Here is a list of all the postings Dusty has made in our forums. Click on a thread name to jump to the thread.
|Thread: How to clean a bandsaw|
If it is the 64 1/2"blade screwfix do it as well.
|Thread: Milling drawbar|
Hear hear John, I have 4 drawbars for my mill with a variety of threads. I only have one which is a pukka drawbar the rest are studding with a nut on top, this nut just has a roll pin through it. As JasonB says it only needs a nip up, none of this he-man stuff. You can if you want make the nut with an integral washer, tap it not quite through so the studding is a nice tight fit, cross drill for roll pin and thats it job done. One other thing make sure the drawbar does not bottom in the morse taper thread.
Edited By Dusty on 11/07/2011 19:16:00
|Thread: Best way to improve fit of main spindle quill in casting (long)|
When you say the quill moves towards the column when applying the clamp are you sure that it is moving out of parallel with the column, with only 40mm of movement on the quill it is not easy to check. Try applying the clamp until you can still move the quill, then clock the the quill in the vertical plane and see what result you get. Ideally you need to clock over a much greater distance but the 40mm will give you some idea of the problem.
A couple of observations and then some questions. Looking at the FB2 and the machine I think you are talking about I notice that the FB2 has a transverse split above the 'clamp'. It appears that this was a scource of trouble in the past, I am not suprised that you think the force to clamp is high, you are trying to distort an almost solid casting. It might be worth considering running a slitting saw through as per the FB2.
I would not try throwing the column to get the head aligned, deal with the head if that is where the problem lays.
How much deviation do you get when clamping? If this is no more than a couple of thou I would live with it, remember these machines are only lightly built, the bigger and heavier the machine the greater the inherent accuracy.
Try re-tramming the head with everything nipped up and see what result you get.
Before you embark on major work you need to ask yourself a number of questions.
The first of which is, does the milling machine work properly i.e. When in use does the quill rattle about when clamped.
Is there signs of wear in the bore in the vicinity of the split clamp.
What is the difference in size beween the bore and the quill.
The usual method of producing a split clamp is for the bore to be machined and then the clamp is split. Try measuring the width of the split above the clamp, then make a packer of this thickness with a hole through it to take the clamp bolt. This is then inserted into the clamp and the bolt is tightened. You can then either measure the bore or try the quill in the bore and see what result you get.
I would add that if something is not broken don't try to fix it.
The last question you should ask yourself is do I possess the skill to set up and machine the bore to the accuracy needed. You could make a very expensive mistake and end up with a milling machine that is inaccurate if not ruined.
|Thread: Using Micrometer/Hi-Spot blue|
I have been pondering over this question since it was posted. The conclusion that I have come to is that two very different methods of bluing are being talked about.
The first, which is the method I was taught is that you have film of blue on the surface plate this should be translucent, in other words very thin. The workpiece is the rubbed onto the surface plate, just a couple of times. The blue will transfer to the high spots. These are then removed by scraper, file or what have you. This is repeated until you get an even pattern of blue spots over the surface.
The second method appears to use a much thicker film of blue which will accumulate in the low points of the workpiece. You then remove the bright areas.
|Thread: Conversion factor|
16.143 or 3/4" to the foot whichever takes your fancy, this works out at 16.
Edited By Dusty on 21/06/2011 10:01:36
|Thread: Vertex Auto Tapping Head|
You may be better off using conventional taps. Because your hole is not complete the fluteless tap will want to push its way out of the gap. Fluteless taps work by deforming the metal, with the gap in the hole the tap will want to take the line of least resistance and try to 'escape' through the gap. Normal taps will also want to 'escape' but because they cut, the effect is less marked. Just an opinion, I would be interested to know. The other alternative would be to make a tapping fixture where the tap was guided through a bush to keep it in line.
|Thread: WM250 screwcutting chart|
The 'H' is for the spacing collar. You should have a couple in with the change wheels. You might find one on the lathe on the end of the leadscrew. Why it is designated 'H' is beyond me. We might find someone who is fluent in chinese who could help, me, I am only fluent in b****ks, or so I have been told.
|Thread: Darjeeling Saddle Tank 0-4-0 New series starting in ME 4378|
As a matter of interest, has anyone machined the cylinder castings, and I do mean castings as opposed to hacking them from solid. I say this because of the shape, with compound angles, I think it is going to be difficult to hold them to bore. The originals were bored from solid using the four jaw, which would be my prefered method for the castings. But with the compound angle you cannot hold it in the four jaw, likewise this same angle will make clamping it to the cross slide or to an angle plate very insecure, as you will only have point contact. I do have a couple of ideas but I want to try them before I commit myself to print. If anyone has an idea I for one would be pleased to hear it.
Steve has beaten me to to the dimensions you asked for. As to the weight there is, floating about a formula that allows you to calculate the weight of a model in relation to the full size. I am afraid that the passage of time has errased that part of my memory which allows me to remember those sort of things or at least where I found the formula.
But using my skill and experience (known by most as bullshit) I reckon that the weight will be about 160/170 lbs. I suspect that Ray, through the services of Donald, may be able to answer that question better than I.
|Thread: milling vices|
Jaw lift is a problem you get with all milling vices (to a greater or lesser degree). In order for the moving jaw to move there must be clearance. The longer the moving jaw the less this is apparent, provided the vice is adjusted properly. When I purchased my K4 vice I spent several hours in making sure that it had minimum clearance on the moving jaw. This jaw should be quite stiff, as opposed to slack. I don't mean you need a torque wrench to move it. for most jobs it will produce acceptable results. I will sometimes use the old trick of interposing a length of round bar between the moving jaw and the workpiece (horizontally)
|Thread: How to dress a small diamond wheel|
I understand that a piece of York stone presented to the diamond wheel will work quite well and remove the accumulated rubbish. I hasten to add that I have not tried this but a tiler who was working for me at the time used this method. I can see no reason why it should not work. Observations gentlemen?
|Thread: Sharpening drills|
I have used this method or a slight variation of it for years. my method is to stone a small rad on the lip of the drill. To be accurate these rad's should be of the same size otherwise the drill will only cut on one side and tend to cut oversize. The other thing is you need to leave only a few thou to take out with this drill, much the same as a reamer. The finish that you get in the hole, provided you feed slowly is generally better than a reamer. The other problem is that if the original hole is not round or off line then the drill will follow it. It is a trick worth knowing, have a little practice on something that does not matter until you are confident in your ability before you use it in anger.
|Thread: The end of IMLEC|
In addition to Kwils suggestions. I would advacate that a nominated day for entries be published, say 10 days after the magazines publishing date. This overcomes any bias towards possible entrants who are subscribers. Entries received prior to this date would be invalid.
|Thread: Correcting pilot error|
If you have a milling machine or acess to one, then you could try setting it up with the hole in the correct relative position and use a 4mm slot drill to pull the hole into the correct position. This will not work with a drilling machine as it is not rigid enough and you need to be able to feed slowly, feed to fast and the slot drill will want to follow the original hole. This works best if the slot drill is new, an old blunt one is doomed to fail. By using a 4mm slot drill you have two more chances at correcting it with 5mm and 6mm slot drills. The other alternative is to set up in the 4jaw and bore it or use a slot drill in the tailstock.
|Thread: D bit grinder work head calculations|
Just to throw a spanner in the works, a flaw in your argument. Once you grind clearance on the tool the shape is no longer a 'D' and can therefore no longer be called a 'D' bit, you will have to call it something else. How about an engraving cutter or single lipped cutter?
Quit while you are ahead, if your lathe as it appears, is turning parallel to within 0.002mm over 220mm. What you do not say is how you machined it, was the bar just hung out of the chuck or was it supported by the tailstock. If the bar was just hung out of the chuck I would have expected a greater variation between the two dia's as you would get some deflection even with perfectly adjusted bearings in the headstock. Before even thinking about moving the headstock you must ensure that the shears are not twisted, that the tailstock is in line with the headstock by turning a test piece between centres. Then and only then could you contemplate moving the headstock. If you were to move the headstock it could result in a lot of blood sweat and tears and of course bad language, the end result could be worse than you have at present.
|Thread: D bit grinder work head calculations|
Firstly can we get one thing straight, what Lawrie is, or appears to be talking about is not a 'D' bit at all but a single lipped cutter. Steve Garnett is right, if the cutter is as shown, tappered it will not cut as the workpiece and the cutter at the cutting edge are at zero degrees in relation to one another. The only way you can induce it to cut is by reducing the cutting edge to below centre line, even then it will be a bit hit and miss. A 'D' bit cuts on its front edge not on its side. Cutting on its side makes it either single lipped cutter or a taper reamer.
|Thread: Facing Cuts - Requires the Carriage to be Locked?|
I have got to say that I agree with Donald Whittmann 100%. The saddle should be locked when facing or parting off. Mgj says that in larger machines the saddle tends not to move, this is true, but you can never guarantee that it has not, unless the saddle is locked. Yes I do face off without the saddle being locked, until it comes to finishing, then it is locked so that I know the face is square or in my case very slightly concave (by about .0005 over a 6" dia). Better that way than the other i.e. convex.
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