Here is a list of all the postings Neil Lickfold has made in our forums. Click on a thread name to jump to the thread.
|Thread: DNMG110408 & CNMG090308 Inserts|
Those insert sizes work just fine on small lathes. As for the actual inserts I cant advise without more info on them.
|Thread: Arc Euro ER16 runout|
I have spent a considerable amount of time looking into errors with the ER collet system. MY conclusions are , if the collet itself is not concentric everywhere, then the errors seem to multiply and get worse. The ultra precision collets are worth it in the end as the tooling does work better as it is held more concentric. ER collets should only be used with parts or cutters that allow the entire length of the collet to be engaged in the collet as well.
Another issue is the concentricity of the thread on the outer body to the inner 8 deg taper, and then the concentricity of the inner thread of the nut to the 30 deg taper. Errors in these, will prevent the collet from correctly locating and being concentric.
I have trued the inner 30 deg taper of the nut, by locking the nut onto the outer with a sleeve. Then made a chisel looking boring bar to just clean up the inner 30 deg taper. In my case a screw cut the M50 thread and then turned the shoulder in the same setup. I had made the sleeve 1st. This has corrected the cheap nuts that I brought. The other nuts with the rotating inner are junk and I found no simple way of correcting these. They will only be to about 0.02mm or so for concentricity . Yes they can be tapped to knock the item into alignment. The RegoFix 1 piece nuts with their low friction coating is concentric to better than 0.005mm when tested on my correction fixture. Did not use a better dti at the time. The cheap 1 piece nuts were out by about 0.03mm aprox. After correction, and using the good collets, a part or cutter can be held and be better than 0.01mm for concentricity all the time.
|Thread: 3 phase vs single phase|
The motor draws the most current at start up. So with my Myford and its VFD, I leave it running in between if making lots of parts. I really like the variable speed the VFD give me, as well as the controlled motor start and stop. With mine the stop can be controlled and take place over a range of program time. Mine is set for either .1 or .2 seconds, cant remember now. It also allows for near instant reverse, just like a regular 3 phase set up does. But because it has a program start and stop, is not as harsh.
Given the choice of full 3phse and VFD, I have chosen VFD over the full 3phase.
I can have a micro switch and stop the motor and feed position when screw cutting internal or external threads.
|Thread: Thread Wires.|
|I still use thread wires but only when I have to. Now that I have a thread mic set to 2 inches I use that most times.i put white grease or vaseline on the wires to hold in place. The plastercine method is only good on small stuff. You would think that the vaseline would make the wire measurement wrong. But no it's just as accurate as if it was dry.the main reason for measuring the thread is so you know what it is for a replacement. As been said, often the mating part is not easily accessible.|
|Thread: Cheap carbide inserts - where's the market?|
The largest cause of insert early failure and chipping is turning to the centre. So where ever possible, just use a centre drill to remove the very centre, unless the part does need the flat face.
I have come to the conclusion that cheap inserts maybe the reason so many think that HSS is still very good. With good inserts, you do not need super fast feeds and speeds like what used to be required 40 years ago with carbide tooling. The newest inserts cut pure copper and leave like a mirror finish , and then you can cut a piece of HSS and turn down the shank to fit something else. With the same insert. With the hard HSS, it will be cutting at 15m/min surface speed, so a 10mm pin turn down to 3/8 will be done at 400 to 500 rpm at afeed rate of 0.05mm /rev or 2thou.
They also last a very long time. The market for cheap inserts is accountant based companies wanting always the cheapest things.
|Thread: Blackening steel parts|
I use the hot bath method. It runs at 135 to 140 C. So some care is needed. It works very well and I have never had any issues with it all. The downside is the time required to heat the bath, and the cleanliness of the parts. Some steels with high chrome content do not blacken very well with this process.
It is cheap to set up though and the basic formula is very simple. My current bath starts with 10 deionised water chlorine free. Chlorine free is important. 10 L of caustic soda pearl, or alternately 10 L of concentrated caustic soda solution, Mix water and pearl very slowly adding the pearl. Ready made solution does not need any extra pearl add. Then after it is close to room temp add 10 l of sodium Nitrite powder/crystals. Mix etc, use care as this is very caustic. Slowly heat to 135C or untill it just simmers. Stir often. The parts will take about 5mins for small sections (less than 25mm thick) to 15mins for 50mm sections) . Remove from the bath, let hang and drip off, then wash in hot water and I use vinegar water to neautralise the basic solution. Dry and oil. All done. This is really a more commercial set up, but does work very well. There are slight adjustments to the basic formula, like adding sodium Nitrate, and some add other stuff as well. If you have a set up in such a manner that you may drop and splash parts into the hot bath, then your set up is wrong. It needs to be arranged so that you can not make any splash of any kind , no matter the reason. You do not get a second chance with hot caustic things. But I am happy with with I have, have been since 09 when I started doing this commercially. Do not allow any non steel parts to contact the bath either.
|Thread: Carbide threading inserts.|
From Koroloy out of Korea. Really good stuff also. These are not cheap, but do work very well. With care the inserts last a very long time. Have not found the full form inserts, but they do have partial form inserts in 60 deg and 55 deg, and there are the internal grooving inserts that can be made into the geometry you desire. The sizing is the minimum bore diameter . You can fit an 11 mm insert onto the 8mm holder. Just requires a shaped washer and a longer screw to do so. I have the 8mm carbide holder and the 14mm carbide holder, but have inserts from all 4 ranges. The holders are not cheap for the carbide, but is more rigid than the steel in the smaller 8mm one, which is about 5.8mm shank for the insert side. The 8mm is on a 12mm shank, the 14mm is on a 16mm shank. Both will fit on a Myford S7 Dixson holder. I did recut a holder to accept the 16mm shank, by cutting the upper portion of the block making the opening 16.1 mm from the 13mm that it was.
|Thread: It's a thread Jim, but...|
Not many people can screw cut a thread of 2mm pitch at more than 100 rpm or so . I don't think it matters if the threading tool is HSS, or a ground carbide insert. Some materials definitely tear and don't cut as well as others. I have a Myford S7 and my choice is a ground threading insert. It is sharp like hss but lasts longer. At the end of the threaded area, I make a thread relief, so am not trying to withdraw the tool at the end of the cut. on a M16, I make the relief diameter 13.75 to 13.8mm and normally I make the relief length about 5mm long. This gives about 1 second to stop at 150 rpm. Keeping the tool holder over hang to a minimum makes a huge difference , especially with a 0 Dickson holder on a deep thread like a 2mm pitch. If the material is difficult to cut, I will put on a cut with the compound, but take some of it off,by 0.05mm with the cross slide. Then retake the cut again, with the cross slide at the zero point. This makes then leading face cut not all in 1 pass. It reduces the total cutting volume and reduces the front length being cut by the tool. It is also called the zigzag screw cutting method. This is good when threads get deeper than 0.8mm deep , so like for M12 and courser pitch threads. It works for internal threads as well.
Roughing out the thread like you are doing. Then finish it with a die. If you want a really good finish just screw cutting on a myford, use the travelling steady and do the in feed etc on the compound slide.
Sulphurised cutting oils help as well, like rocol. Carbide threading inserts are just fine on the manual lathe also.
|Thread: Cutting a keyway without a broach|
If the tool is sharp, you can push through 0.001 inch depth of cut to about 0.002 inch depth of cut, from 0.002 inch diameter to a max of 0.004 inch diameter. Metric 0.05mm to 0.1mm max on diameter. The blade or cutting wants to be around 5 deg or so . If you make it too much like a chisel, it will pull the cross slide in and try to keep making a deeper cut. Having the tool face , the one in line with the bore, if that is set so it is about 1 deg clearance, this will also help to stop the tool digging in. Any material taken out before hand, dramatically reduces the cutting loads. Even if you hand file a rough slot , and then use the tool in the lathe for finishing the key slot works well. HSS works really well for lathe key slot cutters.
|Thread: Lathe or Mill?|
As you mentioned only a manual machine, it will be a lathe with milling attachments and full digital readout, on all axis with the tailstock quill included with an indexing head as well. The lathe spindle becomes the mill spindle, cross slide becomes the X axis, vertical slide becomes the Y axis, and the saddle movement becomes the Z axis.
If you were going cnc, then the answer will be a milling machining centre with a 4th axis. That will do most of what a lathe can do within reason, as well as all the milling functions in 1 machine.
|Thread: Rocol RTD shelf life|
Even salt has a use by date now days.
Some oils do go off, get rancid over time. Not noticed it with any cutting oils since 1984, which is my oldest cutting oil, and rocol paste are both fine, but not much left now.
|Thread: Identity of Glow Engine.|
It looks to me, that it is someones home made engine case, and has used commercial piston liner assembly and carb. They may have made the crank and prop driver as well. But there were several makers who used the flat on the crank for the prop driver, instead of the tapered collet.
|Thread: Carbide Inserts and Holder Recommendation|
There are some modern face mills that take a negative position insert, with a positive cutting geometry. The ones with the un even spacing are just awesome. These newer ones, have the 4 sided inserts, so will make a 45 deg approach, and the inserts have 8 cutting edges. They are quiet as well. Then there is the ones that side cut. The newer versions of these are both un even spaced, with a helical outside geometry , allowing for side cutting or going down a wall. These normally only have 2 cutting edges per insert. Kennametal make a great series and so does Mitsubishi, and Iscar. All 3 brands are available in the USA. Sadly the inserts are sold in boxes of 10, that will last a long time. The milling inserts are very well suited for interupted cutting. You can make a holder to take either of the inserts from the insert milling cutters. A common theme, is to make a holder that uses the un used edges from the vertical insert cutter that uses on 2 edges. Turned 90 deg, it can be used as a fly cutter on the edge that is no longer used. They used to make a face mill that used these inserts that way. Not sure if they still do or not.
|Thread: Myford super 7 chuck problems|
The face of the spindle (where the chuck and face plate seat against) should be zero with a dial indicator. If this is indeed zero, then the next area to look at is the concentricity of the thread itself on the nose spindle. Setting the lathe to screw cut the thread, 12TPI Whitworth I think, but check. Then place a DTI onto one of the flanks, and as you turn and the carriage feeds at the same time, check the concentricity of the thread form. If it is not concentric, it will cause all sorts of inconsistent mounting problems. The thread can be quite loose and still be effective. You can recut the form with a 55 deg included threading tool to correct this error.
To reset all the clearances etc on the lathe and re scraping or getting the surfaces reground, can take quite a bit of work and time, and attention to the detail is a must.
|Thread: Removing and re-chucking a part whilst thread cutting on Myford Super 7|
Another way is to use a collet chuck, that has a radial index, and is placed in the same z position.The collet with the work piece can be removed, tried on the part, returned and carry on with the thread cut.On a 25mm shank holder, if you get it to a radial position with in 0.1mm, the pitch position error is negligible.
|Thread: WT2527 15cc Glow Engine|
Great that you can take pictures as you go, I always forget, or don't have my phone handy etc. Don't have my phone in the shed when making parts, that way I don't get distracted. Looks really nice and coming along well. Looking forward to the video of it running. That will be real music to me.
|Thread: New old 1950's Myford 7 Lathe still in the crate|
I think one reason for no bidding, is the lack of clarity of what you are getting for your money. It looks like a car engine that all there , but not assembled. People are just suspicious when it is not shown , and not all itemised.
I would not bid on it, without knowing more about what you are actually getting for your money, and what is the actual condition of the slides etc.
|Thread: The size and shape of drill holes|
Gun drills are an illusion to me. The trick is to get the balance of the cutting force, from the centre to the outer, so that it want s to stay on centre. So they have support lands etc to guide the drill. The sharpening of a gundrill to drill straight is quite specific for that drill, and material etc. Now days, there is a new very high speed drill, that out dates gun drilling, with a catch. It needs a very accurate spindle, and very high through coolant pressure to work.
Gun drills can be hand re sharpened , but twist drills, some can sharpen them really well, and others not.
The best firm but removable pins, are tapered pins. The reamer can be a simple D bit reamer to a taper that you can easily reproduce. You can also take a tapered pin, and make it into a D bit, assuming that you hardened it of course. Anything from 1.5 deg per side to 3 deg per side does work very well.
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