What Did You Do Today (2016)

[jaCK HobsonParticipant @jackhobson50760]

I got a Microflame torch in a bot of bits at an auction a while ago:

Thanks to JasonB (on another forum) for pointing out I can use squirty cream NOX but the torch wouldn't work. Turns out the needle on the NOX valve was broken and wouldn't puncture the canister. The torch is easy to take apart, Here is tThe NOX valve:

And here is bottom view – a needle should be poking out of this hole:

The needle is glued to the valve knob assy in but I could pull it out. Here is first attempt (top) which I knocked up on a watchmakers lathe with a hand graver. Old broken one is below.

2nd attempt gave better control but still room for improvement.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by jaCK Hobson on 25/11/2016 16:55:13:

Thanks to JasonB (on another forum) for pointing out I can use squirty cream NOX …

.

Well that's my learning-point for today !!

… I thought it was Nitrogen in those bulbs.

Thanks both

MichaelG.

[Anthony KnightsParticipant @anthonyknights16741]

Today I started a major clearout in the workshop. All wood oddments were cut to size to go in the stove. Various recovered electric motors and bits of metal were left on the drive for the local "travellers" to collect on their weekly scrap patrol.

Following advice on another thread, I sorted through a box of 13 amp plugs and scrapped 18 plugs without sleeved pins. It was a shame to scrap them actually, as they were really well made from back in the days when we made stuff like this in the UK. Some of them were so old that the pins didn't fall out when you took the top off.

I will carry on tomorrow and who knows what I will find,

[JAParticipant @ja]

Microflame torch – Does NOX = Nitrous Oxide? It does not in my language and I cannot see Nitrogen Dioxide or Nitric Oxide acting as an oxidizing agent.

Again I may be being pedantic but we had enough trouble at work with the media and other ill informed persons calling Nitrogen Dioxide/Nitric Oxide Nitrous Oxide. They are very very different, just try breathing them.

JA

[modeng2000Participant @modeng2000]

Do you know where to get the butane cylinders from?

John

Edited By modeng2000 on 25/11/2016 20:06:02

[JasonBModerator @jasonb]

I'd don't even remember posting about them

But found an old thread where someone else suggested the whipped cream which does seem to be NOS here

Edited By JasonB on 25/11/2016 20:21:03

[JAParticipant @ja]

Posted by JA on 25/11/2016 19:52:19:

Again I may be being pedantic but we had enough trouble at work with the media and other ill informed persons calling Nitrogen Dioxide/Nitric Oxide Nitrous Oxide. They are very very different, just try breathing them.

JA

On second thoughts, DON'T.

JA

[MWParticipant @mw27036]

Posted by modeng2000 on 25/11/2016 20:05:32:

Do you know where to get the butane cylinders from?

John

Edited By modeng2000 on 25/11/2016 20:06:02

If i may suggest, yes i do knows, try here;

**LINK**

[Michael GilliganParticipant @michaelgilligan61133]

Posted by JA on 25/11/2016 19:52:19:

Microflame torch – Does NOX = Nitrous Oxide? It does not in my language and I cannot see Nitrogen Dioxide or Nitric Oxide acting as an oxidizing agent.

Again I may be being pedantic but we had enough trouble at work with the media and other ill informed persons calling Nitrogen Dioxide/Nitric Oxide Nitrous Oxide. They are very very different, just try breathing them.

JA

.

On research restricted to one product **LINK**

https://www.puregusto.co.uk/isi-cream-whipper-chargers-genuine-isi-n2o-cream-bulbs-10-pk-p531801-x719262.html?gclid=CPvd4Y3mxNACFUWfGwodNLUNGg

They are described as being filled with N2O

MichaelG.

.

Some useful info. here:

http://modeleng.proboards.com/thread/4994/gas-cylinders-microflame-miniature-torch

 

Edited By Michael Gilligan on 25/11/2016 21:13:01

[Bob RodgersonParticipant @bobrodgerson97362]

Today I bust two 5/16 BSC taps while tapping 2 holes and 4 drills trying to open out some holes to clearance size in EN 24T. The job is a restoration of a set of girder forks for a BSA Motorcycle (1930"s side valve).

The restoration involves cutting off the worn shafts that are integral to the links, boring holes in the paired links precisely spaced apart then brazing in new shafts. I think that the brazing process tends to harden the EN 24T . I had already pre drilled the shafts 1/4" through prior to brazing them into position. The links are set up with two shafts, the ends of which are a reasonably close fit in the bored holes and set up on two Vee Blocks to ensure that the shafts are parallel to each other and the links are square to the shafts. After brazing they are cut in two leaving each link with a shaft on each end.

On trying to open up the holes I found that there was a tendency for the drill to grab and wander off course. This then led to the problems of the tap being deflected by the off centre clearance hole causing the tap to snap. It's just as well the taps were Carbon Steel , I was able to drill them out with a Carbide end mill.

Not a very rewarding day, however, I did manage to make 8 Phosphor Bronze bushes using the Rapid Turn attachment on the Tormach and get them pushed into place in the forks.

[Neil WyattModerator @neilwyatt]

I'm not sure I even dare post this, seeing how much trouble astro-kit can cause!

But I've made the Tamiya Panther tank and painted and weathered it. The old gearbox and motors fit perfectly, so now I have to make a gadget to mix throttle and steering servo signals into something that makes a dual motor tank behave like a a real one.

Also looking at a gun raising and turret turning, plus maybe sound and a white LED in the end of the barrel.

One thing I like the sound of is that when you 'fire' the drive momentarily reverses. I won't have gun recoil like the big 1/16 models though!

(yes the point of this IS putting off doing the dial for the jovilabe )

[JasonBModerator @jasonb]

Neil if you have room put the steering servo on a pivot so it can be rocked by the throttle. If you don't have room then buy a good quality transmitter that will allow you to do the mixing electronically same way collective pitch on a Heli is mixed with throttle.

[Neil WyattModerator @neilwyatt]

Posted by JasonB on 26/11/2016 07:26:31:

Neil if you have room put the steering servo on a pivot so it can be rocked by the throttle. If you don't have room then buy a good quality transmitter that will allow you to do the mixing electronically same way collective pitch on a Heli is mixed with throttle.

Thanks Jason, there isn't room for a mechanical solution because it has to fit in a tiny space. I have to make a custom speed controller anyway so mixing in steering will be an interesting challenge (steering is done by varying the speeds of the two motors)

[davidkParticipant @davidk]

Hi Neil

In many ways the throttle & steering mixing is most easily done in the transmitter. If your transmitter doesn't have this facility, it could be added. A small PCB with a few op amps is all that is needed. Try Googling "elevon mixer", there's an example circuit on the RC Groups website.

Regards, David

[Ian PParticipant @ianp]

Posted by davidk on 26/11/2016 09:02:01:

Hi Neil

In many ways the throttle & steering mixing is most easily done in the transmitter. If your transmitter doesn't have this facility, it could be added. A small PCB with a few op amps is all that is needed. Try Googling "elevon mixer", there's an example circuit on the RC Groups website.

Regards, David

I can see that if mixing is done in the transmitter then tuning or making changes can be done without delving into the model, however any changes the user wants are restricted to what the manufacturer put in the transmitter.

Why do you say it easier to do in the transmitter?

A few op-amps and a circuit board sounds like a project all on its own.

I have not used one for a few years but a PIC based module (cost about £5) converted steering and throttle signals to two outputs to create two motor speed signals for steering model tanks. I used one to control the twin propellers of a model tugboat.

Ian P

[davidkParticipant @davidk]

Hi Ian

It all depends on the skills of the individual involved! I can do simple op amp design, but have never really got into programming. I suggested that doing the mixing in the transmitter is easier because all you're dealing with is analogue voltages from the stick potentiometers. I used to work as a test technician for a British manufacturer of model RC gear back in the 80's and that's the way we did it then! If you're into PIC programming, then it can certainly be done that way.

Regards, David

[Neil WyattModerator @neilwyatt]

Why would I want to screw up my transmitter for using it with other models?

I have to make a custom speed control anyway, so its just a case of taking a speed/direction and turn signal and converting them into two speed/direction signals that I can do in the software.

Steering was achieved by having double differentials, that could be 'unbraked' allowing one track to slow, there were seven radiuses dependant on the gear it was are in!.

This means the steering will depend on speed; when moving forwards or backwards, steering will be achieved by slowing the inner track by a fixed amount in seven steps. When stationary both tracks could be moved in opposite directions for a pivot turn but this had to be done SLOWLY or the transmission failed!

Such complexity is much easier to do in software than with a mixer arrangement. maybe over the top, but it will make controlling it much more of a challenge.

The typical range for a Panther before gearbox failure as 81 miles… 6,000 were built and it's probably just as well that many had to be cannibalised for spares to keep others running.

Neil

[davidkParticipant @davidk]

Hi Neil

As you have the software skills, no problem then! All the transmitters I've seen that had mixing also had the facility to switch it in or out, so it could be used on different models.

Regards, David

[JasonBModerator @jasonb]

As David says the modern transmitters have a whole load of functions and can be set for a number of models just like you can set up a DRO with 100 different tools. Just call up whichever model you want to run on the transmitters screen and away you go, all trims and mixing etc will be set for that model.

As you say not much room for a mechanical mixer I have a much modded Tamiya M60 in IDF colours and reactive armor and that has the motor in it but I think that was the single moter version not the twin that you have though servos are tiny these days

[JasonBModerator @jasonb]

Neil have you tried putting Model Tank ESC into Google, plenty of relatively cheap units that allow you to mix steering and throttle like this for example ot this for turret and gun movement as well

Edited By JasonB on 26/11/2016 13:24:25

[Neil WyattModerator @neilwyatt]

I'm already going to try and fit a micro servo for gun elevation and one modified for continuous rotation to turn the turret.

It's a shame that Tamiya don't still sell the motorised versions of the 1:35 kits, the tooling seems to be in excellent condition for stuff having the date 1969 on it!

Wish I could justify getting one of their 1:16 all singing & dancing models!

[JasonBModerator @jasonb]

From that second link I posted looks like you can get the motors and gearboxes etc to put in a static model, and tune up parts for existing ones

[Keith LongParticipant @keithlong89920]

Neil – sounds as if your about to embark on an exercise of "re-inventing the wheel" All the stuff you need is already available, go on to the Model Boats website and send a pm to Dave Milbourn. Tell him what your trying to do, he'll probably be able to quote you the module numbers that you need off the top of his head – he developed them.

So called tank steering using multiple motors is quite common in multi screw model boats with separate motors, either used alone or in conjunction with a rudder or rudders.

[Neil WyattModerator @neilwyatt]

The 140 motor gearbox in that link is what I salvaged from the 70's vintage tank

That website seems to be a bit broken, but it doesn't seem they sell the controller as a stand alone. I want to make my own anyway!

[BazyleParticipant @bazyle]

In a less warlike spirit I spent the day, fortunately sunny not as forecast, around St Katherine's Priory dating from 1159 where Exeter DMES will in future be based so were running their portable track in support of a Christmas Fair. Not a lot of people unfortunately but made a few bob for club finds and gave the members a chance to natter. May have recruited a new member and perhaps a couple from the model railway club 'Shed 72' based there. Will be back there on Boxing day if you are in the area (next to Morissons so your partner can go shopping and you can 'reluctantly' offer to see if you can entertain the kids)

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