Search Results for 'zan'

[Keith Wright 3Participant @keithwright3]

Kwamkono Disabled Children's Trust

We would like to thank everyone who has suggested ways of getting the water up the hill to the children's Centre. We will be deciding next year on a method once we have found out what supplies and equipment is available in rural Tanzania.

Thank you once again

Keith Wright

Founding Trustee and Chair

[SillyOldDufferModerator @sillyoldduffer]

I think this one is really difficult. The pressure in a pipe with a 500m head is about 50bar, or 720psi. As heavy plastic water pipe is only good up to about 100psi, and Schedule 40 steel water pipe to about 175psi, this isn't going to be done with a single lift and ordinary fittings.

Managing the pressure suggests a series of pumps and tanks will be needed. For about £400 a small deep well pump will lift water to about 75m at 80psi and consume about 500W. For a continuous flow you would need seven equally spaced up the slope, each with a holding tank and piping. Also a generator to power the pumps and a control system ensuring that pumps don't run dry or overflow their destination tank.

While not too difficult to imagine a potential solution on those lines, I'm completely stuffed when it comes to working out the details, like how big should the intermediate tanks be. Details and local knowledge are all important when you can't just throw money at the problem. For example, the tanks should be buried to keep the water clean and reduce evaporation. But I've no idea how expensive it is to dig holes half way up a Tanzanian hill-side, which might be solid rock.

Glad I live where cheap clean water isn't a problem apart from those privatised companies who prefer profits to fixing leaks! In the UK leaks are quite a problem – my supplier is currently losing 43Mega litres per day and they're not the worst.

Dave

[Mike JosephParticipant @mikejoseph75242]

Message from friend that runs this trustto all you helpful souls:

Kwamkono Disabled Children's Trust would like to thank everyone who have suggested ways to get water up the hill at the centre.  These  will be very helpful when we investigate possible solutions next year, unfortunately finding information about available supplies and equipment in rural Tanzania is not easy.  

Thank you once again

Keith Wright
Founding Trustee and chair

[not done it yetParticipant @notdoneityet]

Zan,

Have you already used it this decade?

[ZanParticipant @zan]

You need to work down the grades of abrasive, when all the lines are from the current one, it’s time to go onto the next. With f lat material this is easy as the idea is to use each grade at right angles to the previous one, making it very clear when the marks from the previous one have been fully erased. Do not buff! This will seriously round the corners and remove detail, unless you are using it for a final light polish. It’s difficult to keep it even  a Drexel would be even worse, too small and easy to form depressions, tiny, but so obvious when a high finis is wantedAlways use abrasive on some form of backing, hands are rounded, and just holding it will round the work. Sticks, files etc can be used.

If your flywheel is cast iron, a mirror finish is difficult due to the natural micro holes (or pits) found where the free graphite in the iron was previously located. Good luck  mirror polished work in my opinion always looks so poor, it’s completly non standard some people seem to polish everything, although it does have its place with brasswork, but not machined components

Edited By Zan on 30/10/2018 18:29:14

Edited By Zan on 30/10/2018 18:33:35

[Joseph Noci 1Participant @josephnoci1]

Thanks for the comments from all;

Zan,

I can say definitively that the stepper I have used may STILL be to small…It is a NEMA23, double stack motor, which still only gives around 1/2 the torque an NEMA34 single stack motor will give. Diameter relates directly to torque. The problem with torque requirements has nothing to do with being able to turn the table – its all to do with acceleration of the table which in my particular way of implementing the hobber is an issue. I am trying to 'exactly' simulate a mechanically geared hobber. Such a hobber will allow you to stop hobbing teeth in the middle of a job,ie, cut power to the hob spindle, and without disengaging the hob from the gear blank, simply re-apply power to the hob spindle motor. The mechanical gearing will force the blank to keep step with the hob pitch. Acceleration of the blank is mechanically linked to the hob spindle and synchronisation is always maintained.

NEMA23 is not that big? 2.3"x2.3" by about 4" long…

I am not sure this requirement is real, but it seems useful to be able to just stop, clean the teeth and have a gander to see how things are doing, and carry on where you left off?

The blank must do the same even when stepper driven, but now the stepper is driven by pulses that have a synchronised relationship to the encoder pulses from the hob spindle encoder. Typically, the hob on a 'home-hobber' will spin up from 0 to around 300RPM within 200ms to 300ms. As an example, for a MOD 0.8, 20 tooth gear, with a hob rpm of 300rpm, the blank must turn at 15rpm. Assume a typical 40:1 gearing between stepper and blank, the stepper must spin at 600RPM.

So, we need to accelerate the stepper from 0 to 600RPM within 300ms, under load, synchronised to the Hob encoder pulses, without loosing steps…With, in my case the large inertial mass on the rotary table, chuck, etc, and the friction as well. So far the math says the stepper I have used, running at 75volts in Half Step, will do the job within 450ms – difficult to mathematicate better than that, as friction coefficient is a bit of a thumb suck, so err on the high side.

For a 100 tooth gear, the stepper target rpm is only 120RPM, so much easier.

John,

The software is free to all, however as with all these things there are complications! My implementation has buttons, encoders, jog-wheel encoders, seven segment displays and used the STM processor range and the NUCLEO STM Arduino look-alike. You would need the circuits as well to fathom what I have done, but if proficient in C, I have no doubt you could port it to the 'normal' Aduino range.

MichaelG,

I would almost suggest that you go ahead and use the worm/wheel you have and we give it a bash and see how it does! At least you could progress and maintain the interest!

Joe

[ZanParticipant @zan]

Well done that’s a cracking job, but that stepper! It’s huge and it could have been  smaller, and still power the gear I’m wondering about converting my small dividing head to stepper control to work on my cnc and I will be using a much smaller one. That motor is bigger than on my z axis lifting all the head gubbins, but nice work keep it up. Please post again when you test it out.  The results will be interesting.

Edited By Zan on 28/10/2018 15:28:48

[Ian S CParticipant @iansc]

As there is no flowing water, ie a dry river bed, a pump is required, and it would be best if the well was changed to a be quite a bit deeper to get purer water, and more reliable supply as the water table drops in the dry season. A solar electricity supply supplying enough power for two pumps, the fist a deep well pump, the a second HP pump to pump th water up the hill. Suitable plastic pipe should be used as it has low friction to water flow, it is the cheapest, and the cheapest to lay. There would probably be a need for a tank at the well head, and there should be some form of storage at the hospital.

From a brief look on the "net", the problem happens all over Tanzania. One example of a maternity hospital that suggests that you bring your own water, and they don't have water to wash sheets, or nurses uniforms.

Ian S C

[ZanParticipant @zan]

Any condensation would be small fry with the heat from the flue gasses which would soon evaporate that. Another thought…. could it be due to condensation in the pipes during cooling down of the engine? Easy to eliminate by checking the s box during a run.  Or try to chock the loco apply the brakes , crack the regulator and examine the s box but take care! Have somebody with a hand on the regulator!

Edited By Zan on 27/10/2018 01:22:47

[ZanParticipant @zan]

 

Assuming it has passed the hydraulic boiler test, the source of the leak may be hard to find. Examine carefully and look for telltale white marks on the metalwork. Do not use anything hard to clean the smoke box or you may remove the marks. Check the superheater headers , blower, snifting  valve, exhaust blast steam feed to cylinders it could be any of these.

Another possibility is that as the engine is new to you, you could be overfilling the boiler and causing it to prime. Good hunting, but how much is ….a small amount of water?….

Sorry bad spelling from autocorrect 

 

Edited By Zan on 26/10/2018 19:58:51

[I.M. OUTAHEREParticipant @i-m-outahere]

Must be zany German humour again !

Funny thing is if i were trying to sell bikes the last thing i would refer to is something that bolts on to the bike so you can make spare parts ! Does this infer that this bike is going to break down a lot ?

It is a bit like Selling a British made bike that comes with a life time supply of gasket sealer and fold up drip tray .

[ZanParticipant @zan]

But where do you put a lap top, an adequate supply of power and plastic. I’d rather have a stove,food , tent and sleeping bag, but I wonder if it will print the spanner needed to fit the component? However, 3 d printing of metal parts has real application fir medica uses esp in skull trauma, and I hear Boeing are considering it for spares.

Edited By Zan on 25/10/2018 01:13:35

[Dick HParticipant @dickh]

Google "Fog catcher" or "CloudFisher". They´ve been used in Tanzania.

[Neil WyattModerator @neilwyatt]

Posted by Martin W on 23/10/2018 15:50:48:

Had a look at the 'Drinkable Air' site, see Neil's post above and found this data.

Running at 6KWH it can produce between 4.5 to 7 US gallons/hour. These figures were measured when a unit was running in Baton Rouge. Checked the climate in Baton Rouge and it has an average daily humidity of 74% with an average morning humidity of 88%. The blurb also includes all manner of other spurious claims

Looks like a PV powered concentrator is out.

However, it seems the inland, upland climate in Tanzania sees a 20-25 degree diurnal temperature change,enough to reliably drop air at 60%RH to 100%.

You oly need a 12 degree change for reliable dew collection: akvopedia.org/wiki/Water_Portal_/_Rainwater_Harvesting_/_Fog_and_dew_collection_/_Dew_collection_and_storage

So, that sort of range will be more than enough to extract dew from even quite dry air in a passive collector overnight and with passive collectors you don't need to do any more than clean them occasionally.

This site gives some practical results, with a 300 meter square unit able to generate about 20 litres a day.

I'm assuming you have plenty of space and that, say 100 litres a day would be worth having.

Neil

[HopperParticipant @hopper]

Depends too on where in Tanzania. Place is about the size of France and Spain combined, ranging from coastal to desert to freshwater lakeside. Other than the coastal strip, the rest of the place seemed pretty dry to me. Much like the interior of Australia, but that also is very hot in the day and can be quite cool at night. Great idea for water extraction though if there is enough humidity.

[Neil WyattModerator @neilwyatt]

Posted by Tony Pratt 1 on 23/10/2018 14:28:17:

Is there much humidity in Tanzania, just asking?

Tony

Yes, because the daily temperature cycle is so great.

[Tony Pratt 1Participant @tonypratt1]

Is there much humidity in Tanzania, just asking?

Tony

[HopperParticipant @hopper]

Being that we commonly power our whole households with solar panels these days here in Australia, that would seem to be the obvious solution for a similarly sunny climate. Would power a small pump no problem. Security? Well whatever your friend puts in will face the same problem. Three kilometres of plastic pipe is likely to go walkabout too. They may have to hire an askari or two (guards).
Tis quite a lift at 500 metres. Depending on what types of pumps are available down there, it may have to be done in stages with small tanks along the way.

I used to use a bore pump that dropped down the hole and ran on compressed air from a compressor mounted topside. Just a piston going up and down forced by air on one side and pushing the water up the pipe on the other. Worked very well. No idea of the possible lift with it though. And compressor is more high maintenance than a simple electric pump unit, which is a big consideration in Africa.

There must be other water supply systems in use in Tanzania they can model from?

[Mike JosephParticipant @mikejoseph75242]

Here is a challange for the engineers!

Two friends run a charity for disabled children in Tanzania 
and the hospital/accommodation is on top of a hill. Currently 
water is collected using a tractor and something resembling 
a water bowser (cart with barrel).

Down in a valley is the water supply, a well, about 3km 
distance and 500m below.

How can a regular (no matter how small) supply be arranged 
where:

1. fuel is very expensive
2. solar energy is almost unlimited in daylight hours
3. security from theft of the solar panels will be an issue 
   and possibly for the pump also
4. in the valley winds are light

Storage is easy since there are tanks for retaining water in 
the wet season. The supply of water becomes an issue in the 
dry season.

I considered Pulsometer pumps since they have no moving 
parts but require a steam supply, (I think). Also solar 
powered pumps at intervals if enough energy is available.

Any bright ideas?

Mike Joseph

[Colin HeseltineParticipant @colinheseltine48622]

All the organisers do things a little different to each other. At the Bristol show it was nice to be able to go upstairs and see all the model planes and other related stuff such as the flying simulator and dedicated helicopter area. These are not particularly "my thing" but I can certainly appreciate the effort and care (and expense) that has gone into the models and enjoy walking around.

The bit I really liked was the ability to see models (in particular) model i/c engines being run outside. I am trying to build an Anzani 'Y' engine and to see Mike Coles Anzani running was brilliant. It gives an incentive. H&S must not stop all these live activities.

Some of the groups who might want to display models are not necessarily official clubs (e'. I/c engine builders group) and they should be encouraged.

There was one stand at the Midland show where a guy was using a 3D printer to make model "steam type" engines. Its still Model Engineering.

Personally I think need to get other model disciplines involved, so as to get greater footfall. If this means merging shows then so be it. Better a merged show than NO show. A number of the trade suppliers will cross boundaries into other hobbies.

Colin

[Bill StarlingParticipant @billstarling10428]

Thanks for posting all those pictures Emgee and for your kind comments Ramon. It was certainly a great day for the museum as well as for all those exhibitors and visitors that I spoke to. If I'd got my head round posting photos, I'd show one of the 12 ins scale Fowler ploughing engine spectacularly filling the road as it set off at the head of the run for the miniatures road engines. For those that haven't been to Forncett yet, do come and join us next year. Distance is no object – note Emgee's pictures of the Bristol and Anzani aero engines that Dennis Snaith had brought over 200 miles from Co Durham. Thanks again Dennis.

Bill.

[EmgeeParticipant @emgee]

Some pictures from the 26th Model Engineers day at Forncett Steam Museum.

Ramon adjusting his 5cc version of an ED Hunter, runs very well.

1/4 Scale Anzani and Bentley BR2 both expertly made by Dennis Snaith from Co Durham.

More pictures at the Dropbox link here.

**LINK**

Edited By Emgee on 07/10/2018 23:55:44

Edited By Emgee on 07/10/2018 23:56:34

[WatfordParticipant @watford]

From Gilbert and Sullivan's Pirates of Penzance – " I am the very MODEL of a modern Major General "

[Philip SlaterParticipant @philipslater86297]

Thanks i'm assuming the 2 grooves in the output coupling are used only with the vertical head and all the drive for the horizantal arbor comes from the MT3 taper which is secured by the drawbar.

[duncan webster 1Participant @duncanwebster1]

Posted by Fowlers Fury on 18/06/2018 09:44:49:

Duncan:-
'wasn't aware of your 'trick' ~ good one !. That below is a cut'n'paste from Word 2007 apart from the italic text.

Using Windows 10 with Calibri (Body) type face:-

(Alt+2300), release Alt = strange character like O with umlaut

“if you type 2300 then hold down the alt key and type x, release both and wait for a split second
it converts the 2300 to a diameter sign.” = ⌀

I found that alt+ inserts extended ascii characters, not unicode, but not the ones listed in the table at

**LINK**

for instance if I type alt+234 I get Û whereas I should get a greek omega, and the table I found runs out at 255 (8 bits)