Primitive Archer
Main Discussion Area => English Warbow => Topic started by: Inuumarue on March 22, 2011, 03:14:54 pm
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Is ~500 grains / 30g too much for a tudor style point? I may have overbuilt mine.
Adam
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It is a bit, ive got one of hectors that is 12g and others that are well made upto 16g
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Ha! well it seems I've way overshot my goals.. guess i'll have to hollow it out a bit. I've left the walls of the socket fairly thick, so I should be able to remove some material from there if nothing else.
Thanks,
Adam
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I believe (and I'll check just to make sure) there are two Tudor bodkins in the Museum of London. If memory serves me correctly I think they were cataloged at 18 grammes each. So, Ian your 16 gramme Hector Cole heads are just about spot on.
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If it helps the head is 2" long the socket 1.25" deep and the blades are 1.5" from the tip the wall thickness is less than a 1mm about .75
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Well darn. My socket is far too short then. My head comes out at 1 and 7/8ths long, 3/4ths from blade to blade and 1/2 outside diameter with a wall thickness of about 1/16th (all in inches) I'd hazard a guess that the blades are about 1/8th thick. I should loose some weight grinding in the bevels on the blades and smoothing things out, but I doubt it's 10grams worth. My socket only goes in about an inch. Doesn't help the weight that its a brass head either.. (I know it should be steel, working with what I have at hand)
Could you post a picture of your head? I'm a bit confused by the blade measurement you gave.
Heres a link to a photo of the part I'm working with, and some back story. If you see something drastically wrong with the shape please let me know.
http://paleoplanet69529.yuku.com/topic/43008
Adam
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That looks very interesting casting heads, I wonder if the heads will be strong enouth to take an impact.
My heads (http://i270.photobucket.com/albums/jj93/iansturges/bodkin002.jpg)
This is hectors head (http://i270.photobucket.com/albums/jj93/iansturges/bodkin003.jpg)
The album for you to look at http://s270.photobucket.com/albums/jj93/iansturges/
And yes sorry I should stick to one measuring system.
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They look messy when blown up to that size.
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hmm, I'm going off of these points, no clue who forged them.
(http://i783.photobucket.com/albums/yy120/PaleoPlanetGallery/Arrowsmith%20Gallery/Arnes%20Arrows/Medieval%20Poplar%20Arrows/Poplar17.jpg)
I'm going to go ahead and cast them as they are, all 33grams. the thickness should make for better castings. I'll grind away a fair bit when they're finished. For what I know, my 10:1 ratio of wax to brass may be a bit much. So they may come out closer than I predict. If its still too much I'll have to hollow out the insides.
As for holding up to impacts, I have a lot more faith in the gunmetal brass than the cast grey iron we have in the second furnace. Should be able to see if the rubber molds turned out by tomorrow. and move onto making copy waxes by Thursday. I'll weigh a few of them and get an average.
Adam
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Those heads look familiar and well made I am surprised that they are that heavy, please keep us up to date with the casting attempts I would be very interested in a way of mass producing tudor bodkins.
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Inuumarue ,
From looking at your casting photos the thickness of you taper seems excessive as does the strengthening ridge running from the taper to the tip and the width of the blades appear to be far wider than the base diameter of the taper, which isn't the case for the forged ones shown, even for those you posted pictures of. I would suggest that all of these are the reason for your heavy weights.
Craig.
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Thanks Craig.
I had a bit of trouble carving the wax, the first time around it failed completely because I made it too thin. And that was just carving wax, not pouring metal. I'm debating between casting them as they are and altering them later, or altering the waxes before we coat them. Either way I think your assessment it spot on. I'll try and alter the original wax tomorrow to see how far I can edit the wax without it becoming too weak. The blades on the original were added on, rather than carved out, I hope having the head as one solid piece should help carving them thinner.
Ian, If all goes well, this time around I'll try casting some at finished shape for minimal grinding. If they turn out, I'd be happy to look into getting a large run made in steel. But one thing at a time, I have a nasty habit of getting ahead of myself.
Adam
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Craig, Ian. How does the new one look? I've gotten its weight down to 2 grams, which should come out around 20g once cast. There is still a bit of extra material in the blades, so I may make 18g by the time all is said and done. It's next to a wax fresh out of the mold for comparison. I've been pondering over how much I can remove before it becomes a problem with casting. It seems that these will take a fair amount of finishing after the fact but I'd rather put in the work afterwards than cast a whole dozen full of pockets and coldshuts.
(http://i19.photobucket.com/albums/b152/inuumarue/arrow%20asimbly%20and%20tips/IMG_0244.jpg?t=1301021465)
Adam
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That looks spot on for a Tudor bodkin, (the less weight the better for a head) im really looking forward to seeing the final product.
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Hi Inuumarue,
As Ian says this one looks much better and with a bit of judicial finishing it should make an excellent final product. Well done!
Keep us posted as you progress through to the finished head, and don't forget lots of photos.
Best of luck
Craig.
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A lot of the same today. Made some more waxes, the light brown ones. We ran out of the old wax and started on a new batch of harder wax. The new stuff takes forever to solidify, but when it does its as hard as a rock. If I time everything right i can pull it out while its still a bit pliable, straighten everything out and then dip in cold water and harden it for good. This brings the total count of heads to 9, theres one in the mold, plus one near finished dimension wax. So, three more makes an even dozen. I was hoping to make two, but I'll take what I can get.
(http://i19.photobucket.com/albums/b152/inuumarue/arrow%20asimbly%20and%20tips/IMG_0257.jpg?t=1301445972)
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Looking very good, how thick are the socket walls?
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About 1/16th of an inch. From everything I've gathered its the thinnest I can go and still get fairly reliable results in metal. They end up a few hairs thinner when the metal shrinks and then a few more after finishing. I'll be the first to admit that I might be overcompensating thicknesses and bulk, but for a small run I want to make sure they all turn out. Just means i have a few hours of finishing ahead of me.
Adam
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Inuumarue,
Do you have any tools that will allow you to drill/grind out the socket walls? As Ian suggests they still look a bit too thick. If you cannot thin them, then no matter you can still fit them flush to the shaft outside diameter by making a thicker step down from the outside of the shaft to the beginning of the taper. One of the best tools to achieve this step is a small pipe cutter, take it slow as too much of a cut may cause crushing of the shaft. Please note the pipe cutter is used only to mark the position and cut the depth of the step all wood removal will need to be done using other means, knife, file, rasp, grinder etc.
Best of luck with the venture.
Craig.
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Craig,
I have a few tools that may do the job in brass. If I want the socket thinner I'm going to have to do it post cast rather than before. The wax itself has a bit of trouble at the ends of the sockets, I'd hate to have similar problems in metal by going to thin. The pipe cutter trick just blows me away, I have plenty of them laying around, it never crossed my mind to use them for arrows. As it stands now, I get the feeling that I'll have more than enough grinding to do to true things up and get down to weight. A little more to thin out the socket may not even be noticed.
To all,
Sorry for my absence, classes and the general repetition have kept me from updating. Not much has changed from the last time I posted, though i now have a full 2 dozen heads with a few extras in case something goes wrong. The only new development has been adding the heads to a tree. The trees are shared between multiple people, my castings will take up the bottom half of two of the four sides of the tree, when others are finished and add their waxes to the tree, the tree can have the ceramic coating put on and then we can make some more progress to casting. I'll make sure to get you guys detailed descriptions on that part. But here we are today.
(http://i19.photobucket.com/albums/b152/inuumarue/arrow%20asimbly%20and%20tips/IMG_0259.jpg?t=1302398783)
Should have everything attached and all the little runners put on by tonight. Also, the full story is on the link I posted earlier if you all would like to follow along there as well.
Adam
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Well, the process is dead in the water for a little while. Our suppliers have been pulling the "it will be there this week" for the past month. So we have finally hit the point of the process where we can go no further. Our wax supplier has not delivered the wax for the gating and our furnace supplier has not delivered our furnace. The wax shortage does not affect me for the most part, my parts were made with their sprue pre-attached, and I made my own runners and vents by hand. It does stop the rest of the class from moving from wax parts to casting tree. What has me stopped personally is that without the furnace I can not build up and cure the ceramic shell, or melt out the wax afterwards. So with any luck and some stern phone conversations we have a slightly more sincere "it will be there this week" that may follow through. Either way, this pushes back the casting date to the end of April. So I'm sorry to say it, but it doesn't look like much will be happening until late next week. Sorry for the delay.
Best Regards,
Adam
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Thats a shame about the delay, I am intrigued to see them in action. Will you be making more to sell as it is difficult to get good light heads for heavy bows.
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Ian,
The arrow heads from this thread will not be for sale. The delay has given myself and my peers some serious down time, of which most have put to good use refining their parts. There are a select few who have taken the opportunity to mass produce their parts in order to sell them down the road. To be honest I am fairly angry and disappointed with this course of action. The course is fully funded by the university and the fund donated to the foundry program itself. In fact this course is the most expensive course to run per student offered by the university. These funds are not self replenishing and most of the expenditure is in raw materials, be that wax rubber ceramics metal or electricity. The amount of these materials that my enterprising peers are consuming strikes me as selfish and quite frankly greedy. I feel that this is a unique opportunity that we have been given and the fact of the matter is that those peers that wish to profit have given nothing back to the program. In short, I have an ethical objection to profiting from this course.
That being said, I am willing to do two things for anyone interested. If the run turns out well, I will be willing to send off three heads to a few people to test for the cost of postage. The number of people will depend on the number available. I plan to keep at least six for myself and three to be finished mounted and returned to the foundry for display as a small token of gratitude. All I expect in return is a general review. Let me know what you guys think of the part quality, feel, and performance as I do not have near enough experience to judge for myself. Hell, if you wanted to pass them around, the more the merrier.
The second part. If interest is high enough I will discuss with the powers that be doing a few runs to be sold. I will try to negotiate it to be a cost of materials, plus a % to be given to the foundry as a donation. As I would perform the bulk of the work, there will not be a labor cost associated with it. My thoughts are that anyone interested may purchase the amount of heads they want, and pay for their portion of the costs. Then if you wish to sell some of your's you may add your profit and sell as you wish. I will look into casting near net for those batches so that finishing will be minimized. It may also be possible to cast those runs in a stainless steel rather than brass. That being said, it all rides on approval from the foundry and I can not make any real promises.
My hope is that as long as both sides profit for the better it may be possible to establish a healthy business relationship that could last well after I graduate. The thought of selling has cross my mind, and as you can see I've invested some thought into it. The bottom line is unless the foundry program benefits from it I will not sell anything. I hope you can all understand where I am coming from.
Adam
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I understand your problem, its very honest of you not to spin this as a venture then, if the heads go well It may be a good change to pay something back to the project. That's a good idea to have a set mounted for display. I would love to test one for you a mix of distance and armour tests. If it goes to plan I could post on the EWBS forum about ordering a big batch for everyone to make it worth your time, but as you say to early to tell yet.
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Thanks Ian.
If the plan comes to fruition then the EWBS's support would be amazing. I doubt that the professors and staff within the foundry would mind, but I expect that whomever handles money flow for the university might want to weigh in on the plans. I will keep anyone interested in the loop as I look into it.
As for the mounting I was planing on three full taper poplar shafts, 1/2- 3/8th, with horn inserts and bound fletches. I was going to make a simple stand from cherry to display them. But everything aside, I have to get everything to cast first. If you guys are looking for more the link I posted early on has more detail of the process.
Adam
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They're excellent looking heads Adam, very nicely done.
Ian, wouldn't the heads have to be hand forged to be eligable for an official EWBZ flight shoot? Having said that I wouldn't mind having some if they they're affordable.
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You are right that they need to be hand forged, but I was thinking for general use and target, there aren't many good quality target heads at the correct weight.
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Well, I have a heap of bad news and a bit of good. Bad first. Casting is postponed until late May thanks to the constant delays and excuses we're being given. The furnace people have come through for us, and it is on its way to arrive early next week, however its a bit more complicated of an installation than we realized. So that takes up another week of running gas and ventilation and state inspection, plus two days of training. The wax guys seem to have fallen off the face of the earth. That with finals in two weeks when professors are not allowed to ask us to meet unless it is for a previously scheduled final. So that pushed us back to sometime after finals in the later half of May. More bad news, I can not use any of the university equipment for profit. Like I expected the accounting department had something to say. Basically there has to be pricing system in place before anything like that can happen. And then from what was explained to me, it would be more expensive due to the high cost of the equipment.
Good news, I have found an alternative plan. I have some contacts in the CNC department that have a pricing system in place. I'm going to draw up a CAD pattern and core mold for sand casting and have them cut out of plastic. Then I can make these puppies in a sand casting set up in a higher volume with more consistent results and closer to final shape than what I am working on now. I've also been given a few local foundries that would be willing to work out a deal on the casting costs. So if the interest continues there is still hope at whatever volume is required and near any metal you guys could want.
Adam
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this sounds interesting, i might be interested in a few
noel
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Inuumarue ,
Sorry to hear of your delay problems.
Ian.
I was thinking for general use and target, there aren't many good quality target heads at the correct weight.
What weight are you after? I bought some fairly decent, (needed a bit of work but not much) 1/2 inch dia cast Tudor type bodkin heads from Richard Head Longbows.
Just weighed 6 of them the weight ranged from 310 grains to 350 grains with most in the 325 to 335 grain range.
Regards
Craig.
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I have a few of those at the minute but by last batch were a bit to heavy most being 340grains which is just to much, I have heard of people drilling them out to reduce the weight, I will have to give it a try.
Thanks
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More bad news. Last weeks east coast storm took out the power to the foundry for about an hour or so late at night. No one was allowed to go to the foundry due to the tornado warnings in our area so things go downhill from there. When we lost power our two slurry mixers, which hold our ceramic coatings, shut off. The ceramics settle out of the mix rather quickly and the polymer binders start to react when not stirred. So both slurry mixers are now tubs of fairly expensive concrete. To add insult to injury, the safety switches did not activate when the power came back on and the motors for both mixers are completely burnt out. In fact we consider ourselves lucky to not have lost the building as the whole building was filled with smoke the day after. So yet another delay to add to the list... I will let you guys know when things start shaping up.
Adam