Dennis J

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About Dennis J

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    Adelaide, South Australia
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  1. I have a grinder with 8 inch aluminium oxide wheels running at 1725 rpm. I dunk the tool in water every 10 seconds or so to prevent overheating. I grind gouges at about 25-30 deg. Rough grinding a fingernail shape is no problem of course, but honing is another matter. For lower sweep gouges I use a wooden honing guide which clamps the handle and pivots on a screw. But this doesn't work very well on gouges with higher sweeps such as those used on scroll carving, so I do it by hand. To see what sort of jig would work for grinding/honing fingernail shaped gouges look at the Tormek woodturner tools accessories. It gets sort of complicated.
  2. I think I mentioned "ascending angle". What I meant was that the last turn at the eye in Shunyata's photo appeared to be very steep. This means that a gouge cutting vertically needs to be ground/sharpened with a curved (fingernail) cutting edge to make good contact so that a slicing cut can be achieved, rotating around the post as it were. With an edge ground flatter only the corner edge of the blade will make contact with the sloping surface making a smooth cut very difficult. I don't disagree with Catnip's analysis about the width of the scroll, it's obvious. But by ascending I mean the increasing angle at the base of the vertical cut as the volute approaches the eye.
  3. Well it looks like a pretty good job to me and I guess it all comes down to the pattern you are following and the range of gouges you have and how they are sharpened, especially on the vertical cuts.
  4. Something I have found important is to keep the first turn fairly high so that the final turn is not at too steep an ascending angle. It will also allow for a thicker bevel around each turn.
  5. Small planes, 10-14 mm blade, with a flat base and a bevel-down configuration generally need a blade angle of 38 deg. or lower because cutting resistance increases as the blade angle increases so tearout is likely. With too high an angle they become too difficult to use comfortably. Bevel-down finger planes with a curved base also have a problem with tearout but that can usually be controlled by cutting across the grain, and a smooth finish is not the main objective anyway. I've made quite a few finger planes over the past couple of years, and I have thought about different designs for planes with a flat base and a blade width around 20 mm or so. A plane with that size blade can work with slightly higher angles because it can be gripped more firmly or held with both hands. The cutting angle of bevel-up, tight mouth, flat base planes is determined by the angle of sharpening of course, and are at their best when used to take finer shavings. But in smaller size utility planes for say planing areas on the neck a bevel-down plane is probably the only option. But you are right, the higher the angle of the blade the less likelihood of tearout. For instance, planing flat maple rib stock is not practical with a low angle, bevel-up block plane (typical cutting angle 37 deg.) unless its blade is honed at a very high angle to bring the cutting angle to well over 40 deg., even if the mouth setting is tight.
  6. I doubt that the brass pipe plane example is in any way practical. The blade angle must be at least 50 deg. Most small thumb planes are made with an angle well below 45 deg. to enable smooth cutting. If thinner wall brass pipe was made into an oval shape and soldered to a brass base with the back cut out to allow a lower blade angle, a cheap, usable plane could be made at low cost.
  7. Whatever it is I would suggest you get rid of it. It is almost certainly made out of recycled scrap metal which may contain things that may be unhealthy to handle. Cadmium perhaps.
  8. It is probably a "brass" alloy --- copper/zinc/and a lot of lead. Nasty.
  9. Cabinetmakers use planes with convex and concave soles to plane convex and concave surfaces. Plane manufacturers make planes with flat soles to plane flat surfaces. I find, as do others apparently, that flat planes seem to take more off at the end of the stroke, possibly when the toe of the plane passes over the end of the board. Not a major problem, easy to compensate for. It's as simple as that. If you are happy gluing edges together necessitating the use of clamps good luck to you. I prefer gluing flat matching surfaces when joining any two pieces of wood. No clamps needed. And the integrity of the joint made with matching surfaces must be as strong or probably stronger than any other joint. That's just plain common sense.
  10. There needs to be a bit of scientific rigour applied to this subject. How many people responding to this subject have taken the time to examine what happens when they plane a violin wedge. How flat is their plane? How do they test the surface of the planed edge without using a straight edge to see what is happening? I have spent the time and that has proven to me beyond doubt that using a flat plane, large or small, produces a slightly convex shape in the planing process. If your plane has a flat sole the idea that exerting more pressure to the front or back during the stroke can somehow modify the result is fantasy. When a plane with a flat sole and a sharp blade engages the wood at the beginning of the stroke it will cut at the full depth for the full length of the stroke. Why it produces a domed cut is debatable. But is seems to cut deeper at the end of the stroke. If the blade is blunt or the plane sole high at the mouth anything can happen. I don't know who Rob Cosman is but on this subject he certainly knows what he is talking about. And so does Nick Allen.
  11. That is exactly my experience. You do not need a straight edge to test that. If the two planed edges spin when placed together they are longitudinally domed. I've used a straight edge to test for flatness when planing wedges held in the vice and when using the plane held in the vice and they were invariably slightly convex. I probably had the same result using a shooting board, but I can't remember. It would not surprise me if the opposite was true when planing lengths much longer than violin wedges. Maybe you would have to worry about planing concavity when dealing with cello wedges. If you have a good plane it will do what it is going to do, it has nothing to do with experience. If the result is not flat it is easy to make it flat. Trying to flatten plane soles by hand is not practical. I've tried it on all my old planes and even the ones only slightly out of flat would take forever to flatten properly. I only use them for rough work. But some are beautiful tools and worth taking to a machinist.
  12. I have picked up two rock maple plane shavings made by my Veritas Number 4 bevel-up from my workshop floor and measured their thickness. One is .09 mm and the other is .03 mm. The thicker one might have been a test shaving, too thick for what I'm doing. The thinner one represents the majority of the work I was doing. Generally speaking as thin as I would probably want to go. I think it's fair to say that you would need a plane with a fairly flat sole to produce shavings as thin a .03 mm reliably. The worst of my bent planes rocks back to front depending on the pressure applied to the front knob and back handle. And that's not something you can control, so the plane is not suitable for planing flat surfaces. I don't know if my straight edge is truly flat or not. But it's probably the straightest thing in my workshop so I choose to believe that it is. After all ignorance is bliss.
  13. I have about 10 planes dating from 1965 back. Not one of them is flat as tested against my Veritas straight edge. I believe they were probably machined flat but over time the casting warped. At least that seems to be the explanation. I haven't measured the gap on any, but the worst has a gap of probably 1-1.5 mm, possibly 2 mm, at each end of the sole. That amount of deviation from flat can certainly affect the performance of a plane. The main one being the blade coming out of the cut as the plane rocks front to back. It is noticeable when the blade is set to take a fine shaving. So its ability to plane a flat surface is obviously compromised. I have a few Veritas and Lie Nielsen planes and I have tested them and they are all flat. What tiny amount they may be out of flat doesn't worry me because it will not make any significant difference to their performance.
  14. That's a good board, angles the blade. I have used something more basic than that. I have tried all methods without any problems. But my present inclination is the shooting board as the closest to hassle free.
  15. I think I can see some problems in your approach. I would suggest making a shooting board. Keep the wedge flat using shims as I said. Then there is no need to do anything to the wedges as long as they are reasonably flat on the underside. Don't try to flatten the underside and make the joining edge square to it. Plane the underside surface after you have glued the wedges together. As long as the joining edge is roughly square to the underside that is all you need to do. Just plane those edges flat and straight as I described. It's alright to warm the wood if It is cold, but don't make it too hot. Planes are meant to take off nice shavings not sawdust.