This shows perfectly how complicated a 'simple' industrial process can be for a hobbyist. Thanks for sharing all the small issues you encountered.

No need to apologize about not having any injection molding yet, I’m completely here for the process and all of the lessons and takeaways that come with it!

@NochSoEinKaddiFan

8 ай бұрын

I could not agree more, the process to get it working teaches us all so much more than just "hey it worked" :)

@craig5902

8 ай бұрын

same here, sad you had issues BUT glad you had issues so I can learn from your mistakes

As a machinist, you should invest in some proper 2 flute end mills for your machine. It will help your surface finish a lot. The Dremel ball flutes are too small for that much aluminum removal and will clog. You should also setup the final operation of cutting the part free as a separate operation. This way you can look at your part and measure it while it is still attached. You could have made an offset for the tool and run that last pass again to clean it up. Great start!

@ElectricGears

7 ай бұрын

In addition to this, measuring across a cutter like that will give you the wrong dimension if it has an odd number of teeth or i it is highly contoured so you can't be sure you have two points that are diametrically opposed and ALSO part of the cutting edge. Even if it's measured correctly, the ball it's self might not be precisely on the axis of rotation so it ends up cutting a larger diameter when it tuning. The best way to measure it is to cut a slot and a post of a known width (so you can measure the inside and outside dimension). Then measure the dimensions that where actually cut and calculate the actual width of the tool. You can do this trick on the final part, but I would suggest trying it on a test piece first because of the difficulty of getting an accurate measurement with the draft angles.

Just a tip here. In order to shape silicone easily with you finger - just mix water with a little dish soap. Then dip your finger into the water and then shape the silicone as needed. Wipe your finger with a paper towel and dip again in the water and continue. It is very easy to achieve good results.

@ThyerHazard

8 ай бұрын

Spit works great to! haha

@Sandemik

8 ай бұрын

​@@ThyerHazardgross.

@Marco-yk8kp

8 ай бұрын

Just lick your finger be a man

@ThyerHazard

8 ай бұрын

I hate to freak you out, but... there is spit in your mouth. RIGHT NOW@@Sandemik

@TheFeralEngineer

8 ай бұрын

The old caulking trick

Your diagarms and animations are as simple as they are effective. You really are amazing at teaching!

Some tips about silicon molds. For your application: mill the mold using POM or use a resin printer with ABS-like resin -> do not hollow the mold on the resin printer. Design a two part mold. The lower mold must have a overflow trench milled in. I your case at ring around the o-ring in a distance of about .5 to 1mm from your o-ring. So that the excess silicon can overflow into the outer ring. The upper mold part is just flat piece of POM. Use a 2 component silicon! There are different shore hardness typs available. Then you mix the silicon components you will get air inside the mix -> it does not matter-> just fill silicon into the mold and bash the mold several times on the table until bubbles are gone. Than put the upper mol (flat POM) on top of lower mold and press down. Apply preasure with a screw clamp and let it sit over night to cure. POM does not stick to silicon so you can easily remove your parts. This is how I made thousands of silicon parts. About the Al-mold machining: I is eaier to use a torus endmil instead of the ballhead endmill. You can avoid the step on the bottom of the mold as well, by milling bottom and sidewalls with the torus endlmill! Good luck, I hope this is helpfull

@Argosh

8 ай бұрын

Seeing that open mold almost made me cry...

There are special deburring tools to go inside that T-junction in your valve. Some have a swiveling blade that the end of an extension rod, others use kind of a grinding ball at the end of a long rotary tool. This might help you save what ever o-ring you use from getting sheared off too quickly. Another trick to inject your silicone into these molds for the o-rings is to actually transfer some of it into a smaller disposable syringe first, to have much more control on where and how you spread the silicone.

Design and manufacturing engineer with experience in various mold designs, including injection molds. Here are my comments/recommendations. The part should have consistent thickness. From your 3D model, it looks like the ends need to be made thinner to match the arc. For machined molds, flat features with either sharp corners or standard tool radius fillets don't require the extremely time-consuming surfacing operations that round features require. The mold cavity needs to be up-scaled per the shrink value of the plastic that you will be using. The plastic melt temp at injection time and packing density (result of packing pressure and shot size) will somewhat affect this, but the large majority of the value comes from the material properties. Since each plastic has a small range of temperatures at which they are molded, there are well-established shrink values for each material that you can reference. For a very small number of parts (1-10), a resin-printed mold is much faster and easier to produce. You will need a metal frame for them (i.e. they will be mold inserts) with a platen backing. There are mold-specific resins on the market, some quite affordable. You want one that has a high HDT (heat-deflection temperature). The trickiest part will be nailing down the shrink compensation for the resin. Mold clamping should be done with a screw vise or toggle clamp - something quick-release. You want equal pressure across the face of the mold. Bolts create localized pressure, permitting flex between them. Similar issue with single-point contacts like C-clamps. So you need to utilize a thick force-distributing layer (i.e. platen) between the clamp(s) and the mold. For mold alignment, use tapered bosses into tapered or straight pockets/holes. This will correct for slight misalignments when closing the mold. It is also robust. This can be done on the perimeter of the part cavities or along the perimeter. If you have mold inserts in a metal frame, then put the alignment features on the metal frame. Consider the alignment features to be high-wear surfaces, so use replaceable pins and bushings. NOTE: the boss should not bottom out in the pocket when the mold is closed. The threaded holes of this part are best suited to IM threaded inserts. Any thread-forming core (i.e. your bolts) will need to be unthreaded from the finished part - these are referred to as screw-out cores. The bolt cavities will also not seal unless you cut matching threads into the mold. The only way to have perfectly matching threads on the screw-out cores and the mold will be to machine both. The parting surface can be changed so that the draw orientation is parallel to the holes. Yes, this will require deeper molds, but managing threaded inserts will be easy. In this orientation, I would put the entire cavity on one side (the A-side). This will be faster and easier to machine. Another benefit is that the part will cling to the arch of the B-side. The B-side (or moving side) will be the best place for threaded insert mounting bosses and ejection pins. The majority of the length of the air vents can be wide & deep, cut with a ball- or hog-nosed endmill. These can be on both sides of the mold, or only one. The section of the vents that meet the mold cavity should be on only one side, short, flat, and shallow. The depth will be determined by your packing pressure and the plastic selected. @markbayles7840 made a good starting recommendation for depth. These features need to be thin enough that the viscous molten plastic can't penetrate. Same as shrink values, there are well-established rule-of-thumb values for common materials. There will be knit lines at the holes - these will always be weaker. It is a fact of physics regarding IM through-holes.

Depending on the material you're molding, you also have to account for the shrinkage of the material after cooling. Also, your cavity areas should be polished to an almost mirror finish to promote release and prevent artifacts from getting left behind.

Two tips with working with RTV. First, fill a 5cc syringe with the RTV you are using, then use that for applying the RTV. This will give you much greater control. If you find the RTV is still too hard to manipulate with the 5cc syringe, step down to a 3cc syringe. You'll use more, but it cuts the force required down greatly. Next, isopropyl alcohol is your best friend. When injecting the RTV into the cavity, clean the nozzle with a paper towel, then dip the nozzle in the IPA. You can then inject the TRV without it sticking to the nozzle. That is, atleast until the IPA flashes off. Then you just clean and redunk. I use a pump dispensor like those used in nail salons for my IPA in these applications. It makes it easy to control the IPA and not have it flashing off in your storage. The IPA can also be used to help smooth and compress the RTV into the mold by allowing your finger to manipulate the top surface of the RTV and not stick to it. Just be sure to use as pure of IPA as you can get. I use this all the time at work with anhydrous IPA, but 90 percent and higher works too. Oh, and the IPA will accelerate the curing of any RTV it comes in contact with, so expect a rapid skin creation on anything you use this technique on. You can also use this effect to rapidly cure RT going into a mold by dumping some RTV into a bowl of IPA, working the RTV like dough, then quickly getting the RTV into the mold. This is a technique I've used in the past when making the molds for custom action figures. I needed the silicone mold of some very detailed sculpting, but the RTV kept slumping away. Doing this quick cure got the details and allowed additional layers of RTV to stick seamlessly to it.

Great video! I've done a fair amount of rubber injection molding using 3d printed molds. I've found that designing the mold to be a two part mold works best, as well as using a caulk tube and caulking gun for the actual injection of the rubber. Caulk guns can create a surprising amount of pressure and do an excellent job with filling the molds. Design an array of the gaskets and have air holes for each part oriented in a direction to ease trimming from the finished product. Trim the caulk tube so that you can press it to the insert on the mold and create a good seal, then fill the mold until you get push out from all the air escape holes. Looking forward to your next video!

Well done! The section with silicon o-rings was pure comedy! ;)

From a um/mm scale sillcone molder/machining person you may need to reduce surface roughness of your molds for release. Also your o-ring molds look so small relative to layer lines they may be better machined if not printed with minimal roughness (and possibly polished) considering smoothness is a primary property that helps with o-ring sealing.

I appreciate the attention to detail.

This is again an amazing video. It's unbelievable what a hobbyist with the right tools and enough time and patience can achieve nowadays. Thank you very much!!

Fascinating process! Thanks, Michael! 😊 Stay safe there with your family! 🖖😊

Thanks for showing your errors and frustrations too. We’ll all make mistakes while learning something new; a good video like this shows it’s okay, expected, and a learning opportunity.

This takes me back to working in a plastic injection molding factory! So cool to see you make such a mini mold compared to the ones we used that needed forklifts to move lol. Cant wait for more parts!

totally enjoying the series, mistakes included. also appreciate you chosen a functional part like the clamp instead of a useless benchy.

Ahh, RTV silicone. It's just like kitty litter, it gets everywhere. Keep posting these videos. It's not the destination that matters but the journey to get there.

Great insight, I look forward to the next part.

Awesime series! I am so ready for part 3. Hope it comes out soon!

I almost never comment, but I love your videos and this series! I just felt compelled to say something because I recently went through a similar learning experience with molding/casting silicone. I basically concluded that the best way I currently know of to achieve what you were trying to do with the O-rings is as follows: -print / smooth out the exact size ring you think you want -use mold release on the part like you ended up using in the video -put the part in a tiny box (also mold released) and pour a softer silicone to make a mold of the part -when cured, use mold release in the silicone mold you now have (EXTRA IMPORTANT, as you don't want the final silicone part to fuse to the silicone mold) -pour the red silicone you were using into your new mold to cast the part (it should be pretty easy to remove now due to the mold being flexible, mold release, and less if any print lines present) I'm sure this isn't the best method out there. I've just been doing this type of thing recently, and thought I'd share what I've learned! I hope this might help you or someone else looking to use their 3D printer for molding/casting! edit: Or just print a 2-part mold as someone else already mentioned. you will still have to deal with pulling silicone out of a solid object, but it will probably still help. Perhaps printing a mold out of TPU? I've not tried this though...

The result is already very cool and the metal piece are here with teachings. COOL

A wise man once said, "There are zero good reasons to ever fabricate your own O-rings" with how many OTS sizes are available for a custom design. Design around commodity components. You are also greatly underestimating how precise O-Rings need to be for proper sealing function. I'd also recommend using TPU printed (with ironing) molds as they are much easier to eject because you can simply press the parts out from behind...Not to mention how much easier they are to produce. The metal molds don't provide many benefits for exothermic/thermoset materials like epoxy, PU, and RTV. It also helps to cut the petroleum jelly with a spirit as you can get much thinner coats of mold release on the surfaces that don't witness in your parts.

@Sandemik

8 ай бұрын

Yeah and honestly. Dude could have just drilled the hole out a tad wider and boom.

Great work, keep these coming!!

Great work buddy im so impressed. I am a tool maker and it usually takes many years to learn the skills you have displayed, kerp up the great work buddy

Well done, Michael! I’m just starting off with silicone mold making myself but have followed your channel for a while for the 3D printing tips. Those hand cramps are no joke! It was good to see you fail at the exact same points I did while on my journey to understand mold making, I thought I was the only one hahaha Keep up the good work!!

I've never tried molding silicone like this before, but have used silicone in a lot of other operations. Working with a less viscous silicone would help the silicone really conform to the shape you want. If you have access to a vacuum chamber, degassing your mold will help reduce / prevent air bubble voids. Also, to scrape down silicone that is not cured, use distilled white vinegar. Spray it on the portion of the silicone you want to manually form and spray the tool you're using. It could be your finger, credit card, or fillet tool. The silicone won't want to stick to anything that has the vinegar on it and will create a much smoother result. The plus side to the vinegar is that in most cases you can just let it evaporate and don't have to worry about any residue. Worst cause if you still smell it, just get a damp paper towel and wipe down the area after the silicone has cured.

Ok, just can’t resist a couple comments on the injection mold either😀 To align the mold halves, instead of bolts, order yourself some dowel pins and a couple reamers that size (wheel actually a pair of over and under size reamers ). Drill or mill in two holes for these through both sides at once, preferably before you cut the mold, slightly under size. Ream one side to each size, press fit the pins in one side and the other should slide on with a near perfect alignment. At the same time you made these holes, make some bolt holes for cramping force. I’d tap one side and use the usual clearance holes in the other - the pins take care of alignment. Now clamp the two sides together and with the tapped (flat) side down, mill the outside of the two sides together (you can leave a little band at the bottom so you don’t destroy the table - won’t make a difference. Now you have two mold half blanks that perfectly align and since the sides were milled together perfect reference surfaces to use an edge finder to align in the mill/router. I’d Aldo consider dowel pins for the holes in the part instead of screws. It think they call them side pulls in mold making. Instead of machining the holes, clamp the sides together and drill them right on the seam. I’d Aldo team these to either size or with an oversized reamer. Now when you open the mold you can just lay the pins in and close the mold. They should fit tight enough if you use the exact size reamer that no material will flow around them and probably stay in place fine. If you need something to hold them in though, just clamp the mold together, drill out a bit of the pin holes a bit bigger and tap for a short set screw you can put in lightly after the mold is closed to keep the pins in place. If you try any of this, let me know how it works.

we actually use that stuff to seal stuff up you know. it bonds alright.

Video #3 can’t wait to see it! Great and insightful video! :)

You would be SURPRISED at what it takes to do actual commercial injection molding. I work with a company that does injection molding of plastic parts. The molding machines are ENORMOUS and the injection molds equally so. For instance, The injection mold for a 'lawn mower grass catcher lid' weighs in at around 18,000 Pounds and is carved from blocks of steel.

Michael, I'm sure you already know them but, just in case - if you haven't tried Hallite/Transeals in Welshpool give them a go. Further away is Precise Motion Products in O'Connor. They both have massive ranges of sizes - imperial, metric euro, JIS, you name it. So your chance of finding a perfect fit is pretty good. You want a reasonably high duro (hard) viton for that application and o-rings have a round profile for multiple reasons - in this application it means there's a kind of tapered approach as the o-ring hits the edges of the bore and cross holes during installation and operation which will help it load easier. So the square profile shop made ones really aren't going to help you. Enjoying the rebuild and the mouldmaking process, great to see!

Nicely done.

Just a security tip here: Never use gloves on turning/spinning tools like a drill press. I there is a thread loose it can tangle and pull your hand into the sharp sides of your drill. Saw a few videos on that and was concerned about your fingers. Keep it safe!

Use dawn dish soap as a release agent for silicone. It will dry into a solid waxy film that can be washed away with water. Silicone can also be easily released from wax paper. 100% isopropyl alcohol will prevent silicone from sticking to your gloves (frequently wet and soak the gloves). Liquid and gel release agents can be displaced by the silicone which will then bond to the mold.

Use polypropylene filament for the molds, then you can remove the RTV silicone stuff.

I have a question: To open the valve, you need to pull the leaver and push it back, to close it. That's Why the o'rings are damaged. But if you have a Rod, can't You just use Rotational force instead of linear? So You just twist the rod like a valve. Of course the valve need to be prepared for this.

A simple remark, the air release holes didn't need to be in both halves, you could have made them in 1 part of the mold to make it a bit easier.

Instead of bolts for locating, use pins. Simple round pins with an undersized reamer on one side and over sized reamer in the other. Drill and ream the locating holes while clamped. There are more advanced locating pin shapes but that will get you far.

@tomsko863

8 ай бұрын

That's what I was thinking initially. I wonder if he was going to be using those as additional clamps.

i made a 2 part silicone mold for a gasket once Printed it with a 0.2mm nozzle from PLA worked like a charm (without release agent). I had modeled a filling shute that fills the gasket from the bottom pushing the air up and our of a vent. I would suggest to put a thead like your RTV tube has in the mold and push it through.

I am an injection mould maker, you might have problems packing that mould out, the vents are rather large. Depending on what your chosen plastic flashes at your vents should be slightly less, I would take a guess at 0.02mm deep will be enough.

Get yourself a two part casting silicone, it will really make a big difference. And a vibration table will also help any air bubbles in the silicone rise up and pop. My vibration table is a small cheap brushed motor with a 3d printed motor mount bolted to a small piece of wood and resting on top of some cushion foam you can get at a fabric store.

CAM tip. Start with drilling holes. Drills are the fastest method to remove material and spiralling down leads to a taper as the end mill isn't that rigid, plus it is much slower. I would suggest getting some good quality ball mills for aluminium too, burrs are not great for it you need something that can clear chips easily. YG-1 make good quality pretty cheap endmills and they have worked well for me.

I've made some silicone moulds with that RTV to make some high temperature silicone parts with some success. If you want an O-ring instead of a washer, try making the mold with resin printing as a two part mold. You can make a better version of the release agent by thinning the vaseline with some naphtha. Inject your silicone to fill one side and then the other side and then press both sides (remember to overfill it a little because you need to press the mold with some bolts or a press or something to keep the two parts in place. Wait to cure and open the mould and you'll have a perfect O-ring

Nice! Keep these coming. I want to do injection molding as well.

wow this video really made me think... usually (for example) another channel would have just said 'I punched in the bits ball diameter a tad too small" and I would have understood that the it didn't remove all the material it was supposed to.. and I would have been satisfied and kept my brain on 'auto-pilot' - BUT YOU gave a small but of extra effort to make a simple visual representation that made me think about exactly what happened/'went wrong' ... and this way I actually understand something that I wouldn't have given any thought to otherwise, even while watching another channel on the same topic :) THANK YOU!

For tubes like that with caulking, I like to roll up or fold over the end to take up the slack that way all your squeeze pressure is going out the business end instead of ballooning the air filled end.

For a one off or very limited number of injection moulded objects, it would be easier to 3D print the object with a low melting point material and make an investment plaster cast mould from it. As long as the mould is in a rigid container, you should be able to use your injection moulding machine to inject molten plastic under reasonable pressure. Preheating the mould and using vacuum around the mould would give you even better filling and no seam lines at all.

them not knowing the size of their own cutting bit is quite concerning

@ProtonOne11

8 ай бұрын

It's not a traditional CNC machining tool, it's supposed to be used with a rotary tool by hand, so the exact dimensions are not important at all for dremel. You get what you pay for...

@MadeinSwabia

8 ай бұрын

@@ProtonOne11 Yes, exactly. It is a tool but for manual processes. Additionally, even a CNC toolbit behaves a little different in different materials. So I like do process a test part and measure the workpiece dimensions. That’s how I got told in CNC woodworking class during my apprenticeship. And in metal processing it is even more crucial. But then you can invest a little more money in a professional CNC carbide bit for metal milling, and you should get one that is calibrated precisely with a certain tolerance to rely on.

@TheFeralEngineer

8 ай бұрын

Anytime you buy a milling cutter, you should always check the diameter because they are usually given in nominal dimensions and ground undersize. This is especially true in the case of cutters where the shank is the same diameter as the cutter (i.e. 12mm end mill with a 12mm shank). Because the tool needs to have sharp cutting edges, there's a slight margin of error introduced to the business end because enough material needs to be removed to produce the sharp cutting edge. 0.1mm is not outside the realm of realism for a cutter of this kind, considering the shank of a Dremel is designed to hold a 1/8" diameter (3.175mm) shank tool and the ball end is ground slightly below that to produce the sharp cutting edge.

@nicholasmcconnell7853

8 ай бұрын

"Cutting bit"

@ericlotze7724

8 ай бұрын

Rude way to point it out juhotuho, but a bit more reading up may be of use Michael! (Unintentional Pun lol)

I’m enjoying the journey

This video nicely demonstrates why 3D printing is such a big deal for small volume productios...

You might want to consider ptfe sealing rings. They can be easily shrunk and stretched, and if you can’t get the exact size , you can create a split ring, where you slice one side of the ring at a 45 degree angle so that it forms a scarf joint

Fairly precise washers and rings can be cut from silicone tubing.

Hello Thank you very much for your videos, they help me a lot in my modeling projects and give me many ideas thank you kind regards

Most injection molding machines do not use washers, but rather a precise fit between piston and cylinder to seal them. It is alos preferable to use proper ground pins, press fit into undersized reamed holes on the one side and with a slip fit into reamed holes on the other side as alignment pins.

To run a finishing pass after you have removed the part from the machine, just machine a pocket according to your part outer profile in a piece of wood. Make it a fairly snug fit. Put your part in the pocket, clamp down, zero your Z and run your finishing pass again. This also works well for double sided machining. You can also do multiple pocket in a row for several operations if you need to machine more than 2 sides.

Next time, consider using shoulder bolts (in place of the M5 bolts) to create the bolt hole cavity in the part. The precision ground shoulder of the bolt will make a better seal in the mold, and leave a smooth bore in your part.

With the Vaseline, you’ll want to thin it using mineral spirits to get a thinner release film

O-rings can be ordered in any material, durometer (hardness), id, od, and ring diameter (if you measured the oring itself not the overall id or od). The rtv may be good for the high temps, but is a poor choice for something that needs to slide. It's just too soft to withstand the use as you saw. You need something that has a much higher durometer. See if you can find the specs for the original O-rings, and see if you can find some with a slightly larger od. O-rings can also be different shapes. They can be round, square, d, and probably a few others I'm forgetting. Hope this helps.

You want the green HVAC o-rings that can support super-high and super-low temps. Far more resilient.

For the silicon washers; why not make a two sided mold with air holes and then vacuum chamber to evac the air bubbles?

Please don't take this as a criticism of your great work but regarding the sticky valve; do a proper repair rather than cobbling together a half arsed solution that won't stand the test of time. Ream the hole straight with a decent reamer rather than drill bits. Source pre-made silicone or viton O-rings to match the reamer size. Turn a new shaft to expand the O-rings to the desired final dimension. Chamfer/ de-burr the edge where the exit hole intersects the hole for the valve shaft. Cast silicone from a 3D printed mould might be good enough for a hot end sock but it won't be good enough for a moving part which needs to be air tight. I also doubt that RTV silicone has the required wear resistance for a moving part. It is designed for flat immobile surfaces clamped together under high pressure.

Ya thank you anyway for posting the video. This shows why 3d print enthusiasts praise 3d printers. As someone who is just entering it thinking of manufacturing, I realize what a game change 3d printing is so even though you haven't moulded anything, this is a huge win for the 3d printing community as it is.

Go to Parker and use their sizing tools to find a part number for the correct material, ID and cross sectional diameter. From there, go to a distributor (McMaster-Carr or Grainger in the US) to order that size. It’ll show up in 1-2 days.

What do you think about casting a longer cylinder with a hole in the center to cut the washers from after the silicone has cured? Maybe a cutting jig would also be a good idea to get a consistent thickness and surface finish.

for the Cavity i would go with a Toolppath that follows the countrour of it (no idea if kiri:moto allows for that) should give a cleaner result. would also line polish the Mould into your ejection direction, this makes ejecting the part easier and the surface quality better. Would be intresting to see how the air vents turn out, On industrial moulds usually a gap of 0.01mm-0.03 (with ABS as a material) is common.

Try a compression mold, this is a 2 part mold that squeezes out the extra silicone and air bubbles. The easiest one to do is cup shaped and lets the excess squeeze up and out as the 2 halves meet..

Oh, and your o-rings for that valve need a higher durometer (harder) and they must not be so wide that they fill the slot in the shaft when not installed in bore or they cannot deform properly.

Silicone probably stick to 3d print imperfections (think gaps between layers). My experience makes me not to expect silicone to stick to many materials without any release agent. Sure, from somewhat smooth surfaces it "reveals" but more than often not, unless you have a polished surface. From drilling video I'd also assume your holes are not smooth. Drills tend to leave rough edges that can also eat o-rings. Experiments like that are still interesting. For me it is not about to see the great result, more of what works and what not and how to identify and solve the problems and lesson learned from them.

You need to try the Mold function in Cura, printing a mold in PVA with a resin pour could work really well.

Just a couple suggestion to think about. To fill the silicone mold, did you try just putting a big blob at each spot (easier to squeeze) and then use something like a credit card or spatula or squeeze (like for screen printing) to drag across the top, force it into the cavity. A few wipes would likely get it nice and full and level. Maybe a bit of release on the squeegee for the last wipe. And since the tops are going to be flat, maybe make the bottom flat too so they are just cylinders. A second suggestion, if you have a lathe, maybe something like bronze rings, split in half, so they are just a really close fit (maybe ream the hole to size) widen the groove so it can hold 2 or three split rings so the slits aren’t likely to line up. Btw, to get a close fit you’d probably be better making two rings for each final ring and milling half off so they are a perfect 1/2 ring and sides fit tight together. If you saw one in half, you’ll always have a gap unless you have a zero thickness saw hand😁

Look in to the tooling versions of RenShape. It cuts very nicely/faster than Aluminum/Steel for molds and works fine for low volume items.

CNC at home that doesn’t suck when?

I recently saw an engraving laser carve a small, intricate Chinese Temple quite deep into a river pebble. I wonder whether you could laser engrave two part molds into stone?

Okay, so from what I have watched from the my manufacturing experince with injection molding, you dont need such a steep drift angle for the part to relese. 1.5 deg is more than sufficient :). If you want to make O Rings best is to make a small mold out of plastic itself use elastic bands to hold 2 parts and have a release hole that is 2x smaller on the opposite side. When you see silicon coming out on the other side than it means that your mold is filled up with the silicone. Once you open the mold you should have a nicely round O ring with great finish :)

@tomsko863

8 ай бұрын

I would normally agree with you about the draft angle but you can see how rough the surface of his steel is. No offense to Michael, this is his first time and he's learning. In a professional environment the surface would be cut better and then polished. I personally have no idea what the shrink and flow properties are with the material he is using and how the material will flow in such a small press and bla bla bla... This is all uncharted territory even for someone who is experienced with injection molding in an industrial setting.

3d print a tube squeezer - there are plenty on the standard repos to choose from.

@SystemX1983

8 ай бұрын

Had the same idea 😂 Squeeze that RTV out like mustard! Instead of the "wing bolt" of the squeezer, a hex head or 1/4" square hole could be implemented, to use a ratchet for easy squeezy 😂

dremel bits aren't made to very high tolerances, if you get a carbide lollipop mill from a manufacturer like Helical or OSG, it will be the size they say it will be.

If you want good quality aluminum parts, buy solid carbide endmills meant for CNC, rather than dremel bits meant for handheld tools. Tungsten and other coatings on endmills will clog quickly when machining aluminum. Real endmill (even cheap 3mm ball nose from amazon) will come with exact dimensions so there'll be no guessing involved.

invest in some spotting dye or blue dye, and rub it on the core and cav & squeeze them together with a clamp or screw it down, and make sure there's seal off around your part. Otherwise it's going to flash and/or pour out everywhere... t. I make plastic injection molds for car manufacturers

should not have made holes at the ends the mold, plastic will just flow out of them leaving voids inside the mold, the plastic need to be compressed to fill the voids, small vents 2mm from the edge of the parts 2mm deep would have bean sufficient for the gasses to escape. before you close that mold and inject it you may want to spray that release agent in there because that part will probably stick to that mold and with no way to eject it wont be ease to get that part out. just my 2 cents

I'm considering getting a Carvera and I wonder if it's realistic to operate it inside an apartment complex. Will it create a noise disturbance for the neighbors or is it silent enough? Thank you!

Hi,good video,can i suggest making you cnced a 2 parts mold too for the silicone ring,it would be more precise and try the spray!

Maybe use Fusion 360 for cam :D not sure if you can as for personal usage.

Is there not a McMaster Carr in AUS or something similar? O-rings come in standardized sizes, you just need to now the ID from the rod and the diameter of the bore, dynamic seals should be ~0.010"(0.25) total, cross section from the rod is usually 1.2-1.5x the cross section of the o-ring

Guess curious if there is a reason you havent tried sleaving bored out hole? I can think of a couple of reasons but it would be worth considering at least.

For injection molding, can you use your 3d printerto inject pla into it? Have the nozzle pushed into the opening forcing filament into the mould? Maybe heat the aluminium mold so the pla doesn't harden/cool before filling it up.

@Matt3DMaker

8 ай бұрын

Not nearly enough pressure/material flow

@jonathanlawley4863

8 ай бұрын

That would never be fast enough and 3D printer-size stepper motors (or even servos, for that matter) would never have enough torque. Sufficient pressure for mold-packing would likely rip the extruder apart - either the wall of the heat break would rupture or the threads would strip. One of the primary reasons for investing in injection molds is their rapid cycle times. A 3D printer extruder would be marginally faster at filling the mold than just printing the part. ETA: Even if all of the above weren't issues, the mold would still need to be pressed against the nozzle hard enough to create a high-pressure seal, which absolutely zero desktop-sized printer gantries are designed to withstand.

you can take one bigger o-ring and cut in your dimensions ,after glue it with superglue ''locktight'' it will work

You could use pp pellets. We have around 210c for it depending on the molds.

Water with dishwashing detergent might work as mold release. Apply, let dry

really shows how easy and fast and cheap FDM as made functional and prototype manufacturing.

Maybe try reaming the hole, drills do not leave a nice surface for the o-ring to ride on.

On those silicone washers you need to diecut them shuts from a sheet of silicone.

Hi Michael. why don't you just find some silicone tubing with the same inner and outer diameter you require, then cut to your desired thickness?

FWIW, RTV often (usually?) comes with a plastic winding handle to clip onto the end of the tube to give mechanical advantage in squeezing out the contents. If only you had some way of creating such a device......

@TeachingTech

8 ай бұрын

I have since 3d printed such a device. What a time to be alive!

@smorris12

8 ай бұрын

@@TeachingTech Excellent! It's mind boggling that we can just draw up and print out a functional tool in short order.

Nice moobs mick!

WOW... Why didn't you just: A) Use a lathe to deepen the o-ring grove to fit an off the shelf o-ring. or B) put the shaft in a drill and deepen the o-ring grove with a file??

Cast your orings in place on that plunger rod.

Lol, what a cliffhanger !