Member postings for TobaccoBurner

Have used these people Link once or twice in the past for quite complex display and memorial plaques.

Efficient and helpful. You can send your artwork as a PDF. They check suitability and send back a pdf of their manufacturing data for approval before going ahead.

Website defines most material and manufacturing constraints so found the whole process reasonably simple.

Mike

The answer would appear to be yes - have a look at the manual page 113 Section 4.11 Test Run Checklist item 21.

I have no specific knowledge of this kit - just scanned through the manual out of idle curiosity - but based on a lot of commissioning experience I would suggest the following:-

First check that voltage on terminal A1 swings smoothly from 0 to 10v as you rotate the pot.

Second work through the above mentioned checklist which seems to give a pretty good guide to a basic setup procedure.

If there is still a problem it would suggest to me that one of the many functions that appear to be available may have been inadvertently enabled and I think I would be inclined to reset to factory defaults and start again using the checklist as a guide.

Stick at it - you will get there

Mike

A bit more detail - you are right about two tapers.

Took me a little while to work out how it auto locks.

Think you probably have two thirds of some variety of one of these:-

Extract from 'Dormer milling cutter information handbook' Edition M.C. 776

Mike

With some measurements from the engine and the timing info from here (page 121):-

http://rclibrary.co.uk/files_titles/1561/Model_Aircraft_1950_05.pdf

it should be possible to compute (or measure from a cad drawing) the required length.

Am part way through a similar exercise with a DC Spitfire. Having settled on a dimension I ran an animation in Fusion360 to check if it made sense. Now just need do final assembly, find a prop and then we see whether I got it right.

A few weeks ago I pulled apart a 3 HP motor that was in a flood a couple of years back and had been left standing thereafter. The tide mark was half way up the rotor and it was still damp inside.

Hooking the stator up to an old battery charger (good for 4 or 5 amps) for a week sorted the insulation resistance. Cleaned out the rust and silt, fitted new bearings and terminal studs (these were steel) and it now runs silky smooth.

The only hiccup was failing to notice that the two bearings were not the same so had to exchange one - for which a public thank you to Simply Bearings for making this process easy and simple.

In conclusion I would suggest that your motor stands a good chance of being resurrectable. In my opinion you don't need ovens, de-humidifiers or any other fancy equipment unless you are in a hurry. Just be careful not to damage the insulation when pulling it apart.

Mike

"cost-effective solution"

Probably only if you already have the bits.

"It's not actually boosting the voltage so much as presumably generating the additional phases."

Agreed. From what I recall my thinking went roughly thus:

Feed power to one winding and you have effectively a single phase 2 pole induction motor. Put crudely these work because the rotor becomes a 2 pole magnet which is dragged around by the stator field which keeps changing direction. Motors are also generators so we have a 2 pole magnet rotating inside a 3 phase stator. This is an alternator and since everything is vaguely symmetrical the winding voltages ought to be similar.

At this point the project went into 'suck it and see' mode and having achieved success further research and analysis went into the pending tray.

Obtaining waveforms might be difficult. I'm not sure I still have a high voltage probe and I certainly don't have a current probe. The last time I tried to get a current waveform in a power line using a small series resistor I forgot to remove the earth from the scope. Result - one destroyed probe and half the shop floor went dark. It's always the little things that get you.

It turns out I lied in an earlier post. I have found the basic schematic I generated for construction purposes and have uploaded a copy to my album. Treat with caution - e.g. no protective devices are shown.

Thanks again Dean. I can assure you that as soon as it's my turn to win the lottery your ticket will be on it's way.

I have done this successfully. Can’t provide details – never kept any notes but I can give a few pointers.
The need arose when I acquired, very cheaply, a Pollard high speed drilling machine that had a 415v 3 phase motor. Changing the motor would not be easy and a transformer + inverter would have cost far more than the machine but I did, potentially have the bits to make a rotary converter – to whit, a spare 3 phase motor with all connections available and a assortment of capacitors.
Most (all?) published designs based on ‘idler motors’ are 240Vin/240Vout or 415Vin/415Vout. I needed 240Vin/415Vout so:-
Question 1: Will a 415V star connected 3phase motor continue to run with just 240V applied to a single winding (phase to star point)?
Answer: Yes and the rotary transformer action gives a reasonably balanced 415V between phases.
Question 2: Is the current in the single winding reasonable – again yes.
Question 3: Can we get it to self start?
Answer: Not with the components that were to hand. It would start but not at the right speed.
This problem was solved by using a small single phase motor (again from the ‘come in handy one day’ pile) as a pony motor to spin up the idler motor before applying power to it.
So modus operandi:
Press and hold start button while pony motor spins up.
Release start button. This removes power from the pony motor and applies power to the idler motor (you need a few relays to do this sensibly).
Points to note:
All the output power is provided by a single winding in the idler motor so be mindful of the current rating.
The output voltages will not be perfectly balanced but this can be improved by adding capacitors between phases (bit of a select on test exercise).

As a final assessment the converter is actually bigger than the drilling machine but it does work and didn’t cost me anything. Hope this helps.

Mike

Thanks for the information gentlemen. I can now go shopping.

Neil, I agree bronze bushes would be good but given my somewhat agricultural skills may be a step too far. The original didn't use them (these engines were built down to a price) and given the limited running expected I think it would be simpler, while tooled up, to make a couple of spares. In the unlikely event that I ever get back on a flying field it will be my trusty ED Racer that comes out of hibernation.

Dean, Have followed your V12 build with great admiration. How about a world tour so we can see it in the flesh? I'm sure you would pull in the crowds.

Mike

A few days ago I found a DC Spitfire (1cc) on a junk stall. Having extracted it from a liberal coating of what appeared to be a mixture of congealed castor oil and coal dust the general condition is not too bad except for the con rod which is badly worn.

My question to the experts on small engines is what variety of aluminium do I need to make a replacement, bearing in mind that it will only be run for demonstration purposes? It's flying days (and mine) are long gone.

Should be good for a Darwin Award - unless,of course, you already have descendants.

Mike

You could try this: **LINK**

At first glance not very intuitive (see edit button bottom RH corner) but haven't read the help file.

Input limits for free program Free

max total number of pieces to cut out: 100

number of different piece kinds (sizes): 20

max total number of stock items: 100

number of different stock types (sizes): 5

Mike

Bit of a suck it and see exercise since we don't know the inductance of the modified transformer or the resistance of the lamp ( it varies with filament temperature ). I would guestimate that the original charger primary current was around 200 milliamps so this is your target. I would suggest maybe start with a 40W lamp, measure the current and see how hot it gets then adjust as necessary. Nothing will melt instantly.

Incidentally I would enclose the lamp in a substantial cage or tin can with ventilation holes. With the current setup, if you break the glass, you have wires carrying 240V waving in the breeze. I just hope the author has a fully functional RCD on his supply.

Mike

Check out these people:-

**LINK**

Some good advice (in my opinion) and supply a wide range of products that cover most needs. (satisfied customer)

With regard to your plate, if it was mine and with a distinct aversion to hard labour, I would mount it on a temporary backing board, polish with suitable grade buffing wheels and then hand finish as necessary.

Mike

Relative to what?

Another one not far off the line from Bath to Inverness Mill Meece Pumping Station

If not a normal open day just contact us (info is on the web site) to arrange a visit.

Mike

Once experimented with zinc plating some bolts from a car chassis. Simple procedure - degrease with caustic soda solution, wash (tap water), pickle in hydrochloric acid until all rust removed, transfer to plating bath - zinc chloride solution - probably fairly concentrated. Zinc anodes probably obtained from dry batteries. Power supply was a bench adjustable 0-24v probably 1 amp max.

The result appeared to be successful but rather rough. From what I read this roughness is due to using a smooth DC power source - the plating tends to grow whiskers. Using an AC source combined with a DC offset should produce a more even finish. The brief current reversals remove the whiskers.

Never took this any further but if you want a confidence booster I still have a couple of the bolts sitting in a jar on the shelf - no rust after at least two decades.

PS:- Wash well after plating - the zinc chloride is corrosive.

Mike D

Never thought of that - must have a go. By the way, forgot to include First Aid kit in the original list. Essential when using double edged razor blades.

How about a razor blade from Dad and a few pins from Mum's sewing box. This is sufficient for a decent chuck glider.

Next step is a pair of pliers for bending piano wire and a soft brush for dope application. We are now into rubber powered free flight.

When Santa delivers your first engine you may want to add a small hand drill, screwdriver and soldering iron. The sky is then your oyster (if you can find anywhere far enough away from the H & S and noise police to actually fly the thing).

MikeD