Stirling Engine : Laura

[Brian JohnParticipant @brianjohn93961]

Yes, was thinking about that today. I have not seen anybody do that before so I assume that it is not a common practise. What is really needed if the lathe is to be used in this way is a milling attachment so that the work piece could be moved up and down.

The tool holder could be used to hold the disc so that the hole for the grub screw could be drilled but I would need a parallel shank arbor for the drill chuck to be held in the lathe chuck. I could not hold a small drill in the lathe chuck. The M2 hole is not so much of a problem ; I could drill that with a hand drill.

Edited By Brian John on 13/10/2015 13:18:04

[JasonBModerator @jasonb]

The M2 hole is the one that needs to be the most accurate, any slight tilt of your drill from perpendicular to the side of the crank will mean the crankpin leans and your engine will bind.

Get your faceplate sorted out and you can clamp the work to that and drill it accurately

 

Whats the smallest your lathe chuck will close down to? you could alwanys make a couple of split bushes to allow you to hold common sized small drill bits in the lathe chuck. Then the disc could be held in the toolpost to drill the M3 tapping hole

Edited By JasonB on 13/10/2015 13:28:28

[Michael GilliganParticipant @michaelgilligan61133]

Posted by JasonB on 13/10/2015 13:23:11:

Get your faceplate sorted out and you can clamp the work to that and drill it accurately

.

Or alternatively, do as I keep suggesting:

Spend a few minutes learning about 'Wax Chuck' technique, as used by watchmakers.

MichaelG.

[Brian JohnParticipant @brianjohn93961]

Wax chuck technique : very interesting. I will try it next time. I think I would use Loctite 263 rather than super glue.

**LINK**

One other decision to be made now : drill the two holes in each disc first or cut away the material to make the crank shape first ? I think I might tackle the crank shape as I am more likely to stuff this up. I also need to hunt around for a drill press before drilling the M2 and M3 holes. I am not at all confident about drilling in the lathe.

My lathe will close strongly on a 2.5 mm drill bit but it is not quite gripping a 2.0 mm drill bit.

My face plate and clamping kit have been ordered from the US but will take about 3 weeks to get here.

 

Edited By Brian John on 13/10/2015 15:12:50

[Brian JohnParticipant @brianjohn93961]

I will be buying this drill press tomorrow :

**LINK**

It is currently on special for $96 until Friday. I have been to have a look at the display model today and it looks pretty solid but obviously they do not have one set up to use. The chuck guard can be removed ; it is not connected to any reed switches. I am really not sure why it is there as metal chips are more likely to fly off from BELOW the chuck guard where the drill bit makes contact with the metal. 

I will also need a machine vice which I do not have at the moment so maybe one of these will do the job :

**LINK**

http://www.ebay.com.au/itm/Engineers-Drill-Press-Vice-Heavy-Duty-Bench-Clamp-4-/140511149657?hash=item20b71dfe59

http://www.ebay.com.au/itm/4-100mm-DRILL-PRESS-VICE-Bench-Vise-Clamp-NEW-/251150517862?hash=item3a79bcc666

I attempted to cut out the shape of the cranks today : complete disaster. I won't post any photos….I am sure you can imagine ! I thought I could just roughly remove the metal with a dremel tool and do the rest by eye with a hand file but I will have to mark it out carefully next time.

I made two more discs today. I am getting good at this    but I again got that dome shape when parting off. The parting tool was definitely set at right angles to the piece so I am not sure what is happening here and I need to get this problem sorted out. I faced them off by setting them up to run true in the chuck and just leaving about 2mm sticking out so that I could machine it (getting good at this too !).

Tomorrow I will buy a large brass nut to make a wax chuck using Loctite as the glue. I think it is something worth learning and will be very useful in future. I can see myself making a lot of discs before I end up with useable cranks

NOTE : I am aware that I will need to buy more brass bar stock to make the small cylinder and the cylinder cover as I am using it up to make the small crank.

Edited By Brian John on 14/10/2015 08:06:19

Edited By Brian John on 14/10/2015 08:06:54

Edited By Brian John on 14/10/2015 08:11:31

[JasonBModerator @jasonb]

Brian if you look down onto the top of the parting tool is the cutting end ground square across the end or at an angle? If at an angle that will want to push the blade sideways.

That firstvice may be a bit sloppy, the surface the moving jaw runs against looks to be painted, this means there will not be a close fit, the moving jaw will tend to lift as you tighten the vice and tilt the work

 

Edited By JasonB on 14/10/2015 08:15:25

[Ian S CParticipant @iansc]

If you take a bit of steel wire, around 20/18 swg, and wind that tightly around the shank of your 2 mm drill you might be able to hold the drill in the lathe chuck. Another way of doing it if you have, or can get an old electric hand drill that you can pull to bits, take the chuck with it's shaft and clamp that in the chuck on the lathe, I use one that way both in the lathe and milling machine as the bigger Jacobs chucks won't hold drills smaller than 1/16" /1.5 mm.

Ian S C

[Brian JohnParticipant @brianjohn93961]

Jason ; there is a slight angle. I will have a go with the bench grinder tomorrow using the fine grit wheel. I may be able to straighten that edge…..or make a complete mess of it !

Which vice of the other two looks the better ?

Ian : I do have a corded drill which I was going to put in a drill stand. It will not be needed for that purpose now that I will be buying a drill press so I could always take that one apart. We assume that the chuck will have some sort of useable shaft attached to it ?

[Jeff DaymanParticipant @jeffdayman43397]

I agree with Jason's comments about the two vises you show links for. I've had a couple of that type of vise and they are disappointing to say the least. The jaw has too much movement and the base is usually too large for the table of small drill presses. The long slots never seem to line up to allow easy clamping to the table. A wide jaw is not an advantage except for when drilling long barstock.

A much better type is the Palmgren drill press vises. Link below. http://www.ebay.com/itm/PALMGREN-6-Drill-Press-Vise-1-5-In-W-Open-1-1-2-In-/381023984863

These have a small footprint, they have a close fitting jaw, can be clamped with normal c-clamps to the table, can be flipped on their ground flat sides to do ops on the ends of cross drilled stock, have prismatic grooves in the jaws to help hold round work squarely, and are really well made. They sell used on ebay for $50-80 USD. They are the best ones I have found, by far.

There is one small but annoying problem with these vises. If the handle ends up vertical after tightening, it can get caught on the edge of the table as it hangs below it. I did a cheap fix on mine by placing a rubber o-ring over the screw boss crossways over the moving handle. This gives enough friction to hold the handle up away from table edge but does not interfere with handle working. 10 cents well spent…. good luck, JD

[Brian JohnParticipant @brianjohn93961]

Is this what you mean :

**LINK**

By the time postage is added it would cost almost as much as the drill press itself but I concede that a good vice is necessary.

[Jeff DaymanParticipant @jeffdayman43397]

Hi Brian, no, that is not the vise I meant, although it is similar. The one I tried to send a link to has no lugs at the sides – it is ground flat both sides. Not sure why my link does not display as a link. I'll try again below.

**LINK**

A good vise will make a big difference in everyday ops. I fought with cheapies for years before finding the Palmgren one, and when I started using it, all of a sudden it was not a struggle anymore to get work clamped square and straight for drilling and tapping, with minimal effort and no more slipping jaws / ruined work. It has paid for itself many times over through the 15 or so years I've had it and been a pleasure to use almost daily.

Edited By Jeff Dayman on 14/10/2015 13:49:41

[Brian JohnParticipant @brianjohn93961]

Aha, I was looking at something similar today (toolmaker's vice).

**LINK**

 

 

Edited By Brian John on 14/10/2015 13:56:15

[Neil WyattModerator @neilwyatt]

> I am really not sure why it is there as metal chips are more likely to fly off from BELOW the chuck guard where the drill bit makes contact with the metal.

Probably to make it look safer.

Neil

[Brian JohnParticipant @brianjohn93961]

I think these things are compulsory on all machines being brought into Australia now. As long as they are present on the machine nobody ever stops to consider whether they actually make the machine safer. In this case I think it is just a nuisance although it does swing out of the way nicely unlike some other ''safety'' shields I have seen !

Why is it called a toolmakers vice ?

Edited By Brian John on 14/10/2015 14:31:44

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Brian John on 14/10/2015 14:31:15:

Why is it called a toolmakers vice ?

.

Because it's a style used by Toolmakers

… Specifically; it is capable of being laid on its side, for marking out using a scribing block.

MichaelG.

[Jeff DaymanParticipant @jeffdayman43397]

Neil. I think the intent of the "guard" fitted to drill presses is to a) keep fingers and clothing away from the rotating chuck b) to make it more difficult to leave the chuck key in place c) contain rising spiral chips when drilling from whipping out too far and causing cuts to hands nearby holding work.

They don't really succeed at any of these jobs. A bit of user knowhow and common sense goes a lot further, ie a) keep your fingers away from rotating assys if you don't want to lose them b) ALWAYS remove chuck key before starting, and double check it, and/or use a spring plunger key that CAN'T be left in, c) while drilling lift off the down pressure when you see a rising spiral chip get 1" long or so.

If you have to clear chips while chuck is rotating use a throwaway cheap paintbrush. Also good for applying a drop (and I mean a drop) of oil. If the worst happens and the brush gets caught in the works, let go of the damn thing right away.

Good luck, JD

PS the slots on the side of the toolmaker vise parallel to the ways are for finger clamps to hold it down. C clamps on the ways can be used too, but protect the ways with a piece of cardboard or heavy paper if you do that (as well as throwing a rag over it if the foreman comes by). There may also be tapped holes on the vise sides or underside to directly fasten to plates or table with screws.

[michael mParticipant @michaelm]

Generally, the drill press vices sold now do seem a bit dismal and more oriented towards less demanding work. Sadly no longer manufactured, but if you could find a s/h "Nippy" vice in good condition, maybe on ebay, they're very good for the job.

The toolmaker's vices, though very good in their own right, are not always the easiest thing to fit to many drill press tables due to the lack of lugs. Maybe you could consider a machine vice, usually better made and more solid than drill vices and it would be ideal if you acquire a milling machine.

This one, available in Australia, may be worth checking. The prismatic jaws are very useful for less common set-ups.

http://www.ausee.com.au/shop/category.aspx?catid=5116

Michael

[Brian JohnParticipant @brianjohn93961]

I bought the drill press today but I have not set it up yet.

One of the cylinders is to be accurately reamed out to 10mm using a 10H7 reamer (now on order from china). Should I order a 9.8mm or 9.9mm drill bit for use prior to reaming ? I already have 6, 7, 8 and 9mm drill bits so I will drill up in steps.

[Jeff DaymanParticipant @jeffdayman43397]

The old rule of thumb I was taught is never take out more than .005" (0.12mm) from a hole with a reamer. Has worked for me for many years.

So a 9.9 mm drill would be in the ballpark for a finished 10 mm hole – IF the drill does not cut oversize- they often do.

It is worthwhile doing a test hole with the 9.9 drill to make sure your drill does not overcut 10mm or more in dia. You could also turn up a 9.88 dia plug gauge on the lathe on the end of a bit of scrap bar which should just enter a 9.9 hole with no slop.

You could use the 9.8 drill, check the diameter, and if it is truly 9.8, run the 9.9 drill thru, then ream.

Good luck, JD

[Brian JohnParticipant @brianjohn93961]

Which raises the point I have been considering for a while : how do you accurately measure the diameter of a hole ? I have digital vernier calipers to take an inside measurement but unless you are exactly on the diameter then your reading is going to be slightly out.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Brian John on 16/10/2015 07:55:59:

Which raises the point I have been considering for a while : how do you accurately measure the diameter of a hole ?

.

Brian,

There are Bore Micrometers, and various types of 'Plug' Go/NoGo gauge available, but; for what you are doing, the [undamaged] shank of a drill should suffice.

MichaelG.

[HopperParticipant @hopper]

Yes, drill bits are a good way to measure hole size. If you want to get fancier than that, buy a set of ball gauges. You put the ball inside the hole, expand it until it just fits the hole nicely, pull it out and measure it with your vernier. (Although I prefer an old-fashioned micrometer for more accuracy.)

I got a reasonable drill vice from Allied Bearings on Aumuller Street for not too much money. About 100mm wide jaws I think. They may have smaller ones, not sure. Cheap and cheerful but has been doing the job for a couple years now.

[Brian JohnParticipant @brianjohn93961]

Okay, I will use the drill bits for now. I suppose the important thing is that the piston closely fits the cylinder (or axle in the hole) regardless of what measurement is being shown on any type of  gauge. So as you get closer to size, keep testing for fit.

Hopper : I will drop in to Allied bearings next week and see what they have. Bunnings and Masters are useless for this sort of thing !

Edited By Brian John on 16/10/2015 14:22:03

[Brian JohnParticipant @brianjohn93961]

Allied bearings do not have any machine vices with the horizontal and vertical notches. I thought these would be essential for a machine vice ?

I set up the drill press today and tested it. I will have to return it as there is excessive vibration in the motor and the chuck moves slightly to one side at the bottom of the throw. What is the part just below the pulley housing ; it has a wing nut on a spring loaded bolt which pushes against a plate ?

What is an acceptable speed for drilling metal ? It is currently set on the middle speed 1220 RPM.

 

Edited By Brian John on 17/10/2015 06:59:22

Edited By Brian John on 17/10/2015 07:29:43

[Speedy Builder5Participant @speedybuilder5]

BJ, that bolt / spring is there to reduce vibration. When you change belt position, First slacken off the wing nut to allow some slack in the belt, change the belt position and then push the motor in a direction which tightens the belt, then do up the wing nut. On new machines, often the belt is a bit "stiff" and the spring / plunger AKA bolt are not strong enough to correctly tighten the belt.
Some of us slacken the wing nut at the end of the day, most of us forget!!
As for speeds, just look up drill speeds on this site or internet. They will vary due to size and material – also lubricant and type of drill.
BobH

[Author]

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