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Machines, Tools and Fixtures / Do I want to buy a Myford Super 7?
« Last post by DTR on Today at 01:59:17 PM »
I can hear the collective groan of the forum from here  :facepalm:  I'm sorry, I suppose I just wanted to air my dilemma.  A problem shared, and all that.

I currently have an ML7 dating from 1951.  No major issues (touch wood), and I am comfortable with its capacity.  However I have discovered a Super 7 (1960s, I suspect) for sale nearby and its gearbox has piqued my interest.  I don't do much screwcutting, but when I do I long for a gearbox.  I may even be more inclined to screwcut if I had one.

The main advantages of this Super 7 compared to my ML7, as I see it:

Quick change gearbox - no faffing with changegears
Countershaft clutch - less stressful on the motor?  Also handy for screwcutting up to a shoulder, I understand?
Longer cross slide - handy for mounting a rear toolpost
Wider range of pulley speeds
VFD motor already fitted - not sure how useful that will be on a lathe
Myford octagonal stand included - I've long been contemplating a workshop reorganisation, and the stand would save me the trouble of building a new one.

The Super has been advertised for 1,000;  I doubt I could recoup much of that by selling the ML7.  I've yet to view it in the flesh so this may all be moot anyway.

So what say you, oh wise engine makers?  Will my life be immeasurably enriched by the aquisition of a Super 7?
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Specific Engine Help / Engines I have built
« Last post by Jo on Today at 01:57:03 PM »
In this section of the forum we have threads that help people with problems to do with specific engines. As we don't all look in on the forum as often as some and many builds may have happened before MEM, I thought it might be useful to turn the tables and get people to list what engines they have built. So that members could send them PM's with a  :help:

I suppose I should start, with my engines and any known features  :-\

AHC Diesel - Motor Boys International (Ken Croft)
Caloric Gauge 1 Stirling locomotive - ???
Centaur Horizontal Gas Engine (Carb problems )
Crosskill Oscillating Steam Engine - Anthony Mount
Double Tangye Steam Engine - Westbury
Double Tandem Compound - Horizontal Steam engine
Easton and Anderson grasshopper beam - Anthony Mount
Felgiebel - Two stroke Aero Engine (chops thumbs  :paranoia: )
Kiwi Four stroke petrol Engine - Westbury
Kittiwake Four Stroke petrol engine - Westbury
Lady Stephanie Beam Engine - Tubal Cain
Mary Beam Engine - Tubal Cain
R&B Gas Engine - Bruce Davey  (Ornament - carb problems :facepalm2: also squashes thumbs   ::) )
Steeple Engine - Anthony Mount
Stentor two stroke aero engine - Veron
Stothert and Pitt Beam Engine - Jo Thoms
Stuart No 9 - Stuart Models
Stuart No 10 Vertical engine - Stuart Models
Stuart Standard Beam Engine - Stuart Models
Titan 60 Glowplug Aero Engine -  Gemaco

and underway:

Atom Minor III - Westbury
Boulton and Watt Bell Crank Engine - Anthony Mount
Stuart triple (3 off) - Stuart Models
Stuart 5A - Stuart Models
Swan - Stuart Models
Wall Wizard - E Wall (Coles Power Models) :-X

So boys are you willing to admit to what you have built /are building?

Jo
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Specific Engine Help / Re: Straightening copper tube
« Last post by Steamer5 on Today at 01:48:45 PM »
Willy,

It sounds like you are going straight round the bend!!  :stickpoke: :Jester:

Here's a link to the tube straightener that Ian mentioned.....


Cheers Kerrin
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From Kits/Castings / Re: Vulcan Beam Engine - AJ Reeves Castings
« Last post by steam guy willy on Today at 01:41:29 PM »
Hi, Nice looking to start to this engine,  Re the broaching....you were worried about it being a little bit tapered due to the tool deflexion ? however this would be ok as you could make a slightly tapered key to make the flywheel sit really firmly in place ?
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From Kits/Castings / Re: Stuart Beam Engine in Diorama
« Last post by steam guy willy on Today at 01:31:06 PM »


Hi Steam Guy Willy,
You are right. Having that extra boss material 'outside' the width of the sleeve lets you rotate and adjust the sheeve so nicely. That's what Sturart planned as you can see in the first photo.

But when a governor is introduced that extra material is lost. The grub screw ends up in the sheeve. The second photo shows what has to be done to get at it! This is awkward, if you have things hooked up and want to make fine adjustments. You just hope the grub screw is visible when you take off the back of the strap! :???:


Hi, A lovely engine and one is always at liberty to change some of the parts and castings to make it look more authentic. I do have a large pile of redundant castings that might be the basis for a hybrid !! A bit like that motor car in the Johhny Cash song.!!. Having the sheave and strap that way round actually gives you more 'meat' for the grub screw !! but is it a bit awkward drilling the hole for the grub screw ?

[/quote]
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Specific Engine Help / Re: Straightening copper tube
« Last post by steam guy willy on Today at 01:13:27 PM »
Bending it strait  or straitening its bend ??  that is the question !!!!!
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Chatterbox / Re: ALDI Inspection Camera
« Last post by matter8 on Today at 12:48:03 PM »
Thanks for the information. I also think this is a great deal. Regards
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Chatterbox / ALDI Inspection Camera
« Last post by Twizseven on Today at 11:42:33 AM »
ALDI's latest offerings this last weekend included a Workzone Inspection Camera.  Although I have another inspection camera I thought it was worth a look.  The camera head is 5.5mm diameter and that includes the six LED's.  My current camera head is 16.5mm dia so quite a difference.

It is a very good piece of kit, how they do it for 39.99 I do not know.  Image can be colour or B&W, can be mirrored or turned up side down, magnified 1.5 or 2 times digitally, 5 stage LED brightness, picture brightness, Video output port, long flexible shaft, waterproof to 1 metre, complete with magnetic attachment, hook attachment and mirror attachment.  Uses 4 AA batteries.  So impressed I went back and bought 2 more for colleagues.

If you need to see into/access difficult places its well worth it.

No connection with ALDI, just satisfied. ;D

Colin
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Chatterbox / Re: Talking Thermodynamics
« Last post by MJM460 on Today at 11:42:26 AM »
Home, sweet home -

Some of you have noticed that I have been travelling recently.  Just arrived home this afternoon, and it is always good to arrive safely home after a road trip of 12240 km, average fuel consumption 11.2 l/100 km and circumnavigating roughly a half of our continent.  Hooked up our little caravan to the Subaru Outback on July 13, and went, well, outback.  I think Hugh calls it Snow birding, we call it becoming grey nomads.  People from the southern states driving north to escape the winter and find some sunshine make for crowded roads and parks, well sometimes you might see at least 10 other cars in a day.  I suppose we all go at about the same speed, but one time we had to stop for around 5 minutes for roadworks, no one came up to wait behind us.   Then they mysteriously appear, one by one at the road houses and campgrounds, for overnight stops.  But is is a great way to get a real feel for the country, and to experience blue skies and clear starry nights in a way that is not possible in the city.  And to see some wild life in its natural habitat.  We were a little later than most in turning south to put the sun on our backs for the long road home, so perhaps that is why the road seemed less busy than normal.

Thanks Paul for some clarification of wire drawing.  It is consistent with some of my reading and it would seem to be a term more commonly used in the pressure drop sense in the marine industry.  In my industry, it was a term usually muttered while looking at the cutaway in the hardened satellite of a gate valve no longer sealing shut.  Cut like a water jet.  Like you, I would like to see someone start a thread on the indicator diagrams, they are only rarely used in my industry, then only on compressors, as the drivers are all turbines or electric motors.  So I have no experience at all on taking or interpreting them.  However perhaps it is a bit outside the scope of this forum, as I suspect that none of us have available an indicator device suitable for use on our models.

Thanks Willy for those pictures of your boiler and the screen shots of the data sheets.  It seems that the elements may actually be rated for 230 V, so the calculation would then indicate the higher power output at 250 V.  I also note that the tolerance on power is +5%, -10%, but the question of whether this applies to a hot or cold element is not answered, but I would assume cold.  So probably lower output when hot.  The grease is intended as a heat transfer compound rather than a lubricant.  I think we have discussed this before.  I do notice that your boiler seems to have flat ends without stays, though I notice the bushings have not been soldered in the picture, so you may have added stays later in the construction process.  Of course you now have the boiler pressure tested and steaming, so if it is now dimensionally stable, I guess that is practical evidence of its strength.  However, I keep wondering if your pressure housings for the elements could be extended right through and fixed at the other end, just like a large diameter hollow stay, you could then use grease on the sheaths without air displacement issues. 

I am not sure what external pressure the boiler could stand.  The effect of internal pressure being below atmospheric pressure, the condition commonly referred to as vacuum, is that the shell has the high pressure on the outside, that is why I refer to external pressure.  The commonly quoted formula for shell thickness is technically referred to as the thin shell formula, and it's derivation rests on the assumption that the material is in tension to contain the higher pressure on the inside.  Under external pressure, the shell is in compression, the failure mode is the collapse you refer to, and the strength very different, usually much less.  The boiler is relatively short, so the flat ends provide considerable stiffening against collapse, but as you say, it is good to open a path for air before the boiler cools down and avoid the issue.  And if this allows some extra steam to escape, it may speed the cooling.  You have given me the boiler dimensions, so when I get everything unpacked and put away, I will calculate the strength under external pressure for those dimensions.

I think that brings us up to date on the previous questions, so time for a good nights sleep.

MJM460
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From Plans / Re: Jan Ridder's Glass-Cylinder Flame Eater Mk2
« Last post by Ian S C on Today at 10:43:35 AM »
Got my vacuum cleaner dumpster diving, I'v actually got 2 in the workshop. A garage sale cleaner would be ok.
Ian S C
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