Hello Everyone Maintaining the theme of my portable charcoal furnaces, shown here, http://forums.thehomefoundry.org/in...-melting-furnaces-and-foundry-equipment.2211/ , I want to create a flask vibrator that I would be able to use in the wilderness, if necessary or by desire, such as on a camping or fishing trip. Below you will find a rendering of the next piece of equipment that I will be building for my portable foundry. I have 1-1/2 cubic feet of sand. I will use 1 cubic foot for my six gallon flask and the other half cubic foot as a base for my ingot pouring. In between each pour, I will shake out the flask, within the frame, and clean 1 cubic foot for the next pour, and when I am completely done, I will clean all the sand. All comments and suggestions are welcome Edit: It appears as though I will need to buy another bag of sand to completely cover the ingot pouring area.
I think the weedwhacker motor would last longer if you salvaged the flex cable off the weedwacker so the motor is vibration free and able to drive the cable to the off balance weight attached to the flask. It could also power the riddle to sieve the sand ready for another session.
I was thinking the same thing, but I am very eager to start some pours, and that would make it more complicated to get to my pouring. I am going back and forth at the moment. Yea, I had that thought also I think it will be a good setup for portability, not having to rely on 120 volts. I just remembered that I have two surplus mounted bearings laying around, which would be perfect for holding a rotating off-balance weight.
You're at 200lbs of (dry) sand without the apparatus. To each his own but I pack light to camp and fish, and not sure why you'd cast during a trip for either but.....in any case, not sure you'd need a sand pit, especially if just casting aluminum. Since it's a circular flask, assuming it's lost foam casting, I can't see any reason to vibrate more than the sand filled flask. Vibrating the extra mass of the entire apparatus will just make the task more difficult. There's no reason to power riddle lost foam sand. If it wont freely run through the screening, it's not suitable for LF. Best, Kelly
Kelly, I was just using camping and fishing as an example Basically, I meant away from 120/240 volt outlets and urban areas. As for the sand pit, it is for keeping my sand contained, so that it can be easily reclaimed after shakeout, and it also provides a moisture free safe area for pouring ingots, just in case of a spill. As for vibrating the extra mass, I agree, it is not ideal, but I believe that attaching the weedwacker engine to a wooden frame, will be much easier than adapting it to the flask, which may vibrate the flask too much, and I also believe that a weedwacker engine should not have any problem vibrating the whole assembly, but I could be wrong That is a good point If all goes well, providing all of my equipment works as intended, providing I have charcoal, and providing I have two cycle fuel, I should be able to cast metal in the middle of the desert, if wanted or necessary
If I run out of fuel or if my spark plug fouls, I always have a mallet or a hammer handy. The doctor must keep his hands in good working order Admittedly, I am no metal casting expert, but I firmly believe that all of my foundry equipment will work as intended (with the exception that I may need additional support at the top rim of my furnace). After seeing Kelly's castings, I also believe that besides having a well made pattern, some of the most important keys to having successful lost foam castings is having the patterns coated in refractory, having the sand well compacted around the patterns, always cast with a proper aluminum alloy, such as A356, and always pour at a higher than normal temperature, somewhere in the 1500~1550F range.
I have changed my mind. I will now be adapting the motor and vibration wheel to fit the flask. It shouldn't be to hard to accomplish and I think it will be a better setup, with just a crossbar going across the flask, and having two wingnuts for clamping purposes. The running motor all by itself, may be enough vibration for sand compaction, and if not, then I will add the vibration wheel. However, if I do need to add a vibration wheel, instead of using the flex cable from the weedwacker, I will use two v-grooved pulleys and a belt.
I have a new concept for my weedwacker flask vibrator In one of my previous threads, "Ideal Size For Dry Sand", I mentioned and linked to a 6 gallon pail, which I had bought at Menards, and intend to use as my flask. This pail came with a very tight fitting lid. I now intend to go back to Menards and attempt to purchase another lid, since they had a surplus of lids. If I cannot buy one, then I will just use the lid I already have. Anyhow, my intention is to now mount the weedwacker motor straight to the lid. Since it is such a tight fitting lid, vibrations should have no problem transferring to the pail/flask below. By using the lid, I already have a base for the motor to rest on, and the lid can be added or removed from the flask as needed However, I may need to add additional brackets for the motor and fuel supply.
FWIW, I think you'd find it far more convenient to just make a vibrating base you can set the flask on. It keeps the additional weight off the flask and also allows you to pack multiple flasks for pouring more than one mold. The flasks/buckets are also good storage container for the smelly LF sand. Here's a thread that might provide some additional ideas. It also includes my sifting/flask extension. I use pneumatic turbines for vibration because I have compressed air and they are compact and convenient. A 12vdc battery, motor, and a eccentric weight works too. http://forums.thehomefoundry.org/index.php?threads/my-new-lost-foam-casting-rig.516/#post-24052 Best, Kelly
Kelly Please don't misunderstand me and I do not want to seem hard headed, I agree with you 100%, however there are several reasons I am going down this path. The three main issues are my current health, time constraints, and my working environment. As previously mentioned in another thread, I just had double hernia surgery, so whatever I choose to do, I am limited to lifting 10 lbs. maximum, without additional assistance from another person. Due to time constraints, I cannot currently devote a lot of time to designing and building equipment. At this point, I need quick fixes, which will get my casts completed, as well as possible, with the equipment I have available. My working environment sucks My house is built upon an inclined piece of property and I do not have a paved driveway for doing any kind of serious casting. The are only two level sections of land on the property, one is my front yard and the other is 150 yards away from the house, near a river, and there is no electric down there or any flat concrete, just grass, weeds, and water. I do not want to start casting in the front yard, which may draw the attention of the neighbors, so I will be doing my casting down by the river, which is secluded and will give me plenty of peace and quiet for shooting a video and getting my work done. After watching one of your videos, which included the pneumatic turbine, I definitely want one but now is not the time At this point, I have everything broken into small weight portions, so that I can easily lift them, without worrying about reinjuring myself. I will be loading my foundry, tools, charcoal, and sand into a lawn trailer, and use a lawn tractor to get it all down by the river, which will probably take an hour to load and another hour to unload. It is far from being an ideal situation, but I want to cast and I want to cast very soon. As previously mentioned, I appreciate and respect your input, because you are obviously very talented and knowledgeable. I may end up wasting time and ending up with regrets, but I have tried to think it through from beginning to end, while seeking the least path of resistance.
Most of my projects are designed from scratch, but the more I get into this project, the more I am directed which path to take Years ago, my brother offered me a partial weedwacker, which was useless for lawn trimming, but of course I wanted the engine, so I accepted. During disassembly for this project, it became clearly obvious that someone without any mechanical inclination had disassembled it before me I think they were trying to fix the pull starter, because it had problems, which are now fixed. Anyhow, during disassembly I removed all of the protective covers, except for the breather cover. At which point, I began to think about adapting it to the flask, and how I was going to make it vibrate sufficiently. After removing the flex cable and considering my options for driving an off-balance weight, I finally came to the conclusion that adapting the flex cable would be a PITA. I then consider a pulley system and then started moving forward in that direction. Upon changing my mind of just vibrating the flask, instead of the entire sand reclamation area, I then came up with the idea of mounting the engine to the flask lid. Then it became an issue of adapting the engine to the flask lid First I had to modify the crankshaft, by removing the flex cable coupling, which gave me access to what I thought was the flywheel nut. The assumed flywheel nut was similar in concept to a wingnut, in that it had two arms extending outward from the center of the crankshaft, and these arms were fairly beefy. Underneath the assumed flywheel nut was a small diameter, short sleeve and an extension shaft in between going to the flywheel. Without further investigation, I am assuming the short sleeve was some sort of idler for the centrifugal weights used to engage the drive for the flex cable. So what I assumed was the flywheel nut, probably isn't and it's only purpose is to lock the idler in place, which means the extension must be some type of bolt with hidden threads Whatever the case, to make a long story short I decided not to modify this extension, and considering that it was a free engine, I decided to obtain my vibration by grinding down one of the beefy arms on the assumed flywheel nut So at this point, I now have an engine that will vibrate outside of the normal operating parameters. After over-complicating things and considering the adapters I would make for mounting it to the flask lid, I began to look at the factory covers which I previously removed, and wondered how I could modify them to make my adapter. After close examination, I came to the conclusion that no modification is necessary I will use most of the factory covers to wrap the engine back up, and the only true modification that I need, is to modify the flask lid Considering that I abstained from modifying the extension from the flywheel, I must put a hole in the center of the flask lid for this extension to pass through. It will not extend into the flask much, only a little, but I must put a sealed cover over the shaft, on the inside of the lid, to keep the sand inside of the flask and away from the engine. Besides that, I will be using four existing factory threaded holes on one of the weedwacker covers for securely mounting the engine to the flask cover. These four holes originally secured the flex cable housing to the engine shroud. After all of my planning and deciphering, I wish I had this plan when I started Either way, it won't be long and I should have a vibrating flask
It is also worth noting that I have decided to modify the design of my sand box (sand reclamation and shakeout area) to lighten my load a little At this point it should be obvious that I will no longer need a motor mount on the box Additionally, I have also decided to use 1 X 6 instead of 2 X 6, which should lighten the load considerably.
PROJECT UPDATE All things considered, I think the weedwacker flask vibrator should eventually work out well, however I have had a setback When my brother gave me this engine years ago, I should have tried to start it then and run all of the fuel out. As it stands now, the engines starts well, but it will not accept acceleration, so the carb needs a rebuild or a new carb. I have the carb disassembled, but during disassembly, some of the gaskets got damaged, so I definitely need parts at this point. Oh well, it will be nice to have it run top notch anyhow. Additionally, I have been putting a lot more thought into sandbox/shakeout area. I almost made a huge blunder, which would have resulted in a lot of unnecessary work. My initial thought was to combine the ingot pouring area with the sand reclamation area. By doing so, I would have needed to purchase more sand and I would have been cleaning all that extra sand. So I have decided to make two sand boxes, one for shakeout and the other for pouring ingots. As for the ingot sand, I will simply use junk sand that I have lying around and never clean it and I will be keeping all of my specially purchased sand, strictly for the flask. As for the shakeout box, I simply need one that is capable of containing 1 cubic foot with an upper level for vibrating and dumping the flask.
I absolutely agree...the higher temperature was the key to my success the last two pours, thanks to Kelly's advice.
I always say 100F-150F hotter than conventional sand casting. Like in conventional casting, parts with high surface area/volume ratios and thin walls need more heat. Most of my castings are 1/4" wall and 10-20lbs or less. For aluminum I typically pour at 1400F-1450F. If it's not a structural part or part that needs to have good air/water tight density, there's no doubt that pouring hotter will increase the rate of success at the risk of slightly more gassy metal from the higher furnace temps. With an electric, you may tend to suffer a little less from such versus fuel fired furnaces. Best, Kelly
SNEAK PREVIEW While waiting for my carburetor kit to arrive, which should be Tuesday, I decided to forego the waiting and start assembling the flask. In the photo below, you will clearly see the weedwacker motor mounted to the flask lid, with the throttle trigger assembly, lying in front of the flask. The throttle trigger assembly will be mounted to the right of the fuel tank, along the rim, however the aluminum base still needs to be machined a little more, so that it will stand plumb and accept a bolt. The motor kill switch hanging down from the motor, will be mounted in it's original location, within the throttle trigger assembly I am getting there
6 Gallon Galvanized Steel Flask With 2 Cycle Flask Vibrator Having A Throttle Trigger And Kill Switch Assembly So there it is The construction of this thing really made an extra snug fit between the lid and the flask. I have no doubt that the vibrations will undoubtedly transfer from the lid to the flask, without loosening up. During the carburetor rebuild, the welch plug on the Walbro was very resistant to removal and I damaged the carb a little, and I am uncertain whether it will affect operation or not. I have not tested it yet, because it is now too late in the evening, but tomorrow I will fill it up with fresh fuel and give her a go. Hopefully everything will be okay, with a simple adjustment of the high and low throttle. If not, I guess I will need a new carb. Either way, very soon I will be able to vibrate the flask efficiently in remote locations.
I'm drawn to lost foam because it's as simple as lost wax.. After you overcome the problem of imbedding the coated forms, and supplying sufficient vacuum, it gets pretty easy... By easy I mean if you can properly melt and pour the metal.. Kelly has solved most of the pouring problems by building the ceramic fiber pouring basin, and the detailing of the gating in his pours is priceless.. Much like yourself, I need to find a way to embed the pattern, and vacuum the container.. Your mounted motor seems a good way.. It also reminded me I have a small Minn Kota trolling motor that is missing a prop.. I'm thinking it could solve my problem with embedding the pattern.. Speed control, and vibration.. I have some other off the wall ideas for the vacuum side of the equation..
I chose my path pretty much out of necessity There are certainly much easier and less expensive methods of vibrating the flask, such as the pneumatic turbines suggested by Kelly. As for vacuum assisted pours, I highly doubt that I will ever attempt them. I am sure there are probably many situations where vacuum is necessary, but I am going to stick to simple casts, where it most likely won't be a key factor in producing successful casts. In addition to many other things demonstrated, proven, and documented by Kelly, vacuum is not always necessary in producing a quality aluminum casting. I must admit that his ceramic pouring basins caught my attention also, but I am certainly going to attempt some pours with the separable pressure heads that I created many years ago. However I am also certain that preheating will be a necessity to prevent rapid cooling of the molten aluminum.
