Using 3D technology

[Terry Harper]

I am currently working on the lower water manifold for my big 6 cylinder Wisconsin T-head (5-3/4"x7") This is the last major  assembly I have

to fabricate. Like everything else on this beast it was bronze fittings with brass tubing and disappeared many, many decades ago so we have been working

on re-creating as accurately as possible all the missing bits including the intake manifold and upper water manifold - all of which are brass

and bronze as well.

 

A number of years ago I fabricated most of the patterns and core boxes for the lower water manifold but they just were not quite right.

So... over the past few weeks I have been back at it. I started off modeling in 3D each fitting. I worked from sketches and measurements

of originals as well as from silicone molds pulled by a friend off original fittings loaned by our state museum.

 

For some reason Wisconsin decided to use a rigid connection between the front fitting and the water pump. There is a flanged pipe that

connects to the water pump and slides inside the front fitting and is held in place with a big gland nut.

 

Here is a photo showing what I mean:

 

As you can see the angle and offsets are critical so everything lines up. The first step was modeling the fittings in 3D. Below is a rendering

of the complete manifold. To give you an idea of size its 16-1/2" between the fittings. The connector pipes are 1-1/4" brass tube.

 

With the models and the shop drawings done I 3D printed a mock-up of the front fitting to verify that everything worked.

 

The 3D print got a little messed-up at the top of the curved piece. I forgot to turn on "supports" which

creates a temporary structure to support any overhangs etc.  Fortunately (it took 19 hours to print!) that boo boo

didn't affect the fit between the block and the pump. I also didn't bother printing the gland nut.

 

I also created all the models for the core boxes and patterns. These also will be 3D printed. Each fitting requires a five part

pattern - 2 halves for the body, 2 halves for the neck/flange and a backer. Below is one half of a complete pattern on its

backer.

 

There are also two core boxes per fitting. In the rendering below I superimposed a complete core. In reality The cores are formed as

two separate halves and are glued together after curing.  The core boxes will be 3D printed as well.

 

 

 

 

 

 

 

 

[29hupp]

Wow!  I am impressed at your ability to draw the parts with that much detail and accuracy to the original parts.   I needed a horn button for my 29 Hupmobile and 3D printed one.  Most of our local library's have 3D printers that are free to use and you only pay for the material used.  My horn button cost me 80 cents. 

[$um Fun]

That looks fantastic! New technologies have opened up a new ways of making parts.  I cast up some shocks using 3D printed patterns and I cant tell from the original one I used as the sample. The only draw back I found was finding foundries that wanted to make small runs of parts.

[John_S_in_Penna]

Terry, thanks for the detailed explanation.

Your thread here will help anyone who isn't

as familiar with the process.

[Terry Harper]

Quote

The only draw back I found was finding foundries that wanted to make small runs of parts.

 

That is very true. One thing to remember is that there is a fairly large community out there of folks with "backyard foundries"

These are a mix hobbyists and professionals who cast metal for the challenge, fun and their own projects. Most are very willing to

to share their expertise and knowledge. Here is a link to a forum which is a great place to contact these folks through.

 

http://www.alloyavenue.com/vb/forum.php

 

In fact most of the casting I have had done are by a gentleman with just such a setup. He and his wife sell crafts at various venues and he

casts items for it. He also casts and sells items to the Live Steam railroad people and for his own projects. He does demo's at museums and

various events as well. Again, this is a hobby for him - not a vocation, he just enjoys it. When I have something to cast I supply the

metal and patterns and we have a "foundry 101" day.

 

 

Here is a set of patterns we created for the valve shrouds for a 1917 FWD truck. The FWD used the same Wisconsin

model "A" engine as Stutz etc. In this case I used a CNC milling machine to mill the patterns and core boxes.

So far Peter has cast a number of sets to help folks along with their restorations.

 

 

 

Until a few years ago when I started this project I had no clue on how to do this stuff. But like many things we learn.

That's the best part of a interest or hobby - you have the opportunity to learn new skills and like any skill once learned

it can never be taken away.

Edited July 18, 2018 by Terry Harper (see edit history)

[BearsFan315]

love this, doing some of this on my 1929 Chevrolet I am restoring.

 

needed a spacer, none available, designed it up in CAD, 3D printed a few of various thickness and then test fitted.

 

few other parts I am working on as well I do a LOT in CAD, when i have to make a new gasket I digitize the original, then i can print a paper 1 : 1 and trace out on material. this way IF a gasket is detroyed I have a digital file to recreate it no worries.

 

Technology is Grand when you use it for resourceful reasons !!

 

now to 3d print the parts i need and find a guy like you all that can pour and cast them

 

here is a shot of 3 spacers of various thicknesses 

 

wondering if the 3d print was accurate, holes were dead on !!

 

 

Edited July 18, 2018 by BearsFan315 (see edit history)

[Terry Harper]

Here is another project I did last year. I had to (wanted too!). A friend needed a magneto coupling for a Wisconsin T-head.

For a number of years Wisconsin used a proprietary design developed by one of the firm's founders Arthur Milbrath. I had

to reverse engineer it using patent drawings and measurements of some surviving pieces.

 

Again the parts were modeled in 3D and a set of shop drawing created. (I also 3D printed a mock-up) Like the valve shrouds

I used Fusion 360 to generate the machine setups and tool paths and milled the patterns out using the Tormach 440.

 

Here is the exploded view of the assemply

 

Here is the mock-up, shop drawings and pattern components. Once complete the pattern components were mounted on a match plate

and are ready to cast.

 

Here are the finished patterns which allow four sets to be cast at once.

 

 

 

 

 

Edited July 21, 2018 by Terry Harper (see edit history)

[Terry Harper]

In my first post on this thread I posted the renderings of the patterns for part no. A27A (Lower water manifold rear fitting)

Today we finished 3D printing the last of the components for the pattern and core boxes. These will still need to be post processed

- cleaned-up with any imperfections filled and sanded. Once that's done they will be primed, wet sanded and then a gloss top coat

applied - the better the finish the easier the pattern can be pulled from the mold and the better quality casting.

 

Below is a photo of the patterns, follower and core boxes in the raw just out of the printer. You can see some of the rough areas where the

temporary supports were attached. The supports allow you to print over hanging features. They are easily broken away and removed

after the print is complete than the rough areas sanded, filled etc.

 

 

One piece took over 57 hours to print. Granted after doing the setup and sending through the file it simply ran by itself

and I was free to work on other things. In the 3D printing world a quality print equals time - lots of time unless you

are using the megabucks equipment.

 

3D printing reminds me of when Texas Instruments came out with the first hand held calculator - they cost a lot of money back then now I can

spend a couple of bucks and buy a calculator that has the same functions and is a lot smaller. Same with 3D printing. I printed

these using our Creality CR-10 which sells for less than $1,000.00. The quality doesn't match the megabuck commercial equipment

but it does a real nice job.

 

Now its onto printing the patterns for the front fitting.

 

Best regards,

 

Terry

 

 

 

Edited September 11, 2018 by Terry Harper (see edit history)

[Terry Harper]

Its been awhile but I thought I would share the end results. Here we have the completed patterns and core boxes.

This was a set of patterns I simply dreaded fabricating. In fact I am glad I procrastinated because I am sure I would

have had a very difficult time fabricating these by hand out of wood. I am sure it can be done but not with my skill level

or thin wallet!

 

As you can see we have a four piece pattern plus a follower  and two core boxes. Once I had the prints I went over them with

sand paper and filler followed by a two coats of primer and a top coat. The filler was bondo simply smeared on with my fingers as thin

as possible. It sands very easy and works well to smooth the layers left from the printing process as well as imperfections left from

the temporary supports. Since I am not using the most high tech printers this is typical. I use rattle can automotive paint and wet sand between layers.

I probably go over board with the finish but the smoother it is the easier the patterns can be removed from the mold.

 

 

 

Because of the curved part line of the patterns I could not use dowels for the alignment pins since they would

be a different angles to each other and would have made assembling and disassembling the pattern impossible.

 

I ended up using round head rivets which give enough variation in the angle of pull to work.

 

Anyway... now its time to finish the other two sets of patterns and get some bronze poured!

 

Best regards,

 

Terry

 

 

 

[alsfarms]

Nice thread here Terry.  I wish I had availability to have and run a 3D machine.  I have made a couple of patterns the "old fashioned" way.  It is a bunch of work but the outcome is very rewarding, as you have suggested.  Of course, I am watching your progress with sure enthusiasm.

Al

[Terry Harper]

To bring closure to this thread, over the weekend I finished the last of the patterns and core boxes for the Lower

water manifold on my big Wisconsin T-head motor.

 

When I first started this project way back in late 2008 I was advised by some people that it was beyond me

and I should just give the project to someone else. To be sure, trying to replicate the missing brass and

bronze fittings was a daunting task - the brass and bronze Intake manifold, upper water manifold, lower

water manifold, oil pump drive housing and a bunch of little parts all had to be replicated and that required

a large number of patterns and core boxes. At the time I had never had any experience with foundry work

or making patterns - terms such as draft, machining allowance and shrinkage were foreign to me.

 

Well... here we are today and now I have all the patterns and core boxes done. Hopefully, soon I will have some nice

castings to work with and the best part? I did it all myself!

 

Its been a long road... I started out working with wood and learning how to turn elbows etc. on the lathe and casting plaster

core boxes from wood masters. From that I progressed to 3D printing technology.

 

Here is a photo of my very first pattern. This was for the oil pump drive housing. To the left is the only remnant I had left of the original.

 

Here are all the wood patterns and plaster core boxes for the intake manifold

 

Intake manifold casting ready for assembly

 

Below are some of the wood patterns and the new upper water manifold

 

And finally the very last set! These are the 3D printed patterns and core boxes for the lower water manifold. All of these have a four part

pattern plus a follower to hold the pattern in the correct position. In the lower left corner you can see the only remaining original fitting

that I had.

 

 

Now it's off to the foundry! Once the castings for the lower water manifold are in hand I will have replacements all the missing fittings

and parts with the exception of the starter and generator.

 

 

Best regards,

 

Terry

 

 

 

 

 

 

 

[MikeC5]

This is great stuff!  Thanks for sharing Terry.  What 3D modeling software are you using?  

[zepher]

Thanks for sharing your journey and progress with your parts.

Your work is fabulous.

And thank you for posting the link so others can find small foundries in their area.

 

I hope I get to see the day when owner's clubs will have dozens and dozens of files available to download that will allow any member to 3-D print parts for their restoration and maintenance projects.

[Terry Harper]

11 hours ago, MikeC5 said:

This is great stuff!  Thanks for sharing Terry.  What 3D modeling software are you using?  

 

Hi Mike,

I used Inventor Professional for this project. For future projects I have swapped over to SolidWorks. I teach engineering graphics

so they are readily available to me. The 3D printer is a Creality CR10. Its affordable and never seems to quit.

 

For finishing I usually smear a thin coat of bondo on then sand followed by a couple coats of primer (sanded between coats)

and one or two rattle can top coats. The smoother the finish the easier the pattern can be pulled from the 

mold.

 

 

 

 

 

[Mike Macartney]

Thanks' for the extra information. Can you suggest any 'links' for others that might want learn more to try doing similar projects in the future?

[Dennis Hagen]

That is impressive! I was a pattern maker by trade, started making patterns with bandsaws disc sanders and hand tools. Built a tooling/foundry business which I have since sold the business and did in it's time Sterolitography, LOM and 3D printing transitioning to 3D machining. After 40 years of in that business I can say I loved making patterns but dreaded the business end of probably because I focused on fast turn prototype and pre-production machined castings. Fairly new on the scene is 3D printed sand molds with the coring and gating built in, I think the future is printed sand molds even for production.

[BearsFan315]

Terry

 

gonna use your insights for finishing & top coating some parts i have been working on. sure you do thin light coats as not to stray far from design intent dimensions. 

 

I have been Using Inventor for years (using Inventor Pro), and is my go to software, recently been training on Solidworks Premium and while it is nice, i prefer Inventor, especially when trying to do intense designs as well and customize the software for user interaction. I know what i want to do in Solidworks just can not get it to do it, or takes more steps than usual, and clicking the Check mark or esc is driving me CRAZY !!! also have experience using Pro E, which is now Creo, actually that is where i started.

 

just need to get more in depth into the creating of custom parts. i have the software and a 3d printer, mainly printing PLA

[Terry Harper]

2 hours ago, BearsFan315 said:

Terry

 

gonna use your insights for finishing & top coating some parts i have been working on. sure you do thin light coats as not to stray far from design intent dimensions. 

 

I have been Using Inventor for years (using Inventor Pro), and is my go to software, recently been training on Solidworks Premium and while it is nice, i prefer Inventor, especially when trying to do intense designs as well and customize the software for user interaction. I know what i want to do in Solidworks just can not get it to do it, or takes more steps than usual, and clicking the Check mark or esc is driving me CRAZY !!! also have experience using Pro E, which is now Creo, actually that is where i started.

 

just need to get more in depth into the creating of custom parts. i have the software and a 3d printer, mainly printing PLA

 

I feel your pain in regards to SolidWorks. It doesn't seem as intuitive as Inventor. On the other hand there are some tasks that are

easier.

 

In regards to bondo and the top coat. Yes, generally all I am trying to do is fill any imperfections and mask the layering. Most of the bondo and first

primer coat get sanded away in the process. The idea is to get a good finish on the pattern so it will pull cleanly from the mold.

 

On my early wood patterns, in many instances I used a coat of shellac rubbed down with steel wool to seal and fill the wood before the finish coat.

Below is a set for the valve shrouds for a Wisconsin model "A" in a 1917 FWD truck. For this set I imported the model into Fusion 360 to generate the tool

paths then exported the G-code to Pathpilot for our CNC milling machine.

 

Best regards,

 

Terry

 

 

 

Below, are the castings along with the original piece we used for reverse engineering.

 

 

 

 

 

[BearsFan315]

lol, yeah perks on both sides

 

how are you casting hollow parts, are you printing/making a core as well ?? or pouring solids, then removing all the material ??

[Terry Harper]

26 minutes ago, BearsFan315 said:

lol, yeah perks on both sides

 

how are you casting hollow parts, are you printing/making a core as well ?? or pouring solids, then removing all the material ??

 

I fabricate core boxes. These are filled with core sand and once cured the cores are bonded together

and placed in the mold and accurately positioned using the core prints.

 

In this photo the patterns have already been rammed-up in the drag (lower half of the mold) - excuse me if I get these reversed! The drag has been flipped over and the

other half of the patterns placed. Next the sand will be added and rammed-up to form the cope or top half of the mold.

The pattern will be pulled and the gates, runners etc. will be cut. Then the patterns will be removed (pulled) and the cores set in place.

 

In the photo below is a set of cores all cured and ready to be glued together.

 

Here are the cores (coated with graphite) positioned in the drag (lower half of the mold). These particular pour was for the intake

manifold.

 

Here is the cope (top half) ready to be placed. You can clearly see the core prints that locate the cores as well as the runners, gates

and shrink bob and vents cut.

 

Here are the fresh castings with the cores knocked out.

 

Ready for machining and polishing!

 

 

 

[BearsFan315]

yeas sounds right, at work we work a lot of foundries doing large scale stuff, we have a lot of cast parts various materials, methods, etc...

 

we have old wood patterns, cores, etc.. and newer aluminum style, and even foam cores now then investment casting (wax)

 

thanks for sharing and keep me in the loop, love this kind of engineering

[Mike Macartney]

Thank you for posting the details and photos of the casting details of the intake manifold. I find this all very interesting and fascinating.

[John_Mereness]

Fun !

[Terry Harper]

As a follow-up I thought I would post this. While the topic was about using 3D-technology I thought I would include this to show what can be done with the simplest of tools

and at the time.... very limited skills.

 

The other day I decided to mock-up the intake manifold for the big Wisconsin using some scrap pipe. That way I could figure out all the pipe lengths without

worrying about wasting new brass tube. 

 

When I started this project the intake manifold patterns were the first pieces I developed patterns for. In fact I learned how to

use a lathe and quite bit about pattern making working on these.  In a previous posts you can see the patterns, raw castings and some of the casting process.

 

Here is the manifold all mocked-up. Next I need to clean it all up and solder it all together. being very careful to get it all straight and plumb. Its hanging loose in the photo so there are a few humps and dips that will be adjusted out. In addition to the intake manifold I also had to develop the patterns and core boxes for the upper water manifold as well.

 

Again these are about as close to the original as you can get. When I started all I had were measurements and photos

of  an OEM intake manifold. After creating the patterns and having the castings done I ended-up with a factory drawing of the manifold.... Fortunately my work matched

perfect! Otherwise it would have been a huge setback!

 

 

FYI: Here is How I made elbows.  I start with square stock laminated-up and cut into quarters. The critical part is getting the intersection of the 

quarters centered - otherwise the last step won't go that well. I don't have a dedicated wood lathe so I used my 1942 South Bend 13"x5'

Yes, that's actually a parting tool I am using but it was cutting very well so..... I used it! I believe I paid around $1,000.00 For the lathe, chucks

and collets as well as a new single phase motor. It's the best money I have ever spent! Its paid for itself 20 times over!

 

Its like making half a bagel. Once you have a circle you cut a series of facets (22.5  degrees etc.) than round those off with sand paper or a file.

To make sure your making the piece with a nice half-round section You can check the contour using a template

 

When done you simply match the quarters together. I used wood screws from the back to secure the stock to the face plate

however, brown wrapping paper and wood glue work just as well. It also works very well when turning split pattern. After turning you can easily 

pull the pieces apart leaving a nice clean part line.

 

 

 

 

 

 

 

Edited July 22, 2019 by Terry Harper (see edit history)

[Mike Macartney]

Thanks for sharing that. Very inventive use of the metal lathe - I like it.

[Terry Harper]

Today I finished assembling the intake manifold. Next is some minor adjustment, clean-up and polish and

its done! One brand new as per factory design intake manifold for a Wisconsin T-head.

 

The best part............. I made it all myself

 

 

 

 

 

Edited August 18, 2019 by Terry Harper (see edit history)

[Terry Harper]

To add to this thread....  recently we decided to reverse engineer and fabricate a radiator cover and locking knob 

for the Maine Forest & Logging Museums 1928 Lombard Model "T" dump truck. One of only two that exist

the radiator cover had gone missing decades ago. Since the other surviving machine is missing its original

cover as well we had to start from scratch.

 

 

It was a great opportunity to involve my Drafting & Engineering Technology students and apply 3D technology.

Using the dimensions for the radiator opening they were able to adjust the scale of a period photograph and develop

the general form. Next they used Soildworks to develop 3D models of the components. At this point we 3D printed a

plastic mock-up which was used to verify the fit and appearance. (mock-up's are non-functional prototypes are) and

developed the shop drawings.

 

 

 

 

At this point the Advanced Manufacturing Facility at the University of Maine graciously offered the 3D metal print the 

parts for us. Unfortunately the cover itself is rather large and with its thin cross  section they were worried 

about warping. However, they did 3D metal print the locking knob which we received the other day.

It came out excellent! There is layering visible and will take some work to clean-up. However, it is solid and fully

machinable.

 

In the photo below you can see the 3D printed mock-up and the 3D metal printed locking knob

 

I had never worked with 3D metal printing technology so it was interesting and I came away with a few bits and

pieces of knowledge. First its not a do-all and everything technology. Like any technology it has its limitations. 

For one thing with the system used - MME (Metal Material Extrusion) for this project there is a 20% shrinkage rate that needs

to be accounted for and can affect precision of the part. (other types of 3D metal printing - PBF, MBJ, DED, etc. may vary).

Post processing (sanding, grinding etc.) to remove the visible layering can be time consuming and difficult and you really have

to be careful not to affect the geometry of the part. Again the degree of post processing can vary depending upon the type of

3D metal printing and the equipment. For this particular part we will sand and fill and paint.

 

Thinking about it from another angle could I CNC the knob from solid? Yes I could. However the time and waste of material

for anything but a one-off part would be un-acceptable. However, what if I 3D metal printed the part adding machining allowance

Then used CNC to mill and turn to final shape? Absolutely! Now I would be removing a small amount of material and maximizing

the strengths of both technologies.

 

In regards to the cover itself? Well we 3D printed a pattern taking into account draft and shrinkage for grey cast iron and it

hopefully will be poured next week.

 

 

 

 

All fun stuff!

 

Best regards,

 

Terry

 

 

 

 

 

 

 

 

[Billy Kingsley]

This has been a very interesting read. I know in my scale modeling hobby 3D printing is seen as the wave of the future, but I had no idea it could print metal or was being used in full size automotive restoration.

[yachtflame]

Terry,

  Thank you for the look into you work and process.  I also do a lot of mold making and casting.  Mostly investment casting with silicone molds, wax then bronze. Bronze has 3% shrinkage and usually isn’t too bad but on long thin pieces, it tends to become a problem. I also have problems with spline recesses on door handles. I try to cast these slightly larger but I usually end up having to press a hardened door splined shaft into the handle to make a sure fit. 
 For a couple of years I have been considering the possibility of having a handle scanned and the file enlarged by 4% then printed in plastic in order to make a mold which would include the shrinkage of the wax as well as the bronze. I’ve never worked with a computer much less a scanner and printer, so I’m not really sure if this is the proper way to do this. I don’t know any one with this skill or equipment. I am quite close to UMass, Amherst but don’t know anyone in their engineering department. I’m thinking there must be a student or grad student that would know the answers to my questions and might even take this on as a side project. I guess I’ll have to go over there and start asking around.

[bryankazmer]

The plastic dept is better known at UMass Lowell , I'd try that first

[Gary_Ash]

I just had some more parts cast in silicon bronze for a rear view mirror to be mounted on the outside cowl of my 1941 Studebaker Commander.  I had a Jay Fisher reproduction one for the right side but there were no left side ones available.  I have since come to believe that ones offered by the late Mr. Fisher for '41 Studebakers were really meant for another brand of car, maybe he did a little machining on the base to adapt it.  The mirror in the Studebaker accessory catalog looks different than the Fisher version.  I tried 3D scanning it anyway, but couldn't capture the details of the shape.  Parts with shiny paint or plating are almost impossible to scan anyway.  And, having a commercial place scan a part and make a CAD file is expensive, like $500+.  I thinks it's better to pay some high school or college student with CAD skills to draw the part in 3D at exactly the size of the original part and capture every little detail.  This is the part of the process that is the biggest holdup for most people - CAD software takes a while to learn and you had better be good on the computer to start with.

 

From the CAD file, exported as an .STL format file, you can 3D print the part at any scale you want, so adding 3% for shrinkage during casting is easy, as is flipping left and right.  There are plenty of places on line that will print out parts for you, but you can buy a good 3D printer for $200 these days (Creality Ender 3, for example).  For my recent parts, I had to work with a new-to-me foundry since my old guy retired and closed the shop.  It took me a while to convince the new foundry guy that he could just take my 3D printed model in PLA plastic and use it in his plaster investment casting process just like it was wax, but I've had this done a few times and he had not done it.  I print out the plastic parts as a mostly hollow shell with just an inside and outside skin so there isn't a lot of material.  He attached wax gates and a wax sprue, then poured the plaster over the assembly.  With the plaster mold inverted, he fired the plaster at about 1100 F, which melted and burned out all the wax and plastic.  The PLA plastic burns clean, no chlorine or fluorine fumes, just CO2 and water vapor.  The molten bronze gets poured into the hot mold.  If you are only making a few parts, it's quick and easy enough to run the 3D printer a few times instead of making silicone rubber molds and getting wax replicas.  The foundry just called me yesterday to say the castings are ready, so I'll get them next week.

 

It's worth spending time with the 3d printed parts to sand the surfaces smooth to 220-400 grit so that the cast parts don't need much work.  Silicon bronze parts are good for chrome plating.

[58L-Y8]

Its interesting to see what is being done with 3D CAD modeling and rapid prototyping equipment these days.  I worked for a major company you'd recognize in that field trained on Unigraphics software and had parts made from polymers for various projects.  That is, up until the tech bubble burst in 2001 and the economy tanked.  After which, the demand for those 3D skills dropped to zero and stayed there for five years.  Legions of us saw our skills atrophy in those years, turned to other work which paid the bills but wasn't nearly as interesting or satisfying.  Its a shame, we had more real contributions to make to the advancement of applying that technology for industry and they affectively killed it for most of a decade.   

[Terry Harper]

Very Nice Gary!

 

I really enjoy following your build on the Speedster section of the forum!

 

I have not tried lost PLA casting yet. My foundry guy is strictly a sand mold adherent at the moment.

But I have seen some wonderful results from the process. 

 

Yes, CAD software is a bugaboo and can have a rather steep learning curve.

I am fortunate that I have it available through my day-job teaching Drafting & Engineering Technology and have worked with it for

many years. Amazingly, the other day I actually sat down and worked on some conceptual hand sketches and renderings.

Its amazing how bad my hand lettering is now!

 

 

AutoDesk now offers Fusion 360 for home, non-commercial use. 

 

https://www.autodesk.com/campaigns/fusion-360-for-hobbyists

 

Fusion 360, in addition to offering 3D modeling and 2D drawing capabilities, also has a neat manufacturing package which allows for interface

with CNC. I use Fusion to generate setups and tool paths then post process to G-code. There is a lot to the program

but its fairly intuitive and there are a bazillion tutorials on Youtube and elsewhere.

 

In addition, if you are an educator or student, you can qualify for free access (3 year license) to a ton of AutoDesk 

CAD and design software including Inventor Professional which (in my experience at least) is comparable to SolidWorks.

As Gary pointed out if you can generate your own CAD files then 3D printing and rapid prototyping becomes all that more affordable.

The 3D modeling and generation of supporting shop drawings etc. (if required) is a huge part of the cost.

 

Important things to consider with reverse engineering or designing a component or assembly is understanding the design intent - 

how does the part function and/or interface with other parts? Fits (rotational/sliding, location and force fit and the class of fit) and tolerance - 

Maximum material condition (MMC) and Least Material Condition (LMC). In other words (simplified) what is the minimum dimension

and the maximum dimension a feature can be that will allow for proper interface and fit with an adjoining part?

 

Precision - no such thing as the perfect part and more decimal places adds $$$$. Only use more decimal places where required.

 

There also must be an understanding of the processes that will be used to fabricate the part. (machining, casting, 3D printing etc.) and any

special requirements or limitations associated with them that needs to be considered in your design - draft, shrinkage, machining allowance

and surface finish come to mind.

 

Its not rocket science but if you recognize these needs and are willing to do a bit of research then you are halfway there.

Besides, learning something new and developing new skills is never a bad thing!

 

A copy of "Machinery's Handbook" is an excellent resource for all of the above.

 

Best regards,

 

Terry

 

 

 

Edited December 15, 2019 by Terry Harper (see edit history)

[Terry Harper]

When we think of 3D technology often our first thought is 3D printing. While 3D printing is a form of Additive Manufacturing

we also have Subtractive Manufacturing as well which has a much longer history and is very well suited (with the correct application)

to 3D rapid prototyping. CNC has been with us since the 1950's however, over the past few decades, when teamed with 3D modeling 

and the amazing advances in CNC equipment (5 axis milling comes to mind) it is indeed a very potent tool!

 

At the museum we are trying to fill in all the holes in dash panel of the 1928 Lombard dump truck. The day the Lombard arrived we

swapped out a non-functioning, non-original magneto switch with another non-original magneto switch. Last week I was thinking about

how we could make the new switch at least look like the OEM switch which went missing eons ago. 

 

The original switch was a rotary switch with the knob acting as a key. In this application we used a modern push/pull switch

(I think old Farmalls used this style). Our thought is that it looks like the original and will get us by until we can find and/or afford

a original switch.

 

Here is the sketch:

 

Armed with Measurements of an original correct style American-Bosch switch I again used Solidworks to model the components.

Next stop was AutoDesk Fusion 360 (again, this is free home non-commercial use) which I use to generate the tool paths and export the G-code

which is then up-loaded to our Tormach 440 CNC milling machine. (I love this machine)

 

My first run was with a wax block to test that everything was ok. Then in scrap aluminum to test the engraving before I committed to brass.

 

Today, I finished it up.  All that is left is a bit of polishing to remove the last of the tool marks and tap the face plate for the stem of the 

switch. The American-Bosch logo on the knob is indeed etched in the CNC mill using a 30 degree engraving tool.

 

Interestingly the brass for the knob was from an old grounding rod my dad gave me years ago - kind of an appropriate use!

 

 

 

 

And a photo of an original switch for comparison:

 

 

 

 

 

 

 

 

 

Edited December 17, 2019 by Terry Harper (see edit history)

[Gary_Ash]

I got my rear view mirror parts from the foundry.  The "lost PLA" process using the 3D printed patterns came out great.  I just need to drill and tap them in a couple of places, then send them off for chrome plating.  You can see one of the advantages of using 3D printed patterns in the semi-rectangular opening in the end of the arms to attach the mirror head:  traditional methods would have required a core to produce the hole.

 

[Terry Harper]

Gary,

 

Those came out great!

 

T

[Gary_Ash]

Terry:  Although I haven't done it yet, I've seen YouTube videos of using the "lost PLA" method for sand cast aluminum and bronze, too.  Apparently the first molten metal into the sand will vaporize the PLA, as in the "lost foam" process used for some Chevy and other engines.  Printing the 3D pattern with thin walls and only 10-20% infill should help the quality of the cast part as this will minimize the amount of PLA to be vaporized.  Clear PLA is better than white as it has no fillers added, white has 5% talc.  Maybe your foundry guy would be willing to try it.