Scott flame licker build

[Brass_Machine]

Good reading. Even I am able to understand what your are explaining.

Thanks!

Eric

[Bogstandard]

I'm glad you lads are able to understand it as I go along.

I was hoping for that to happen, as it will mean I won't need as many pictures. I can just describe it in a few words and you will remember what was done from before.

Another evening only post maybe today, if at all.


John

[shoey51]

Thanks John that was very informative i think im beginning to understand


cheers Graham

[NickG]

John, your preperation and the DRO made short work of that base! I guess it just takes a bit more concentration if you've got manual dials but I know my dials aren't accurate so I'd have to mess on  marking things up some how.

NIck

[Bogstandard]

Nick,

It is a shame that everyone doesn't have DRO's, I am lucky on that score.

But even so, I used to do a lot of my casting work on a basic imperial mill/drill with real 'iffy' backlash problems (almost a full half turn), before I fitted scales to it, and I used to use the same methods then, purely by zeroing up the handles when the datum was hit, and working from them. I found that it was accurate enough to get all the holes in the correct relationship to each other, as long as you crept up on the setting and hit it spot on. If you went past, you would then have to start from the datum again, just to make sure the backlash was taken out.

Been there, got the t-shirt AND the baseball cap.

You have to work with what you have, and make the very best of it.


John

[NickG]

John,

I was going to put sliding scales on my mill but have taken the advice from people on here and my experience using proper DRO's at university and digi verniers not to bother. I think it'd be better than what I currently have, but not enough to justify and the extra for a proper DRO would be well worth it. So I'll wait until I can afford a proper one with glass scales. Not sure whether to put money into a DRO, or a rotary table and QCTP next.

I have come to the conclusion that on my machine, there must be a pitch error in the screws. The handwheels work ok for small movements but if you have to wind something on a few inches, the error gets greater and greater!

You're right, I'll make the best of what I have. I hope to have the all singing and dancing stuff one day but for now I need to improve my skills by a long way to justify anything like that I think! The other argument is, is it worth putting on my machine, is it good enough.

Looking forward to the next post.

Thanks

Nick

[Bogstandard]

If things are that critical Nick, maybe you could cobble something together with a bit of ali plate and some magnets, and get a digivern on there as a temporary fitting.

I personally, thru experience, wouldn't recommend the scale type of DRO's, except where there is no swarf or liquid, say on the quill. I fitted them in the very beginning, and with all the messing around and changing them, I could have bought a full blown glass scale one with the amount of money I spent on them in the two years I had them fitted. I used to have to carry spares scales in stock, as they would go down for no reason, half way thru a critical job.


John

[AdeV]

Nick - it sounds like you've got a metric screw & imperial dials - or vice versa. I don't know what mill you have, but it might be worth seeing if you can hunt down a set of alternative dials?

John - this is a fascinating build, I'm watching it with great interest. The more you show, the more I feel my slowly growing machining skills might be up to building something like this. So, thanks for that!

One question - can you tell me some more about this cutter:



It looks almost like a T-slot cutter to me (only deeper), but I'm sure it's not...

[NickG]

Ade,

if I remember I'll take some pics and show you them tonight. Think they are both metric and imperial, it's like a chester century.

[Bogstandard]

Ade,

I thought I had given you one of these cutters, almost everyone else that visited got the offer of one, shame I don't have any spare ones left.

They are a special solid tungsten end and face cutter, just like the larger diameter ones that look like large slitting saws. These are designed to rip thru hard materials like nimonic steels, but are accurate and sharp enough to take a wisp off, which is the way I use it, in both planes. It can reach down a face where a normal end mill can't get, by taking a few swipes at it, I can face an end by about 6" deep, as the cutting face is just larger than the outside collet.

It really is too large for a normal collet to hold in my machine, I think 1.125", I am limited to 1" normally, so I have to use a special outside R8 collet to hold it, but that won't allow me to do very heavy work with the cutter, maybe 50 thou max cut in steel before it starts to tell me enough is enough.

I wouldn't say working from castings is diffiicult, it is just you have to treat them in a slightly different way than when making from bar stock. Once you get the basic understanding that nothing you will get hold of will be either square or flat, then you can start to work accurately with them.
Parallels, a DTI, a small level and machinist jacks will become your best mates, and of course, a bit of jig plate. When I get to do my larger casting build, the vice has got to go, everything will be held down to the table on the largest bits, thats when things like machinist jacks come into play.


John

[madjackghengis]

By the by, John, what exactly is the magneto being built for, if you don't mind my asking?  I have a special place in my heart for such things, and am a bit of an expert on their use on full sized engines.  I also wanted to say that casting of the hopper is an absolute beauty, and I kind of hope the flames cause the paint to fall away, so it can be fully cleaned up and be a show piece in and of it's self.  It is much larger than I thought from the drawings and looks great.  To Nick, I used a two in travel dial indicator mounted on a magnetic base as my last resort before buying a DRO.  It worked better than clamping two digital calipers on the x and y axis'.
   By the way John, that was a very smooth move in the way you got all your horizontal bores in line, and done exactly right, that jig plate worked great.  The fact that it remains a good piece of "jig plate" or a spare piece of metal when you're done only makes it practically free, as a jig.  Your pictures make this a great build log too. cheers, mad jack

[Bogstandard]

Jack,

The magneto will be used on a R&B engine that I bought the castings for last year and Rob is actually making his own.

http://madmodder.net/index.php?topic=3137.msg34848#msg34848

It will end up something like this, mine will have 2x9" flywheels instead of the one 12"



I'm glad you liked the way the jig plate worked. The R&B will have the same done to it once the base is flattened level.

John

[Bogstandard]

Mainly a load of piccies tonight, and only a bit of machining.

These concern the next part to be machined up, the water hopper.

Even though it looked OK from a distance, when I got up close and personal with this casting, I was a little disappointed, as will be seen. I spent nearly an hour, trying to make a descision how I was going to machine it back to how I wanted it. At least one specific face had to be machined perfectly square to the foot, and then bored for the cylinder.

As you can see by the fettling marks, this side has an outwards bulge, and when handled, is more pronounced than shown on this photo.




As can be seen from this shot viewed from the side, the shape is more like a leaning parallelogram rather than an oblong.




When viewed from the top, you can also see that it tapers from one side to the other.
Luckily, although in parts, the casting is under nominal size, there is enough meat on it to get it all square.




I decided the best place to start was the already fettled base, which was reasonably flat, so it was gripped in the vice with the base set level to the table.
I just needed to make sure the cutting forces were kept as low as possible.




With a bit of extra support from the backstop, I used my flycutter, cutting in one direction only (towards the backstop) and with only a 0.005" cut, the base was cleaned up after a couple of passes.




This shot shows just how much inwards lean at the top there is on the sides. The next cut has to be getting the side face that requires boring square to the base.




The casting was set up again in the vice with the base sticking out.
By using a 3 2 1 block and a nut and bolt just slightly smaller than the holes in the block, I jacked the base end up so that the base was perfectly square to the table. Hopefully it will remain in that square position while the face is machined. The block and jacking screw were left in position to help support the part.




I tried to skim this unfettled face with my flycutter, but the skin was a little hard and didn't really want to cut. You can see by the machining marks just how far out this face is.




So I resorted to one of my favourites, a 16mm razor sharp cutter. This went thru it like it was butter.




This slightly fuzzy shot shows just how bent the face was, and this isn't down to full cleanup depth yet.




After going down to just over 60 thou, I had the face cleaned up, and yes, it was perfectly square to the base.
Now I have these two faces, everything else will be an easy job. Even though the angles are slightly out to each other on the two angled faces, as of yet, I have decided they won't be machined, and left as cast.




To me, it is looking better already.




I hope to finish this part tomorrow, then this build has to stop while I get a couple of private jobs done.


Bogs

[Stilldrillin]

That's looking good John! 

I regularly used to mill fabricated drill rig sections. The welder's ideas of straight and square, were nothing like mine! 

Machining straight and square. Leaving an unmachined witness area as necessary, sometimes almost amounted to alchemy.......   

David D

[NickG]

John, the hopper does look way better than when you started with it. I remember now why I got frustrated with the sweet pea castings. The material was ok but the shape of the bits weren't as good as they should have been. E.g., for the pony wheels the flange that was cast in was useless - there was so much material there it all had to come off, which infact meant doing it with castings was pointless - it would have been cheaper and easier just to use round steel.

The cylinders to me look the same - I could just make them from a square block of cast iron, the only advantage is there is a core down the bore (that won't be anywhere near in the right place though so would have to do Stew's trick) and a radius on the outer so less material to remove, but these are outweighed by the fact that there are no datums and it'll be difficult to hold.

Obviously that hopper is hollow and has a bit of shape to it so it'd have been a huge job to make from solid or fabricate. I think you've done it in the best way possible. 

Nick

ps that gas engine is a beast, must be capable of real work.

[Bogstandard]

David,

I know exactly what you mean.

Unfortunately, I am the sort of person who demands excellence from myself, when really, on a job such as this, it could be a little more haphazard.

But on this particular casting, this squaring up and flatness had to be done this aggressively on these two sides, the whole of the engine depends on how square the bored hole is. The top will also get the squaring treatment, as I have a bit of a bling plan for that, but the opposite side to this machined one, I am going to see if it can just have a recess cut square and level, so that three sides get left with the rough casting faces on them.

Nick,

The gas engine isn't designed as a model, but a full sized 1 to 1 working engine based on the sizes of portable engines of the time it is supposed to represent. Just like jobbers who do work now, they used to carry their small power tools around with them, and so the power souce as well (instead, we have the modern day battery packs).


John

[NickG]

Ah right, didn't realise that John. Thought it looked more complex than most models though so it makes sense now.

[Bogstandard]

The final bit for this week and at a good stopping point.

Last time I had got the two faces square to each other and nice and flat. This time is getting the third face square or parallel to the other two.
This is the standard set up technique, one good face down and tapped onto a pair of parallels, with the other square and flat face against the fixed chuck jaw. A piece of soft material, in this case ali, is placed between the moving jaw and the fourth rough side. Doing that puts all the pressure onto one small point and takes up some of the irregularities on the job. You don't want to go putting on heavy cuts while in this sort of setup, in fact, I changed my normal cutting direction, from X to the Y axis.




The top surface was soon cleaned up.




I need the big offset hole in the top cleaning up for a feature I will be adding, so the boring head was roughly centred and set to work.




This is as far as I want to go with this piece at this time. It still need a few small holes drilling, and boring for the cylinder sleeve. But I want to wait until that is finished first, as the boring is a more controllable exercise than bringing the sleeve down to size.




I hope to be restarting this post later next week, depending how I get on with the Minimag build.


Bogs

[saw]

Looks great Bogs, I'm folow you'r log with the greatest interest. 

[Stilldrillin]

Squared up. Centralised. Sorted..... 

Able to be comfortably set aside. For later, easy pick up and resume......   

A good satisfying feeling! 

David D

[Bogstandard]

Saw,

Glad you are enjoying it. I will soon be onto the fiddly bits, that is the part I like the most, and where I hope to leave some of my bling ideas. I hate engines that all look the same, with just a few little changes, it becomes personalised.


Dave,

You have got it spot on, just like I always like to leave a break in a project, pick it up and you are into it straight away.


John

[NickG]

Looks great John, it's without a doubt already looking like the best version of this I have seen.

My engines usually look different because I use what I have to hand or make it easier to make! The only differences on my poppin are slightly smaller flywheels but I put 6 holes in them too, I prefer the look. It has less fins as the grooves are the width of my parting tool, piston design is different and graphite and I have omitted radii and base as I feel they are unnecessary extra work!

Can't wait to see what you have planned here, will pick up on your minibar in the mean time though.

[madjackghengis]

Hi John, that is a fine looking engine you're getting ready to build, to go with the minimag, appreciate the picture, worth at least a thousand words.  I truly admire the work you've done on this build, it's coming along very nicely, well planned out, and coming together very nicely, that job on the hopper worked out well, and should have the cylinder in the right place when you've bored it, and the engine ought to be able to do some work in its own right.  are you doing a build log on the minimag?  I for one, would be highly interested in seeing it, and I suspect there are others lurking out there who would like to see it done up.  Now I am also looking forward to your build of the R&B engine, when its time comes.  I'm really looking forward to seeing this engine running, it looks to be something with some power and stamina, with that hopper to cool it, and the secret plan you have involving the bored hopper top. cheers, mad jack

[Bogstandard]

Nick,

I'm not doing a lot to the engine, no reshaping of major parts. Just fitting a nice filler funnel top to the hopper, to get away from the squarish shape and make reshaped rods, rather than the straight bits called for on the plans. As long as the pivot points are in the same positions, and nothing catches anywhere, then almost anything goes.


Thanks Jack.

I have a couple of private jobs to do, and once those are completed, I will be doing a full build on the minimag. I had a first look at the plans last night, and also the preliminary build instructions, which require following as close as possible to prove them. Looks like I will have to find the swivel base for my vice that I dumped somewhere in the back of the shop, I've never had to use it before.

The R&B will be many moons off, I have to complete all my backlog jobs first.


John

[DMIOM]

....... will pick up on your minibar in the mean time though........

Nick - is that a Freudian slip? 

- are you in fact referring to the the minimag ?

Dave