Electric buggy twistgrip proportional control

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Richard Smith

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Oct 20, 2021, 12:56:48 AM10/20/21
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This is for a colleague.
I couldn't defer a call of nature as my "mind's eye" saw this one and
had me belly-laughing very involuntarily.

Technically, he's got a disabled persons' buggy, replaced the 12V
drive motor(s) with a 24V variant from some other moving machine,
added a second 12V battery to give 24V in total - and when he tried it
it went straight to full power and "wheelied" off.

My "mind's eye" had the seaside harbour tourist destination
interrupted by a mobility buggy "wheelie-ing" and squealing its tyres,
lunging across the quay and slingshoting itself and its occupant off
the harbour wall at about 25mph, flying on a parabolic arc and
crashing into the sea some distance off. Its occupant letting out a
cry as his watery immersion came ever more imminent.
I could see dumbfounded holidaymakers there with icecream dropping off
cones onto the floor thinking "did that really just happen??" "what
am I supposed to do about what my mind is telling me just happened?".

Anyway - back to the technical point...
How can he get twistgrip proportional control back for his new 24V
setup?

He was asking around at work, but while they do seriously powerful
hydraulic drives and mechanisms with some electro-hydraulic valves,
this proportional control power electric drive is outside the
experience.

So technical help would be appreciated.

Other forms of help implied - well, it can be a bit demented in these
far-flung fishing ports clinging to the side of rugged landscapes, so
this is nothing too outside the local normal to deal with.

Regards,
Rich Smith

danny burstein

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Oct 20, 2021, 1:42:17 AM10/20/21
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[snip]

My personal Amigo brand Amigo mobility scooter, which
apparently is the sort of thing you're talking
about, uses two 12V batteries in series to get 24V,
and has a lever control for the power output.

Pretty much their entire line uses these systems,
and many other companies do as well.

My suggestion is... call the local vendor/repai shop
handling these scooters. Chances are they've
got exactly what you need either in their junk
box for a nominal $5, or brand new for $50ish.

(the brand new ones will vary a HUGE amount depending
on how much they think they can get from you).


--
_____________________________________________________
Knowledge may be power, but communications is the key
dan...@panix.com
[to foil spammers, my address has been double rot-13 encoded]

Jim Wilkins

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Oct 20, 2021, 7:10:01 AM10/20/21
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"danny burstein" wrote in message news:skoa7l$jmg$1...@reader1.panix.com...

[snip]

My personal Amigo brand Amigo mobility scooter, which
apparently is the sort of thing you're talking
about, uses two 12V batteries in series to get 24V,
and has a lever control for the power output.

Pretty much their entire line uses these systems,
and many other companies do as well.

My suggestion is... call the local vendor/repai shop
handling these scooters. Chances are they've
got exactly what you need either in their junk
box for a nominal $5, or brand new for $50ish.

(the brand new ones will vary a HUGE amount depending
on how much they think they can get from you).

------------------------

I have to agree, talk to a pro who has insurance. Although I've repaired
mobility equipment and built electric vehicle prototypes I feel that the
liability concern is too great for home shop re-engineering.

Richard Smith

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Oct 20, 2021, 1:50:16 PM10/20/21
to
The fellow isn't physically disabled, by the way.
Whether he has other "challenges" I will sidestep.
Apparently he has been directed to a "regulator" which does the
needed.
Sorry I am short on background - I didn't even want to go there about
questions like "why?".
Regards,
Rich Smith

Jim Wilkins

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Oct 20, 2021, 5:39:13 PM10/20/21
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"Richard Smith" wrote in message news:lybl3j7...@void.com...
--------------------------------

You or he might get better results by searching for information on
do-it-yourself electric bicycle controls.

As a technician I was put in the difficult position of being asked to design
and wire electric motorcycle controls after the electrical engineers decided
to back away from that project. I've done enough in that and the medical
electronics field that I've learned to be very careful about what I write. I
was almost sued for using a circuit I found in my car's shop manual, that
another company claimed was their proprietary secret.


Bob La Londe

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Oct 20, 2021, 6:54:42 PM10/20/21
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I share to a certain degree Jim's trepidation, but I think a search for
24V *PWM Speed Control might help you find an off the shelf speed
control. Then its about getting the right mechanical bits together to
make it practical to use.

* PWM Pulse Width Modulation.

FYI: PWM is one of the more efficient ways to control power (speed)
with a DC source and DC load. Its not anything new. Not even in retail
applications. I have a 12V PWM controller for an electric trolling
motor that dates back to the 1970s.

P.S. If you find the perfect control that's cheap let me know. I have
a couple DC buggy motors on the floor under a work bench courtesy of a
fiend that used to sell and maintain electric mobility scooters.

P.P.S. I've got a buggy crane I think might someday make a good vise
crane in the shop courtesy of the same friend. Just need to find the
right DC power supply for it without having to maintain a battery on its
cart.

--
This email has been checked for viruses by AVG.
https://www.avg.com

Clare Snyder

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Oct 20, 2021, 10:57:42 PM10/20/21
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On Wed, 20 Oct 2021 05:42:14 -0000 (UTC), danny burstein
<dan...@panix.com> wrote:

>[snip]
>
>My personal Amigo brand Amigo mobility scooter, which
>apparently is the sort of thing you're talking
>about, uses two 12V batteries in series to get 24V,
>and has a lever control for the power output.
>
>Pretty much their entire line uses these systems,
>and many other companies do as well.
>
>My suggestion is... call the local vendor/repai shop
>handling these scooters. Chances are they've
>got exactly what you need either in their junk
>box for a nominal $5, or brand new for $50ish.
>
>(the brand new ones will vary a HUGE amount depending
>on how much they think they can get from you).
Some can be "reprogrammed" - or get a high output e-bike controller
- or a golf cart controller

Richard Smith

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Oct 21, 2021, 1:42:50 AM10/21/21
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Thanks guys - you've been great. Knew what is obvious and easy to you
would be valuable here.
Best wishes

Jim Wilkins

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Oct 21, 2021, 7:26:04 AM10/21/21
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"Bob La Londe" wrote in message news:skq6nd$e8t$1...@gioia.aioe.org...

On 10/20/2021 2:38 PM, Jim Wilkins wrote:
> .....

P.P.S. I've got a buggy crane I think might someday make a good vise
crane in the shop courtesy of the same friend. Just need to find the
right DC power supply for it without having to maintain a battery on its
cart.
---------------------------
A Bruno hoist? I have one that was removed from an old SUV but I found a
pickup truck bed crane mounted on a taller pipe swivel stand to be more
adaptable.

When I need a temporary means of lifting and moving something heavy I set up
the outdoor extension of one of my overhead gantry tracks. It's made of two
pieces of 3" by 8' steel channel, surplus pallet rack shelf supports I
bought for $10 each. Its easier to install than a length of I (wide flange)
beam because each piece weighs only 33 Lbs and the straps bolted between the
ends are good hangers. Changing their position requires simply drilling new
holes through the webs.




Bob La Londe

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Oct 21, 2021, 2:46:43 PM10/21/21
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I do have a standard cherry picker / engine hoist. Its not really
convenient for placing a vise on a mill table or a chuck on a lathe
spindle. I do plan to make a heavy tool cart for the new (new earlier
this year anyway) South Bend Mill in the back. I expected it will be
plenty heavy enough when loaded up with tools to allow a small crane arm
to swing a 100lb vise out over a table, and when not in use the arm can
swing back over the cart to not be in the way. In fact I wish I had
already set it up. I want to move one of my 8 inch vises from the Hurco
to the South Bend, but haven't done it because I am not looking forward
to lifting it with my arms extended over the machine. (I have in the
past. These vises were originaly on the Charter Oak piece of trash bed
mill.

For other not excessively heavy things a chain off the bucket of the
front loader works too. Its rated for 750 lbs, works fine to about
1200, and has lifted upto 2000 but maxes out with just a few inches of
lift at that weight. I also rebuilt one of the hydraulics recently...

My shop is pretty crowded though. Bringing the loader inside to do any
real work optimistically takes a half day of moving things to clear a
wide enough path.

Leon Fisk

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Oct 21, 2021, 3:32:21 PM10/21/21
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On Thu, 21 Oct 2021 11:46:37 -0700
Bob La Londe <no...@none.com99> wrote:

<snip>
>I do have a standard cherry picker / engine hoist. Its not really
>convenient for placing a vise on a mill table or a chuck on a lathe
>spindle. I do plan to make a heavy tool cart for the new (new earlier
>this year anyway) South Bend Mill in the back. I expected it will be
>plenty heavy enough when loaded up with tools to allow a small crane arm
>to swing a 100lb vise out over a table, and when not in use the arm can
>swing back over the cart to not be in the way.

I've seen some little cranes mounted to lathes similar to the HF pickup
truck bed version. Able to lift item off the cart and on to the
machine...

They use to make really nice mechanical cranes similar to today's
hydraulic engine hoists. Nice big solid wheels for rolling around the
shop. No hydraulics to leak out:

https://archive.org/details/BuhlSonsCo1918/page/n638/mode/1up

--
Leon Fisk
Grand Rapids MI

Jim Wilkins

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Oct 21, 2021, 7:57:47 PM10/21/21
to
"Bob La Londe" wrote in message news:skscie$avg$1...@gioia.aioe.org...

On 10/21/2021 4:25 AM, Jim Wilkins wrote:
.....

I do have a standard cherry picker / engine hoist. Its not really
convenient for placing a vise on a mill table or a chuck on a lathe
spindle. I do plan to make a heavy tool cart for the new (new earlier
this year anyway) South Bend Mill in the back. I expected it will be
plenty heavy enough when loaded up with tools to allow a small crane arm
to swing a 100lb vise out over a table, and when not in use the arm can
swing back over the cart to not be in the way. In fact I wish I had
already set it up. I want to move one of my 8 inch vises from the Hurco
to the South Bend, but haven't done it because I am not looking forward
to lifting it with my arms extended over the machine. (I have in the
past. These vises were originaly on the Charter Oak piece of trash bed
mill.

For other not excessively heavy things a chain off the bucket of the
front loader works too. Its rated for 750 lbs, works fine to about
1200, and has lifted upto 2000 but maxes out with just a few inches of
lift at that weight. I also rebuilt one of the hydraulics recently...

My shop is pretty crowded though. Bringing the loader inside to do any
real work optimistically takes a half day of moving things to clear a
wide enough path.

-----------------------

This inspired me to build a similar portable hoist:
https://www.liftingsafety.co.uk/product/tripod-gantry-crane-3102.html

Mine has a tripod at both ends and optionally shear legs supporting the
center splice, for big loads such as the 2100 Lb oak log. Boat trailer
winches attached to the tripod legs by muffler clamps raised and lowered the
16' long, 200 Lb track. On a more conventional previous version I found that
trailer tongue jacks make good cheap retractable casters.

My mill and lathe are small enough that the vise and chucks are manageable
by hand, but that wasn't the case at work. My personal favorite
tight-quarters heavy lifter is a platform stacker. Its base is too small to
support a cantilevered load so the feet have to run under the destination,
for example a mill table cranked out to the side. A sling around the
platform converts it for a load with lifting eyes at the top, ie the engine
of my tractor. For the lathe you might need a wooden cradle that holds the
chuck at (slightly below) spindle height and a well supported ramp to the
platform.

I added a table to my engine hoist that lists the maximum load at each boom
extension position based on tipping forward. They aren't the same as the
limits based on boom strength. Since it has been converted into a towable
trailer if the load exceeds the table I chain the mast top down to the
tractor.

Jim Wilkins

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Oct 22, 2021, 8:19:48 AM10/22/21
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"Bob La Londe" wrote in message news:skscie$avg$1...@gioia.aioe.org...

My shop is pretty crowded though. Bringing the loader inside to do any
real work optimistically takes a half day of moving things to clear a
wide enough path.

-----------------

A solution that worked well for me when I needed to move heavy oak beams
from one well defined place to another was hooks or slings on roof rafters
above both places. I hung a chain fall above the destination and a block and
tackle above the source, with both attached to the load. The block and
tackle lifted the heavy beam off the trailer, then raising the chain fall
swung it into position in the storage shed.

Actually the chain fall hung from a gantry track so the beam could move in 3
dimensions, but you only need 2 from the cart to the spindle.

Two chain falls would certainly work but they are more expensive and more
susceptible than ropes to damage from dragging in dirt. Two blocks and
tackles are awkward to operate simultaneously. The chain fall at the
destination leaves both hands free to align the chuck without needing a
nearby tie-off cleat.

If you don't have a convenient hanger directly above the lathe spindle, one
behind it would let you position the chuck horizontally using both hoists.
Even a ton can be positioned pretty accurately with one hand while raising
or lowering it with the other.

I chose a 2 ton chain fall as the heaviest I could maneuver onto a hook
straight overhead with one hand while on a stepladder, plus a 1 ton because
it hoists twice as fast. When running the sawmill the 2 ton lifts logs, the
1 ton stacks cut beams. They were from Harbor Freight and so far have given
me no trouble.

David Billington

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Oct 22, 2021, 10:52:42 AM10/22/21
to
Having been seriously injured about 10 years ago I decided to avoid
unnecessary heavy lifting of things like my rotary table. As it's stored
on a shelf near the BP mill I made a bridge to fit between the two so I
just set the table level with the shelf and install the bridge and slide
the RT on and off the BP table without any lifting other than the minor
lift to get the RT over the lip of the shelf onto the bridge.

Leon Fisk

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Oct 22, 2021, 4:50:09 PM10/22/21
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On Thu, 21 Oct 2021 15:32:17 -0400
Leon Fisk <lfi...@gmail.invalid> wrote:

>I've seen some little cranes mounted to lathes similar to the HF pickup
>truck bed version. Able to lift item off the cart and on to the
>machine...

Here's one mounted to the carriage:

https://www.practicalmachinist.com/vb/general/made-myself-bday-present-tool-post-crane-163300/
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