This was a unique project. Create trade show racking that would be able to be self standing, able to hang at least 160 scarves or headbands from and be somewhat easy to assemble. This project was completed for Möbius Threads; a scarf/headband company for use at trade shows all across the province. First we need to cut some hangers. 14ga hot rolled steel, heavily nested with very little scrap!
Not much work needed to clean them up off the table. We cut a lot of 14 ga steel and they come off the table virtually dross free, these went in an acid bath to strip off the mill scale and any minute dross. The only problem with acid bathing parts with very little dross is that the parts tend to stick together and don’t get 100% clean, so they need to be agitated from time to time to ensure all the surfaces are exposed to the acid. Heavier dross parts don’t have this problem as the dross naturally spaces the parts apart while the acid removes the mill scale and ultimately the dross falls off at the end of the process.
Here we have the feet. They are designed in Solidworks as a solid body, then converted to a multi-sheet metal part. So in this case each leg has five pieces split apart from one model. This allows the part to be easily fabricated and functions exactly as intended. Having the bends where the tube will slide into the “receiver” portion is nice as it’s a smooth radius, not a welded edge that would then require blending to make totally smooth. Just simple tweaks to making a simple to produce part. Here they are being tacked and partially welded on the inside. Utimately the perimeter is welded and the welds are blended away.
This is what the feet look like in CAD, exactly like the real thing. Very simple to produce and not requiring much effort or skill. Just time to ensure everything is square, tight and that saves time on the blending the welds at the end. The parts were all shot with a hammer tone paint to mask the inevitable scratches and dings that would occur setting up and tearing down at a trade show.
This is what the initial rendering looked like.
And here it is at the first Möbius Threads trade show in Saskatoon!
Thanks for looking! If you are interested in any of our services please take your time to browse the site. Any questions or if you want us to begin your future project, don’t hesitate to contact us via the Contact page.
With this project we had a client come to us with respiratory issues and had a very strict requirement for clean air. These are two projects rolled into one, one of which we had something to improve, a premium OEM passenger vehicle pleated paper filter which is charcoal impregnated. And the other we had to create from scratch, creating a charcoal filter basket to fit an existing housing that would be secured to the top of a motor home.
Housing number one was fairly straightforward, measuring the existing filter, mocking it up in CAD and then creating a sheet metal part that will be a slide in replacement. The one thing to note (that the pictures don’t show) is that with a slide in metal box, there would be a concern about vibration noise, so we made the part smaller and lined two of the edges (like the OEM filter) with black felt.
Here are the 18ga 304 stainless steel pieces cut on the CNC table, lightly orbital sanded to give a consistent finish and self-clinching fasteners CLS-440 (otherwise known as PEM’s) installed. Note you can lightly see the plate marked bend bend lines for the piece on the right. It makes bending material so much easier and faster! It beats having to create a flat pattern drawing and dimensioning all the bend locations, then using a pair of calipers and scribing those locations onto the part. It’s all done during the CNC process. Also due to the small size of hardware (#4-40) and the tolerance on the hole needed for a self-clinching fastener, all the holes were centermarked with the plate marker and easily drilled out to the correct size. The piece of the left had the holes drilled and countersunk to allow the countersunk undercut screws to fit flush and ensure no binding when it is installed.
The OEM piece and the custom piece (still need holes drilled in the cover). Onto the next one!
There are a few projects sitting on the table, what to take notice of is the three round pieces and the long flat piece on the right. The flat piece is slip rolled and is used to attach two of the rings (the top two rings) together. Then the ring on the bottom will get secured with #4-40 screws. Note the use of slots on the bottom ring, the cover, this allowed the perimeter to be cut in one shot, allow for some adjustment while screwing the hardware in. This will also eliminating a post drilling operation, which saves time and the customer money.
Here’s the welding time lapse video of the welding process. Just a quick 30 second snippet!
And here’s the fabrication completed and test fitted part on the housing for the motor home. Just making sure everything fits and nothing was overlooked prior to prepping the part for powder coat.
The parts are now blasted and have silicone plugs installed to prevent powder from building up in the threads.
It worked out perfectly having two sacrificial #4-40 screws to allow the entire piece to hang horizontally during powder application and when it goes into the oven. Note: MIG welding wire makes great disposable hanger material.
Here are the final products. Brushed 18ga stainless steel and 14ga steel powder coated with super durable wet white powder. Both using #4-40 stainless steel screws and self-clinching fasteners. The client will cuts out a cotton filter which is reinforced with wire mesh that will go on the bottom of the filter cartridge, the filter is filled with high quality charcoal and then another cotton filter is placed on top. The cover is secured and the cartridge is put in the air stream and ready to be put to use!
Thanks for reading and we’ve got a lot more to show! So please hit that follow button if you want to keep up to date of the projects we’re working on. Or browse through our list of services to allow us to help you create your next project!
Here’s another project where we’ve built another steel crate used to secure oxygen tanks on the back deck of a truck. It has specific requirements from the customer in terms of loading capacity as well as transportation requirements. It is using 1.5″ steel tubing, has a 14ga steel top, 10ga steel floor and horizontal support as well as flattened expanded mesh side panels. This tank is specifically built to transport oxygen tanks and so there are steel sleeves welded into the horizontal support as well as the floor to keep the tanks steady during transport. This will also allow for easy insertion and removal of the tanks and ensure that no tanks will be loose during transport. This is the approved CAD model (sans mesh, handle and chain limiting strap).
Here you can see the frame being welded up. The use of a square (not shown), 3/8″ steel scraps, ratchet strap and clamps are to ensure that everything is square prior to tacking. This will keep everything nice and square and ensure it won’t need any tweaking before or after welding.
Some portions of the frame are MIG welded for speed, others are TIG welded for cosmetics. Gotta love TIG…
The 14ga cold rolled steel lid welded to the lid frame and mocked up on the crate. The 14ga sheet was cut on the plasma table, then the edges were formed in the box and pan brake to give it a nice radius edge prior to being welded into the lid frame.
Here the floor and horizontal support are cut out from a 4’x4′ sheet of 10ga steel.
Here we have the steel tubes welded in place on the 10ga horizontal support.
Here it is mocked up sitting on top of the crate. The crate will get flipped upside down and the horizontal support will be blocked the correct distance and then it will be welded into the frame. The smaller holes on the horizontal support are to allow for the optional use of a bungee cord. There is some clearance between the tube and the tank (as seen on the right), and the use of the bungee cord will pull the tank to the side of the tube and eliminate any vibration or noise. Also notice the drain holes in the steel floor, just a small detail, but the last thing we’d want is the tubes on the floor to collect and pool water! The feet were also CNC cut from 1/4″ steel, they’ll distribute the load of the crate as well as the strapping load across a larger surface on the wood deck of the truck, the pounds per square inch were calculated to meet the customer requirement.
Here’s the crate with it’s first coat of paint. Notice the mesh is missing? That’s because you can’t easily paint the inside once the mesh is in place. So the inside needed to be painted first, then the mesh welded on and then the entire crate gets another final coat of paint before it’s ready to go. The masking tape is to avoid over spray onto the flat surfaces that the mesh will be welded onto.
Here’s the completed crate (sans latch) still drying from paint.
Thanks for looking! If you have any questions or a future project you want us to work on, please don’t hesitate to contact us via our Contact page.
We’ve been a bit a bit behind here with the blog! This was a project completed a little while ago for an industrial client who needed a prototype crate to be custom designed with specific loading criteria and to meet certain Transport Canada requirements. Once we had all the requirements listed from the customer the project was modeled in SolidWorks to present the overall design. It only needed to go through one iteration during FEA (finite element analysis) to meet all the requirements.
This image shows the loads on the crate when strapped onto the deck of a truck (in the worst case scenario) while the cage is fully loaded. The mesh panels are not intended to be load bearing and would have made the FEA process unnecessarily complex, so the panels were omitted. However they do add some additional strength and rigidity to the design.
Once the FEA is completed, the tubing is cut to length as per the mechanical drawing, the 1/4″ thick feet and 10ga steel floor are cut on the CNC plasma table.
C-clamps and scrap 3/8″ steel plates from the CNC table make great guides. They are used to align the lid to the top of the crate before the hinges are tacked and welded in place.
Weld on hinges with built in grease zerks may be overkill for a lid, but our customers expect the best and we make sure they get it.
Loaded and ready to deliver to the customer!
Thanks for looking! If you’re interested in following the Mint Design blog, click on the bottom right of your browser on the follow button! We’ve got quite a few more projects that have already been completed or are nearly finished to be posted in the next while. Posting items to the blog have been a bit slow due to us moving! The move has allowed for more room in terms of mechanical and electrical project design, but the fab. shop will stay put for now, but there are future plans in place!
Lots of parts passing through the Mint Design shop in the last few weeks. Lots of TIG welding and powder coating, and even showing off The Can Carabiner at a trade show! We sold quite a few and had a lot of interest in it. There were also a few “What the heck is that?” and after explaining it we got a lot of, “Whoa that is awesome!”. After some field testing and feedback from our customers we’ve got some very minor tweaks in store for future units and the presentation down the road.
Now back into the shop! We have a custom 1/8″ 5052-H32 radiator shroud for a custom 2JZ Toyota truck project. The fabricator/client provided the dimensions and the requirement for the “Teq” and “Supra” logo to be engraved into the metalwork. It was easy enough to do and model in Solidworks and then create the flat pattern. The CNC cut part was provided to the customer to form, weld and finish. Note: you can even see the 1/2″ tick marks to indicate the bend line location.
Here we have a house sign being fabricated out of some 1/8″ 304 stainless steel sheet. The customer chose the custom font and determined the overall size. First the part is cut out on the CNC table, then the backside was lightly brushed and the corner areas were prepped for welding the 5″ stainless steel rods. The rods will be slid into the wall and secured with construction adhesive, ultimately allowing the sign to float from the wall 1-2″. Clamping here may seem overkill, but the more work spent now means less work sanding the front. Reason being is that stainless steel warps very easily and with having a perfectly brushed front surface, any uncontrolled warpage from the backside will make that much more work sanding the front. The polyimide tape is heat resistant tape and also protects the backside from unnecessary scratches.
Here’s the front side, the HAZ (heat affected zone) is very minor and will brush out quite easily. The stainless is wiped with isopropyl alcohol to avoid any oils or contaminants to come into contact with the sanding belt. The belt also never touches or sits on anything, unless it’s clean stainless. No need to grind in contamination which will only show up over time when the sign is exposed to the elements. Also by “coincidence” the dowels have the perfect spacing that it can drop into the fixturing holes of the table. Which makes sanding that much easier as no clamping is needed and there is 100% access to the entire top surface of the part.
And this is what it looks like when it’s done. No signs of welded dowels and they are spaced wide enough to make the sign sturdy, but also narrow enough that they’ll be fairly hidden when the sign is floating a few inches from the wall.
These projects make me sad, however I do get joy and satisfaction when it’s done and I can see how happy it makes people feel. This was CNC engraved, plasma cut out of 1/4″ 304 SS plate and the use of some 1/2″ stainless steel rod. The rod is TIG welded and allows the cross to be buried in the ground and secured in place with concrete and lightly covered with dirt. It is not blank after “Baby” and “October”, it blurred out for privacy.
Powder coating…where do we begin! Did some really cool script font lawn ornament in 10ga steel which was powder coated in Desert Charcoal (same as The Can Carabiner).
Then we got these 7M-GTE parts in needing to be degreased, blasted, baked, blasted and then powder coated. There is quite a bit of prep work required as anything that is cast and has been around oil just requires that much more work to ensure a quality finish. Powder coating is the easy part, it’s all the work prior that takes the time.
Once again our favorite tape around the shop. Polyimide tape, heat resistant and leaves no residue. Super useful as we use for everything from powder coating to welding. And it kind of makes everything look like it’s meant for NASA. These parts are all masked, trimmed, plugged and ready to go.
Notice the pin holes in the masking, this prevents plugs from popping out in the oven and just allows the part to “breathe”. This intake manifold is ready for the powder to be applied.
All the finished parts. The wrinkle black and desert wrinkle white turned out awesome!
Coming soon…Cadillac 304SS exhaust system, our Arduino project powered by Newark Electronics, some custom steel crates and much much more! If you like what you see please subscribe to our mailing list and you will be able to get up to the date content in your mailbox, just click on the “Follow” tab at the bottom right of your browser. If you are interested in any of our services please take a minute to browse our site and contact us if you have any questions or would like to discuss a future project.
Clients sometimes bring us interesting projects to work on, or we come up with interesting ideas as well. The Can Carabiner idea came about the need for cooling canned beverages while fishing or near a beach. It won’t bring your drink to ice cold temperatures, but at least it’ll cool it down enough it will be cooler than the ambient air temperature. After a few evenings of modeling in SolidWorks, a few prototypes later we have a final design. A can retainment system that also has an integrated bottle opener, utility saw and a loop section to allow for wrapping of some paracord (which would be attached to the carabiner). This allows up to six cans to be secured and attached to a paracord rope which can then be tied off while you’re fishing or swimming.
We have done everything from the mechanical design, CNC cutting, pickling, bead blasting and packaging in house. Also even production of the tooling to form offset bends in the metalwork. All 100% designed in Solidworks prior to any steel being cut or welded. Admittedly this tooling would be easier to produce if it was CNC machined as opposed to plasma cut and then having the plates laminated together by welding, however that would take away our ability to do everything in house. Also the dies use regular 44W steel, which will wear over time, replacements can be easily cut out and re-tacked into place. Or we can source some tool steel to cut and weld in place, which will offer a longer life. This versatility allows us to make changes quick if something were to arise.
Here’s one of our small production runs. Tightly nested, 100% cut in house with our CNC plasma table.
These parts have very minimal dross, but it can be easily removed via the pickling process. During this process the mill scale is removed as well. This happens prior to blasting which speeds up the blasting process dramatically, and allows for a clean textured surface for the powder to bond to. In the future we will be automating the surface prep process after pickling. This will reduce labor costs and ultimately improve throughput.
Here are the three colors available. We also sell the bottle cap opener fish as well.
There has been a huge amount of interest in this product, to the point we’ve been doing small batch runs and taking in customer feedback. This feedback and initial small scale production runs will allow us to achieve our even bigger plans in the fall! This product is open to wholesale clients, so please inquire if you’re interested in carrying this product in your store(s). We don’t have an online store yet, but if you’re interested these are going to be selling for an introductory price of $45 CAD so send us an email through our Contact page if you would like to purchase one. Shipping is generally $15-30 depending if you live in Canada or the US as well as how many you plan on ordering.
We’ve so busy in the shop lately we’ve managed to slip our new powder coating booth in the queue. We modeled it in SolidWorks to ensure it will be the right size for our use, as well as maximize the use of all the material purchased. It will allow us to powder coat multiple parts while being hung from the copper grounding bar. The hangers will have swivels so it will allow the part to rotate in place as well.
Here is the 3D model before we cut any wood. We haven’t modeled a vent hood for the filter just yet. That will be the next part of this project.
And here is the booth assembled on the workbench and almost ready to go.
We typically work with thousanths of an inch or tenths of a millimeter, so working with wood which is not dimensionally accurate at all is a test of our patience. However this booth came together pretty easily and really at a minimal cost. The vent will most likely be something cut off the CNC table and welded up. It will be nice once it’s done and this booth will get a lot of use in the shop.
Take a look at our powder coating services page for more info on what we can do for you!
We always have new and interesting projects come through the shop. This one was a wellhead casing project which consisted of a few tasks:
All these steps were done in house to reduce lead time and improve quality control.
Design
The design of this project was based loosely around the existing prototype developed. The prototype was quickly reverse engineered in order to have a 3D model to compare our new design against. This will allow us to compare the range of motion and limitations of the prototype vs the new proposed design. There was also a list of requirements that the new design had to achieve that the existing one couldn’t do or perform, one example is the lack of a guard on the sheave/pulley.
Here is the prototype, ready to be reverse engineered.
Here it is modeled up and mocked up on a small wellhead. The hardware was not modeled as they wouldn’t add any value to the new design.
Now we began our design process taking the reverse engineered prototype into account. Here is the preliminary design compared to the prototype. The new design took requirements from the client as well as added a few other features to compact the design as well as make handling and setup easier. The handles on either side make carrying the unit easier as well as adjusting the position of the sheave. The handle is also located very near to the COG (center of gravity) of the part so it makes it very easy to carry. Here you can see the prototype and the new proposed design overlaid on top of each other.
Since the functionality of the new design is different in a few ways than the prototype, it is submit for a design review and no modifications were needed. The 3D model is then set it up for FEA (finite element analysis). The initial design is to show the concept of how it will work, now with taking loads into account we can factor in how it will actually perform and meet all the requirements of the client.
Here you can see a stress concentration on the arms, this was the final design, prior to this the concentration was higher around the radius as it was tighter. Just a simple tweak in the design and we minimized this stress to an acceptable level without any real added weight.
The design could have been optimized further by reducing the material thickness of members under low stress, however the design also considers the cost of fabrication. The minor cost increase and weight to a part being thicker than necessary outweighs the cost of having to load multiple sheets of various thickness material onto the CNC table to be cut. In this case everything was designed to be cut out of 1/4″ plate except for the top of the guard which would be done out of 10ga steel (1/4″ would have made it far too heavy and cumbersome). Here is the final design mocked up.
Now that the design achieves the clients requirements and has been approved, the project proceeds to the fabrication phase.
Fabrication
Once the design was completed all the parts were exported to our CAM software, nested and cut out of 1/4″ 44w steel plate. Hardware was brought in based on the hardware selected in the design.
Next the pieces were acid dipped to remove the mill scale to prepare it for welding and eventually powder coating. The TIG welding process does not cooperate well with burning through mill scale and it takes a tremendous amount of time to media blast mill scale off. Our in house acid bath works quick and takes little effort. The parts are susceptible to some light oxidization due to the steel being stripped bare, no protective coating is applied since it would have to be removed prior to welding and the part is going to be blasted prior to powder coating anyways.
Here the parts are being welded and tacked up.
These plates were sandwiched together and a groove was CNC cut in two locations, these locations were TIG welded to secure these pieces all together.
All the parts are 100% welded up, blasted and ready for powder coating.
These parts were powder coated with RAL 3016 Coral Red. Here is one of the arms ready to be cured in the oven.
And here they are out of the oven, assembled and ready to be used.
This project started with a physical prototype and ended up with a commercial functioning/looking product. This project combined mechanical design, CNC cutting/engraving, TIG welding and our latest powder coating service. Everything with this project was done in house to reduce lead times and achieve the highest quality product for our client.
We’re building almost anything and everything. This time we’re working on a custom built roof rack. We had completed the design work for this roof rack a few weeks ago, it was a collaborative project with the customer as he had quite a few requirements. Once all the requirements were listed a 3D model and subsequent drawing was created, the drawing was reviewed and the build process began. The advantage of designing it is that we could figure out the actual mass, in this case 47.55lbs (not factoring in the weight of welding filler). The rack uses a Ø1-1/4″ perimeter hoop and seven Ø1″ horizontal crossbars. Here’s the 3D rendering of the roof rack. The tab at the rear is for an LED powered flood light, the two tabs at the front are for a LED light bar.
All the plate pieces were cut on the CNC table and prepped for welding to the rack.
Here are the pieces laid out on the shop floor prior to tacking and welding the main hoop and the coped Ø1″ tubes. Also notice all tube ends/mating faces are sanded prior to TIG welding, this ensures a high quality structurally sound weld. All joints were wiped down with alcohol prior to welding as well.
There are a lot of things we can do at Mint Design, some of which we don’t advertise until we have a few projects go through using the new piece of equipment or technique. In this case it’s tube and pipe bending. We will be adding this to our list of services in the near future.
Here are the CNC cut mounting plates TIG welded from the underside of the rack. The nice thing about designing with CAD is that everything just “fits”. There is no slop and everything lines up. The time spent on the computer saves us more time in the shop so in most cases it’s saving the customer money if it’s designed properly from the get go. In this case the use of Ø1″ crossbar tubes along with the Ø1-1/4″ perimeter tube is that the 11ga steel plates fit up nearly flush with the outside tube once welded to the Ø1″ crossbars.
100% TIG welded at all the connections.
One thing to note, to speed up fabrication as well as improve accuracy and consistency we CNC cut a pair of tubing spacing jigs. This allows us to make sure the rungs are evenly spaced from front to back and from side to side. This eliminates any guesswork and makes fabrication work that much easier. Here’s a shot of the super simple jigs.
And here is a picture of the finished rack installed. The light bar on the front wasn’t snugged down yet… The customer is going to have the rack powdercoated. One neat feature about the rack is that it can accept a double set of gutter mounts to distribute any extreme loads evenly across the gutter rail.
It’s always fun doing artsy projects that force us to be creative. This is a CNC cut skateboard coat rack that was modeled, CNC cut, fabricated and painted in one day. It’s constructed from 14ga 44W steel with TIG welded hangers on the back. This pushes the deck 1/2″ away from the wall and gives it a 3D look. The long horizontal slots were intentional because the TIG welding process will cause warpage these slots allow for this warpage to be dramatic. This pushes out the text further than the area above and below the top and bottom slots, this giving a greater 3D look. Also after the part was cut we forgot to form the tails on the 3D model, so we formed them after the part was cut. Here’s the rendering before we began cutting any steel.
We didn’t get any photos during the cutting and forming process since this was something that had to be done quickly. However here it is prior to paint.
Since the mounting bracket is viewable from the front, they were necked down along the slots so when viewed from the other side they look like the axles from the trucks. The bolt pattern through the deck and mounting bracket are the same as an actual skateboard so in theory you could bolt up a set of trucks to it.
We used a rocker guard paint to finish it off as it’s textured to look like grip tape as well as being really really durable.
Follow the links to our CNC cutting and welding capability. Thanks for looking!
We may give off the impression that that almost all we do is fabrication. Which is not entirely true, which is why we would like to see what goes on behind the fabrication. Here’s some of the last things we’ve gone through on the CNC table. Lots of 1/2″ and 3/8″ lifting rings and turbo flanges.
With jobs like that there is very little design work required, just nesting and setting up tool paths to cut them out as efficiently as at the highest quality possible with our table. We do a lot of mechanical design that is either “behind the scenes” once the part is fabricated, like this roof rack we will soon be building for a client.
Everything is designed to ensure that it will be easy to fabricate and the CAD files are used to produce the flanges that will be welded onto the tubing. It also allows us to determine the correct amount of material and reduce any amount of waste due to errors during the fabrication process. It’s much easier to update a CAD model than it is to re-cut and re-weld pieces. All of which waste time and money. Here’s the flanges cut awaiting the tubing to formed, cut and welded.
We also have many projects that are designed and sold strictly as a design, it is then left up to the customer to use those drawings and models to create what was designed. Some of these designs have NDA’s signed or have potential for a patent application so we cannot post any of these, however here are some other examples of what we’ve designed.
These are only some of the dozens and dozens of parts we have designed. Please take a look through our gallery for more images of what we’ve designed.
Well we’ve been busy in the shop with a variety of projects. Here we’re entering into a small CNC mannequin production run for a luxury fashion designer, Nosakhare Osadolor, based out of London, UK. The website for Nosakhari is http://www.nosakhari.com.
We adopt a lean manufacturing process where we try to carry as minimal inventory as possible, so once the job was put in place the material was put on order and picked up on a rainy day. It was all unloaded into the shop, the sheets were then cut in half to have it loaded onto our CNC table) and the CNC cutting could begin.
This is one of five sheets that were CNC cut out of 44W mild steel to form the body of each mannequin. With this order we are producing two mannequins, one male (first time we’ve made one) and one female. The female weighs in at 47.8lbs and the male comes in at 70.8lbs, they aren’t lightweights!
We just recently got a set of laser crosshairs for our CNC table. This allows us to easily square up material and to reduce waste, which will ultimately save our customers money and be more productive! here it’s cutting the vertical body section of a female mannequin.
This job required five sheets of material to complete the two mannequins.
Once the pieces are cut up they are marked, removed from the table, dross is removed then they are ready for test fitting. These are all the pieces required to make one male mannequin.
These mannequins could be used for modeling everything from scarves to jewelry to welding helmets or PPE gear. Right now they are being test fitted to ensure that everything fits and there will be no issues when they are reassembled by our client in London. Due to the high cost of shipping, these mannequins will be disassembled and flat-packed to be re-setup by the client just in time for a fashion exhibition in the following week. Here are some finished photos.
Iron Man with his two Iron Maiden’s? You bet!
Making custom boxes isn’t the most enjoyable task, however things go by quicker when you have custom built shop tools to create perforated folds.
All packed and ready to go! They are just waiting for the FedEx driver to arrive.
Click here to see our customer update!
We’ve done multiple iterations of dimple designs over the years and put together a sort of in house “bible” on what should and shouldn’t be done. This is a snippet from our bible on when cutting a hole in a panel to dimple die or flare it.
Do not place flared holes in panels situated in high stress areas, it will reduce the overall strength of the design. The idea is that if you have a seamless panel (no through holes or flared holes) in a high stress area it will be stronger in most cases due to the lack of stress risers/concentrations. A correctly produced flared hole in most cases will be stronger than a through hole in a panel. If a flared hole must be used in a high stress area the flare should protrude to the side that is bending outwards under load, this will minimize the reduction in strength from the removal of material.
Example:
This example forces the high stress location to be where the flared holes will be located. It offers a good comparison in terms of flare direction in regards to overall part strength. The strength in this case improved 4.5% by having the flare in the direction of the bending panel. However keep in mind it is still 30% weaker than if the part did not have any flared holes to begin with.
Left – “wrong” dimple die direction (flared inwards)
Right – better dimple die direction (flared outwards)
Locate the low stress areas, such as web components, and remove weight from those areas by flaring. Removing the mass and flaring the holes in these areas will reduce the weight while providing greater strength.
Example:
Here is the part without any modifications under load:
Now you can see the majority of the stress is on the top flange surface, it would not make sense to dimple die this area. Here is what would happen:
There is a lot less red visible since there are extreme stress concentrations located on the edges of the flared holes. Having the flared holes in this location reduces the part’s effective strength by 20%. Therefore it is a terrible misjudgment to locate flared holes in this high stress region.
Now notice how the sides have very little stress as opposed to the top surface. Having flared holes there would:
The interesting bit is that the part is 6% stronger than the part without any modifications. In this case the flared holes improved the strength of the part, while also reducing the weight by 6%. As you can see strategic placement of flared holes can produce a lighter part, as well as a part that can take a greater load. If the flares were inverted in this example (having the flare protrude to the bending side of the panel) the part would be even stronger.
Don’t take the exact #’s too literally, just understand that flared holes are only beneficial in low stress areas and can offer greater overall part strength when done effectively. To do it as effective as possible only FEA (finite element analysis) can be performed and the optimal setup can be determined. Otherwise it’s a “best guess” in where and what size flared holes to put in a panel.
If you are designing or just building something that you know has an extremely high factor of safety, then having flared holes in conservative locations should only improve the design by removing un-necessary weight. If designing a structure, don’t let the use of flared holes allow for a sloppy/overbuilt design.
Please note, this article does not consider the removal of material to be substituted with extra material in the high stress areas. Also this article does not consider panel deflection due to load. Those two are entirely different (but related) topics that are documented in our full “bible”. So rest assured when we punch or cut a hole in a steel part to flare it, we know what we are doing! Please take a look at our dimple die service that we offer.
We had a neat project this week, design and build an interlocking steel mannequin for modeling scarves. We normally use Solidworks as our primary CAD design source, however Autodesk has come out with a pretty neat piece of software called Autodesk 123D. It takes 3D models (.stl and .obj files) and allows you to manipulate the model in many ways, in this case we are creating an interlocked sliced 3D model. This will allow us to slice the model into sheets and allow us to cut in on the CNC table and weld the pieces together. This 3D model we are dealing with is a steel female mannequin for mocking and displaying infinity scarves for our sister company, Möbius Threads which is run by Jaylene Andres.
Before we cut any steel we cut out a small 4″x4″ template with various notch sizes. That will allow us to find the correct notch size and ensure that when we cut out all the pieces they will fit up tight, but still have some room to slide together easily. Along the back where the horizontal sheet meets the vertical sheets, they will be tacked in place via the TIG welder. This will lock all the pieces together and allow this structure to be transported from the sewing/cutting room floor to trade shows and open houses.
Here’s what the template looks like:
Based on the kerf width of the plasma a notch of 0.108″ (in CAD) is ideal. Just enough room to be loose for assembly but tight enough that once all the pieces are in it’ll be a solid structure. Another way around this would be to measure the actual kerf width, then update the CAM software, then make a template. It’d come out with a more realistic CAD notch size, as the material being cut is 14ga steel (which is 0.074″ in thickness), but the method we took is quicker and worked just fine.
With that info of the ideal CAD notch size the model is updated, exported to a .dxf and then tool paths are created. The total cut time took about 1/2hr. The metal pieces were cleaned up and assembled. Here are all pieces after coming off the CNC table.
This is the final product.
And now it’s modeling some Möbius Thread scarves.
Not sure if it’s going to be powdercoated or if a patina will be applied to it. That’ll be decided shortly. He’s a video of it cutting one of four panels to create this steel mannequin.
We put a lot of miles on the Mint Design Rav4, and not always in the best weather conditions. It was time for a lighting upgrade.
3D model.
The design allows the two CNC cut plates to be linked together and then bolted to clamp onto the crash bar.
Wired up and one step closer…
And installed!
To go with the platforms and cabinets we designed for Cross Borders Consulting, we designed these rated winch points to hoist the platforms up to the truck during transport. Factor of safety and deflection under load were critical during the design of this project. To allow for a lightweight frame that is easy to assemble on a truck as well, but also being stiff enough to resist deflecting under load with either winch running. Also the use of standard components were used throughout the frame, universal winch mounts along with corner gussets and frame mounts make repairs or replacing parts easy out in the field.
FEA.
3D model.
This was a pretty substantial project with a lot of constraints and requirements. Designing a working platform to be modular, strong/durable and easy to replace out in the field was the major requirements. Our customer, Cross Borders Consulting, is 2-1/2 hours away so after a one day trip measuring out everything we needed the design work began. The list of requirements were noted, OH&S guidelines reviewed and we began sketching out some ideas. After the design review a few modifications were made, FEA was completed and the drawings were produced. The stairs were the trickiest part, as it had to be adjustable in height, since the platform can be raised or lowered 12″ (in 1.5″) and the stairs had to accommodate that amount of travel and still meet OH&S guidelines with still being functional, hence the add on step. And they also had to collapse underneath the deck while in transport, which was tricky on the passenger side due to the leg that collapsed under the step. Also when the platform is in it’s lowest position there are two steps that drop into place that allow a step up from the platform into the back of the truck, all meeting OH&S requirements. Here is the final product.
3D model.
FEA testing.
And the final product (built by the customer based off our drawings).
This was a fun project. It had a few requirements, the shelf capacity had to withstand at least 250lbs, the exterior dimensions and that the cabinets could be standalone or attach together. There are some subtle things in this design that allow for each cabinet to bolt together. These cabinets may not sitting on a flat surface or have a flat wall to butt up against, so the design of the cabinets allows for misalignment both 1/2″ in the vertical direction and 1/2″ from the front to back. This makes assembly easier and more accommodating. These were designed for Cross Borders Consulting.
3D model.
And final product (built by the customer based off our drawings).