In my case, the OD of the pipe is First I colored the face and then marked the center. This is going to be the main chamber of the Heater block. For the cartridge layout, you need to keep the heater as close to the main chamber so that heat transfer doesn't take much time. The material also plays an important role in this. Usually, materials like copper and aluminum have higher thermal conductivity but brass have half of these materials, but the disadvantage of aluminum and copper is that they are not easy to work with and often clog the bits and mills.
Slow feeding and proper cooling are absolutely mandatory for these soft metals. For the ceramic heaters, I chose two opposite corners. Since I have to press the outer wall to squeeze it so that they can grab the cartridge tightly and be able to transfer the heat much faster. Once this is done I mark the center punch and start the drilling work. For drilling the holes I started from the center one which is the main chamber.
I use a 3mm drill to drill the hole all the way. My drill doesn't make a straight hole, but at the other end, it deviates 2mm. After that, I drilled two holes for the ceramic heater. For the heater, you don't need to drill a complete hole. Since our heater cartridges are 20mm long and block length is 40 mm therefore a 30 mm hole is required in this case. Having a higher thermal conductivity I found that heaters have no issue in heating the material to the required state.
Also, the heater wires are crimped that's why it's important to secure them also and for that placing them 10 mm down from the top is a good location for this.
Usually, ceramic heaters come up in a size of 6 mm which you can normally find over the internet and I am using two of them having the power of 40 watts each. Definitely, it's not a fast heater but it's capable of retaining the heat for a longer duration. I found that gradually drilling the hole from smaller to larger one gives a much better wall finish.
For the center hole, it's highly recommended to have a tapered hole like a converging hole so that the material heats up well. I tried with a step drill but it didn't work as I wanted. In a 40 mm long block the first hole is kept Definitely, it's not good compared to the converging hole but I have no other option, but I strongly urge you to go with a lathe or some other tool so that you are able to have that converging type hole.
If the hole has these steps formed inside it then the motor needs to do a bit more effort to push the material.
Since the stainless steel pipe and the hole didn't have much of a difference that's why I decided to go with a heat and press fit.
Once the hole for the heater and the main chamber drilled I start the process of grabbing them to their place during the printing because if the heater block starts to heat even if there is a precise hole drilled for the heater cartridge after heating that hole going to expand and that precise fit gonna lose and heat is not going to flow effectively.
In my previous attempts, I used a hacksaw and jewelers saw but they took a lot more time and cutting is not going to achieve straight so at this time I made a fixture and clamped the grinder to its place securely. The grinder is a variable speed grinder and I am using it at the slowest speed. I made a riser block so that I am able to lift the block at the center mark which I marked on the center block and then insert the block into the wheel to make a cut.
During these cuts, I kept on cooling down the copper block and using all safety measures. So this carefully or if you have a milling machine then this setup is not needed for you. After an hour-long work, I am able to achieve cuts on both sides.
To pinch the block to hold the heater cartridge I made a mark that lies in the center of that cut and then drilled a hole for the M3 thread. One thing I recommend is that in the area where you have to apply force for clamping or tightening mechanism, in that area it's much better to use a bigger screw to avoid thread stripping or you can also use thread inserts.
A thermistor is a sensor that is going to sense the heat and tells the firmware. Now normally the thermistor is installed closer to the nozzle but in my case, I decided to install it in the middle of the entire block.
Being a copper it's going to distribute heat evenly so whatever the temperature is it remains the same in the entire block. To hold the wire to its position I also drilled and thread another hole for the M3 bolt.
The thermistor is closer to the ceramic heater therefore it's not going to take too much time to read the temperature. Once the copper block is ready it's time to attach the heat breaker or the stainless steel pipe.
The reason for using stainless is because its thermal conductivity is very poor and it does not transfer the heat very easily to the heat sink area.
For that, I place the stainless-steel pipe in icy water for 30 minutes and in the meanwhile I clean the copper block and start heating it. The expansion is not too High but with a change in dimension of both the materials, it's definitely going to make a big difference.
With the help of a torch, I heat the copper and then place the pipe over it and smash it with a hammer. Later on, after trimming it to the required length I press more with the help of a bench vice.
Once the heater block work is finished I start the work onto the pellet feeder, although the nozzle hole is still left I continue in the upcoming section. For the feeder I learned from my previous attempt, I have to increase the size so that I am able to feed the bigger pellet also. I am using a 1-inch pipe having inner dia around I cut two pieces from the aluminum pipe one is going to be the main chamber in which the auger screw is going to rotate and the second one is that through which pellets are being fed into the main chamber.
In my previous attempts, I found that with a diameter of 13 mm the pellets get locked from each other and it's difficult to print until you poked something into the chamber but I found that with 18 mm pipe it's not a big deal.
The pellet feeder pipe is going to be welded at an angle of 45 deg. I also decided to make a heat sink onto the pellet feeder because if any amount of heat travels from the heater block to the main pellet feeder and brings the temperature to the melting stage then the entire system is going to be clogged up.
The dimensions of the heat sink are going to be around 50 X 50 mm. Once the material is cut down then I move onto my belt sander and start deburring the edges and make everything smooth. Since there is a pipe needed to be welded at an angle of 45 deg that's why I need to make a notch in one of the pipes also.
For that, I use a 1-inch side of the belt sander and use it to grind down the 45 deg side of the pipe. After this it's ready. Once the material has been cut down and cleaned up I start the work onto the welding the pieces together. To weld the pieces I need to drill a one-inch hoke in all of them. So after marking the center, I hold them in vice and then with the help of drill and hole saw made a one-inch hole in all of the pieces.
The pieces come a tiny bit lose but since I am going to weld them, therefore, they are able to transfer the heat very easily to these fins and keep the chamber cool during the printing process.
After that, I deburr the holes and clean them in acetone. From thereafter they are ready for welding. The first piece is the thicker one, and by keeping the piece perpendicular to the pipe I made a complete weld. From here after I use 3mm carbide rods which were in my drawer and use them as a spacer. I am not good at aluminum welding so onto the thin strips I use only three tack on one side and 3 on the opposite side to make it secure.
I think this is plenty enough to transfer the heat and then cool the entire feeder area. For this, I need to drill down a hole in the main chamber so that pellets can enter inside the chamber and be able to feed into the heater block.
I manually hold the piece into hand and then with the help of paint make a mark and later on drill down a hole. Because of paint on this area, I get absolutely worse welding joints but with the grinding, it's not gonna bother.
Once the hole has been drilled hold the piece into the vice and makes tack weld first from thereafter making a complete weld. Later on, with the help of carbide burr grind it flush. Once the feeder is completed I start the work onto the motor mount. The design is pretty simple and the material I am choosing here is a 6mm thick aluminum sheet.
Being aluminum it's also going to act as a good heatsink and I think able to keep the motor cool also. I marked the dimensions onto the plate and then with the help of my table saw I cut two strips both have different dimensions one is 43mm wide and the second is 55 mm wide. Two of these strips are needed to be cut equal to the length of the motor so that I am able to make some space to tighten or loosen the coupling. Because of the odd motor design there, I need to install two plates having holes in the center but both having different diameters.
The front one also needs to drill some holes so that I am able to fasten the motor to the mainframe. The holes are kept a bit oversize so that I have a slight wiggle room for errors. There are also two more square pieces that are cut down which are going to join the motor mount to the feeder area but in one of them, u also need to make a hole for a 10 mm bearing.
Having OD 26 mm. In my few failed attempts the frame I was using was 3d printed but I noticed that as soon as the motor starts to turn the entire frame gets rotated and also creates a crackling sound. So that was also the reason for making it with aluminum and I think it looks more professional than the printed version. Once the material has been cut down it's time for the prep work. I cleaned the pieces with the help of acetone and also deburr all the edges. First I made a tack weld to two sides one is bigger and one is smaller.
I clamped it to a bigger piece of aluminum to make it stable during the welding process. To prevent the over-tightening of the motor mount I place a piece of thick paper so that after shrinkage there is enough space left so that I am able to freely insert the motor into the frame. I just make a tack weld while the motor is inside the frame.
Make sure not to overheat the motor and avoid keeping it inside the frame during welding. After that, I grind the sides onto my belt sander and make everything flat and flush. There are few fish eye holes left due to welding skills but I leave them as it is. In the area where belts can reach I use a file to remove the material and make it completely flush Side which is going to be the front side onto I also made a hole so that the wire didn't have any problem coming out of the mounting.
As I told you earlier there are going to be two plates which are going to be used for connecting the motor mount and the pellet feeder. I marked the center and drilled hole for the clearness of the coupler and in the second one made a hole to fit the bearing. Along with this I also marked the hole location on both the plates because later on, they are going to be used for a bolted connection for easy disassembling.
There is the third plate in between both the two assemblies which are going to act as a barrier and prevent the auger screw lifting movement which I noticed in my first few attempts.
If that thing happened then all the force went straight in the motor and it has to bear two forces one is rotation and the second is this pushing force. So this piece is absolutely mandatory. I welded a piece to the motor mounting assembly and a second to the feeder. On the feeder side, I use the bearing to lift the feeder so that the bearing remains completely flush to the surface and that the barrier plate doesn't interfere with the rotation.
Once the welding work is finished with the help of file and flap sander flush smooth the surface. Later on, onto the marked position, I drilled some holes and then tapped them with an m4 thread tap. Onto the motor mounting assembly, the holes do not contain threads. To mount the entire assembly I need something along the sides so that I am able to mount it onto the CNC. For this, I use a 30 mm wide strip of aluminum and then weld it along the sides of the motor assembly.
During the welding, I placed it onto a flat piece tack weld first and then made a complete weld at the back from there after making a complete weld onto one side. During the welding, it's good to have separate brushes but I kept contaminated the surface with other metals and I think that is also the main reason for bad welds. So if this is happening to you make sure to have a separate dedicated brush for cleaning aluminum.
Later on, I cleaned up the welds and made them uniform and used grit sandpaper to even the scratches. My initial plan is to hold the piece with a grub screw but I noticed that the amount of force made by the motor is pretty high and often with that force the heater block pops out from the feeder, therefore to counter that force I welded a metal strip around the pipe and then fusion weld with tig.
Now off camera, I made some groves so that it's easy to enter the heater block in and out. Since that needs to be attached with a screw that's why I need to make some threads in the feeder area.
At first, I was using an M3 screw but during further testing when threads failed I had to use the bigger M5 screws and from then everything is fine. Along with the bigger screw I used some brass washer custom made for this to reinforce the strip.
I have to do this work because I underestimated the motor force. But glad it failed and I get a chance to share this with you. That's why in my earlier statement I said it's good to use thick bolts if there are possibilities and areas under tremendous force. Being a completely custom-made extruder the nozzle also needs to be custom made, but due to lack of tools, I decided to go with my method.
Since I didn't have a lathe and broke many. Now during this, I made many different nozzles having different lengths but during this, I showed only one but the construction process is the same. Earlier I was using a regular m6 hotel but I noticed that due to the big inlet that the tiny opening of the V6 hot end gets clogged because it suddenly shrunk to a smaller size.
So to counter that problem I decided to make my own with an M10 Allen bolt. I drilled the hotend and tapped it with an M10 thread. Then I filled the cap with welding and then started grinding it. Once it gets grind down I give it a regular nozzle type shape and also the one which is easier to tighten with the help of a single wrench only.
Off-camera I made different inlet nozzles with the same outlet of 1. The one with an inlet diameter of 3 mm pays much more pressure onto the motor compared to 6 mm. And in the 10 mm dia bolt I found that if the nozzle inlet opening is 6mm then it's good compared to one with a 4mm inlet opening.
Once I drilled the hole at the threaded end with the help of a smaller drill I made another to the facing end but they definitely don't coincide with each other. I think if they made lathe that would give extremely good results. I have to say this part I really love the most. I never made an auger screw but after watching a couple of videos I thought that I could do this job. At first, I did this with a smaller shaft of 5 mm but due to the force some of the washers weldings got broken and ended up clogging the path and the feeder is no longer able to feed the material.
I also ordered a wood auger bit because it's not available locally and it was a 14 mm dia bit. I thought I could grind it a little bit and fit in my previous design but after watching each part fail I dumped that idea and made a bigger feeder with a bigger screw which was the end result. For the screw, I used m10 washers and a 10 mm stainless-steel shaft which was laying in the shop.
In my test, I found that the auger bit dia of the washer needs to be slightly bigger than the shaft, in my case I found that a 12 mm screw is sufficient enough to give me a good travel distance. I first drilled a 12 mm hole in the washer which I am going to use. Then I cut them from one side with the help of Hexa blade. After that, I hold half the portion into the vice and another half with the locking plier. Then with the help of a gentle twist, make a twist in the washer and this will also stretch it a little bit.
I think for a much better explanation it's good to see the video of how I made them twisted and kept checking them by inserting them into the vice. If it comes loose then stretch them a little more. Or you can also measure the opening also to maintain consistency. Once I prepared a bunch of these washers then I started the welding process.
One by one I aligned them and then welded them together. Once it's done. I secure the top and the bottom spiral to the main shaft and after that.
With the help of a hammer and chisel make them look uniform. I knew that I could use an auger drill bit but I thought this would generate much pressure compared to a wood auger because of these spirals. Once the bit seems to be uniform I start the complete welding process. Once the screw is made it's time to give it a look of a real screw. First I started grinding it onto my belt sander since the surface is flat it will keep the entire screw flat as possible it could be.
Then I hold it inside the drill bit and then with the help of foredom and angle grinder start shaping it. And I myself get amazed to see how well this came out.
One thing I found out after using it to polish the entire screw. That will help to pour the material without any friction and hopefully be able to save some of the motor energy. The two most important components include the stepper motor that drives filament at a consistent rate, and the hobbed bolt or shaft that grips filament and keeps it in place during extrusion.
There are two main types of cold end setups, including direct- and Bowden-style cold ends. Direct extrusion simply means that the cold end is located directly above the hot end. In the simplest terms, direct extrusion is good for most filaments, but is particularly good with flexible filaments and retraction.
Bowden extrusion separates the hot and cold ends of the extruder, locating the motor and hobbed mechanism onto the frame of the 3D printer instead. Without the added weight of the cold end, the hot end is free to move more quickly, which aids in printing speed.
Typically, most people prefer direct extrusion for its superior retraction and filament compatibility. This is where the magic happens. Solid filament controlled by the cold end reaches the hot end, where a number of components heat the filament to liquid form.
The heat block, heat sink, thermistor, heater cartridge and a few other components work together to precisely heat your filament to liquid before extruding it from the nozzle.
This is also typically where most extruders fall short. If the hot end is lined with insulation tubing, like PTFE, it limits the number of filaments you may use. Upgrading from the stock PTFE hot end that most printers come with to an all-metal hotend or even just a nicer, more precise hot end, makes all the difference in print quality and fixes a lot of problems like clogged extruders and print imperfections.
Although technically considered part of the hot end, we think nozzles deserve their own category. The two main points to consider when choosing a nozzle are nozzle-point diameter and construction material. A wider nozzle prints thicker layers faster.
A thinner nozzle point prints smaller, more refined layers at a slower pace. Be sure to consider filament feed speeds, as well as hot end temperature, when changing nozzle diameters. The other consideration is nozzle material, and here you have a few choices. Moving on, you can find nozzles made from higher grade metals like steel or tungsten carbide, and even nozzles with ruby tips to help withstand printing with abrasive filaments.
Extruders are largely responsible for the quality of your models. A good extruder feeds filament at a steady, controlled rate while maintaining precise temperatures during a print. Print accuracy improves and post processing becomes minimal with a good extruder.
So what should you look for when buying an extruder upgrade? First, make sure the extruder you want is compatible with your machine. Some 3D printers use proprietary extruder setups, while others use common, interchangeable extruder builds. Check the dimensions and electrical compatibility of an extruder before purchase.
Next, look for equipment from a reputable company. It costs more to buy from a brand like E3D or Micro Swiss, but you get what you pay for.
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