Mini gas burner
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Stilldrillin
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Thinking of you, and yours, John......
David D
David D
Because I have been dragging my a**e on this post, someone who has been following along with it, has actually overtaken me and finished one off.
Over the last couple of days, we have been in PM contact, and he has shown me the great results. Not the right thing to do with me, as I will take advantage of the info I get.
He doesn't want to show his finished product until I get mine up and running, but under the circumstances, where mine won't be finished for maybe another week or so, and also because mine is a full warts and all build. He doesn't know I am doing this, but I have no qualms about forcing him out into the open, and showing what he has shown me.
[ame]http://www.youtube.com/watch?v=YnQ2H5_h2LA&feature=player_embedded[/ame]
He told me that this was without a proper regulator. With one, I reckon the results will be even better.
Well done Dean, come out and take a bow.
Bogs
Over the last couple of days, we have been in PM contact, and he has shown me the great results. Not the right thing to do with me, as I will take advantage of the info I get.
He doesn't want to show his finished product until I get mine up and running, but under the circumstances, where mine won't be finished for maybe another week or so, and also because mine is a full warts and all build. He doesn't know I am doing this, but I have no qualms about forcing him out into the open, and showing what he has shown me.
[ame]http://www.youtube.com/watch?v=YnQ2H5_h2LA&feature=player_embedded[/ame]
He told me that this was without a proper regulator. With one, I reckon the results will be even better.
Well done Dean, come out and take a bow.
Bogs
My dirty little secret is brought to the light of day.
Nice of you John, putting some other guy's stuff in your thread.
FWIW, I made the D-bits same as John showed in this write-up. Ditto for the angle of the needle for the valve. All worked as advertised.
Dean
Nice of you John, putting some other guy's stuff in your thread.
FWIW, I made the D-bits same as John showed in this write-up. Ditto for the angle of the needle for the valve. All worked as advertised.
Dean
Just a little more to add to the post, this time it is making the metering needle, and might be of help if anyone has to do one similar.
I rooted about in my stainless box until I had enough offcuts to do the job. I use stainless because it is slightly easier to get a decent finish than silver steel (drill rod), and of course the needles don't have to be hardened as they don't rub on anywhere, it is the gap around the taper that gives the control. You could use almost anything for the needle, as long as it will withstand the rigours of use. My bar is 1/8" ground stainless.
When cutting fine points such as this, you have to plan ahead, because putting the right cut in at the wrong time can cause failure, plus you need to get heavy cutting done while you still have the rigidity of the original material. Your cutting tool needs to be razor sharp. Mine looks to be all shapes, but the bit that does the cutting is sharp enough to shave with, and was dressed on the top face with an oilstone before starting the job.
The taper I wanted was set up on the topslide, and by using the topslide feed, I took a full cut to almost full depth. Then I was was left with a tiny skimming job to get to final size. If I had done it in stages, I would be losing the rigidity of the original material and the taper would be liable to bend and be ruined.
The black mark on the taper is a pencil mark to see if I was at the right size with the hole it would be going into.
Next came the plain portion of the needle, again this was taken down to size in one cut.
Then the area for cutting the thread, that was done in the same way, one cut. Mine was cut to 0.110", the correct size for a 6BA external thread, you would need to make this size for whatever thread you were using. Now normally at this stage, I would put in the runout groove for the thread to be cut, but going by experience, I know that if I did that, the part would break into two at that groove, caused by the cutting forces of the threading. So that will be left until after the threads are cut.
Every operation moves a bit further along the needle length, and each operation is completely finished before moving onto the next. This gives you maximum support for the operations you are carrying out.
As you can see, I used a motley collection of bar ends, but it doesn't matter, because when the part is finished, you won't be able to tell where they came from.
These are now ready to have the threading done. So I need to get a bit of scrap bar to set my die up to give a perfect fit into the internal thread.
I will see if I can get a bit more done later, it all depends on when Ralph leaves. Friends always come before machining.
Bogs
I rooted about in my stainless box until I had enough offcuts to do the job. I use stainless because it is slightly easier to get a decent finish than silver steel (drill rod), and of course the needles don't have to be hardened as they don't rub on anywhere, it is the gap around the taper that gives the control. You could use almost anything for the needle, as long as it will withstand the rigours of use. My bar is 1/8" ground stainless.
When cutting fine points such as this, you have to plan ahead, because putting the right cut in at the wrong time can cause failure, plus you need to get heavy cutting done while you still have the rigidity of the original material. Your cutting tool needs to be razor sharp. Mine looks to be all shapes, but the bit that does the cutting is sharp enough to shave with, and was dressed on the top face with an oilstone before starting the job.
The taper I wanted was set up on the topslide, and by using the topslide feed, I took a full cut to almost full depth. Then I was was left with a tiny skimming job to get to final size. If I had done it in stages, I would be losing the rigidity of the original material and the taper would be liable to bend and be ruined.
The black mark on the taper is a pencil mark to see if I was at the right size with the hole it would be going into.
Next came the plain portion of the needle, again this was taken down to size in one cut.
Then the area for cutting the thread, that was done in the same way, one cut. Mine was cut to 0.110", the correct size for a 6BA external thread, you would need to make this size for whatever thread you were using. Now normally at this stage, I would put in the runout groove for the thread to be cut, but going by experience, I know that if I did that, the part would break into two at that groove, caused by the cutting forces of the threading. So that will be left until after the threads are cut.
Every operation moves a bit further along the needle length, and each operation is completely finished before moving onto the next. This gives you maximum support for the operations you are carrying out.
As you can see, I used a motley collection of bar ends, but it doesn't matter, because when the part is finished, you won't be able to tell where they came from.
These are now ready to have the threading done. So I need to get a bit of scrap bar to set my die up to give a perfect fit into the internal thread.
I will see if I can get a bit more done later, it all depends on when Ralph leaves. Friends always come before machining.
Bogs
I had to go way back to find this article, it is so long since I did anything with it, but I have now nearly finished the control needle and this is an insight into how I went about it.
For some reason some of my shots didn't turn out too well, but I will try to talk you thru them, and you will have to use your imagination. At one time, I would have gone back and set everything up, can't seem to do that nowadays.
So, as mentioned in the last post, I used the long redundant end of one of the made needles to set up the die for cutting the thread. I used the needle holder to make sure it was a snug, but not tight fit. The better the fit, the less work the sealing washer has to do.
You can't see the thread very well, but all the needles were power cut until the die nearly touched the shoulder on the needle. You don't want to go all the way to the shoulder, otherwise the die is liable to cut a taper onto the shaft, because of the built in feed taper of the die. That is a thing you don't want to happen.
The die was turned around in the holder, and set up to the same settings as before (counting the number of turns and part turns of the adjusting screw). The needle was then set up with the shoulder level with the collet nose (you would use the chuck jaws). So in operation, the die runs up and touches the collet before reaching the shoulder. By turning the die around (good quality dies only) you will get a full depth thread cut all the way along the length. Sometimes you get dies that have a taper lead in at both ends, if that happens to me, I grind the back side of the die down until there is no lead in taper left, and that ensures I get the full depth cut.
Again, I mentioned this in the last post. Normally for larger threads, I would put the runout groove in before threading, but when dieing down such small diameters, the forces involved would almost guarantee that the thread would break off before it was completed, so in this shot, it shows me putting in that runout slot. This cleans up the end of the shoulder and ensures there are no tapered threads at the very end. It isn't really necessary on this job, as I have calculated out that the threads should never bottom out, but old habits die hard, and besides, it makes the job look more professional.
All the needles were cut to length with a hand held cutting disc. I left a couple longer than the others, just in case a burner needs to be installed in a tight place. I suppose they could be almost any length.
The next job was to make up a few handwheels for the needles, so I straight knurled a couple of short lengths of brass, and drilled down the centre with a 1/8" bit. It doesn't look too pretty, but I am not worried, as you will see later.
Using the standard method for making multi parts like this, the bar was mounted into the RT, and using a 2mm stub drill, for rigidity, I drilled half a dozen anti heat transfer holes down as far as I could go.
This is what they look like from the end. Discs were then parted off these rods to give handwheels of 0.060" (1.5mm) wide.
Now you can see why I wasn't worried about the knurling. They are so narrow, all you can see is a bit of knurl on each one, and they look perfect, even though when all together on the bar, they looked terrible.
Because I am expecting to make a few more of these units, I am making custom holding jigs as I go along. These wheels need to be perfectly square to the needles, so I will make up a silver soldering jig to ensure that is the outcome.
You'll get a bit more when I do it.
Bogs
For some reason some of my shots didn't turn out too well, but I will try to talk you thru them, and you will have to use your imagination. At one time, I would have gone back and set everything up, can't seem to do that nowadays.
So, as mentioned in the last post, I used the long redundant end of one of the made needles to set up the die for cutting the thread. I used the needle holder to make sure it was a snug, but not tight fit. The better the fit, the less work the sealing washer has to do.
You can't see the thread very well, but all the needles were power cut until the die nearly touched the shoulder on the needle. You don't want to go all the way to the shoulder, otherwise the die is liable to cut a taper onto the shaft, because of the built in feed taper of the die. That is a thing you don't want to happen.
The die was turned around in the holder, and set up to the same settings as before (counting the number of turns and part turns of the adjusting screw). The needle was then set up with the shoulder level with the collet nose (you would use the chuck jaws). So in operation, the die runs up and touches the collet before reaching the shoulder. By turning the die around (good quality dies only) you will get a full depth thread cut all the way along the length. Sometimes you get dies that have a taper lead in at both ends, if that happens to me, I grind the back side of the die down until there is no lead in taper left, and that ensures I get the full depth cut.
Again, I mentioned this in the last post. Normally for larger threads, I would put the runout groove in before threading, but when dieing down such small diameters, the forces involved would almost guarantee that the thread would break off before it was completed, so in this shot, it shows me putting in that runout slot. This cleans up the end of the shoulder and ensures there are no tapered threads at the very end. It isn't really necessary on this job, as I have calculated out that the threads should never bottom out, but old habits die hard, and besides, it makes the job look more professional.
All the needles were cut to length with a hand held cutting disc. I left a couple longer than the others, just in case a burner needs to be installed in a tight place. I suppose they could be almost any length.
The next job was to make up a few handwheels for the needles, so I straight knurled a couple of short lengths of brass, and drilled down the centre with a 1/8" bit. It doesn't look too pretty, but I am not worried, as you will see later.
Using the standard method for making multi parts like this, the bar was mounted into the RT, and using a 2mm stub drill, for rigidity, I drilled half a dozen anti heat transfer holes down as far as I could go.
This is what they look like from the end. Discs were then parted off these rods to give handwheels of 0.060" (1.5mm) wide.
Now you can see why I wasn't worried about the knurling. They are so narrow, all you can see is a bit of knurl on each one, and they look perfect, even though when all together on the bar, they looked terrible.
Because I am expecting to make a few more of these units, I am making custom holding jigs as I go along. These wheels need to be perfectly square to the needles, so I will make up a silver soldering jig to ensure that is the outcome.
You'll get a bit more when I do it.
Bogs
Kevin,
I used one of my standard sized 0.050" parting and grooving tools that I grind up myself. So it was just a matter of feeding 0.110" from the last cut using the topslide. Done in no time.
Still taking it very steady, I don't want to go hurting myself.
John
I used one of my standard sized 0.050" parting and grooving tools that I grind up myself. So it was just a matter of feeding 0.110" from the last cut using the topslide. Done in no time.
Still taking it very steady, I don't want to go hurting myself.
John
Glad to see greasy fingers in your thread again, John. (Meaning, pleased you are out in the shop!)
This post ties up a few loose ends, for me, concerning the metering needles. They look very nice!
Glad to see someone point out a thread run off cut at the end of die cut threads. It does make a difference in appearance, and I think speaks of good shop habits.
Thanks for the new post!
Dean
This post ties up a few loose ends, for me, concerning the metering needles. They look very nice!
Glad to see someone point out a thread run off cut at the end of die cut threads. It does make a difference in appearance, and I think speaks of good shop habits.
Thanks for the new post!
Dean
Dean,
Just taking things steady at the moment, but I have got a bit more done, not on the burner, but for the burner.
This is a little jig I made up. That is a 3" square in the background to show some sort of scale.
Front view
Back view
And this is what it is for. It is a silver soldering jig.
Because the disc is a slack fit on the shaft to allow silver solder to flow into the joint, it would be very difficult to stop it flopping about.
So this little thing holds the needle and disc nice and square and in the correct position to each other while I dab on a tiny bit of solder.
It is adjustable so that it can cater for different lengths of needles.
No use making a jig for just one, but for the quantities I expect to be doing, it is a worthwhile investment of my time.
The next time you see this it will be in use.
Bogs
Just taking things steady at the moment, but I have got a bit more done, not on the burner, but for the burner.
This is a little jig I made up. That is a 3" square in the background to show some sort of scale.
Front view
Back view
And this is what it is for. It is a silver soldering jig.
Because the disc is a slack fit on the shaft to allow silver solder to flow into the joint, it would be very difficult to stop it flopping about.
So this little thing holds the needle and disc nice and square and in the correct position to each other while I dab on a tiny bit of solder.
It is adjustable so that it can cater for different lengths of needles.
No use making a jig for just one, but for the quantities I expect to be doing, it is a worthwhile investment of my time.
The next time you see this it will be in use.
Bogs
Stew,
I had thought very early on about how I should go about fixing them together, threading, turned down shoulders etc. But this is more veratile, as the needles can be any sort of length, right up until they get joined, just hack it to the correct length and stick 'em together, no extra machining to be done.
I can use any sorts of short offcuts to make the needles out of, as long as they fall within a certain diameter, length and material type. In fact if it can be silver soldered, and 1/8" in diameter, it will do.
John
I had thought very early on about how I should go about fixing them together, threading, turned down shoulders etc. But this is more veratile, as the needles can be any sort of length, right up until they get joined, just hack it to the correct length and stick 'em together, no extra machining to be done.
I can use any sorts of short offcuts to make the needles out of, as long as they fall within a certain diameter, length and material type. In fact if it can be silver soldered, and 1/8" in diameter, it will do.
John
Dean,
I could just have easily said that the bits were soldered together, but because this is a warts and all post, I am trying to show even tiny details, all because one person might be able to pick up on something and use it to help them overcome a problem.
Sometimes 90% of the job can be figuring out how to hold things to get the part made.
In fact, very soon, I have a special bit of tooling to make for my tailstock, so that I can get another job done on this build. As you know, I only have complete use of the thumb and forefinger of my right hand, and sometimes I have trouble getting my big fingers in to do the dastardly deed as the duff three are tucked into my palm and get in the way. So I am modifying a tool I found on Chris Heapy's site to allow me to get more feel on the end of my forefinger when drilling tiny holes on the lathe.
http://www.astronomiainumbria.org/a...anica/easyweb.easynet.co.uk/_chrish/plans.htm
Tailstock sensitive drill attachment.
John
I could just have easily said that the bits were soldered together, but because this is a warts and all post, I am trying to show even tiny details, all because one person might be able to pick up on something and use it to help them overcome a problem.
Sometimes 90% of the job can be figuring out how to hold things to get the part made.
In fact, very soon, I have a special bit of tooling to make for my tailstock, so that I can get another job done on this build. As you know, I only have complete use of the thumb and forefinger of my right hand, and sometimes I have trouble getting my big fingers in to do the dastardly deed as the duff three are tucked into my palm and get in the way. So I am modifying a tool I found on Chris Heapy's site to allow me to get more feel on the end of my forefinger when drilling tiny holes on the lathe.
http://www.astronomiainumbria.org/a...anica/easyweb.easynet.co.uk/_chrish/plans.htm
Tailstock sensitive drill attachment.
John
Now to get onto silver soldering all the bits together.
When doing a small production job like this, I make sure everything is to hand and prepared for use. That way, you can get a bit of a rhythm going and the job gets done in no time.
The flux is prepared to get it to a nice runny mix, the silver solder wire has been wrapped around a drill bit to give me the correct sized circles to fit the job, and stainless implements and long nosed pliers for moving hot bits into the quench/citric acid pickle bath.
This is showing the very first bit to be soldered using the set up jig, no practice here, it has to work from the off.
What has been done is that the needle has been dropped into the jig, a tiny bit of flux put onto the top, and the disc has been pushed onto the needle. This ensures that there is flux down in the hole. Then another drop of flux followed by the solder ring.
No special torch used here, just a standard plumbers gas blowtorch played onto the needle just under the disc. I want this to get up to temp as fast as possible.
The first one done, as shown, the solder has stayed where I wanted it and flowed down into the joint (towards the heat) and formed a nice fillet underneath.
They were all very quickly completed. The jig turned black when I quenched it so that I could adjust for the longer needles.
That will be put with all the other bits I have made for this job, just in case I want to make some more.
A quickie clean up on the lathe to put chamfers either side of the knurl, and a fibre brushing on the buffing machine to clean out the knurl recesses.
This pic shows roughly what they will look like when finished. The needles were perfect length as I had designed them, and the o-rings collapsed really nicely to hold the needles in their set position, but still allowed movement with a little extra effort.
A bit more silver soldering now, to get the needle holders mounted into the main assembly.
I have mentioned this before, and Dean has made his without soldering, but I am a bit of a belt and braces chappie, and so everything gets stuck together.
So the first bit was to make some solder rings for the job to come. I wrapped it around an old knitting needle that was slightly smaller than the needle holder, and cut down the edge to form the rings. This will allow the slightly stretched solder wire to grip the holder by itself, and not be floating about as the initial heating is carried out. After the first heat, the flux will boil off and form a hardish crust that will then hold the solder in the correct position ready for more heating.
I started by getting as much prepared as I could, as I will be doing these in two batches.
A ring was put onto the holder, then flux was painted down into the main hole. After the two parts were assembled, a ring was put onto the other side and a tiny dab of runny flux painted onto each solder ring.
This is the first batch, they don't look very pretty, but once a bit of heat is on there, things will get a lot tidier.
As I work down the row with the torch, from left to right, the next one along will be warmed up and the flux solidified enough to hold things in place, ready for the main blast of heat. You can just make out where the torch is pointing, down at the base of the part. That will heat it up from the bottom upwards and as the flux and solder begin to melt, by capillary action, be drawn towards the heat and then will fill in the gap inside the joint.
This might seem to be like a load of bull-sh, but believe me, you can work out very accurately how much solder is required and where it will end up. I very rarely rod feed, it is just too inaccurate and wasteful for the sort of joints I want to produce.
With silver soldering if the joint is just filled, it cannot be made any stronger by piling on more solder, it just makes the job look unsightly and you also have to spend hours cleaning off the excess.
One packet of wire costing less than a pound has done all of the joints on this job, and I still have some left over for another job.
Job done, the flux has done it's job and the solder is exactly where I want it to be, inside the joint, not running all over the place as normally happens when you rod feed. Very little cleaning off to do.
After a few minutes in the pickle, I brushed one down with a fibre glass pencil. This shows how little cleaning up will be required.
So these will be left to stew until tomorrow, then I need to drill and tap for the jets, and then get another bit made, the air control ring.
Bogs
When doing a small production job like this, I make sure everything is to hand and prepared for use. That way, you can get a bit of a rhythm going and the job gets done in no time.
The flux is prepared to get it to a nice runny mix, the silver solder wire has been wrapped around a drill bit to give me the correct sized circles to fit the job, and stainless implements and long nosed pliers for moving hot bits into the quench/citric acid pickle bath.
This is showing the very first bit to be soldered using the set up jig, no practice here, it has to work from the off.
What has been done is that the needle has been dropped into the jig, a tiny bit of flux put onto the top, and the disc has been pushed onto the needle. This ensures that there is flux down in the hole. Then another drop of flux followed by the solder ring.
No special torch used here, just a standard plumbers gas blowtorch played onto the needle just under the disc. I want this to get up to temp as fast as possible.
The first one done, as shown, the solder has stayed where I wanted it and flowed down into the joint (towards the heat) and formed a nice fillet underneath.
They were all very quickly completed. The jig turned black when I quenched it so that I could adjust for the longer needles.
That will be put with all the other bits I have made for this job, just in case I want to make some more.
A quickie clean up on the lathe to put chamfers either side of the knurl, and a fibre brushing on the buffing machine to clean out the knurl recesses.
This pic shows roughly what they will look like when finished. The needles were perfect length as I had designed them, and the o-rings collapsed really nicely to hold the needles in their set position, but still allowed movement with a little extra effort.
A bit more silver soldering now, to get the needle holders mounted into the main assembly.
I have mentioned this before, and Dean has made his without soldering, but I am a bit of a belt and braces chappie, and so everything gets stuck together.
So the first bit was to make some solder rings for the job to come. I wrapped it around an old knitting needle that was slightly smaller than the needle holder, and cut down the edge to form the rings. This will allow the slightly stretched solder wire to grip the holder by itself, and not be floating about as the initial heating is carried out. After the first heat, the flux will boil off and form a hardish crust that will then hold the solder in the correct position ready for more heating.
I started by getting as much prepared as I could, as I will be doing these in two batches.
A ring was put onto the holder, then flux was painted down into the main hole. After the two parts were assembled, a ring was put onto the other side and a tiny dab of runny flux painted onto each solder ring.
This is the first batch, they don't look very pretty, but once a bit of heat is on there, things will get a lot tidier.
As I work down the row with the torch, from left to right, the next one along will be warmed up and the flux solidified enough to hold things in place, ready for the main blast of heat. You can just make out where the torch is pointing, down at the base of the part. That will heat it up from the bottom upwards and as the flux and solder begin to melt, by capillary action, be drawn towards the heat and then will fill in the gap inside the joint.
This might seem to be like a load of bull-sh, but believe me, you can work out very accurately how much solder is required and where it will end up. I very rarely rod feed, it is just too inaccurate and wasteful for the sort of joints I want to produce.
With silver soldering if the joint is just filled, it cannot be made any stronger by piling on more solder, it just makes the job look unsightly and you also have to spend hours cleaning off the excess.
One packet of wire costing less than a pound has done all of the joints on this job, and I still have some left over for another job.
Job done, the flux has done it's job and the solder is exactly where I want it to be, inside the joint, not running all over the place as normally happens when you rod feed. Very little cleaning off to do.
After a few minutes in the pickle, I brushed one down with a fibre glass pencil. This shows how little cleaning up will be required.
So these will be left to stew until tomorrow, then I need to drill and tap for the jets, and then get another bit made, the air control ring.
Bogs
That's a good bit on hard soldering, John. Many people find some mystery in it.
I see your fingers in the pickle. Are you using citric acid? It's what I use, but find it takes quite a while to do the job. Safe, though.
Thanks for the progress report. Nice write up and pictures.
Dean
I see your fingers in the pickle. Are you using citric acid? It's what I use, but find it takes quite a while to do the job. Safe, though.
Thanks for the progress report. Nice write up and pictures.
Dean
Sure is citric Dean, last years lemonade. I must mix myself a new batch up sometime.
With the flux I use, I find that an hour is plenty long enough to clean things up.
There is no black magic involved with silver soldering, just keep it clean, get a good quality flux and use a good technique for heat control. By doing that, 99% of the time, you are guaranteed the right result, and that is no boast, anyone can do it. It is just like parting off on the lathe, follow a few basic rules, and it is just becomes another string to your bow.
I am going to try to get a few slow hours in today, but it all depends if we have visitors or not.
Have a good Easter break.
John
With the flux I use, I find that an hour is plenty long enough to clean things up.
There is no black magic involved with silver soldering, just keep it clean, get a good quality flux and use a good technique for heat control. By doing that, 99% of the time, you are guaranteed the right result, and that is no boast, anyone can do it. It is just like parting off on the lathe, follow a few basic rules, and it is just becomes another string to your bow.
I am going to try to get a few slow hours in today, but it all depends if we have visitors or not.
Have a good Easter break.
John
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BogS
Good to be able to see how the experts do it. After my recent experiences I'd anticipate to end up with a brass blob on the end of the needle. However, thing are improving for me on the soldering front.
I'm finding that brass in the pickle is taking on a copper coating, My pickle has turned pale blue which I assume is copper sulphate from the boiler parts that have been in there. Do you have separate pickle tanks for copper and brass?
Good to be able to see how the experts do it. After my recent experiences I'd anticipate to end up with a brass blob on the end of the needle. However, thing are improving for me on the soldering front.
I'm finding that brass in the pickle is taking on a copper coating, My pickle has turned pale blue which I assume is copper sulphate from the boiler parts that have been in there. Do you have separate pickle tanks for copper and brass?
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