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: heat-treated S2 steel alloy - machining|
You can turn hardened S2 with ceramic turning inserts. Dry cutting is about 90m/min surface speed or 900rpm.
Depth of cut with a 0.4mm radius tool is 0.2mm so 0.4mm on diameter max depth, and a feed rate of 0.06mm per rev, or 2 thou per rev. So a very fine feedrate.
Seco make series TH1000 grade insert, in a few geometries , these will also cut hardened steel, but at 25 to 50 m/min, so 1/2 to 1/4 the surface speed of the ceramic inserts.
The above inserts are available to the TNMG16 tool holders, the triangle 6 edges, negative holders.
|Thread: HAS ANYONE MADE A SINE BAR ?|
It is nice if it is a nominal number for the centre distance to the rollers or roller to centre in a sine table. But the important part is knowing what that centre distance actually is, then it will be as accurate as possible. Having support side arms to aid in keeping it's correct position is a really good idea. Then the gauge blocks don't need to be kept in place. Of course there are many way's to setting the height for sine tables and sine bars.
|Thread: Thread gauge|
Is that with a sharp pointed tool Jason. eg 2 inch with 4 tpi thread, from touch on the outside diameter, the minor will become 1.680 inches diameter using a 55 deg included angle tool?
|Thread: Hand or Machine Reamers?|
Hand reamers have their place, like any other tool. The advantage of most hand reamers is that the taper is very useful in some situations where you may want a slightly tapered hole, or a tapered start to a hole. You may want to have a slightly oversized portion, and hand reamers will do this , as most hand reamers are in the 0.015mm to 0.02mm over the nominal reamer size at the very back of the reamer, depending on the tolerance range of the hand reamer being purchased.
I lap hand reamers down, to make special undersized reamers for press fit holes. The front tapered section is not touched. By undersized , it is only in the -0.02mm to -0.03mm to make a permanent press fit for pins.
Edited By Neil Lickfold on 04/10/2019 21:35:30
|Thread: cutter slippage using ER series collets|
Yeah I would think that it would be tighter. But in the machine, using 2 levers I think is the better way to tighten the ER collets.
So when you have a spanner holding the tool body, and a spanner holding the nut, as you bring the two tools together , there is no twisting moment on the spindle. As you bring both hands together, you can get them a lot tighter than just trying to pull on 1 lever. Mechanics do this all the time on fittings. The same in reverse, you an pull the two levers together to undo very tight fittings.
It is very important for the cutter body, to have the full length of engagement in the collet itself. If the cutter is 3/4 of the way in the collet body, there is a high probability of it walking out on a big cut for sure . The thinner wall collets require the full length absolutely. It is for this reason that I have different collet sets, with the smaller series collets for holding the smaller cutters. Cutters with a 4mm shank or smaller I use the ER11 set. For 10mm to 5mm I use the ER16 set and for over 10mm use the ER32 set or ER40. Hanging onto a cutter with less than 1.5 diameters is never a good idea , so then you are better off buying a longer series cutter.
Using a pair of tools to tighten the collet nut is a zero torque arrangement and you can get a lot higher closing pressure instead of using just 1 tool and locking the spindle or 1 tool and a bench holder.
Buying precision collets saves a lot down the line. I suggest buying the highest precision collet you can afford at the time. Then buy more as you need them. Having cutters run better than .01mm every time is important and does make the cutters last longer. Also it means you have confidence is setting up a part and know it is concentric within the collets accuracy. I bought some AAA from China collets that are better than 0.005mm but not 0.002mm though.
Even though they seem expensive , precision collets really are time savers in the long run.
|Thread: Myford vfd|
What I like best about the VFD and 3 phase motor on my myford is the use of a microswitch for the stop of the lathe when thread cutting. Especially when cutting internal stuff. I know some run it backwards and then feed out, but feeding in knowing that is is going to stop within 0.1mm every time is just great . I have breaking and soft start settings. I put a 3/4 kw motor on my myford about 1hp approx. I just wish I had done it many years earlier. It is smoother running and quieter over all. The smother running shows up in the improved surface finish of parts.
Not cheap , that is true, but well worth it in my view.
|Thread: Screw cutting is over complicated|
I really like the Hardinge top slide method. As it has a cam that retracts the tool on the flank angle.
The way I set it, is set the compound at 1/2 the thread angle. Have the lever in the forward position, and the compound wound to the forward stop position. Wind the cross slid to a touch, and then go in the full finished depth. Leave the cross slide at this position. Use the retract at the end of each cut. Wind back on the compound. Take all cuts using the compound slide only.
Without the retract lever, I do the same on my Myford, and do all the feeding to zero on the compound. For most threads, 1 turn on the compound is the max required amount of retraction required.
I have done the feed only on the cross slide method as well. But prefer the feed on the compound. Unlike the youtubers, my method does not require and trig to get the depth of cut. That is set from the cross slide , the same as if you were not incrementing the compound slide.
|Thread: EN40 nitrided repair|
Get some of the same material you made them from. Create sticks of that same material, and then get it welded up with that material. Grind through the nitrided layer first for the area to be welded up. Then recut to correct profile and re nitride again. Welding with parent material is the best solution. Remove the nitrided area first, as the nitrided material is no longer the same as the original material, and it will crack trying to weld through the nitrided area.
|Thread: Recommendation for Tool and Cutter Grinder|
Wire edm is the better process to make small tools from hss or carbide. Yes you can grind such a tool on your tool and cutter grinder. But asking how long it will take, is very difficult to answer. The grade of hss steel, the type of wheels you are intending to use, the type of cooling you are using etc etc. From 40 mins to several hours will be a ball park time figure. The other issue is the precision required of the tool dimensions as well.
|Thread: Why are insert toolholders so expensive?|
Good industrial holders are expensive for many reasons, some because the retailer wants to tripple their margin, some because of the materials used, and increased difficulty in manufacturing, the heat treatment, the vibration dampening qualities, or other vibration control technology as well.
Then there is the through coolant range , where the coolant comes out near the cutting edges , like the new series of grooving and turning tool holders. These work well with coolant or chilled air for the dry cutting technology.
There is a fairly new material for tool holders so that the tool does not ring. No idea how it works or what it actually is. This is used in many of the shrink type milling holders, and some of the insert holders.
Mitsubishi part off tooling grooving
Kyocera turning tool holders
Edited By Neil Lickfold on 10/09/2019 20:29:50
|Thread: 4 jaw Self centering chuck recommendations please|
I have an Emco 4 jaw self centering chuck that is a really good and has great repeatability as well. No idea if they are still made or their price now days.
|Thread: Lathe rigidity|
One issue is that the collet is being supported by a Mt2 or MT3 shaft.
If the collet chuck was more solid, so like a plate that connected to the spindle with the collet int, would be more rigid. What you have is basically like turning a part at the end of a 60mm extension that is only 20 mm or so diameter.
Another separate issue is the bearings of the spindle itself and their influence as well..
So check the inside of the er chuck , and then see how little pressure is needed to move it 2um. It won't be as much as you might think. Next do the same but on the spndle directly, same again, the amount of pressure to move 2um. This time it should be considerably more. If it is about the same, there is something not quite right with the front bearing of the spindle.
|Thread: 4 jaw chuck axial allignment|
Using a finger type DTI can help in setting the swash of the part on the side of the jaws if it has a flange to reference from. If it is a piece that has flat sides, then running an indicator up and down the length is the only way to check it is running true. You have to spend Serious money on a 4 jaw chuck that can hold flat stock true to the run of the chuck. Another option is to use sacrificial pads that are used to hold the part. Then it can be held and as you indicate the length, tap it true at the free end. It can take some time to set up some jobs and not that long with others. Having more than 1 indicator can be helpful, as well as 2 keys for the 4jaw chuck.
|Thread: Model Turbines|
How viable are ceramic bearings for turbines these days ?
|Thread: Myford colours|
The grey on my Myford is no longer the same as the fixed steady which has been in a box in the dark for the last 20 years or more. I don't use it often. But the main paint of the lathe is either faded or oxidised or Both. If you have a sample piece like a cover or accessory, they can scan it these days and make a matching colour. New paints also have UV stabilisers in them, something that may not have been in the original paint.
|Thread: R8 spindle advice required|
The pin is only to ensure that the tools are placed in a repeatable radial position. Especially when they are made from bored in position collets. If your quill is near perfect, the pin wont make much difference.
|Thread: Wiggler or edge finder?|
I have used a Starret one for years and recently bought a ceramic one with a 10mm ceramic pad instead of the Starret 6mm pad. What I like about the ceramic, is it is un effected by parts that have become magnetic. The wigglers do work but are not as good as the Starret or the ceramic centre finders.
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