Step 22: Propeller Pt 3/4 - End Cone

The end cone is the attachment to the hub that makes the assembly more aerodynamic (or hydrodynamic) when travelling through a fluid. The base diameter is 2" to match the hub diameter and the height is 2" chosen to give a streamlined surface without being too long. The overall shape is a parabola what has been reloved around a central axis.

To build it a plug was machined from 1" polystyrene foam in two halves (Photo #1). 0.05" was left at the bottom to stop the parts coming loose on the last pass (Photo #2, I need to learn how to use the holding tabs feature in CamBam when I get the time). The two havles were then glued together using a thin layer of white glue after the swarf was removed with a utility knif and some 220 grit sandpaper (Photo #3).

To give the endcone a hard durable shell I covered it in a layer of fiberglass using the vacuum bag method using the following steps:

-I assembled the materials in Photo#4. I was working outside with good ventilation to protect myself from the fumes.

-I measure out the epoxy in to 2:1 ration of resin to hardener using the measuring cups. Shown in Photo #5 is 15ml of mixed epoxy, I ended up using 30ml.

-Starting the fiberglassing I wetted out a piece of fiberglass cloth 3"x3" (larger than the cone's base) onto the piece of waxed MDF. Photo #6

-Next I placed the foam endcone plug in the middle of the wetted fiberglass. Photo #7

-and draped a piece of fiberglass cloth over it. Photo #8

-I wetted out the cloth until all areas were saturated with resin. In Photo #9 I still have creases in the cloth. These will not lay flush even after vacuum bagging so small slits will have to be cut in the fiberglass overlapping the edges to smooth the material out.

-Next an oversized piece of peel ply is layed over the fiberglass. Photo #10

-And then a layer of breather cloth (Photo #11). I put an elastic band around everything at this stage to hold it all together while I made the bag. Photo #12

-I placed everything on one side of the vapour barrier (Photo #13) and doubled the plastic over sealing the edges with duct tape while inserting an air line from underneath the breather cloth and out a corner (Photo #14)

-The exit point of the air line is the hardest place to seal. I used plasticine around the airline as shown in Photo #15. This takes a long time to get right an is quite frustrating. The next time I vacuum bag something I will take the time to make a proper sealed connection using brass fittings.

- A vacuum is now applied using a pump made from this instructable. With this setup I can pull up to 25" Hg.

-After 24 hours to let the epoxy cure the part was taken out (sorry, forgot to snap a picture of this step), the excess glass cutoff around the bottom, a coat of primer applied and sanded to be flush with the propeller hub. Photo #16

-When I was happy with the fairing (more a function of the time I had available than the results, it could have been a lot better) I gave it a couple more coats of primer. Photo #17

-I cut out a recess on the bottom and using autobody filler attached a #6-32 nut and washer. I covered a 1/2" long #6-32 machine screw in Vaseline to prevent the autobody filler from sticking to it and assembled it through the mounting hole in the propeller hub (Photo #18). This makes it possible to remove the endcone from the top side of the hub. I later decided that removing it wouldn't be necessary so I faired the hub and endcone together with drywall compound and made them one piece.

-Using metalic autobody spray paint I had on hand (Photo#19) I gave the endcone/top hub assembly and the bottom hub three coats of paint followed by a layer of clear coat. Photo #20
<p>Very good project .</p><p>I am going to buld one for me.</p><p>Could you please post the list of NON wood parts please?</p><p>I plan to buy those parts on Ebay or banggood : any reference to them please ?</p><p>Thanks</p><p>iw2fvo@yahoo.com</p>
<p>Hello everyone ...</p><p>Thank you for everything you give</p><p>Of something precious I consider it a treasure trove of information that will help us to build less expensive for this wonderful product thank you <a href="https://www.instructables.com/member/nick2334/" rel="nofollow">nick2334</a> &amp; also <a href="https://www.instructables.com/member/diykiwibloke" rel="nofollow">diykiwibloke</a></p>
<p>Holy Smokes! That's a humungously accomplished 'ible nick2334! Do you rent out your brain? I can only imagine the hours you've spent in putting this tutorial together. Thank you - it's <strong>very</strong> inspiring and encouraging! Just off the top of your head, what would one need to make your CNC handle aluminum as well?</p>
<p>where can i find code of that </p>
<p>I am working on a similar project. But it's a laser cutter.</p><p>Neat project! </p>
<p>Hi Tim:</p><p>I am interested in making a cnc laser to cut clothes stacked, I would like to know how it was with the manufacture of this cnc instructive or if you have additional information.</p>
<p>I was planing on building something similar to this but I was using draw-slides. The project was stopped do to high cost if controllers and lasers. </p><p>Tim</p>
<p>Hi Nick, good job.</p><p>I haven't read through all the comments, yet, but since it's been over 4 years since you built this, (assuming the Apr '12 post date isn't long after completion), I wondered if you have done an assessment of the build, evaluated the actual performance vs anticipated/hoped for and how you would change v 3.0? If you have done an assessment, have you written/posted it anywhere?</p><p>Also, depending on where you live, you might be able to scavenge some components for building structure &amp; support for the axis rails, and other parts and pieces which could stiffen up the overall structure, given hard material capabilities.</p><p> I'm not up on CNC terminology, I intend on building a CNC router, which will be my first foray into CNC. It's a way down on my 'to do' list, so all I'm doing at this point is trying to get familiar enough to know what to grab when I'm scavenging. It will not be my first foray into building tools, though. I have built a number of fabricating machines. Most of what I've built have been re-purposed, frankenstein stuff, like the dual belt, 1 x 42&quot; sander I made from an old radial arm saw. I shortened the radial arm, connected to the deck mounts, used a single cogged belt sprocket to drive a custom dual drive for the belts. I used serpentine belt pulleys from a Dodge/Chrysler V6 for the belt rollers, (get the right ones from the wreckin' yard and they have replaceable roller bearings and a choice of lips/no lips on the edges of the face, (a mix works best). The platens, (the surface supporting the belt where the grinding takes place), are a design I 'pinched' from some commercially available narrow belt sanders. The base equipment has a square tube 'socket' like the better trailer hitches have, allowing different platens to be built for different sanding profiles: flat, convex, concave, etc.</p><p>I've been fabricating with wood, metals, stones &amp; plastics for nearly 50 years. For all you young guys, don't bother with grinders, get/build tools using abrasives. Belt sanders, drum sanders, spindle sanders give you better performance, less expense for a variety of grit, and much more accuracy.</p><p>Old table saw motors can be found with dual arbors, 1HP for $40-50. A pair of arbor extension/adaptors to std R &amp; L thread for ~13.00, and some thoughtful protection of the motor internals from grinding dust, and you have the equivalent of 600.00-800.00 industrial grinder buffer. If you have never used a 1hp grinder buffer, better hit the gym and work on your forearms!</p><p>The drum sander mentioned above is a jeweler's tool. Uses a 2.5&quot; by 6&quot; diameter abrasive belt you can buy for ~3.00. They are metal eaters! There's another design, (hard to find), which splits, and uses flat strips of abrasive cloth, (defective belts from a belt sander work great in these, and the gap where it splits is NOT noticeable in use).</p><p>I will never buy/use a bench grinder stone or a puny .25 or .33hp bench grinder, ever again. I put a small, (4-5&quot;) diamond grit saw blade on a Ryobi bench grinder I got at a garage sale a number of years ago, and turned it into a great fab tool.</p><p>The last question I have for you about your router, ( I eventually get back on topic), is have you tried any foam core PVC as a material? I've used it for proof of concept and prototype mock ups for a long time. It's a 'fast' material to work with, will hold threads, and has enough strength to make early stage working prototypes. Recently, though, I've been spending half my time in NY. My apt on LI is right down the street from a sign shop, and I suddenly have a near in-exhaustable supply of foam core PVC. The result has been I've discovered it is tough enough to use for structural material. The dump apt is scary, so rotted and dry-rotted, the 0.125&quot; thick paint on the walls holds up the old 3 story house converted to apts. I built a kitchen base cabinet completely out of foam core, scavenged doors &amp; drawers from street side trash. I mounted the drawer slides and hung the cab doors from the plastic. It won't last as long as particle board or wood, but it's waterproof, didn't need any finish, and is easy to cut &amp; drill. Plus, once you have it fit &amp; squared, you can glue-weld the stuff together with plumbing glue, and it essentially becomes the same as if you machined it from a 2 x 3' x 5' block of foam core PVC, with the added strength of the hard shell on two sides of all the individual pieces.</p><p>I worked at a mobile home factory when I was 18-19, my PVC cabinet is tougher than a lot of stuff put into mobile homes, OR sold by Ikea! Find a sign shop, and see what you can scavenge, they'll be glad to give you what will go in the dumpster, otherwise. A lot of what is made from plywood, could be made with foam core, and gain increased rigidity.</p><p>Again, good job. Would love to see a look back on v.2.0 from a Monday morning QB perspective.</p><p>Thanks,</p><p>GeoD<br></p>
<p>Hi, I've added your project to <em style="">&quot;</em><em style="">The Ultimate Collection of DIY Workshop Tools</em><em style="">&quot; </em>Collection</p><p>Here is the link If you are interested:</p><p><a href="https://www.instructables.com/id/The-Ultimate-Collection-of-DIY-Workshop-Tools/">https://www.instructables.com/id/The-Ultimate-Colle...</a></p>
<p>Wow that spindle is just perfect, I will definetly use that in my cnc :) Do you happen to have any video of the machine running, I am curious about sound levels :) thank you for the excellent instructable :)</p>
<p>Likewise the Shapeoko3 has beefy aluminum rails and steel plates for the router. I love DIY as much as the next guy, but if the money is the same, I'd rather end up with a more solid result.</p>
<p>I'm looking at the X-Carve from Inventables. It comes with a Dewalt 611 trim router for $1600 delivered to my door in Canada. Nice build but I think I'll but the kit for the X-Carve.</p>
<p>Hola, tienes un dise&ntilde;o del equipo mejorado actualmente?, costo?</p><p>Tiempo de entrega?, costo de env&iacute;o?, requerimientos d hardware y</p><p>software,? etc.Estoy en M&eacute;xico, D.F</p><p>Tel.52- 5555-27-21-21</p><p>movil. 044555-4196924 Gracias.</p><p><br></p>
<p>I see this was made 3 years ago any improvements since then ? and could you use nema 23 with this build </p><p>thankyou</p><p>Richard Westerfield </p>
<p>Anyone know how to size/pick the timing belts and pulleys?</p>
<p>Approximate cost?</p>
<p>What driver board did you use? </p><p>Thanks</p>
<p>Great Job Nick.</p>
<p>I built one, cost $750 and has a cutting area of 3'x3'x4&quot; you can see my videos in Youtube under my name bubalettow</p>
<p>Why you worked in the unit inch?</p>
<p>i wonder where you put the usb or any communication cable to communicate between the CNC machine to the PC *i assume this CNC controller is PC-based. and if there is, where di you pluh that cable on the machine? directly to the stepper motor or add an additional built-in controller. Thanks</p>
<p>Excelent work</p>
<p>Hi Nick, this is such a good instructable. I have a little question if you don't mind. I noticed that in the plan of left-right gantry sides one of the holes (where you attached limit switch) is missing. Do you get that hole later after installing everything or you just forget to draw it? Or maybe its position is given different on the plan?</p>
<p>Is this 130 oz-in unipolar rating of the stepper motor? And will the dimensions change if we use any other motors....</p>
<p>Hi everyone, I'm getting a lot of messages asking if I have a 3d model for this project. Unfortunetly I don't. I only have the 2d dimensioned drawings attached in the steps.</p>
<p>amazing work </p>
thanks thanks thanks .... so much... <br>ill try its
great article!!! very informative!!!
Just to let everyone know, i am working on a sketch up of this project (minus the custom sled hardware) to be made with standard length aluminum extrusion, and all 3/4mdf (for ease of construction and rigidity). if you would like a copy let me know <br>
A great project! I would like to have access to your latest mods and CAD drawings. <br> <br>Thank you, <br>
I'm interested in this sketch up. I'm about to rebuild my CNC.
Here is a list of my modifications so far. I have not finished the mock-up so this is not the final list <br> <br>Moved mount for y axis motor up 4 inches <br>changed gantry assembly for moved motor mount <br>replaced bearing block with alernitive gantry sides <br>shortened overall gantry height for added clearence <br>modifed track for easier assembely <br>modified ider bearings for timing belt security <br>modified base for new tracks and timing belt tensioner <br>changed belt tensioner to 3/4 mdf
I'm looking forward to seeing your modifications. My one suggestions would be to avoid using MDF if you can. I used it on my first machine for cost reasons and found it to be less than ideal as is its much heavier and not nearly as stiff as ply.
The reason that I wanted to do this in all mdf is because it is half the price of 3/4&quot; ply. This is also just to be able to have a machine that i can use to cut more sturdy, expensive woods, such as the 3/4&quot; ply or other soft lumber (because a 1by is actually 3/4&quot;). <br> <br>These modifications are only for a first machine to make the better machine, not for a really long term use (put it together, make new parts, replace, repeat) <br> <br>:)
i would like to know what type of sepper motor make and model you used and is your roter large enough to use on 1/4 steel if not what would you recumend ? <br>thank you <br>richard westerfield
Richard, this machine is not even close to being stiff enough to machine steel. If you want to machine steel you will need to use a proper milling machine such as a Sieg mill. There are a number of tutorials online on how to modify one for CNC use and this website (http://www.littlemachineshop.com/Info/minimill_compare.php) has a great breakdown of the different models sold by distributors.
+1 for Shigley's!! That's my bible.
you are too good man. can i use stepper motor with 80 oz in( 0.6 Nm) .will it work or not. <br>thks
You jump so quickly from hardware to software. Could you give more information how you work to load your designs to the machine. Also which motor drivers do u use? <br>Thank you so much
The Instructable was meant to focus on the hardware as software could vary depending on personal preference. In general I used Rhino 3D for the CAD work, exported as an STL which was loaded into CAMBAM. From there I generated G-code which was read by Mach3 and sent to the Hobby CNC driver board. Let me know if you need any more information.
Thank you for this instructable! I'm planing on building a similar one with some modifications on the Z axle to have a little bit more depth and I will be using a dremel 4000 as the cutting unit. you mentioned metric units...do you, by any chance, have the metric drawings for this? I am converting everything, but I then have to match it with commercial sizes and if had already done that... ;) <br> <br>another question...have you tried to cut either copper or aluminium with this machine? do you recoon it is stable enough for that? <br> <br>once again, thank you for sharing this ;)
It shouldn't have any troubles cutting aluminium using a dremel as long as you get a high quality double fluted, spiral, carbide end mill. I have quickly found that the cheap HSS cutter I have are limiting the machine's performance. As for metric drawings all I have are the imperial ones. As long as everything is sized as the closest metric alternative it should all work out with only a few holes needing to be re-bored larger.
that's what I've been doing ;) maybe i'll just cut all the parts in imperial sizes and make all the holes in metric size because it's easier to match with screws and nuts ;)
I want to built a 50&quot;x50&quot;x@5&quot; high routing capacity,what is yiou recommendation regarding the electronic and motor,i built several composit airplanes 4 passenger and i am designing a twin with Mazda rotary rx-8 engine. <br>First i get quote from several place with a big CNC router and they came up about$11000 to do the fuslage half mould from polystyrene. <br>This is why i started to look building my own from aluminum rectangular structure. <br>i do design with Rheno and any recommendation can be appreciated,my experience in router is very limited but i am learning very fast and i dont see any <br>problem of building the structure
The motors will depend on the weight of the gantry. Cutting polystyrene won't give much resistance at all so as long as the motors can move the machine it will be able to cut. The folks over at gecko drives have a good write up on how to estimate the size motors required (http://www.geckodrive.com/support/choosing-a-drive.html).
I was going to build this over the summer with my father, he used to sell CNC machines and he has always wanted to own one. We were wondering if this CNC Control Board would work with your instructable. <br>( http://www.ebay.co.uk/itm/CNC-Kit-3-Axis-Stepper-Motor-Driver-Nema17-12V10A-220V-/270900965305?pt=UK_BOI_Industrial_Automation_Control_ET&amp;hash=item3f12f4afb9 )
The only issue I see with the board is the 62 oz-in steppers. The motors I used are 130 oz-in and I have never noticed them stalling or loosing steps but compared to other builds I have seen, they are on the small side. The axes have a little resistance to overcome but not enough that I wouldn't expect those motors to be able to move the machine so the question is how much torque is left over to do the cutting. If you want to cut platic and wood I don't think it would work but if you're interested in cutting foam and milling PCB's I reckon you could get away with it. <br> <br>On another note, it is the first time I've seen a diver board being run off of a switch mode power supply without a few hefty caps to smooth things out. I'm not terribly knowledgeable on the electronics side of things but I would imagine that performance would be reduced compared to that if it was run on a beefier linear supply.

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Bio: Engineering is more than a job, its a lifestyle.
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