Stirling Engine : Laura

A. I realise now that I should have marked out that smaller hole BEFORE I drilled the larger centre hole ! But I have stuffed up like this before and as Hopper suggested it can still be marked correctly. Yes, I can see how the three jaws of the chuck will help to mark it out.

B. Regards the glass cylinder : I just did not want to make any part of the engine out of glass. I can see now why aluminium will probably not work and that stainless might be really stretching my small lathe. I do have a set of engineers drills (1 to 6mm in 0.1mm increments ) so maybe if I took it slowly, I might be able to make a stainless steel cylinder (or find one from somewhere). I can drill mild steel in this lathe. How much tougher is stainless steel ...twice as hard ?

C. All the drilling I am doing here is done on the lathe. I do not have a bench drill, only two hand drills (corded and cordless). I was thinking of mounting the corded drill in a stand and making a bench press out of it but I am not sure how successful that idea would be. You can buy the stands from ebay.

D. The parting tool was definitely set dead square. The edge of the parting tool lines up exactly with the edge of my top slide which is very convenient. I was very careful to get it square. I need to get this problem sorted out before I do anymore parting off. The top edge of the tool is thicker than the bottom edge but that should not be the cause as only the top edge is making the cut.

E. I will try some sort of packing with washers in the lathe and attempt to grip the discs for a facing cut using the external jaws. This should be interesting...working very close to the chuck !

Especially when working close to the chuck, after setting up, it is a good idea to turn the chuck and spindle one or two full turns by hand (with power cord unplugged). Do this to be sure nothing is fouling the chuck jaws or carriage, before switching on.

With most drill stands I have seen for holding corded hand drills, it is difficult to get the drill set up truly 90 degrees to the table and keeping it there. The frustration is not worth the effort. Small drill presses have gotten very affordable in recent years and a good one will be a pleasure to use for dozens of jobs in any shop. I'd look for one if I were you. If shopping for one, take a 6" square and verify the table is at 90 degrees to the column and a drill in the chuck is 90 degrees to the table. Also extend the quill as far out as it will go and wiggle it - if there is perceptible play, look for a different one. For this reason it is wise to buy a far-eastern-made drill press in person.

Good luck, JD

I have machined the ''domed'' surface of those two disc. I used the same internal jaws and simply set the discs in the chuck to run true by eye (with a small amount sticking out) and took facing cuts with a LH tool. It actually worked ! I did try to use the external jaws and washers for packing as per the above suggestions but I just could not see how to do that. Anyway, it is done now and I have two discs to work with. I placed them on my graph pad to get them centred, marked off the M2 hole and then punched it....looks good. I also punched the hole in the edge for the M3 grubscrew. I then realised that I could not drill this by hand ; I am going to need a drill press before I go any further.

There is an axle supplied and it is the correct diameter of 6mm (actually 5.97mm). I just had to face off the ends to get it to the correct length. I then decided to try turning my own axle from some 6.35 steel rod I have. What a mess : I just could not get a good finish on it. I did not think I would need a fixed steady for this as it is only 60mm from the chuck to the dead centre ? I did try to polish it up with some 400 grit paper but it seemed to make things worse. I am really not sure what went wrong here today but it was not the fault of the lathe.

Edited By Brian John on 13/10/2015 08:05:27

Edited By Brian John on 13/10/2015 08:06:55

Edited By Brian John on 13/10/2015 08:07:31

Edited By Brian John on 13/10/2015 08:08:05

Edited By Brian John on 13/10/2015 08:29:30

You may be able to devise a way of drilling the holes, if you look at your lathe you'll see that it is a drill press laid on it's side, so you might be able to hold the parts in the tool post, and the drill in the lathe chuck, or if the tail stock drill chuck will fit in the head stock maybe use that.

Ian S C

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

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

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Or alternatively, do as I keep suggesting:

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

MichaelG.

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

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

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

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

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 ?

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

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.

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

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

**LINK**

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

> 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

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

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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.

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.