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: 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.
|Thread: cutting BMS, filing edges of cut BMS|
Tip of the day. I make no claim as to this being mine, it was in fact passed on to me by my Grandfather more years ago than I care to remember.
When sawing (this applies to whatever material you are sawing) repeat this little rhyme
"Hold on tightly, press on lightly", this will give you three complete strokes of the saw.. This will give you a good rythmn for sawing and remind you of what you are supposed to be doing. Sawing faster may seem like a good idea, but all you will acheive is knackering yourself. Use the full length of the blade, it has teeth all the way along, use them.
As to files, I like to use a file that is slightly convex for roughing down as you are not cutting over the full width of material.
Vice jaws, a good way of protecting your work is to use a couple of pieces of 16g ali which you bend over the jaws. The other alternative is as a lot of toolmakers do.,discard the hard serated jaws and make up a set of mild steel ones. Do not throw away the serated jaws as they do have their uses.
|Thread: Steam Boat Ban|
Please, please, please do not suggest that all our boilers should have an independant (by which I think you mean professional) inspection. It took many hours of negotiation by the M.E. federations to convince the H.S.E that we have a robust inspection facility within our clubs and boilers are tested according to the appropriate federations minimum requirements before a test certificate is issued. These certificates are not open ended but require re-testing at laid down periods. If a re-test is missed it invalidates the certificate and that boiler/locomotive/traction engine cannot be used.
The boiler must be inspected by the Club boiler inspector during construction.
It is on completion hydraulicly tested to twice designed working pressure, it then undergoes a steam test to ensure safety valves etc work properly, then and only then is the certificate issued.
The steam test is repeated anually and the hydraulic test every four years.
This is acceptable to both H.S.E. and Insurance Co's. But it appears not to you!
You are not a boiler inspector are you?
|Thread: Bought a mill to go with the lathe|
£200-00 of Model Engineering tokens! I nearly had a heart attack when I read that. Maybe stretch to £20-00 but I would need guaranteed results.
|Thread: WM280VF Fixed steady|
It is not clear from your post if you are looking for a spare to modify or you do not have a fixed steady at all. The lathe when supplied should have had a fixed steady with it. In any event , a first point of call should be Warco themselves.
I should be a simple job to make new fingers for the steady and incorporate a small ball or roller race. Ideally this race should be supported on either side by the new fingers,i.e. forked ends. If the loading is light you could get away with fixing the race to one side of the finger.
|Thread: brass wire mesh in 1mm weave|
Try Squires Tools Bogonor Regis. It's the sort of thing they stock.
|Thread: MiniMill Table Accuracy|
remember to check both x and y axes, as you will no doubt realize slackness in one can effect the other. A good test is to remove the leadscrew and try pushing the table up and down the machine. If you can push it without any effort it is too slack. You should feel some resistance.
|Thread: Stainless Steel|
O.K. Here we go, this is the way I would tackle it. In fact two contributors have suggested the answer. I have only combined the two.
First I would use 'oilcans' method with the difference that I would cut two pieces of 1/4" thick mild steel at an angle of say 60 deg, sandwich the metal to be bent between them. This needs to be with the straight portion of the bar aligned with the top edge of the plough share so that the angle crosses the share blade, the tip of the angle probably needs to be 1 1/2" to 2" up from the base. The reason for this is that the 1.5mm plate will want to turn about its own centre line. By the way make sure you clamp the tips of the angle with toolmakers clamps. Then bend away, you will probably need to bend through 100 deg as the material will want to spring back, in stainless this will be even worse.
Now MGJ suggests a hard wood former, having got the basic shape, with the hardwood former and a few taps with a hammer you should have something which looks like your plough share. These should all look the same. There will need to be a bit of trial and error and as MGJ says have a go with some alli.
Best of luck, please let us know how you get on.
Edited By Dusty on 20/04/2011 09:23:59
What your post does not say is that you require 6 of these plus another 6 of the oposite hand. Do they need to be made of stainless? Stainless steel is not the most forgiving of materials, a better bet would be Mild Steel sheet. I see from your sketch that the height is 1 3/4". From this, are we to take it that the 3" width you quote is the developed size? or are you trying to bend material that is later going to be cut away? Can you provide us with a sketch of the front elevation which may help us to help you.
|Thread: Machining lugs|
Richard, with great difficulty with the equipment you appear to have. I would turn the dia of the bar to size and then on the milling machine cut a keyway into the bar to whatever length and width you require. Now make up a key to fit the keyway, this can be fixed into the keyway with socket head cap screws (allen screws) with the heads lost in the key.
|Thread: Technical and engineering drawing.|
I fear that Terry is preaching to the converted, on this Forum. I would applaud any attempt at teaching us all, as I know we would all learn something from such an excercise. If it only improves the quality of drawings sent to David for publication it would be worthwhile. I like Steve Garnett am hacked of with drawings with multiple datums or datums in the middle of nowhere and you have to go back through 7 or 8 dimensions to find where they originated. I think everyone should be capable of producing a reasonable engineering drawing before they indulge in 'Satans Tool' I mean CAD.
|Thread: Identifying Silver Solder|
C4 is a 24% silver alloy which melts 740/780 centigrade and yes, it will appear quite brassy. The other silver solder is an unknown and should be treated as such. By all means use it for prefabing parts but it should not be used for constructing boilers. If you are making a boiler all the components should, including the solder should be of known quality and type. In industry you would need every item to have a traceable origin and the material certified. Silver solders vary in their composition and some should not be used on boilers. The other bunch of solder is probably 42% silver alloy(easyflo type) this would account for its silvery look but it is no good guessing. Some others who are far more knowledgable than me may have different views. But I still stick to my view' do not use it on a boiler!'
|Thread: Piston ring|
Remove the rings from the piston and insert them into the cylinder bore. If there is no gap or you cannot insert them then they will need re-gapping, if the gap is O.K. then they will probably just need running in, or you have problems with the depth of the ring groove.
It stands for 'total indicator reading' The indicator being a clock,dial gauge or whatever you know it as. Total reading is twice the runout i.e if the reading is .002" then your runout is .001". We all come across these things from time to time when we do not know what the term really means. I was allways told if you don't know ask, it is no good guessing.
|Thread: Travelling Steady.|
I am sorry but you will never convince me in a million years that your way is right . I understand about the forces involved and where you are coming from, but as a practical engineer with over 50yrs experience which includes toolmaking and building special purpose machinery, I am afraid we must agree to disagree.
Oh dear, you have missed the point I was making. The travelling steady is to prevent the workpiece deflecting whilst machining long items, the fingers should allways lead the tool. it is immaterial what happens to the workpiece after the tool has passed. It is not possible to stradle the cut when screwcutting, as the burr thrown up by the tool will cut a helix in the fingers equal to the pitch of thread being cut. This helix will grow in width as the screwcutting progresses. If you are screwcutting with a travelling steady the fingers must lead the tool and the burr thrown up by the tool must be removed on every pass. We are not talking about optimum support we are talking about practical application. When talking about leading the tool I would use about 1cm, this gives room to view what is happening with the cut and gives reasonable support.
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