Countryman’s Steam – Chain drilling

[JasonBModerator @jasonb]

In the latest issue Tony suggests chain drilling out the wheel rims by stepping out 1/8″ along a scribed circle and then drilling 3mm holes, all well and good so far.

 

He than says to open out the holes to 4mm BUT not any that are likely to run into adjacent holes. 4mm into 1/8″ spacing won’t go so the holes will run into each other.

 

Is it a typo and should the beginner be stepping out at 3/16″ or just drilling 3mm and sawing these holes.

 

It would also help the beginner if he gave a radius for the chaindrilled holes and also the radius the rivits should be drilled at as its not on the drawing

 

There is also no mention in the text or on the drawings of what thickness angle the rims are made from if rolled. I would assume it should be 1/16″ rather than the beginner looking for 18swg x 3/8″ angle. Also does not mention that the angle will need cutting down to 3/8×11/32″ approx 

 

And being nit picky there are too many dotted hidden detail lines on the hub section, it should only show the bore dotted and not the outer spigots carried through. Also why colour one spoke? is it to show it in section if so why not the hub & rim

 

Hopefully these items will be sorted as it will confuse beginners that this series is aimed at.

 

Jason

Edited By JasonB on 04/04/2011 15:15:36

Edited By JasonB on 04/04/2011 15:17:35

[JasonBModerator @jasonb]

[David Clark 13Participant @davidclark13]

Hi There

I have checked the original text and dimensions are correct as published.

I would suggest marking out at 3/16in. apart might be a better bet.

I would make the hole pitch circle diameter 1/4in. smaller than the inside of the wheel rim.

 

regards david

 

[JasonBModerator @jasonb]

And for any beginners that will work out at 6 1/8″ dia which will mean the holes come just inside the Angle leg NOT the rim

 

Jason

[Clive FosterParticipant @clivefoster55965]

Jason

Probably a typo on the chain drilling. Drilling every other hole on 1/8″ spacing out to 4 mm will clear the webs between the holes with minimal chance of drill wander. Or maybe drill every other hole 4 mm in the first place by going round twice. The inexperienced worker can do without slightly misplaced holes running into each other on their first efforts at chain drilling. Not to mention the broken drills!

Mixing imperial (1/8″) and metric dimensions may be frowned upon but its an excellent way of getting a small clearance / space with limited tools and no need for super accurate measuring gear. Laying divider points onto a good engraved rule is very accurate, especially via a magnifier.

Often thought that a proof reading panel would be good for beginners constructional series articles. Normal ones are hard enough to write when at least you can assume that a bit of reader experience will click in to tide over small errors and “not quite what I meant” phrasing. Beginners stuff is a nightmare for the experienced guy to write, especially as he has his head full of the design and how he made / will make it. Infinite scope for “mentos” (mental equivalent of typos). Hard for experienced workers to spot too as we tend to read what is meant not what is written. Our overworked editor doesn’t have time for the detail attention needed.

Clive

[V8EngParticipant @v8eng]

 

I cannot find anything about the Countryman’s Steam series in issue 4400, it does not seem to be in the ‘next issue’ listing for 4401 either.

 

Where are you finding the drawings and ongoing articles?

 

Edited By V8Eng on 04/04/2011 16:19:21

[JasonBModerator @jasonb]

It is in 4401 which postie dropped off today although it does not say its going to be in the “next issue” in 4400

 

Should be in the shops Friday

[David CostelloParticipant @davidcostello75947]

Jason 4401 comes after 4400,Sorry Jason i understand now it will be in 4401

Dave

Edited By David Costello on 04/04/2011 17:33:27

[V8EngParticipant @v8eng]

 

 

Thanks Jason, I do get my copy from shop so look forward to reading the next part.

Edited By V8Eng on 04/04/2011 17:44:19

[JasonBModerator @jasonb]

Two other points on the hub cross section

 

1. No diameter shown for the reduced central section, assume it should be about 7/8″ Would also look better with radiused internal & external corners as it represents a casting

 

2. The 1/4″ dimension given for the hub flanges is not in proportion to whats drawn, the 1/4″ should have been dimensioned from the outer face of the cover “washer” to the back of the flange. 

 

Jason

 

Oh and no idea what the bits in the bottom right are meant to be, hopefully the next installment will enlighten us

Edited By JasonB on 04/04/2011 18:47:30

[John OlsenParticipant @johnolsen79199]

This might seem a bit like overkill…but if you select a stub drill of a suitable size, for straight lines you can use the coordinate drilling idea. For instance my mill has 2.5mm leadscrews, so by selecting a stub drill that is a little under that, say 2.4mm, you can step along one whole turn of the leadscrew each time and be assured that the drill will not wander into the last hole. ( or use 4.8 and do two turns.) For a circle you can do much the same thing, by establishing what size drill will suit a fixed number of degrees on the rotary table. If you can manage to have nice consistent lands between the holes it does become easier to remove the waste piece afterwards.

 

regards

John

[KWILParticipant @kwil]

If you are “chain drilling” along a straight line in a mill, then use a 3 flute cutter and chain mill, then any slight overlap will not hurt, I use the same technique in a circular fashion as well.

Edited By KWIL on 05/04/2011 09:01:13

[Laurence BParticipant @laurenceb]

Posted by JasonB on 04/04/2011 18:41:43:

Two other points on the hub cross section

 

1. No diameter shown for the reduced central section, assume it should be about 7/8″ Would also look better with radiused internal & external corners as it represents a casting

 

2. The 1/4″ dimension given for the hub flanges is not in proportion to whats drawn, the 1/4″ should have been dimensioned from the outer face of the cover “washer” to the back of the flange.

 

Jason

 

Oh and no idea what the bits in the bottom right are meant to be, hopefully the next installment will enlighten us

Edited By JasonB on 04/04/2011 18:47:30

Like Jason,I have no idea quite what the figure bottom right represents.Also missing from the drawing is the spoke thickness.Is it supposed to be 18g or 16g as implied in the text,or if the angle rims are equal at 5/16,should the spokes be 1/8″ thick?

And despite giving the tyre width of 3/4″ twice on the drawing,there is no mention of how thick that should be.

 

Why not put all the dimensions needed to make the wheels on the drawing,especially as the series is aimed for the beginner?

 

Again it poses the question about the standards of some of the drawings published in the magazine,whereas those excellently provided by Ray McMahon and Peter Rich for their respective locomotive designs should be what all contributors should aim for.

I hope Mr Webster and the Editor accept my comments in a constructive way,as I think this is a most interesting project.

 

Whether we love or loathe the subject,technical drawing is the language of engineering,whether at full size or in ‘our’ scales.

[TerrydParticipant @terryd72465]

Posted by KWIL on 05/04/2011 09:00:45:

If you are “chain drilling” along a straight line in a mill, then use a 3 flute cutter and chain mill, then any slight overlap will not hurt, I use the same technique in a circular fashion as well.

Edited By KWIL on 05/04/2011 09:01:13

Can I ask why, if chain drilling for a slot on a milling machine, one should not use a slot drill and just cut the slot. Is there a reason I should know of? Or is there another reason apart from a slot that one needs to chain drill. I thought that the reason for using this method of profiling is for beginners who may not have fully equipped workshops.

 

Thanks and best regards,

 

Terry

[David Clark 13Participant @davidclark13]

Hi Terry

The simple answer is it is a lot quicker to remove material with a drill than a slot drill.

Secondly, slot drills can cut oversize and also can keyhole the end of a hole.

 

To cut a through slot, I would normally drill undersize holes at each end, finish the hole to size with a size slot drill, remove the material by chain drilling or an undersize slot drill and finally finish each side with an undersize slot drill.

 

However, if cutting a keyway, I would plunge the end of the keyway to full depth then run along the keyway slowly (using feed if available) from one end to the other.

I would also use a new cutter for a keyway for each batch of keyways I did.

 

regards David

Edited By David Clark 1 on 08/04/2011 15:53:54

[David Clark 13Participant @davidclark13]

Hi Laurence

Bottom right are the spokes.

regards David

 

[JasonBModerator @jasonb]

Terry I think Kwil was mostly talking about cutting curves to remove the central waste( which is what the thread is about), just set the DRO for a large number of holes on the correct PCD so they just overlap and then plunge cut with an endcutting 2 or 3 flute cutter which won’t wander into the adjacent hole. Something like This

 

Laurence, I did not comment on the tyres as hopefully the thickness and fixing method will be covered in the next issue but agree it should all be on the same drawing or are we going to get a second drawing which will waste space. Agree about the possible two spoke thicknesses and the angles needing to be unequal.

 

David, Are there any photos that show the flanging process, I have spoken with several other people and they all agreed that the text was hard to follow and a pic or two would help a beginner no end. I know this portable was built a few years ago so maybe there were no work in progress photos taken, this would be a real let down on a beginners series.

 

I can’t see how that can be the spokes as they are drawn in the wrong plane relative to the angle at the extream right, have a kink in them and a hole drilled their full width??? and also not to the same scale/proporting as the rest of the drawing. Also would be nice to referance the drawings some way eg Fig. No or even just say “back wheel” then we all know what drawing is being refered to.

 

Jason

Edited By JasonB on 08/04/2011 17:09:08

[JasonBModerator @jasonb]

Two maybe three other items missing from the drawing

 

1. Tapped holes for hubcaps

 

2. Position of spacers where the two half circle flanges are rivited together so they don’t get crushed

 

3. Should there be a tapped hole in the hub to take an oil tube?

 

 

J

 

[David CostelloParticipant @davidcostello75947]

Much confusion already on this beginners build.Looking through “Reading Iron Works” by Brown & Green,the drawings & photos show these portables with round or oval spokes set into channel rims,possibly made of wood,none of the drawings show flat section spokes or the angle T rims.

Dave

,

[JasonBModerator @jasonb]

Thanks for the info Dave. Though to be fair to the author if he was basing his model solely on the etching that appeared in the first installment then that does seem to show the double angle rims with flat spokes which are quite a common construction on portables.

 

Jason

[David Clark 13Participant @davidclark13]

Hi There

Original drawing attached.

We can only publish what we are given.

It appears to have been redrawn correctly.

I will ask the author about spoke thickness and hub dimensions.

regards David

Edited By David Clark 1 on 08/04/2011 22:24:09

[JasonBModerator @jasonb]

“We can only publish what we are given.”

 

This brings us back to the earlier comment about proof reading, if the authors sketch is just handed to a graphic designer to tidy it up for publication then you will only get whats supplied but if it were checked or drawn by someone with engineering background it would soon be clear that the item cannot be made from the information given particularly by a novice.

 

Same with the text about drilling the holes if ME just prints whats supplied without copy proofing it then as you have said above the hole sizes just won’t work

 

I also subscribe to another magazine that includes drawings with each issue, in the early days there were quite a few small errata but they then got an experianced draughtsman who was an engineer to produce the drawings and now 99% of the time you can build the engine from the drawing.

 

Hopefully part 3 has not been sent to the printers yet and the article can be checked to bring this series back on line after a shaky start. It would be a shame to put people off as its a good way for a novice to progress from simple stationary engines towards a traction engine or other roadsteam subject.

 

J

[GoCreateParticipant @gocreate]

Posted by David Clark 1 on 08/04/2011 13:31:32:

Hi Laurence

Bottom right are the spokes.

regards David

 

I still do not have a clue what this view reprsents, how it relates to the spokes or what the 13/16″ is for. I just can’t fathom it.

 

Any body able to explain?

 

Nigel

[Nicholas FarrParticipant @nicholasfarr14254]

Hi, no! I can’t fathom out how this view relates to the spokes either. I have studied it several times and joggled about with some of the dimentions to see if the 13/16″ can throw any light on it, but nothing seems to make any sense.

 

Regards Nick.

[JasonBModerator @jasonb]

No, I’m baffled

 

I did think it may be some form of drilling jig but couldn’t be bothered to work out if the 13/16 would give the next hole around the rim but as the radius for the rivits is not given you can’t do the trig. Can’t see why there is an angle ring shown at the end where the “spokes” radiate from, also there should be a second size for the smaller front wheels.

 

Could also be some form of bending or wheel building jig but again why show the angle rings?

 

Hopefully all will be revealed in teh next set of text

Edited By JasonB on 09/04/2011 09:50:42

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