)

[2carb40]

I'm still here! Thanx for posting. Luv ta here any info as I'm near completely ignorant about this radio I acquired! Although there was so much interesting history happening at that time. Very nice job on the knob. I musta piqued your curiosity for that to happen that quickly. What now for that little treasure?

[Peter J.Heizmann]

On 12/29/2021 at 5:41 PM, edinmass said:

The  magic of 3D printing hasn’t come full circle yet. The scan and go directly to metal printing  item doesn’t exist. It takes a talented draftsman and engineer to make things come out right. Gary was very generous to help me out several times, and I actually took time to see if I could get a set up and try to be able to do it in house. Fact is even if I learned to do cad-cam and scanning;  without an engineering background there are just way too many variables that take education and YEARS of experience to get things to come out correctly. Understanding how the original part was manufactured, how 3D printing works, 3D printing a pattern for lost wax castings, understanding shrinkage and draft on patterns........all of this takes talent, experience, and education. Fact is, if it were easy, everyone would be doing it. With time and luck I think the future in this field will work out to be a great benefit to the hobby.........and I expect it will be another ten years where we get better access to it at cost curves that make sense.

Agree 110%, Ed.  In my 46 years of foundry and casting engineering I have heard it all (I thought).  

 

More times than I can remember people would contact us, ask us to make a part using a rusty sometimes broken part as a pattern.  Sometimes we could use the original by fixing and cleaning up however the shrink of the original made the new part about .030 or so less.  I have been reading the many threads on this forum about 3-D printing.  What is rarely discussed is the material of the original part.  When I would ask people is what metal do they want.  The usual answer was "oh just pour it in plain grey iron or standard aluminum or I don't know.  I would turn them down immediately unless they have a destructive test via a spectrometer performed to ascertain the metal being copied.  There are metallurgical labs out there that can provide this.  Also, "destructive" means a small wedge must be cut out of the original part.  

 

There is an active thread right now from Dandy Dave about the broken transmission part and the material was described simply as "cast iron".  There are many grades of cast iron.  In my shops we poured a base iron Class 25.  By inoculating with copper for instance you can get a stronger Class 35 and upwards.  Ductile iron has various grades with hardness levels achieved by heat treating.  What I am getting at is if those not in the know simply look at a metal part and say "oh, it is plain 'ole cast iron when in reality it may be a high strength forging.

 

Peter J.  

[bryankazmer]

today hand-held Xray fluorescence or LIBS analyzers can do the composition in literally seconds - some scrap yards have these.

 

I'm often surprised that people who can be very detailed about the width and color of a pin-stripe make no distinction between materials in categories as broad as "metal," "plastic," and "wood."

[Peter J.Heizmann]

2 hours ago, bryankazmer said:

today hand-held Xray fluorescence or LIBS analyzers can do the composition in literally seconds - some scrap yards have these.

 

I'm often surprised that people who can be very detailed about the width and color of a pin-stripe make no distinction between materials in categories as broad as "metal," "plastic," and "wood."

True, Bryan however nowhere nearly as precise readings as a degreed metallurgist can obtain using a spectrometer.  I know in the day we would never take the word of a scrap yard workers hand held readings.  Our customers would also perform on site updates for our ISO certification and ask to see our spectrometers and the date of the last calibration in our metrology lab.  If I told them we opted to switch to our scrap dealers employ taking composition readings using a hand held unit they would break out laughing then flunk us.

Edited January 4, 2022 by Peter J.Heizmann (see edit history)

[bryankazmer]

I also ran third-party ISO17025-certified labs.  The new hand helds can have annual calibration to certified traceable standards.  I'm not saying that benchtops or spectros(what kind?) don't still have a place, just that handhelds are certainly now capable (if set up properly) of identifying alloys accurately.

[Peter J.Heizmann]

40 minutes ago, bryankazmer said:

I also ran third-party ISO17025-certified labs.  The new hand helds can have annual calibration to certified traceable standards.  I'm not saying that benchtops or spectros(what kind?) don't still have a place, just that handhelds are certainly now capable (if set up properly) of identifying alloys accurately.

I do not deny your thoughts on hand helds.  Only saying within the commercial foundry industry customers with a hand held would not be acceptable due to potential lawsuits should any of our castings fail and the legal beagles ask to see our testing procedures

 

Peter J.