D.S. Adams Posted November 2, 2022 Share Posted November 2, 2022 New here, glad I am surrounded by some experienced people here. I have been forging for about 2 and a half years and have made and heat treated successful knives from 1084, and 5160, I have started challenging myself with a generic medieval crossbow and steel prod and have finished grinding tried hardening and tempered and even fired some bolts accurately from the assembled crossbow. However, unlike the 1084 I don’t think I’m hardening the 5160 like I can with the 1084 as files do not skate off the 5160 before or after tempering cycles. I have constructed a expanded volume forge from wood stove tubing and casted refractory cement that I intended to replace my last two forges (2 40 psi propane burners)to have enough space for the prod and other wider objects. I have a vertical quench tank of 43 inches tall and 6 1/2 inch tube diameter that replaced my 4 inch diameter quench tube. I have evenly heated the prod a little past non-magnetic and quickly and as accurately as I can plunged it into the oil and agitated it best I could. I’ve tried pre-heating the oil to 130f before quench but I am not able to evenly heat the oil in the tube all the way down/ evenly at the moment. im considering an immersion heating/ boiling element. precision temperature control/ soaking steel pre-quench is impossible for me at the moment. I’m not worried about tempering it because it fits into a conventional oven. The prod sits in the forge out of direct flame and is heated by ambient heat inside the chamber from the flame. What am I missing/ misunderstanding / doing wrong here? quite frustrated my first first steel crossbow slowly loses power due to unsuccessful hardening. Happy to provide forge internal and external dimensions as I’m not sure if I straight up decarburize from to much heat / too little space in forge/ uneven heating, I do have minimal scale when at or above non-magnetic? help! Thank you Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted November 2, 2022 Share Posted November 2, 2022 Are you sure its 5160? Some suppliers like Admiral steel didnt always send what was ordered. They got me once when I ordered L6 and they sent something else, a low alloy called 8670m How are you hardening it? you didnt say Quote Link to comment Share on other sites More sharing options...
D.S. Adams Posted November 2, 2022 Author Share Posted November 2, 2022 The steel is said to be 5160, ordered from Jantz supply. I am quenching in corn/ canola oil, i cannot afford dedicated quench oils currently. Thank you for replying Quote Link to comment Share on other sites More sharing options...
Irondragon Forge ClayWorks Posted November 2, 2022 Share Posted November 2, 2022 The file should skate after quenching, not so much after tempering. At what temperature and time are you tempering it in the oven and is the ovens thermostat accurate? Quote Link to comment Share on other sites More sharing options...
D.S. Adams Posted November 2, 2022 Author Share Posted November 2, 2022 385f for an hour for 3 times and cooling in the oven after each. This is experimental with addition of inexperience with hardening and tempering longer pieces. If I had hardened it I didn’t want it to be too brittle and destroy the work or too soft after after tempering and not hold the draw weight because of the nature of its intended use. I should have file tested post quench but I was eager to clean off the oil and go to tempering. I am not totally sure if oven temperature is exact and I intend to get an accurate thermometer to stick inside. The oven is new bought within 3 years ago. Quote Link to comment Share on other sites More sharing options...
Irondragon Forge ClayWorks Posted November 2, 2022 Share Posted November 2, 2022 Our propane fired range & oven is off on the oven temperature by 50° F according to the good oven thermometer. I usually temper 5160 at 400°F for an hour. To reach that temperature I have to set the ovens thermostat at close to 450° F. The way I warm up the canola oil is to heat about a foot of 1 inch stock to orange and place it to the bottom of my quench tank. Of course I have never made a crossbow prod so my info may be all wet. Quote Link to comment Share on other sites More sharing options...
George N. M. Posted November 2, 2022 Share Posted November 2, 2022 I have always been hesitant to forge, harden, and temper a cross bow prod because if it fails when drawn it can have some really nasty results for the archer. It sounds like you have the opposite problem, that the prod is losing its "springiness" over time. This may be the result of over tempering. That is, drawing the temper too far back from the original hardness and brittleness. I suggest taking some samples and temper them at different temperatures and times to see if there is a difference and what is the optimum treatment of retaining maximum springiness without brittleness. BTW, is your release mechanism the traditional rotating notched nut type? "By hmmer and hand all arts do stand." Quote Link to comment Share on other sites More sharing options...
D.S. Adams Posted November 2, 2022 Author Share Posted November 2, 2022 Thank you. Yes, rotating nut cut and ground to shape from 1018 mild steel, I thought of other traditional nut materials or stronger steels but decided to go with an easy steel to grind for convenience, the trigger is of the medieval type and is a single axle trigger and forged to shape from 1084 as well as the stirrup Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted November 2, 2022 Share Posted November 2, 2022 you still have not told us hot hot before the quench Quote Link to comment Share on other sites More sharing options...
D.S. Adams Posted November 2, 2022 Author Share Posted November 2, 2022 I have no way of knowing aside from checking with a magnet for reaching critical temperature or by obtaining a high temperature contactless thermometer that I’m in the works of getting. Thank you for your patience Quote Link to comment Share on other sites More sharing options...
Frosty Posted November 2, 2022 Share Posted November 2, 2022 Have you talked to a spring shop about heat treating a spring? It's nothing like hardening and tempering a knife blade which is the general process you're following. Lastly to be sure of what you're using for the prod get a drop from a spring shop and ask THEM how to heat treat or have them do it for you. to bandwagon with George heat treating a steel prod yourself opens you up to some seriously ruinous litigation. Imagine if you will, cocking your weapon and the prod fails near the center. It then straightens pivoting on the string while the other half snaps straight and throwing the broken half about 1/3 the throw distance of a bolt. If you have a spring shop heat treat it someone ELSE'S insurance will handle it if there's a catastrophic failure and someone is injured. You or someone watching 50' away. A few of us in high school metal shop made cross bows with prods aluminum bow stock until the school admin got word and that was it for bows even. All but the first two cross bows which had gone home already were confiscated, student's can't be making deadly weapons you know. Fuddy duddys! <Sigh> It's a fun project just be REALLY careful! Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
D.S. Adams Posted November 3, 2022 Author Share Posted November 3, 2022 I have considered that to be a risk as well as being warned by some, I am not a student or minor thankfully and am not currently involving anyone in the potential test or proximity to it. I do not or have not intended to take on this project without considering risks or liability involved with the amount of potential energy haha Unfortunately I am in a mountain town and do not have a spring shop. I genuinely appreciate the responses and insight. Quote Link to comment Share on other sites More sharing options...
George N. M. Posted November 3, 2022 Share Posted November 3, 2022 I have always thought that a sleeve of heavy leather put over the prod would help contain any shrapnel in case of a catastrophic failure. Possibly laminating heavy leather on both sides of the prod would work too. Besides sending sharp pieces of metal in the direction of bystanders I can see a scenario where the string and a sharp piece of metal attached to it could come whipping around and strike the archer. Again, leather reinforcement could contain fragments. I think it would have to be heavy saddle leather if not some sort of extra heavy bull or buffalo leather. Also, is your prod tapered in thickness toward the tips or is it uniform along its length? "By hammer and hand all arts do stand." Quote Link to comment Share on other sites More sharing options...
D.S. Adams Posted November 3, 2022 Author Share Posted November 3, 2022 Thank you, It is tapered to each end from center Quote Link to comment Share on other sites More sharing options...
Frosty Posted November 3, 2022 Share Posted November 3, 2022 I live in the woods but only about 80 minutes from the spring shop I used to go to. There are a couple solutions come to mind. First and probably the most likely to be optimum would be order one to be shipped. More likely would be finding a small trailer ditched in the woods or the scrap yard with leaf springs. Perhaps a wrecked ATV or snow machine. If you're careful you can grind spring tempered spring stock without altering it and happily it's a forgiving heat treat so you aren't likely to work harden it. IF you're careful about pressure and heat. What I was visualizing for a catastrophic failure was just snapping a limb off and slinging it like a knife blade. Whipping back around and trimming the archer's skull is a possibility. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
D.S. Adams Posted November 3, 2022 Author Share Posted November 3, 2022 Thank you I will consider that, I hoping to challenge myself with this project and have the ability to produce proper spring temper to make this personal crossbow self sufficiently, I do not intend to sell this or give it away. I was hoping to forge it from scratch from bar stock and woodwork the maple and create the mechanism which I have, all I need to accomplish this it to iron out the heat treatment Quote Link to comment Share on other sites More sharing options...
Frosty Posted November 3, 2022 Share Posted November 3, 2022 I'm with you, probably most of us are. Nobody gets into blacksmithing if they don't like to make things for themselves, that doesn't really include folks who want to be a blacksmith to make money. It's not the same as wanting to get into it, not at all. I'd call spring shops until you find one that'll tell you how to heat treat a leaf spring. Don't lie but don't tell them you want to make a cross bow, they may decide they don't want even that little bit of liability. It's why I NEVER tell a plumbing supply I'm building propane burners when I ask where the left handed double ended flare widgets are. Getting an even heat on something that short isn't hard if you use a muffle. Basically a piece of steel pipe large enough to fit the prod with room. Heat to critical temp and insert the prod. When it "disappears" assumes the same color as the muffle. Pull it and quench soonest. Do not let it soak at temp, do not let the temp start going down. Ideally you want to quench on a rising temperature. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
velegski Posted November 3, 2022 Share Posted November 3, 2022 Answer might be the string and not the prod. It might be still stretching into final length. Eye splices in particular like to stretch until everything settles into place. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted November 3, 2022 Share Posted November 3, 2022 I built one based on the plans in Payne-Gallwey's "The Crossbow"; but I cheated on the prod; used one from a commercially made/sold crossbow that I found at a fleamarket. Failure modes were too scary! P-G advised folks to use his springmakers in Liege Belgium; of course there has been two world wars since he last used them... It was my term project for a Senior/Graduate level Medieval Studies course at the University. Given: write a research paper at that level or do a project; well the project won hands down. Though walking on the Campus wearing a Maille shirt and sword and carrying a crossbow was a bit adrenaline producing... Did you slant the cut where the prod rests so that the string does not touch the wood in it's travel? Quote Link to comment Share on other sites More sharing options...
Frosty Posted November 3, 2022 Share Posted November 3, 2022 Me? I never finished my crossbow and heck only fired the 35lb. aluminum recurve bow half a dozen times before deciding the designer was NOT an archer. It was terrible but sold so . . . I went back to my 48lb. Bear recurve, it shoots like a dream I fired it for years without an arm guard it fit me so well. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
D.S. Adams Posted November 4, 2022 Author Share Posted November 4, 2022 Yes the place where the prod makes contact with the stock is indeed angled. To reduce friction from stock and string as much as possible Quote Link to comment Share on other sites More sharing options...
SubterraneanFireForge Posted December 17, 2023 Share Posted December 17, 2023 it’s beautiful! Did u forge in or grind the taper? and what was the length and thickness and draw weight I’ve never made a steel crossbow but I’ve made a couple yew ones and string stretch has been an issue. u can tell if the string is if you’re brace hight decreases. whats the string made of? Quote Link to comment Share on other sites More sharing options...
D.S. Adams Posted April 6 Author Share Posted April 6 The taper was forged in, I have yet to complete the new prod due to time constraints, thank you for your interest, the project is on hold while I make swords, and continue forging knives, be safe, have fun, research well, take recommendations and constructive criticism, best of luck Quote Link to comment Share on other sites More sharing options...
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