Need to cut small grooves

[smuttley]

Can anyone point me too a forum post that explains how and what tool to cut say 2mm wide by 2mm deep grooves in a cylinder head for cooling fins?

Thanks in advance,

Regards

Steve

[derekwarner_decoy]

Hi PD's....Steve ...best spend a few hours in the WEB site

Th engine cylinder heads are best left as 'heat sink common'.........& certainly can/should be insulated

The cooling fins you talk about are the increased surface area on steam lubricators .....to condense the oily water/steam oil condensate

Welcome to our PD site ...........Derek

 

[steamboatmodel]

Hi Steve,
If you have a lathe, you could use a parting tool. If you do it by hand, hacksaw blades stacked together will do it.
Regards,
Gerald

[bogstandard]

Steve,

grooves in a cylinder head for cooling fins?

You haven't told us whether they should be around the head or cylinder, or across the head, as in over the top.

Both have different techniques involved.

I gather you don't have a mill, but do you have a vertical slide for the lathe? I ask this because really, over the top finning is usually a milling operation, and really needs either of the above bits of kit to get consistent results.


John

[smuttley]

I have a lathe, but as bogstandard mentioned, I have no milling machine yet. I was after cutting fins in a cylinder or round stock for practice, as I have not been machining for long and trying different methods of cutting, for the day when I build my fist engine or two. I have a HSS parting tool, but anything other than soft metals is hard going. Just wondered how other do it and pick some tips up.

No vertical slide yet John, but the wife says she is going to get me one for Christmas (I hope).

[bogstandard]

Steve,

Because you are a total newbie to machining, I don't know if you know how to set the correct tool height, so the first crap-o-cad sketch shows the method that I teach to beginners. Tool height is one of the most critical setups you need to do, get it wrong and you will hit all sorts of problems.

The  line on the sketch is in fact a strip of metal, I use an old six inch rule. Gently trap the strip between the tool tip and the workpiece, then look from the end. By comparing what you see with the sketch shows what you need to do. Once the strip is vertical, you are close enough on centre height, and you should have no machining problems on the height score.

Cutting finning grooves.

Start simple, no fancy stuff, just get a nice even row of fins, equally spaced.

Look at the second sketch, the top shows what you want to achieve. Select yourself a relatively soft material to practice on, brass, aluminium or nylon. No steel for the moment, start simple and build up to the difficult stuff.

You will need to grind yourself up a grooving tool. For shallow depth cuts, the one I have shown is perfectly good enough, you don't need the tip tapered front to back yet, parallel sides will do OK. Make sure you put the top rake and front rake on, something near is close enough for now. Also ensure that the tip is square to the sides, not angled.

The easy way now is once you have set the tool to the correct height and square to the job is to wind your topslide fully back and ensure it is lined up at 0 on the degree scale. Then using the saddle fwds/back and crossfeed get the tool to touch the end of the job as shown. Lock your saddle so that it cannot move side to side then carry out the numbered sequence, feeding sideways using the topslide.

For about 3/4" bar, a speed of around 400 to 500 rpm should be OK, if using a soft metal a little squirt of WD40 will help with the cutting action, more so if aluminium is used.

Practice is the only way to do this exercise. Once you can get good results doing it like I have said, then you can progress onto more complicated tool shapes and materials.

I am not being patronising, but until you can get the basics under your belt, you shouldn't take too big a step. It is better to have a lot of little successes rather than one massive failure.

Just take everything steadily and logically and all of a sudden, things will start to fall into place.

Hope this has helped.

John

[smuttley]

John,

Your a genius, your method for finding centre is fantastically simple and effective. I am working at the moment, but as soon as I can get back in to the shed, I will give it a shot,

Thanks again,

Steve

[bogstandard]

Steve,

Not a genius at all, just passing on information I have picked up along my journey.

With regards to tool height. Derek brought to my attention thru PM that really the tool should be set a couple of thou below centre, and of course he is perfectly correct. But at this time, rather than confuse the issue, setting spot on will be fine. It all depends on how beefy the toolpost is and the size of cutter. Someone like myself who has a very rigid machine and rather large cutters (16mm) would need to set that lower cutter, but it is now readily accepted, with lighter machines and smaller cutters, the tip will be deflected downwards by the action of the cut.
It is this phenomenon of tool deflection that causes most of the problems of chatter marks on smaller 'hobby' type machines when taking heavier cuts. So playing around slightly with tool heights (only very small settings) and keeping the tool tip as close to the toolpost as possible might eradicate some of the problems.

John

[derekwarner_decoy]

Hi PD's.....bogstandard also suggested in a PM that these newer .......assumed as 'cemented carbide' triangular bits that have 3 cutting faces on one side ....then three faces on the obverse ....or reverse.........tips may not be as crisp+sharp as a home ground HSS tool piece....& hence the issue of 'Tool Pressure' ...........to attain a certain result..

Whilst John acknowledges my old  training........I am totally lost with the concept of these new THINGIES ....in the tool post...of my planned lathe/mill combo unit  of the future  .... Derek

[steamboatmodel]

The 'cemented carbide' triangular bits are primary used in large industrial machines (high horsepower, massive and rigged), ether manual or more likely CNC. The type of machines most of us acquire do not have the HP or rigidity to use them as intended, and quite often a properly sharpened HSS bit will out perform them for the type of work we do.
Regards,
Gerald

[bogstandard]

Gerald,

I couldn't agree with you more.

Here is an article I did for a machine retailers site, the third post, in reply to the second, shows my real opinions on tungsten tooling, and the problems encountered with it in the modern day.

http://www.atfreeforum.com/chesteruk/viewtopic.php?t=315&mforum=chesteruk

It seemed to have touched the spot, as the chappie never replied.

John

[smuttley]

Looks like I have a lot of reading to do.

Here is a pic of the type of tool I am using.

I have a left and right cutter and a boring bar only at present, all 12mm to suit my tool holder. They are not cheap to buy at around AU$250 with ten tips. As a NEWBIE I have already come to the conclusion, that the most important part of lathe work is a correctly set up machine, second to this is the cutting tool, not only using the correct tool, but the danger involved in using them incorrectly. I have grate respect for anything moving and flying in my direction.

I have not broken a tip yet, as I am going very, very slowly (shallow cuts), this maybe a problem as I may not be cutting deep enough for the type of tip I am using and at the correct speed. I do feel that my lathe is underpowered at times and labours with harder metals, when this happens I back the tool off and take smaller cuts, and again this could be wrong.

[steamboatmodel]

One of the problems with the 'cemented carbide' triangular bits is they do not handle interrupted cuts too well. I do use them (I also use HSS), and most of the ones I have chipped have been on either interrupted cuts or intermittent cooling (another thing they don't like).
Regards,
Gerald
PS John,
I can't agree more your posts in the link. I think you should copy them and have Eddy put them in a sticky.

[derekwarner_decoy]

Hi PD's....& this is a good learning thread......but  ..Steve ....you still have not mentioned why you want to provide cooling fins on an engine cylinder that should be kept at an optimal constant hot temperature

The steam exiting the model boiler is in the order of 150 degrees C [without superheat] & we lag the boiler to engine steam line to attempt to maintain the highest steam temperature to the engine for firstly ......engine rotation but also expansion of steam to do work.... which naturally reduces the temperature of the steam [this expansion of steam is sort of like FREE energy..but if we do not harness it ....it is wasted] .....Derek

[smuttley]

......but  ..Steve ....you still have not mentioned why you want to provide cooling fins on an engine cylinder that should be kept at an optimal constant hot temperature

Sorry Derek,

I did mention further up the thread that I wanted to practise small grove cutting in cylinders or round stock. Not for cooling steam (changing phase), just for decoration of say support pillars. I will be building other engines besides steam, hopefully build petrol, compressed air and Stirling engines etc. I was more after the technique of how others do this.

I must mention that I work in a very large refinery in Western Australia, part of my job is to look after the steam distribution lines, steam trapping, condensate recovery systems and shell and tube heaters, we consume over 650 Tonnes per hour from our own power station for heating our process. My expertise is in condensate induced water hammer, eliminating this and educating others of it's dangers. As you say, cooling steam is the last thing one would want to do, other than de-superheating down to or near steam saturation temperature for heating.

I have for a long time wanted to build my own steam engines, as I am fascinated by the stuff,

Regards

Steve