Super Simplex – Motion Plates from Model Engineers Laser

[Neil WyattModerator @neilwyatt]

Posted by Stewart Hart on 16/01/2016 08:17:49:

No 34 is a number drill size its an old imperial system you have No drill 1 to 60:- 1 being the largest 60 the smallest above 1 you go to letter sizes, the system is mathematical based I think its a geometric progression I'm sure some smart Alex will correct me if I'm wrong, just do a google search for number drills and all will be clear. Its is a good system though and still in widely used.

I've been trying to find a solid , proven reason for what the steps are for years, and as far as my digging says, there is no formula, sometime the steps are tiny (0.001&quot sometimes several thou, even in small sizes.

My guess is they are basically the steps that one or more drill manufacturer's dies used to produce, plus some useful sizes (for tapping or certain fits) that may have needed to be added.

[KWILParticipant @kwil]

Neil,

Closest is Stubbs Steel Wire Gauge, almost but not quite. Still, stands us in good stead for a drill size range.

[David WassonParticipant @davidwasson11489]

I used 4-40 flat head screws with a recessed hex drive. The first screws I used on my Super Simplex had heads. Although they mostly were not in the way of the wheels, the countersunk flat screw made for a much neater installation. I would go with flat heads for sure. You can just see a row of them behind the wheel.

David

[John KinnaneParticipant @johnkinnane64270]

Thank you David I am going to do the same it looks very neat. I am however going to invest in a good machinist's book such as the little black book. Thank you to everyone who answered my thread, all your comments are greatly appreciated. Kind regards John Kinnane Tasmania

[Speedy Builder5Participant @speedybuilder5]

So here we have it – an explanation of number drill sizes – its all in the dream world of aesthetics – apparently !! And after reading it, I still didn't fully understand how SWG affected Number drills, but some interesting reading all the same.
**LINK**

BobH

[Michael GilliganParticipant @michaelgilligan61133]

Great find, BobH

Many Thanks

MichaelG.

[John KinnaneParticipant @johnkinnane64270]

Greetings everyone from Tasmania I would like to pose a question on taping. Is it important that every time you tape a hole that you finish up with a plug tape, no matter how small I would like to know if you have to do it every time .

Thank you John

[Michael GilliganParticipant @michaelgilligan61133]

Posted by John Kinnane on 18/01/2016 09:46:29:

Greetings everyone from Tasmania I would like to pose a question on taping. Is it important that every time you tape a hole that you finish up with a plug tape, no matter how small

.

John,

Plug taps are only usually needed for blind holes.

… If you are tapping through a plate, then the Taper [First], and Second taps usually have ample lengths of full-form.

MichaelG.

[David WassonParticipant @davidwasson11489]

I completely agree with Michael. All of the holes in the frame spreaders are blind, so, yes, they all get a plug tap in each of the threaded holes. When you drill these holes, drill them deep enough to give plenty of clearance for the end of the tap.Start with the taper tap and finish with the plug tap.If you have not tapped small holes before, it might be a good idea to practice on a test piece are few times. Small taps are easily broken in the process, especially if you have not done this type of work before.. Also, make sure your taps are sharp. I bought brand new taps before starting the spreaders. Lots and lots of blind threaded holes here!! Also, consider High Speed Steel taps versus carbon steel. The HSS taps stay sharp longer, but are more difficult to remove if broken. All of my spreaders were tapped with HSS. Also, some sort of a guide to keep the tap straight is helpful. It can be as simple as a block of metal that has a hole drilled straight through it. Put the block over the hole you want to tap, and put the tap through the hole in the block while keeping the block against the work.

David

[John KinnaneParticipant @johnkinnane64270]

Thank you got the very helpful advise Tassie John

[John KinnaneParticipant @johnkinnane64270]

G'day David I looked at the 4-40 countersunk bolts, there look very small including the heads, how long are the one you put in. Thank you John

[John Andrews 2Participant @johnandrews2]

Hello John,

I live in Melbourne, and I have followed your attempts to come to grips with this hobby with interest.

It's pretty obvious that you will be struggling to build the Simplex and you need some help.

What is being offered via the forum is excellent advice, but I feel that some personal contact would be very useful.

I don't know in which part of Tasmania you live, but there are three clubs ther of which I am aware.

They are at Evandale, near Launceston, Morven Park, Barclay St., Every Sunday, (Mail address PO Box 1422, Launceston),

Hobart, Lindisfarne, 289 Flagstaff Gully Rd, 1st and 3rd Sunday ( PO Box 930 Rosny Park 7018),

and North West, Ulverstone, Maskells Reserve, 51 Alexandra Rd, 1st and 3rd Sunday.

I only know one person in Tas in the hobby, and that is Peter Lawson at Evandale, and I'm sure he would be able to advise you. Tas is pretty small so no matter where you live, you should be able to find a club. You could also buy Australan Model Engineer – the January-February edition 2016 has a listing of all clubs in Aust and NZ.

Best of luck.

It is a long job. My current loco build has been going since 2008

John A

[John KinnaneParticipant @johnkinnane64270]

Hello John thank you for suggestions I am 58 yo and have never attempted anything like this but I have always had a passion to build one. I am joining the Hobart miniature steam society in March, and I have already contacted them on what I am building, and they are very helpful. In the intrum I am persevering with it. The biggest problem is getting my head around British Associaion and imperial measurements, I do feel confident that I will overcome this in time, but for now I am reading a lot I have subscribed to the English and Australian model engineering mags. This forum I find very helpful, I know that it will take me a long time to build the Super Simplex but I am in no hurry, and prefer to take my time. Thank you again John it was very kind of you to reply to me. Regards John Kinnane

[David WassonParticipant @davidwasson11489]

Hi John,

I'm gad you found a club so you ca talk to someone face to face about your project. As for the screws I used on my frame spreaders, the 4-40 flat head screws are 5/16" in length.

David

[John KinnaneParticipant @johnkinnane64270]

Thank you David John

[Neil WyattModerator @neilwyatt]

Hi John,

Sorry if this confuses things but SOME tap sets have taper and second taps that are slightly undersize compared to the plug tap.

Simple answer – if the screws are a tight fit, run the next size tap into the hole… if not, don't bother.

Neil

[John KinnaneParticipant @johnkinnane64270]

Hi David thats very good of you to offer the chart which I would like. How do you go about sending a private email address as I have never done it before and do you know where I could buy a set of tap guids in ba. That would be great regards John

[David WassonParticipant @davidwasson11489]

Hi John,

I have sent you another PM with my email address.

David

[David WassonParticipant @davidwasson11489]

As mentioned at the very beginning of this thread, a "fix" for the incorrectly placed window for the connecting rod, is to simply mount the motion plate 1/16" below the top of the main frame. A result of this, is that the window for the radius rod is now 1/16" low. I was unable to discover this until the reversing gear and reach rod were complete. The radius rod will collide with the top of the window when in the full reverse position. I opened up the top of the window by .100". The two photos show the window machined .100" to clear the radius rod in the circled area. The radius rod is in the full reverse position.

I did the machining with a small end mill cutter (5/64&quot in order to keep the radius in the corners very small.

The bottom of the window may also need to be opened a little bit. A file should be sufficient to do this.

With clearance for the radius rods, and a bit of filing here and there, I spent all day finally getting the full valve travel to 9/16" as specified by the drawings. Yes!!

David

Edited By David Wasson on 25/01/2016 00:14:13

Edited By David Wasson on 25/01/2016 00:15:29

[John KinnaneParticipant @johnkinnane64270]

G'day David, I have come across seamless copper tube for the bioler of the Super Simplex. The length to the bioler throat seems to be 11 11/16" with an OD of5". The cost is $24.00 an inch thickness is 1/8". Would you buy the barrel a little bit longer and what was the length from your drawings. Any advice would be most helpful. Thanks David kind regards John Kinnanw

[David WassonParticipant @davidwasson11489]

Hi John,

You will need a tube that is the entire length of the boiler, which is 19 inches. The top outside of the fire box is made from the same tube. You make a cross cut on the tube at the throat plate, which is 7-1/4" from the fire box end. Then you make a lengthwise cut from the fire box end to the cross cut. This will allow you to bend open the tube to form the outside legs of the fire box. These legs will not be quite long enough, so pieces will have to be added to make the legs the complete length. If your cut from the firebox end to the throat plate cut is off set, you will only have to add an extension on one side.

As for price per inch, Blackgates, Kennions, Macc and Reeves have copper 5" 10 SWG tube for prices around 7.08 to 8.13 pounds per inch. I think this is much less that what you have quoted. Check them out! Blackgates offers a Super Simplex Boiler Kit which is supposed to include most every supply you will need to build the boiler. I do not know the price of it yet, but am going to inquire very soon. This seems like a good way to go for me.

David

[John KinnaneParticipant @johnkinnane64270]

Hi David, thank you for your reply, I looked at the drawings but couldn't work out if the out side fire box was part of it or not. I did notice the 19" which you have put me straight on.. I do not plan on building the boiler for a long time and I will get help from the club. If the boiler tube was a fare price I would have secured it now and kepted it aside.

Thanks for the heads up about Blackgates, the price for the boiler kit over here is $1400.00 complete so I will be heading that way. Thank you David regards John

[John KinnaneParticipant @johnkinnane64270]

G'day David I am about to start building the buffer beams and I would appreciate if there is any thing I should know. One question I do have in relation yo the buffers did you machine your own or buy castings? Thanks David regards John

[David WassonParticipant @davidwasson11489]

Hi John,

To be honest, I have not yet made the buffers! My plan is to make them from solid stock. I have the material already, but, have not started the machine work. My plan for getting it to the point of running on air, was to only concentrate on making those parts that are necessary to get it going. Obviously the buffers would take up much valuable time that could be used to make the more important parts. Now that it is running on air, I will come back and make the buffers.

My loco is getting uncomfortably heavy, so I am working on a construction stand that will allow me to turn the locomotive upside down. As parts of this, the buffers must be completed, as they are the part that attaches to the construction stand.

David

[Tim StevensParticipant @timstevens64731]

Just 2 comments on earlier parts of this thread:

I think I read somewhere that number drills were arranged to fill in the gaps between the 'standard' imperial drill sizes measured in sixty-fourths of an inch. So, where there is a big jump in size it is likely to be a fractional size (which you are assumed to have got already for Christmas from Grandma). I have not checked this info, and the long winter evenings are behind us, so …

And yes, some taps are made to cut a reduced thread to start with – usually the outer surface is ground off. This makes it easier to tap difficult metals like stainless. The name for these taps is 'Serial Taps' and the taper and second ones have one and two rings around the end next to the square. ArcEuro has some in his catalogue.

Regards, Tim

[Author]

Posts