Member postings for Neil Lickfold

A really great idea. Thanks for sharing.

You blue is too wet to get best reading results. Put some blue onto a paper towel or a piece of printer paper. The paper will wick away the excess oil. Then you will get a much better read of where to scrap. As you have it, it can wick to an area and create a false impression. You are on the right track with taking off only on the very tight spots.

Neil

There was a youtube video on drilling square and lobbed holes. It had a template that the tool followed and that inturn generated the shape hole.

One other option, is to make your own. Requires a lathe and a method to slit them, and debur afterwards. Pre hardened steel around 40Rc like 4340 steel bar works great. Can still be all done with hss tooling if you don't have carbide, and can be slit with a hacksaw or junior hacksaw if you don't have a mill with slitting saws.

Neil

My best collets are the regofix high precision ones for my ER32 collet chuck. The best nuts are the Regofix ones as well. As far as tightening goes, the regofix have a special coating on them, called the Hi Torque series. I use a bearing one at work as they wont spring the cost for a regofix brand one.

It is important that the thread of the chuck is concentric to the inner taper. The cheap nuts I bought are junk. Need to be set up and have the taper of the nut made concentric to the threads. Another job that is easier said than done.

I did get some er11 collets off ebay that were rated AA quality and said that they were within 0.008mm for tir and they are definitely better than that.

There was another company from Taiwan , making an ER system and the nut has a slot in it for a special spanner that allows the nut to be done up or undone and extract the collet. No spanner flats etc on the nut and no eccentric retention piece as well. The threads were ground and the nut taper ground as well.

They also work very well. Tried finding them to take a photo but are in the moving lost stuff at the moment.

Most F2A engines use a Bronze or BeCu for the liners, with 30% Si piston material. Some still use steel balls while most now use ceramic balls in the bearings.

Awesome Barrie. The work that has gone into that engine is nothing short of incredible. Quite a team effort from design concept to the manufacturing. I have seen the amazing gear Rob has and the skills he has to us it as well. The edm of the ports really is something, and will be a big part of the consistency and the performance gains that does not happen with every casting. The precision that is on one of these is hard to explain to people and to why it is needed. I like the way they can calculate quite accurately the thermal changes in a running engine and then the dimensional changes that are occurring. Some parts 5 micron doe snot really matter, other parts a 5 micron error makes it become an also ran engine.

Thanks for the posting and pictures etc.

Great to see.

Neil

A photo of what you are getting is a bigger help. And what tooling you are using as well. Then more accurate advise can be offered. There are some carbide inserts that are very sharp these days. They work well on lower powered home hobby lathes. The very sharp inserts are made for cutting plastics and Aluminium. But do work very well on steels with light cuts. Sometimes you need a small nose radius to reduce deflection and tool cutting pressure.

Sometimes the poor surface finish comes from other factors, like vibration from the motor or belt drive system etc.

So no one answer to the problem. A photo can help to eliminate the various options.

Nothing wrong with hss steel and learning to grind and hone your own tools. Sometimes a shaped piece of hss is the best option , especially for forms or repeating short length tapers etc

Neil

We have at work a Darex drill sharpener. It works well, but I still hand grind mine. Yes with deep holes, the more accurate you have the drill sharpened, the straighter the holes turn out. And yes they take less pressure when sharpened correctly. With most drills to 1-1/4 (32mm) I just drill directly. No pilot , just start from a centre drill.

Set up is important as well. Things to check is tailstock alignment when drilling in the lathe.

In my experience the life of the resharpened drill is seriously effected by the surface finish on the grind itself. Rough out using the standard grade wheel of 40 or 60 grit, and then finish with a fine wheel of 120 or finer. An alternate is to hone the edge. These will last every bit as long a s a new drill, and if sharpened correctly will drill a hole to be better than 0.05mm of the drill size and have a roundness of the hole better than 0.03mm tir. Hand sharpened or fixture sharpened should be giving the same results. Hand sharpening drills is a skill that some can never manage. Although it looks ok, when used won't be. You know when it is right as the swarf comes off fairly evenly from each drill flute. I have seen many new drills that require a touch up to get them to drill proper holes.

Out here I can only get it from an industrial chemical supply place, and have to have a current chemical handlers licence to purchase and use.

Well out of curiosity of looking at the new Kitchen counter top, engineered stone. With the light and reflections looks fairly flat. I set up a dti and a plate with 3 point and moved it around the place. The whole area is better than 0.04mm. The majority of the centre area is well better than 0.02mm. So instead of buying a 1m granit plate for the shop,when she is not home, the kitchen top will work just fine. Thanks for the heads up on that. I have no idea how they even get them that good. Not often I am marking out pieces longer than 300 mm. But when needed have ample space as long as it is not heavy, oily or will not scratch the top. Just have to make sure the height gauge base is clean first.

I bought a few years ago a digital height gauge. One of the cheaper ones. About 1 weekend after using it a lot that weekend, wish that I bought the type with a hand wheel like Mitutoyo make. Did not need to be Mitutoyo but that type. My friend did pick up a brand new Mitutoyo for a rediculously cheap price, because they were no longer going to be stocking that model any more. Ahhhh

Sometimes you can spend more time getting what you want from inferior gear, and the right gear allows you to have Sunday free to enjoy a nice meal and glass of wine.

With internal O ring grooves, I use a tool with 0.4mm corner radius and is 1.5mm thin. On the last pass, move it along to make a finish pass. A 3mm groove I take in 3 passes and leave 0.1mm for the final clean up on along the diameter. Having a vfd and finding the best rpm is the easiest way. Having the tool slightly above centre I found is needed for internal grooving, around 0.1mm usually does the trick. At centreline, as the tool drops, it is actually taking a deeper cut. Above centre line the tool as it drops, takes a lesser cut, unless it goes too far and then gets deeper clearly.

They are a great little tool. Many years ago, Tesa were offering them with their finger dial indicators in a promotional offer. The kit came with shims to adjust the centre line of the indicator ball. It is a great exercise to make one as well. It is interesting seeing the different approaches to making the parts.

Neil

Some materials are difficult to get a good finish on. Sometimes having the surface shiny may actually be a worse actual surface finish than one that looks dull but has no tearing. In general , a depth of cut of 1/4 the radius of the tool ,and a feedrate of 1/4 to 1/8 feedrate. So with a 0.4 radius tool, a 0.1mm depth of cut (0.2mm diameter) and a feed rate of 0.1mm to 0.05mm per rev .Sometimes an oil can help improve the surface finish, sometimes a soluble coolant can help as well.

Use a marker pen, on the outside of the spindle. Mark where the high side is and the low side and 1/2 way between. Now keep rotating, to see if it is consistently high on the high side and low on the low side. If it is, then the bearing is unlikely the cause. You can tilt the head over, and reskim the inner taper of the spindle to get it true on the front taper. If you snug the gibs and raise and lower the column, should be able to make it as round as the concentricity of the spindle bearings. The more difficult part to test is the concentricity of the parallel register, further up inside the spindle. If that has a run out of 0.02mm, that error will show about 75mm below the spindle .

Neil

You need to dress the mounted point with a sharp diamond, not a dressing stick. Looks like I did not mention that important part. Sorry. You can easily see if the wheel is dressed sharply or not,by just putting a scrap piece of the material to be ground, against the wheel, or mounted point.

Neil

I grind cork and rubber with a Dremel on my lathe. I use the hand extension and made a simple clamp to hold it .I use the sanding drums, 120 grit or 80 grit for a fine finish, and the 40 or 60 grit for the roughing. I use a vacuum cleaner hose very close to the set up , mainly to suck away any rubber off the sanding drum, to reduce it from being blocked. This turned out to be quite important and keeps it all cool as well. The fine grades, need to be very sharp, and for my set up, they do not take a lot of volume of material . The course grade will take away a very large volume of material. I did make some 38mm drums that screwed onto the handpiece, and used the pre adhesive commercial sanding belt material. It worked very well. I quickly learnt why they have a spliced joint arrangement. Contact adhesive worked very well for using carborundum wet/dry paper. The carborundum paper in eiether the sanding drums, or on my 38mm drums, worked the best of the various paper types available. For smaller holes in urathane, I use the cheap open structure mounted points. The white ones were best, but the pink ones also worked quite well, Use the coursest grit available. The course desic diamond wheels also work, but will block or clog quite easily. Using just some water with a small amount of dish wash water to break down it's water tension worked quite well. Small holes being around 3mm to 12mm ID.

Hope this helps some people out..

Neil

Out here during this corona virus lockdown, places are not taking cash. Supermarkets are refusing to accept cash for the groceries. Cards or go hungry.