For what it's worth - identified the rock-drill I used.

http://weldsmith.co.uk/tech/minerals/condurrow/231207_rockdrill1st/231224_holman_silver_900.html
"rock-drill of 07Dec2023 - Holman Silver 900"

One of the volunteers was a driller and said this machine is only
usable on hard granite. That on any other rock - which in Cornwall
would mean the "killas" which is the "country rock" - is a
metamorphosed sedimentary rock - it is difficult to control.
Use the popular smaller "303" - which is easier to carry too, etc.

Rich S

"Richard Smith" wrote in message news:lysf3pmqx5.fsf@richards-air-2.home...

For what it's worth - identified the rock-drill I used.

http://weldsmith.co.uk/tech/minerals/condurrow/231207_rockdrill1st/231224_holman_silver_900.html
"rock-drill of 07Dec2023 - Holman Silver 900"

One of the volunteers was a driller and said this machine is only
usable on hard granite. That on any other rock - which in Cornwall
would mean the "killas" which is the "country rock" - is a
metamorphosed sedimentary rock - it is difficult to control.
Use the popular smaller "303" - which is easier to carry too, etc.

Rich S

---------------------------------------
https://www.sunritadrillbit.com/holman-303-rock-drill/
What is "lofty-quality steel"?

"Jim Wilkins" <muratlanne@gmail.com> writes:
> ---------------------------------------
> https://www.sunritadrillbit.com/holman-303-rock-drill/
> What is "lofty-quality steel"?

This looks to be a copy (something like a copy?) of the Holman Silver 303.

The expression in English about the drill is brilliant.

Air-powered, at one place it's got an internal petrol (gasoline)
engine - in another it has an internal diesel engine ... (!)

I imagine "lofty quality" is excessive use of a thesaurus to find
synonyms for "high" - "high quality"

Rich S

"Richard Smith" wrote in message news:lyv88kdqtd.fsf@void.com...

"Jim Wilkins" <muratlanne@gmail.com> writes:
> ---------------------------------------
> https://www.sunritadrillbit.com/holman-303-rock-drill/
> What is "lofty-quality steel"?

This looks to be a copy (something like a copy?) of the Holman Silver 303.

The expression in English about the drill is brilliant.

Air-powered, at one place it's got an internal petrol (gasoline)
engine - in another it has an internal diesel engine ... (!)

I imagine "lofty quality" is excessive use of a thesaurus to find
synonyms for "high" - "high quality"

Rich S
---------------------------------
I would be worse translating to or from technical French or German. I
subscribed to the German language version of the Daimler in-house magazine
and couldn't find many of the high tech words in a dictionary. Although much
of English descended from Saxon German the modern usage is considerably
different, they don't translate word for word the way French sometimes does.
https://emercedesbenz.com/tag/high-tech-report/

I watched a pile driver that was obviously a Diesel from the black smoke
puffs. Are Diesel hammers practical for horizontal drilling in tunnels?

"Jim Wilkins" <muratlanne@gmail.com> writes:

> "Richard Smith" wrote in message news:lyv88kdqtd.fsf@void.com...
>
> "Jim Wilkins" <muratlanne@gmail.com> writes:
>> ---------------------------------------
>> https://www.sunritadrillbit.com/holman-303-rock-drill/
>> What is "lofty-quality steel"?
>
> This looks to be a copy (something like a copy?) of the Holman Silver 303.
>
> The expression in English about the drill is brilliant.
>
> Air-powered, at one place it's got an internal petrol (gasoline)
> engine - in another it has an internal diesel engine ... (!)
>
> I imagine "lofty quality" is excessive use of a thesaurus to find
> synonyms for "high" - "high quality"
>
> Rich S
> ---------------------------------
> I would be worse translating to or from technical French or German. I
> subscribed to the German language version of the Daimler in-house
> magazine and couldn't find many of the high tech words in a
> dictionary. Although much of English descended from Saxon German the
> modern usage is considerably different, they don't translate word for
> word the way French sometimes does.
> https://emercedesbenz.com/tag/high-tech-report/
>
> I watched a pile driver that was obviously a Diesel from the black
> smoke puffs. Are Diesel hammers practical for horizontal drilling in
> tunnels?

The "Delmag" type pile-driver...

They work by the piston falling in gravity.
For a horizontal cylinder there could be a spring or gas pressure.

The problem would be clean combustion.
You wouldn't want sooty and tarry waste gases down a mine.

Maybe use something like propane, with spark-ignition.
Would still need ventilation - would get through oxygen in the air.

Beauty of air-tool is exhausts breatable air and the tool gets cooler
as it works - makes it handlable for hard work.

I think suffer the inefficiency of compressed air systems for the
simplicity, robustness, safety, avoidance of environmental problems
down the mine, etc.

My impression is compressed air systems are about 10% efficient.
eg. 3kW into the compressor motor to get the equivalent of about 300W
of electrical power in something like an angle-grinder.

I've never seen a diesel hammer in action.
Seen air-driven and hydraulic.

On Wed, 27 Dec 2023 23:10:16 +0000, Richard Smith <null@void.com>
wrote:

>"Jim Wilkins" <muratlanne@gmail.com> writes:
>
>> "Richard Smith" wrote in message news:lyv88kdqtd.fsf@void.com...
>>
>> "Jim Wilkins" <muratlanne@gmail.com> writes:
>>> ---------------------------------------
>>> https://www.sunritadrillbit.com/holman-303-rock-drill/
>>> What is "lofty-quality steel"?
>>
>> This looks to be a copy (something like a copy?) of the Holman Silver 303.
>>
>> The expression in English about the drill is brilliant.
>>
>> Air-powered, at one place it's got an internal petrol (gasoline)
>> engine - in another it has an internal diesel engine ... (!)
>>
>> I imagine "lofty quality" is excessive use of a thesaurus to find
>> synonyms for "high" - "high quality"
>>
>> Rich S
>> ---------------------------------
>> I would be worse translating to or from technical French or German. I
>> subscribed to the German language version of the Daimler in-house
>> magazine and couldn't find many of the high tech words in a
>> dictionary. Although much of English descended from Saxon German the
>> modern usage is considerably different, they don't translate word for
>> word the way French sometimes does.
>> https://emercedesbenz.com/tag/high-tech-report/
>>
>> I watched a pile driver that was obviously a Diesel from the black
>> smoke puffs. Are Diesel hammers practical for horizontal drilling in
>> tunnels?
>
>The "Delmag" type pile-driver...
>
>They work by the piston falling in gravity.
>For a horizontal cylinder there could be a spring or gas pressure.
>
>The problem would be clean combustion.
>You wouldn't want sooty and tarry waste gases down a mine.
>
>Maybe use something like propane, with spark-ignition.
>Would still need ventilation - would get through oxygen in the air.
>
>Beauty of air-tool is exhausts breatable air and the tool gets cooler
>as it works - makes it handlable for hard work.
>
>I think suffer the inefficiency of compressed air systems for the
>simplicity, robustness, safety, avoidance of environmental problems
>down the mine, etc.
>
>My impression is compressed air systems are about 10% efficient.
>eg. 3kW into the compressor motor to get the equivalent of about 300W
>of electrical power in something like an angle-grinder.
>
>I've never seen a diesel hammer in action.
>Seen air-driven and hydraulic.

I've seen diesel pile-drivers in action. Like this:

..<https://www.youtube.com/watch?v=VmIhSh_7gVA>

Joe Gwinn

On Wed, 27 Dec 2023 18:51:25 -0500, Joe Gwinn <joegwinn@comcast.net>
wrote:

>On Wed, 27 Dec 2023 23:10:16 +0000, Richard Smith <null@void.com>
>wrote:
>
>>"Jim Wilkins" <muratlanne@gmail.com> writes:
>>
>>> "Richard Smith" wrote in message news:lyv88kdqtd.fsf@void.com...
>>>
>>> "Jim Wilkins" <muratlanne@gmail.com> writes:
>>>> ---------------------------------------
>>>> https://www.sunritadrillbit.com/holman-303-rock-drill/
>>>> What is "lofty-quality steel"?
>>>
>>> This looks to be a copy (something like a copy?) of the Holman Silver 303.
>>>
>>> The expression in English about the drill is brilliant.
>>>
>>> Air-powered, at one place it's got an internal petrol (gasoline)
>>> engine - in another it has an internal diesel engine ... (!)
>>>
>>> I imagine "lofty quality" is excessive use of a thesaurus to find
>>> synonyms for "high" - "high quality"
>>>
>>> Rich S
>>> ---------------------------------
>>> I would be worse translating to or from technical French or German. I
>>> subscribed to the German language version of the Daimler in-house
>>> magazine and couldn't find many of the high tech words in a
>>> dictionary. Although much of English descended from Saxon German the
>>> modern usage is considerably different, they don't translate word for
>>> word the way French sometimes does.
>>> https://emercedesbenz.com/tag/high-tech-report/
>>>
>>> I watched a pile driver that was obviously a Diesel from the black
>>> smoke puffs. Are Diesel hammers practical for horizontal drilling in
>>> tunnels?
>>
>>The "Delmag" type pile-driver...
>>
>>They work by the piston falling in gravity.
>>For a horizontal cylinder there could be a spring or gas pressure.
>>
>>The problem would be clean combustion.
>>You wouldn't want sooty and tarry waste gases down a mine.
>>
>>Maybe use something like propane, with spark-ignition.
>>Would still need ventilation - would get through oxygen in the air.
>>
>>Beauty of air-tool is exhausts breatable air and the tool gets cooler
>>as it works - makes it handlable for hard work.
>>
>>I think suffer the inefficiency of compressed air systems for the
>>simplicity, robustness, safety, avoidance of environmental problems
>>down the mine, etc.
>>
>>My impression is compressed air systems are about 10% efficient.
>>eg. 3kW into the compressor motor to get the equivalent of about 300W
>>of electrical power in something like an angle-grinder.
>>
>>I've never seen a diesel hammer in action.
>>Seen air-driven and hydraulic.
>
>I've seen diesel pile-drivers in action. Like this:
>
>.<https://www.youtube.com/watch?v=VmIhSh_7gVA>
>
>Joe Gwinn
From my experience about sixty years ago, the crew opperating a
"Delmag" pile driver, wear black (beige when new) coverals!

Gerry <geraldrmiller@yahoo.ca> writes:

> On Wed, 27 Dec 2023 18:51:25 -0500, Joe Gwinn <joegwinn@comcast.net>
> wrote:

>>>> ...

>>>
>>>I've never seen a diesel hammer in action.
>>>Seen air-driven and hydraulic.
>>
>>I've seen diesel pile-drivers in action. Like this:
>>
>>.<https://www.youtube.com/watch?v=VmIhSh_7gVA>
>>
>>Joe Gwinn

> From my experience about sixty years ago, the crew opperating a
> "Delmag" pile driver, wear black (beige when new) coverals!

From grease lubrication and from part-burned fuel?

"Richard Smith" wrote in message news:lyplyrhrv1.fsf@void.com...

Gerry <geraldrmiller@yahoo.ca> writes:

> On Wed, 27 Dec 2023 18:51:25 -0500, Joe Gwinn <joegwinn@comcast.net>
> wrote:

>>>> ...

>>>
>>>I've never seen a diesel hammer in action.
>>>Seen air-driven and hydraulic.
>>
>>I've seen diesel pile-drivers in action. Like this:
>>
>>.<https://www.youtube.com/watch?v=VmIhSh_7gVA>
>>
>>Joe Gwinn

> From my experience about sixty years ago, the crew opperating a
> "Delmag" pile driver, wear black (beige when new) coverals!

From grease lubrication and from part-burned fuel?
-------------------------------

The video shows what I remembered, except for the smoke color. The firing
rate is at or below once a second so the chamber walls may not warm to
operating temperature quickly.

Last night I dreamed about being offered a very inexpensive batch of used
lawnmowers with a strange electric drive, powered by a 2 cylinder rotary
(like WW1) engine built into the rotor of the alternator, as simple to make
as a model airplane engine, and cheap surplus 90V electric motors to spin
the blade. The seller's explanations all made sense, but I woke up before he
answered if it required unavailable carbon brushes or castor oil.

Speaking of weird lawnmowers, I helped restore an MTD Yard Bug.
https://www.ebay.com/itm/175849445818

"Richard Smith" wrote in message news:ly8r5f44yv.fsf@void.com...

My impression is compressed air systems are about 10% efficient.
eg. 3kW into the compressor motor to get the equivalent of about 300W
of electrical power in something like an angle-grinder.

------------------------------
I saw about 20%, comparing the metered 2.48KW of my air compressor to the
claimed 500W of an electric angle grinder. The time to grind welds was
similar for both tools. I didn't measure carefully because I can't fine tune
the process, only choose between them.

I read an analysis of a proposed compressed air automotive drive that said
the energy loss was mainly from compression heating and expansion cooling,
and in the installation they proposed insulation and a heat exchanger would
increase efficiency, for instance if the compressed air remained hot its
energy would be retained. PV=nRT. Compound steam engines were developed to
reduce the loss from steam cooling the cylinders as it expanded.

"Richard Smith" wrote in message news:ly8r5f44yv.fsf@void.com...

I've never seen a diesel hammer in action.
Seen air-driven and hydraulic.

-----------------------------
https://en.wikipedia.org/wiki/Paslode_Impulse

On Thu, 28 Dec 2023 08:00:42 -0500
"Jim Wilkins" <muratlanne@gmail.com> wrote:

<snip>
>Speaking of weird lawnmowers, I helped restore an MTD Yard Bug.
>https://www.ebay.com/itm/175849445818

Only saw one once mowing in a ditch... but thought the "Hover Mowers"
were pretty unusual😉

https://www.ebay.com/sch/i.html?_nkw=flymo+hover+mower&_sop=12

--
Leon Fisk
Grand Rapids MI

On Wed, 27 Dec 2023 23:10:16 +0000
Richard Smith <null@void.com> wrote:

<snip>
>I think suffer the inefficiency of compressed air systems for the
>simplicity, robustness, safety, avoidance of environmental problems
>down the mine, etc.
>
>My impression is compressed air systems are about 10% efficient.
>eg. 3kW into the compressor motor to get the equivalent of about 300W
>of electrical power in something like an angle-grinder.

See the Taylor Hydraulic Air Compressor for some interesting reading. A
patent with some info and related pointers here:

https://patents.google.com/patent/US4797563A/en

and an old report:

https://archive.org/details/IllustratedDescriptionOfTheTaylorHydraulicAirCompressorAndTransmission

--
Leon Fisk
Grand Rapids MI

On 12/28/2023 10:41 AM, Leon Fisk wrote:
> On Thu, 28 Dec 2023 08:00:42 -0500
> "Jim Wilkins" <muratlanne@gmail.com> wrote:
>
> <snip>
>> Speaking of weird lawnmowers, I helped restore an MTD Yard Bug.
>> https://www.ebay.com/itm/175849445818
>
> Only saw one once mowing in a ditch... but thought the "Hover Mowers"
> were pretty unusual😉
>
> https://www.ebay.com/sch/i.html?_nkw=flymo+hover+mower&_sop=12
>

My uncle had one of those back in the late 50's (?) or maybe early 60's
.. As I recall it did a reasonably decent job .
--
Snag
Si Vis Pacem Para Bellum

You know you might be overdoing arcane interests when you get strange
dreams on the topic... :-)

"Richard Smith" wrote in message news:ly5y0iov83.fsf@richards-air-2.home...

You know you might be overdoing arcane interests when you get strange
dreams on the topic... :-)

---------------------------
While visiting Britain my sister bought a fairly technical book on the
Spitfire at the IWM for Christmas and I've been reading it, but it's not
related to WW1 rotaries or lawnmowers.

She also caught Covid there.

On 12/28/2023 3:47 PM, Richard Smith wrote:
> You know you might be overdoing arcane interests when you get strange
> dreams on the topic... :-)
>

Well , I wouldn't call my dreams about guns "strange" ... disturbing
maybe . But not strange .
--
Snag
Si Vis Pacem Para Bellum

On 12/28/2023 4:25 PM, Jim Wilkins wrote:
> "Richard Smith"  wrote in message
> news:ly5y0iov83.fsf@richards-air-2.home...
>
> You know you might be overdoing arcane interests when you get strange
> dreams on the topic...  :-)
>
> ---------------------------
> While visiting Britain my sister bought a fairly technical book on the
> Spitfire at the IWM for Christmas and I've been reading it, but it's not
> related to WW1 rotaries or lawnmowers.
>
> She also caught Covid there.
>
>

Did you know that a Harley 45° V-twin is actually a partial radial
engine ?
--
Snag
Si Vis Pacem Para Bellum

BOn Thu, 28 Dec 2023 04:29:38 +0000, Richard Smith <null@void.com>
wrote:

>Gerry <geraldrmiller@yahoo.ca> writes:
>
>> On Wed, 27 Dec 2023 18:51:25 -0500, Joe Gwinn <joegwinn@comcast.net>
>> wrote:
>
>>>>> ...
>
>>>>
>>>>I've never seen a diesel hammer in action.
>>>>Seen air-driven and hydraulic.
>>>
>>>I've seen diesel pile-drivers in action. Like this:
>>>
>>>.<https://www.youtube.com/watch?v=VmIhSh_7gVA>
>>>
>>>Joe Gwinn
>
>> From my experience about sixty years ago, the crew opperating a
>> "Delmag" pile driver, wear black (beige when new) coverals!
>
>From grease lubrication and from part-burned fuel?
>
Black rain!

"Jim Wilkins" <muratlanne@gmail.com> writes:

> ...
> She also caught Covid there.

Is everywhere and endemic now.
I assumed I must have had it without symptoms having worked all the
way through covid19 pandemic - then a year ago got something which
really left me flattened for a week which was covid. Had to stay warm
under two duvets to mitigate the discomfort of it.
It clearly mutates "like mad" so comes in waves as variants evade
natural immunity to previousl strains.
We are getting "normal" "colds" again - streaming but only for a day
or so. Immune systems back up and running after the "lockdowns" which
if prolonged would have themselves lead to higher mortality. Everyone
without honed immunity and when a virus does break through it would be
at the worst time, likely mid-winter, and we would have had the huge
wave of serious illness and mortality we sought to avoid.
Looking back - slowing the initial propagation, at huge effort, was a
good idea. Turning it into a "Wow this is good - let's do it for
ever" was manifestation of general pervasive institutional stupidity.

Hope she enjoyed time in England / Britain.

I remember a couple of disturbed dreams during my doctoral years.

In one I was on holiday in Yugoslavia - was during the break-up.
Given I fondly remember Yugoslavia.
I was crawling between rocks try to admire some monastry or something
like that while bullets went overhead.

In another I was in a laboratory which was all brown dark and dusty,
hopelessly cramped so you could only move sideways in some places and
the floor kept collapsing - your foot kept going through the
floorboards.

It is plausible that these were connected to what was happening.
The situation was politically tense during my research.

The workshops were a mess. Only had to be gone a few days and every
machine was - well, motors and things ran, but saw blades had not a
tooth left due to misuse, coolant was run-out and the machines were
jammed-full of swarf, etc.
I'd have to do a lot of "housekeeping", refill soluable-oil coolants -
and get out my own sawblades to do the proper cuts through a lot of
plate steel (then put the toothless on back in - they'd reduce a good
blade to the same state in minutes to an hour anyway).

Gerry <geraldrmiller@yahoo.ca> writes:

>> ...
>>
>>> From my experience about sixty years ago, the crew opperating a
>>> "Delmag" pile driver, wear black (beige when new) coverals!
>>
>>From grease lubrication and from part-burned fuel?
>>

> Black rain!

The exhaust has thick liquidy raining-down hydrocarbon residues?

"Snag" wrote in message news:uml25o$i904$1@dont-email.me...

Did you know that a Harley 45° V-twin is actually a partial radial
engine ?
Snag
------------------------
Sort of. The forked connecting rod puts both cylinders in the same plane,
but the V-12 Merlin is built that way too. A real radial has one master
connecting rod that rides on the crank pin and the other rod "big ends" are
on pins around it.
http://www.aviation-history.com/engines/radial.htm

The lawnmower engine/alternator was a 2 cycle opposed twin, like this;
https://www.ebay.com/itm/235110607332
but set up as a rotary, with the cylinders part of the alternator rotor
casting. I have no idea what prompted that notion but the seller's
explanations all seemed logical even after I woke up, which is unusual.

I saw a one cylinder, 4-stroke Saito FA-80 model engine at a flea market and
examined it until the seller dropped the price to $30. At that price it
doesn't have to run, just sit on a shelf with other curios.
https://saito-engines.info/

This interview mentions fully developed ideas popping up.
https://www.harpersbazaar.com/culture/features/a22020940/taylor-swift-interviews-pattie-boyd/
"There are definitely moments when it’s like this cloud of an idea comes and
just lands in front of your face, and you reach up and grab it."

Often while I was in the shower and couldn't write it down immediately.

I found that link while researching song inspirations, Pattie Boyd was the
subject of quite a few. In the 60's I was the tech/roadie for a film maker
who was doing music videos so I saw something of the off stage lives of
musicians on tour, and was happy -not- to be one. His studio partly imitated
Warhol's Factory, minus the drugs.

"Richard Smith" wrote in message news:lyh6k1mrf3.fsf@richards-air-2.home...

I remember a couple of disturbed dreams during my doctoral years.

In one I was on holiday in Yugoslavia - was during the break-up.
Given I fondly remember Yugoslavia.
I was crawling between rocks try to admire some monastry or something
like that while bullets went overhead.

In another I was in a laboratory which was all brown dark and dusty,
hopelessly cramped so you could only move sideways in some places and
the floor kept collapsing - your foot kept going through the
floorboards.

It is plausible that these were connected to what was happening.
The situation was politically tense during my research.

The workshops were a mess. Only had to be gone a few days and every
machine was - well, motors and things ran, but saw blades had not a
tooth left due to misuse, coolant was run-out and the machines were
jammed-full of swarf, etc.
I'd have to do a lot of "housekeeping", refill soluable-oil coolants -
and get out my own sawblades to do the proper cuts through a lot of
plate steel (then put the toothless on back in - they'd reduce a good
blade to the same state in minutes to an hour anyway).

------------------------------
The Goes Wrong Show. I was put in charge of an open-access company model
shop that fit that description. You can't cut a rotary lawnmower blade on a
bandsaw at woodcutting speed, though someone kept trying. The gearbox was
broken so I couldn't drop it to the lowest speed. Fortunately the electrical
engineers didn't understand and weren't tempted to abuse the other machines.

In the sci-fi novel The Mote in God's Eye the aliens show the Earthlings a
museum of technology, in which the chief engineer notices that everything is
defective. It's a test of mechanical aptitude, which for the aliens
classifies one as Aspergic with no interpersonal skills. They are amazed
that he can also function as a supervisor. As an electronic technician I had
to be careful to not slip into that bin, thus my exposure to the arts.

"Jim Wilkins" wrote in message news:ummjvq$rp7s$1@dont-email.me...

"Richard Smith" wrote in message news:lyh6k1mrf3.fsf@richards-air-2.home...

The workshops were a mess. Only had to be gone a few days and every
machine was - well, motors and things ran, but saw blades had not a
tooth left due to misuse, coolant was run-out and the machines were
jammed-full of swarf, etc.
I'd have to do a lot of "housekeeping", refill soluable-oil coolants -
and get out my own sawblades to do the proper cuts through a lot of
plate steel (then put the toothless on back in - they'd reduce a good
blade to the same state in minutes to an hour anyway).

---------------------------
I bought a how-to book, whose title I apparently don't remember well enough
for Google, that turned out to be a British socialist fantasy of communal
ownership of all lawn and garden equipment, to avoid the alleged waste of
everyone buying their own. I suspect it was written out of frustration that
the neighbors had learned not to lend anything to the author.