Jump to content

owen bush

Super Administrators
  • Content count

    1,993
  • Joined

  • Last visited

  • Days Won

    15

owen bush last won the day on December 16 2018

owen bush had the most liked content!

Community Reputation

157 Excellent

About owen bush

  • Birthday 06/25/1971

Contact Methods

  • Website URL
    http://www.owenbush.co.uk
  • ICQ
    0

Profile Information

  • Gender
    Male
  • Location
    London England
  • Interests
    Profesional smith ,More and more I am interested in the history of out craft ,It just drags me back .

Recent Profile Visitors

3,280 profile views
  1. owen bush

    NO FLUX WELDING

    well 6 years on (time really flys) I do almost all of my billet welding in a gas forge without any flux. It is certainly a better process. the dis advantage is some grinding... it takes longer in total time than when folding under the hammer , but is slightly less "work time" if you do not count time hreating. however the welds are certainly better and not using borax is sooooooo much better for my health and forge! the only time I now personally use flux is when teaching hand forge welding or for final welds on multi bar billets...I can do small ones fluxless but use flux when the billet is longer than the forge.... its a great improvement.....big thanks to JD and others who put this out there...
  2. owen bush

    12th Annual Fire and Brimstone Hammer-In

    I wish I could make it this year.... But I will most certainly be back.
  3. owen bush

    first 2*72 belt grinder, question about grinding speed

    Well, I have found myself grinding on the edges of my platten to get a smaller contact area on the belt to get more pressure on the belt to remove more material....I enquired about getting 1" belts and making a 1" platten but my supplier cant do that and I'm not sure how sensible putting 10hp through a 1" belt is and Then I thought why not have the platten ground so that there is a smaller contact area in the middle of the belt. I got James Wood who was working here to grind a couple of faces the full length of the platten recessed back about 2mm or so so now I have a faceted plattern 2/3" in the center and 2/3" flats either side the full length top to bottom so I han grind hard left side , hard middle middle orhard right side with minimal contact area anu get the full width of belt used up and hog away. it works very well..finish is not quite as good but its more agressive and allows better use of the 24grit ceramica I use.
  4. owen bush

    first 2*72 belt grinder, question about grinding speed

    I am running a 10hp grinder as fast as the belts will allow hogging on a faceted platten (smaller contact area) but I turn it right down when I get to tips or tricky grinding. get it wrong at full speed and the metal or you will get eaten!
  5. owen bush

    Cutlers anvil

    It sure does look that way!
  6. owen bush

    Cutlers anvil

    Ill dig some out, I must have 8 or ten of these anvils now.
  7. owen bush

    Forge Welding by Hand

    I would always weld under a power hammer if given the choice. If not available I would buy the material from someone else (it would be cheaper than making it by hand). However I do teach hand welding up a billet for twisting, along side of making damascus ander a power hammer it gives context to the speed of the power hammer... I really would not bother making high layer folded material by hand hammer...I have done it once with a team of 3 people and sledge hammers ....never again. If working by hand there is a limit to the size of stock that is workable. 1" wide by 1" thick would be my limit. I weld up an 8" billet of around 7 to 11 layers (each 2 to 3mm thick). this takes about 20 to 25 minutes with an already hot gas forge.. it then takes me another 1 hour to size the material and twist it and another half an hour or so to forge the material into knife stock. It's all bloody hard work 2 to 2.5 hours bloody hard work against 10 minutes under a power hammer and 10 minutes twisting..... Tips for hand forging billets. weld up your billet in the middle as well as the ends to keep all of the pieces touching and allow capilery action of the Borax between the layers. Heat from the end , if you dump the while billet in the fire the outside layers will bow out and form a gap that is too big for borax to be drawn into, aply borax ahead of the heat (low heat oxidation is probably the biggest problem I see.). My indication for the end of the billet to be at welding temp is that the borax bubbles vigerously and smokes when taken out of the fire... hammder each section with fast overlapping blows, imagine the borax like the dreggs at the end of a tube of toothaste. you need to squeese it all out from one end. I repeat every forging twice. I make sutre that each set of blows overlaps the previous set(s) and progress down the billet in 4 or 5 steps. applying more borax ahead of the hot steel . I pay extra attention to the back end of the billet as its the bit I tend to ignore (most other people as well). when the billet is fully welded I work back down it with more hammer blows ...I then allow the billet to cool off and clean all the edges with agrinder looking for delamination. it should look like one bar of material ...I then forge to square and then round (for me 15mm or so) , twist the bar (at least i full twist per cm of material) and then flatten out. this will give ma enough material for 5 or 6 paring knife blades...like this
  8. owen bush

    Cutlers anvil

    just a few comments.... Most of the sheffield cutlers anvils are mounted onto (or into) large stone blocks, traditionaly using rotted horse manure to tamp them in. I have a few cutlers anvils with the tooling slots. ( or toolmakers anvils)and they range in weight from around 150 to 700 lb. Most of these were designed for large scale manufacturing ...so repetativly making the same product 1000"s of times. I have tooled up one of mine and it works just fine... sure many of you have seen it...ive watched it many times a lot to learn from this guy. https://www.youtube.com/watch?v=zpeyhC-UIFg
  9. OH wow...I love it..something about the ridiculously made mundane object really does it for me... I thought Howard Clarks damascus potato peeler was awesome but this takes the biscuit.
  10. owen bush

    Awesome video of forging Golok machetes.

    That is pretty cool.
  11. owen bush

    Moonlight Seax

    really elegant knife, thanks for showing.
  12. owen bush

    Spring rate

    welllll.....I would try an not reinvent the wheel...especialy when it can take your face off!. I have had 3 of the spring hammers I have owned break springs so obviously these machines take the material to the point of fatigue , I doubt that mild steel would be an improvement.
  13. owen bush

    Spring rate

    The maths for a crossbow is quite complicated...very complicated. I was discussing it once with my good Friend Leo Todescini ( a cropssbow maker) and a professor of engineering ( whos name escapes me) , what could we do to try and model the optimal shape of prod (thickness and width at any point) for a given poundage or draw length ...the conclusion after a page or two of Math was that it would be a great summer project for one of his PHD students....if we were interested in funding it! lots of changing vectors involved in the way an arrow or bolt is accelerated...not simple at all.
  14. the best hack I have heard of for museums (cant remember who told me though) is to attatch two lazer pointers to trammel arms on a ruler (lazers set parallel) to get accurate length and width measurements through glass! I would love to see the reaction from museum staff.....you would need mission impossable music ...
  15. owen bush

    Spring rate

    well there is a lot of head scratching that goes along with crossbows and steel prods, some of it is counterintuative all of it is potentialy dangerous if you get it wrong. I have made hundreds of crossbow prods over the years from 150lb to 1400 lb..... and hardening and indeed temper temperature does not effect the rate of energy return (we tested it! with a crono and prods multiply tempered to reduce hardness in steps) it is so counter intuative. however it is very easy to make crossbow prods that will bend under use (if they are unherdned or high tempered) and the tillering is incredibly important (bot in thickness and width) so as to share the bend over the whole limb. steel crossbow prods are by thier nature not great at returning energy , a lot of the return energy harnessed in the spring is needed to overcome the inertia in the mass of the material. a hardned and tempered prod can be lighter and give a greater draw than an unhardned or mild steel prod. having measured quite a few origional prods I would guess they are hardned steel as they would deform if wrought or low carbon . that is if you take origional dimentions, short prods and a short draw. If you go outside of this with thinner bigger prods and a much longer draw its totaly possable you could use mild steel...but to what end, as this is not what was done. I would not think that origioanl crossbows had a huge rate of failure, failure could be catastrophic or fatal, but i do understand the relative diferences in risk adversity as we go back in time...life being cheap and all. I see the means of securing as a way to allow flex through the center of the prod (where the most leverage is occuring). I will add that the risk is certainly there though. historic crossbows are interesting and can be disapointing unless you view them from a materials and physics POV a 900lb crossbow will be easily out performed by a 150 longbow ..however with the rite mechanism it can be cocked by anyone., certainly not the case with a war bow.....Wood is much more eficient at returning stored energy into kinetic energy its lighter for one.. crossbows seem to do well at delivering heavy projectiles but by their nature are not that fast. the big advantage of a steel prod over seemingly more eficient wooden prods is that it needs relativly little care , grease it up and leave it in your dingy damp castle keep for a decade and when you get attacked all you need is fresh strings and its to the ramparts...your wooden prod would certainly be ruined if not cared for. If you are used to modern fiberglass crossbows a steel prod is very disapointing... Take care , look into spring temper temperatures for the material you chose ( not getting it to blue but real temperatures that real modern springs are tempered to, often much higher) and I reemphasise these things would easily take your face off if you get it wrong.
×