|
Over the past 4 months, I have been working on a gear reduction package (bolt on retrofit) for the Real Bull lathes.(aluminum bearing end cap types).The Sieg type motor (plastic motor encaps) is?possible. Robert Furmanak has a version of this. My arrangement differs as an idler gear has to be incorporated into the the assembly so as the spindle rotates in the normal anti clockwise direction without having to have the machine set in reverse.For some reason,Real Bull lathes have a common problem of slower RPM when in reverse. The first trials show the torque has increased by 65% but there is a RPM decrease of 35%, now at a maximum 1800 RPM.I never machine at the top end of 2400 RPM.Surface
speed is more important,and tool?geometry. Still plenty of RPM for polishing.As I never machine wood on my lathe,I don't see this as a problem. I machine large?diameters regularly,this new system has been a welcome change from stalling motors and the other associated bogging down problems of the past years. The short video (my first?Youtube) shows cutting out a 90mm dia hole,eccentric to the major diameter,bolted to a face plate, 3 mm deep cuts with a standard boring tool.and running in High range.The machine even sounds and
feels like it has just grown up. Bolt on retrofit kits?may be?commercially available soon. It uses the standard motor,belt and the 19T / 31T belt pulleys. Some?modification is?necessary to the Forward/Reverse feed screw lever. I would like to thank Hugh
of Amadeal UK and Robert Furmanak for?their?valuable support and assistance on this project.? Hope it is of interest.
John L Spain.
|
That looks very impressive John!
I reduced my Real Bull's gearing, last year. It really does feel like a grown up lathe!
David. Derbyshire. UK.
toggle quoted message
Show quoted text
--- In 7x12minilathe@..., John Lindo <bechetboat@...> wrote:
Over the past 4 months, I have been working on a gear reduction package (bolt on retrofit)
for the Real Bull lathes.(aluminum bearing end cap types).The Sieg type motor (plastic motor encaps) is???possible.
Robert Furmanak has a version of this.
My arrangement differs as an idler gear has to be incorporated into the the assembly so as the spindle rotates in the normal anti clockwise
direction without having to have the machine set in reverse.For some reason,Real Bull lathes have a common problem of slower RPM when in reverse.
The first trials show the torque has increased by 65% but there is a RPM decrease of 35%,
now at a maximum 1800 RPM.I never machine at the top end of 2400 RPM.Surface speed is more important,and tool???geometry.
Still plenty of RPM for polishing.As I never machine wood on my lathe,I don't see this as a problem.
I machine large???diameters regularly,this new system has been a welcome change from stalling motors and the other associated bogging down problems
of the past years.
The short video (my first???Youtube) shows cutting out a 90mm dia hole,eccentric to the major diameter,bolted to a face plate,
3 mm deep cuts with a standard boring tool.and running in Highrange.The machine even sounds and feels like it has just grown up.
Bolt on retrofitkits???may be???commercially available soon.
It uses the standard motor,belt and the 19T / 31T belt pulleys.
Some???modification is???necessary to the Forward/Reverse feed screw lever.
I would like to thank Hugh of Amadeal UK and Robert Furmanak for???their???valuable support and assistance on this project.???
Hope it is of interest.
John L
Spain.
|
Hi John.
That seems to work really sweetly. What motor do you have on your RB?
Mine is nearly 9 and came with the 350w and whilst it is fine for most of what I do the larger diameters, especially in steel, become a pain because you have to feed slow and keep a good eye on the motor temperature as it can heat up quickly at low motor rpm.
The current RB lathes with 550W motors as standard are probably a lot better but I've never had the chance to try one. I don't think the lowering of the top speed will seriously affect most people, mine seldom gets out of low gear and the occasional change into high is hardly a hardship. Gerry W Leeds UK
To: 7x12minilathe@... From: bechetboat@... Date: Sun, 19 May 2013 00:14:44 -0700 Subject: [7x12minilathe] Gear reduction for real Bull lathe.
?
Over the past 4 months, I have been working on a gear reduction package (bolt on retrofit) for the Real Bull lathes.(aluminum bearing end cap types).The Sieg type motor (plastic motor encaps) is?possible. Robert Furmanak has a version of this. My arrangement differs as an idler gear has to be incorporated into the the assembly so as the spindle rotates in the normal anti clockwise direction without having to have the machine set in reverse.For some reason,Real Bull lathes have a common problem of slower RPM when in reverse. The first trials show the torque has increased by 65% but there is a RPM decrease of 35%, now at a maximum 1800 RPM.I never machine at the top end of 2400 RPM.Surface
speed is more important,and tool?geometry. Still plenty of RPM for polishing.As I never machine wood on my lathe,I don't see this as a problem. I machine large?diameters regularly,this new system has been a welcome change from stalling motors and the other associated bogging down problems of the past years. The short video (my first?Youtube) shows cutting out a 90mm dia hole,eccentric to the major diameter,bolted to a face plate, 3 mm deep cuts with a standard boring tool.and running in High range.The machine even sounds and
feels like it has just grown up. Bolt on retrofit kits?may be?commercially available soon. It uses the standard motor,belt and the 19T / 31T belt pulleys. Some?modification is?necessary to the Forward/Reverse feed screw lever. I would like to thank Hugh
of Amadeal UK and Robert Furmanak for?their?valuable support and assistance on this project.? Hope it is of interest.
John L Spain.
|
Hi John, Gerry,
I to have a RB 550w. Great mod John, and Gerry i to have to watch not to over do the little fellow especially in steel.
Regard,
Jan from the Netherlands,
toggle quoted message
Show quoted text
--- In 7x12minilathe@..., gerry waclawiak <gerrywac@...> wrote:
Hi John.
That seems to work really sweetly. What motor do you have on your RB?
Mine is nearly 9 and came with the 350w and whilst it is fine for most of what I do the larger diameters, especially in steel, become a pain because you have to feed slow and keep a good eye on the motor temperature as it can heat up quickly at low motor rpm.
The current RB lathes with 550W motors as standard are probably a lot better but I've never had the chance to try one.
I don't think the lowering of the top speed will seriously affect most people, mine seldom gets out of low gear and the occasional change into high is hardly a hardship.
Gerry W
Leeds UK
To: 7x12minilathe@...
From: bechetboat@...
Date: Sun, 19 May 2013 00:14:44 -0700
Subject: [7x12minilathe] Gear reduction for real Bull lathe.
Over the past 4 months, I have been working on a gear reduction package (bolt on retrofit)for the Real Bull lathes.(aluminum bearing end cap types).The Sieg type motor (plastic motor encaps) is possible.Robert Furmanak has a version of this.My arrangement differs as an idler gear has to be incorporated into the the assembly so as the spindle rotates in the normal anti clockwisedirection without having to have the machine set in reverse.For some reason,Real Bull lathes have a common problem of slower RPM when in reverse.The first trials show the torque has increased by 65% but there is a RPM decrease of 35%,now at a maximum 1800 RPM.I never machine at the top end of 2400 RPM.Surface
speed is more important,and tool geometry.Still plenty of RPM for polishing.As I never machine wood on my lathe,I don't see this as a problem.I machine large diameters regularly,this new system has been a welcome change from stalling motors and the other associated bogging down problemsof the past years.The short video (my first Youtube) shows cutting out a 90mm dia hole,eccentric to the major diameter,bolted to a face plate,3 mm deep cuts with a standard boring tool.and running in High range.The machine even sounds and
feels like it has just grown up.Bolt on retrofit kits may be commercially available soon.It uses the standard motor,belt and the 19T / 31T belt pulleys.Some modification is necessary to the Forward/Reverse feed screw lever.I would like to thank Hugh
of Amadeal UK and Robert Furmanak for their valuable support and assistance on this project. Hope it is of interest.
John LSpain.
|
On 05/19/2013 12:14 AM, John Lindo wrote:
My
arrangement differs as an idler gear has to be incorporated into
the the assembly so as the spindle rotates in the normal anti
clockwise
direction
without having to have the machine set in reverse.For
some reason,Real Bull lathes have a common problem of
slower RPM when in reverse.
Why not just swap the + and - wires to the motor so it runs the
other way?
--
Jerry Durand, Durand Interstellar, Inc.
tel: +1 408 356-3886, USA toll free: 1 866 356-3886
Skype: jerrydurand
|
John,
Do you have pictures of the gearing arrangement you used?
Thanks
Dick
toggle quoted message
Show quoted text
--- In 7x12minilathe@..., John Lindo <bechetboat@...> wrote:
Over the past 4 months, I have been working on a gear reduction package (bolt on retrofit)
for the Real Bull lathes.(aluminum bearing end cap types).The Sieg type motor (plastic motor encaps) is?possible.
Robert Furmanak has a version of this.
My arrangement differs as an idler gear has to be incorporated into the the assembly so as the spindle rotates in the normal anti clockwise
direction without having to have the machine set in reverse.For some reason,Real Bull lathes have a common problem of slower RPM when in reverse.
The first trials show the torque has increased by 65% but there is a RPM decrease of 35%,
now at a maximum 1800 RPM.I never machine at the top end of 2400 RPM.Surface speed is more important,and tool?geometry.
Still plenty of RPM for polishing.As I never machine wood on my lathe,I don't see this as a problem.
I machine large?diameters regularly,this new system has been a welcome change from stalling motors and the other associated bogging down problems
of the past years.
The short video (my first?Youtube) shows cutting out a 90mm dia hole,eccentric to the major diameter,bolted to a face plate,
3 mm deep cuts with a standard boring tool.and running in Highrange.The machine even sounds and feels like it has just grown up.
Bolt on retrofitkits?may be?commercially available soon.
It uses the standard motor,belt and the 19T / 31T belt pulleys.
Some?modification is?necessary to the Forward/Reverse feed screw lever.
I would like to thank Hugh of Amadeal UK and Robert Furmanak for?their?valuable support and assistance on this project.?
Hope it is of interest.
John L
Spain.
|
Jerry I have something?lodged?in the back of my brain, that?I have read somewhere not to swap the wires. I am no electronics boff,and tend to leave PCB's etc well alone.If I don't see it move,I tend to leave it to experts in?their?field. Maybe you or
other members can spread more light on this. Also I never really got from the forum many months ago,a reasonable answer as to why when the switch on the control box is turned to reverse,? the Real Bull lathes run slower. Siegs I believe do not seem to have that problem. The idler set up is no show stopper at the moment,and fits into the total package nicely. John L Spain.
From: Jerry Durand
To: 7x12minilathe@...
Sent: Sunday, May 19, 2013 5:22 PM
Subject: Re: [7x12minilathe] Gear reduction for real Bull lathe.
?
On 05/19/2013 12:14 AM, John Lindo wrote:
My
arrangement differs as an idler gear has to be incorporated into
the the assembly so as the spindle rotates in the normal anti
clockwise
direction
without having to have the machine set in reverse.For
some reason,Real Bull lathes have a common problem of
slower RPM when in reverse.
Why not just swap the + and - wires to the motor so it runs the
other way?
--
Jerry Durand, Durand Interstellar, Inc.
tel: +1 408 356-3886, USA toll free: 1 866 356-3886
Skype: jerrydurand
|
On 05/19/2013 11:10 AM, John Lindo
wrote:
Jerry
I have
something?lodged?in the back of my
brain, that?I have read somewhere not
to swap the wires.
I
am no electronics boff,and tend to leave PCB's etc well
alone.If I don't see it move,I tend to leave it to experts
in?their?field.
Maybe
you or other members can spread more light on this.
Also I
never really got from the forum many months ago,a
reasonable answer as to why when the switch on the control
box is turned to reverse,?
the
Real Bull lathes run slower.
Siegs I
believe do not seem to have that problem.
The
idler set up is no show stopper at the moment,and fits
into the total package nicely.
John L
Spain.
Some brush type motors are built with the brushes offset to make
them run better in forward.? I haven't taken my motor apart but from
what I gather the typical Seig motor has centered brushes and other
than a short wear-in they don't care which way they go.
As to some running slower in reverse, see above to protect some
motors.? Also, they might do that since you're probably just backing
up between threading cuts.
--
Jerry Durand, Durand Interstellar, Inc.
tel: +1 408 356-3886, USA toll free: 1 866 356-3886
Skype: jerrydurand
|
Hello Dick. Yes I do. I will send some to you in a few days.I will send via PM. Please remind me if I forget. John Spain.
From: Dick
To: 7x12minilathe@...
Sent: Sunday, May 19, 2013 7:05 PM
Subject: [7x12minilathe] Re: Gear reduction for real Bull lathe.
?
John,
Do you have pictures of the gearing arrangement you used?
Thanks
Dick
--- In 7x12minilathe@..., John Lindo wrote:
>
> Over the past 4 months, I have been working on a gear reduction package (bolt on retrofit)
> for the Real Bull lathes.(aluminum bearing end cap types).The Sieg type motor (plastic motor encaps) is?possible.
> Robert Furmanak has a version of this.
> My arrangement differs as an idler gear has to be incorporated into the the assembly so as the spindle rotates in the normal anti clockwise
> direction without having to have the machine set in reverse.For some reason,Real Bull lathes have a common problem of slower RPM when in reverse.
> The first trials show the torque has increased by 65% but there is a RPM decrease of 35%,
> now at a maximum 1800 RPM.I never machine at the top end of 2400 RPM.Surface speed is more important,and tool?geometry.
> Still plenty of RPM for polishing.As I never machine wood on my lathe,I don't see this as a problem.
> I machine large?diameters regularly,this new system has been a welcome change from stalling motors and the other associated bogging down problems
> of the past years.
> The short video (my first?Youtube) shows cutting out a 90mm dia hole,eccentric to the major diameter,bolted to a face plate,
> 3 mm deep cuts with a standard boring tool.and running in Highrange.The machine even sounds and feels like it has just grown up.
> Bolt on retrofitkits?may be?commercially available soon.
> It uses the standard motor,belt and the 19T / 31T belt pulleys.
> Some?modification is?necessary to the Forward/Reverse feed screw lever.
> I would like to thank Hugh of Amadeal UK and Robert Furmanak for?their?valuable support and assistance on this project.?
> Hope it is of interest.
>
>
>
> John L
> Spain.
>
|
Both lathe run slow in reverse. It only takes a simple wire cut to
restore full speed in reverse. Mine been like that every since I got
it, hasn't hurt a thing. After 5 years of use.
On 05/19/2013 01:15 PM, Jerry Durand
wrote:
toggle quoted message
Show quoted text
?
On 05/19/2013 11:10 AM, John
Lindo wrote:
Jerry
I have something?lodged?in the back of my brain, that?I have
read somewhere not to
swap the wires.
I am no electronics boff,and tend to
leave PCB's etc well alone.If I don't see it
move,I tend to leave it to experts in?their?field.
Maybe you or other
members can spread more light on this.
Also I never really got
from the forum many months ago,a reasonable answer
as to why when the switch on the control box is
turned to reverse,?
the Real Bull lathes run
slower.
Siegs I believe do not seem to have
that problem.
The idler set up is no
show stopper at the moment,and fits into the total
package nicely.
John L
Spain.
Some brush type motors are built with the brushes offset to
make them run better in forward.? I haven't taken my motor
apart but from what I gather the typical Seig motor has
centered brushes and other than a short wear-in they don't
care which way they go.
As to some running slower in reverse, see above to protect
some motors.? Also, they might do that since you're probably
just backing up between threading cuts.
--
Jerry Durand, Durand Interstellar, Inc.
tel: +1 408 356-3886, USA toll free: 1 866 356-3886
Skype: jerrydurand
|
See message 63084, and there are others as well.
toggle quoted message
Show quoted text
--- In 7x12minilathe@..., Robert Francis <bobf0648@...> wrote:
Both lathe run slow in reverse. It only takes a simple wire cut to
restore full speed in reverse. Mine been like that every since I got it,
hasn't hurt a thing. After 5 years of use.
On 05/19/2013 01:15 PM, Jerry Durand wrote:
On 05/19/2013 11:10 AM, John Lindo wrote:
Jerry
I have something lodged in the back of my brain, that I have read
somewhere not to swap the wires.
I am no electronics boff,and tend to leave PCB's etc well alone.If I
don't see it move,I tend to leave it to experts in their field.
Maybe you or other members can spread more light on this.
Also I never really got from the forum many months ago,a reasonable
answer as to why when the switch on the control box is turned to
reverse,
the Real Bull lathes run slower.
Siegs Ibelieve do not seem to have that problem.
The idler set up is no show stopper at the moment,and fits into the
total package nicely.
John L
Spain.
Some brush type motors are built with the brushes offset to make them
run better in forward. I haven't taken my motor apart but from what I
gather the typical Seig motor has centered brushes and other than a
short wear-in they don't care which way they go.
As to some running slower in reverse, see above to protect some
motors. Also, they might do that since you're probably just backing
up between threading cuts.
--
Jerry Durand, Durand Interstellar, Inc.www.interstellar.com
tel: +1 408 356-3886, USA toll free: 1 866 356-3886
Skype: jerrydurand
|
Hi John,
I didn't know if the details were hush-hush as you mentioned a possible commercial kit.
If not could I beg a photo too please
Gerry W
Leeds UK
To: 7x12minilathe@... From: bechetboat@... Date: Sun, 19 May 2013 11:16:50 -0700 Subject: Re: [7x12minilathe] Re: Gear reduction for real Bull lathe.
?
Hello Dick. Yes I do. I will send some to you in a few days.I will send via PM. Please remind me if I forget. John Spain.
toggle quoted message
Show quoted text
From: Dick
To: 7x12minilathe@...
Sent: Sunday, May 19, 2013 7:05 PM
Subject: [7x12minilathe] Re: Gear reduction for real Bull lathe.
?
John,
Do you have pictures of the gearing arrangement you used?
Thanks
Dick
--- In 7x12minilathe@..., John Lindo wrote:
>
> Over the past 4 months, I have been working on a gear reduction package (bolt on retrofit)
> for the Real Bull lathes.(aluminum bearing end cap types).The Sieg type motor (plastic motor encaps) is?possible.
> Robert Furmanak has a version of this.
> My arrangement differs as an idler gear has to be incorporated into the the assembly so as the spindle rotates in the normal anti clockwise
> direction without having to have the machine set in reverse.For some reason,Real Bull lathes have a common problem of slower RPM when in reverse.
> The first trials show the torque has increased by 65% but there is a RPM decrease of 35%,
> now at a maximum 1800 RPM.I never machine at the top end of 2400 RPM.Surface speed is more important,and tool?geometry.
> Still plenty of RPM for polishing.As I never machine wood on my lathe,I don't see this as a problem.
> I machine large?diameters regularly,this new system has been a welcome change from stalling motors and the other associated bogging down problems
> of the past years.
> The short video (my first?Youtube) shows cutting out a 90mm dia hole,eccentric to the major diameter,bolted to a face plate,
> 3 mm deep cuts with a standard boring tool.and running in Highrange.The machine even sounds and feels like it has just grown up.
> Bolt on retrofitkits?may be?commercially available soon.
> It uses the standard motor,belt and the 19T / 31T belt pulleys.
> Some?modification is?necessary to the Forward/Reverse feed screw lever.
> I would like to thank Hugh of Amadeal UK and Robert Furmanak for?their?valuable support and assistance on this project.?
> Hope it is of interest.
>
>
>
> John L
> Spain.
>
|
Hi John,
For me to, I would appreciate if you send me some photo's from the gear reduction.
Best regards,
Jan from the Netherlands,
toggle quoted message
Show quoted text
--- In 7x12minilathe@..., gerry waclawiak <gerrywac@...> wrote:
Hi John,
I didn't know if the details were hush-hush as you mentioned a possible commercial kit.
If not could I beg a photo too please
Gerry W
Leeds UK
To: 7x12minilathe@...
From: bechetboat@...
Date: Sun, 19 May 2013 11:16:50 -0700
Subject: Re: [7x12minilathe] Re: Gear reduction for real Bull lathe.
Hello Dick.Yes I do.I will send some to you in a few days.I will send via PM.Please remind me if I forget.JohnSpain.
From: Dick <old_toolmaker@...>
To: 7x12minilathe@...
Sent: Sunday, May 19, 2013 7:05 PM
Subject: [7x12minilathe] Re: Gear reduction for real Bull lathe.
John,
Do you have pictures of the gearing arrangement you used?
Thanks
Dick
--- In 7x12minilathe@..., John Lindo <bechetboat@> wrote:
Over the past 4 months, I have been working on a gear reduction package (bolt on retrofit) for the Real Bull lathes.(aluminum bearing end cap types).The Sieg type motor (plastic motor encaps) is possible. Robert Furmanak has a version of this. My arrangement differs as an idler gear has to be incorporated into the the assembly so as the spindle rotates in the normal anti clockwise direction without having to have the machine set in reverse.For some reason,Real Bull lathes have a common problem of slower RPM when in reverse. The first trials show the torque has increased by 65% but there is a RPM decrease of 35%, now at a maximum 1800 RPM.I never machine at the top end of 2400 RPM.Surface speed is more important,and tool geometry. Still plenty of RPM for polishing.As I never machine wood on my lathe,I don't see this as a problem. I machine large diameters regularly,this new system has been a welcome change from stalling motors and the other associated bogging down problems of the past years. The short video (my first Youtube) shows cutting out a 90mm dia hole,eccentric to the major diameter,bolted to a face plate, 3 mm deep cuts with a standard boring tool.and running in Highrange.The machine even sounds and feels like it has just grown up. Bolt on retrofitkits may be commercially available soon. It uses the standard motor,belt and the 19T / 31T belt pulleys. Some modification is necessary to the Forward/Reverse feed screw lever. I would like to thank Hugh of Amadeal UK and Robert Furmanak for their valuable support and assistance on this project. Hope it is of interest. John L Spain.
|
I don't know this product, but I do know that if the motor has
either lead strapped to ground or common, swapping the red and black
wire blindly may well release the "magic blue smoke".....
....magic blue smoke is essential for the motor speed controller
operation.....
....replacement magic blue smoke is NOT available from Little
Machine Shop....only replacement motor controllers.....
One would certainly need to check the schematics, service manual,
and even using an ohmmeter, check and see that neither terminal is
commoned to the ground, chassis, or one side of the power supply.
I would strongly suggest checking with an expert on that machine or
proceed with extreme caution if blindly moving forward....
If it is a true DC motor, and there is no ground path, only the
motor load, it is certainly possible that this will work without
damage.
Warren
On 5/19/2013 2:10 PM, John Lindo wrote:
toggle quoted message
Show quoted text
?
Jerry
I have something?lodged?in the back of my brain, that?I have read
somewhere not to
swap the wires.
I am no electronics boff,and tend to leave
PCB's etc well alone.If I don't see it move,I tend
to leave it to experts in?their?field.
Maybe you or other members can spread more
light on this.
Also I never really got from the forum many
months ago,a reasonable answer as to why when the
switch on the control box is turned to reverse,?
the Real Bull lathes run slower.
Siegs I believe do
not seem to have that problem.
The idler set up is no show stopper at the
moment,and fits into the total package nicely.
John L
Spain.
From:
Jerry Durand
To:
7x12minilathe@...
Sent:
Sunday, May 19, 2013 5:22 PM
Subject:
Re: [7x12minilathe] Gear reduction for real
Bull lathe.
?
On 05/19/2013 12:14 AM, John Lindo
wrote:
My
arrangement differs as an idler gear
has to be incorporated into the the
assembly so as the spindle rotates in
the normal anti clockwise
direction
without having to have the
machine set in reverse.For
some reason,Real Bull lathes
have a common problem of
slower RPM when in reverse.
Why not just swap the + and - wires to the
motor so it runs the other way?
--
Jerry Durand, Durand Interstellar, Inc.
tel: +1 408 356-3886, USA toll free: 1 866 356-3886
Skype: jerrydurand
|
Some of the controllers are set up to add a speed limiting resistor in reverse. That's supposedly because the brushes are advanced a few degrees to improve efficiency when the motor is running in the normal direction. In reverse, the benefit becomes a loss.
Roy
toggle quoted message
Show quoted text
--- In 7x12minilathe@..., Jerry Durand <jdurand@...> wrote:
On 05/19/2013 12:14 AM, John Lindo wrote:
My arrangement differs as an idler gear has to be incorporated into
the the assembly so as the spindle rotates in the normal anti clockwise
direction without having to have the machine set in reverse.For some
reason,Real Bull lathes have a common problem of slower RPM when in
reverse.
Why not just swap the + and - wires to the motor so it runs the other way?
--
Jerry Durand, Durand Interstellar, Inc. www.interstellar.com
tel: +1 408 356-3886, USA toll free: 1 866 356-3886
Skype: jerrydurand
|
That may be true on some motors.? However, my gear reducer lacks John’s idler, and I have been running my lathe motor in reverse for 3 years now without any ill effect.? My motor, which is a 350 watt motor off of a Sieg Mini Mill, appears to run equally well in both directions. ? Robert ? ?
toggle quoted message
Show quoted text
From: 7x12minilathe@... [mailto:7x12minilathe@...] On Behalf Of Roy
Sent: Sunday, May 19, 2013 9:19 PM
To: 7x12minilathe@...
Subject: [7x12minilathe] Re: Gear reduction for real Bull lathe.? ? Some of the controllers are set up to add a speed limiting resistor in reverse. That's supposedly because the brushes are advanced a few degrees to improve efficiency when the motor is running in the normal direction. In reverse, the benefit becomes a loss.
Roy
--- In 7x12minilathe@..., Jerry Durand <jdurand@...> wrote:
>
> On 05/19/2013 12:14 AM, John Lindo wrote:
> > My arrangement differs as an idler gear has to be incorporated into
> > the the assembly so as the spindle rotates in the normal anti clockwise
> > direction without having to have the machine set in reverse.For some
> > reason,Real Bull lathes have a common problem of slower RPM when in
> > reverse.
> >
>
> Why not just swap the + and - wires to the motor so it runs the other way?
>
> --
> Jerry Durand, Durand Interstellar, Inc.
> tel: +1 408 356-3886, USA toll free: 1 866 356-3886
> Skype: jerrydurand
>
|
I've heard time and time again, the motors being set to run in
the"main" direction, but never have I seen it documented by the
equipment manufacturer. I think it's an old wives tale!
On 05/19/2013 08:19 PM, Roy wrote:
toggle quoted message
Show quoted text
?
Some of the controllers are set up to add a speed
limiting resistor in reverse. That's supposedly because
the brushes are advanced a few degrees to improve
efficiency when the motor is running in the normal
direction. In reverse, the benefit becomes a loss.
Roy
--- In 7x12minilathe@...,
Jerry Durand wrote:
>
> On 05/19/2013 12:14 AM, John Lindo wrote:
> > My arrangement differs as an idler gear has to
be incorporated into
> > the the assembly so as the spindle rotates in
the normal anti clockwise
> > direction without having to have the machine set
in reverse.For some
> > reason,Real Bull lathes have a common problem of
slower RPM when in
> > reverse.
> >
>
> Why not just swap the + and - wires to the motor so
it runs the other way?
>
> --
> Jerry Durand, Durand Interstellar, Inc.
> tel: +1 408 356-3886, USA toll free: 1 866 356-3886
> Skype: jerrydurand
>
|
That's why I weasel worded what I posted! The controllers are standard commercial units, they're presumably set up to work with any suitably sized motor without damaging either the motor or controller. Reducing reverse speed satisfies that requirement.
Roy
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--- In 7x12minilathe@..., "Robert Furmanak" <rfurmanak@...> wrote:
That may be true on some motors. However, my gear reducer lacks John's
idler, and I have been running my lathe motor in reverse for 3 years now
without any ill effect. My motor, which is a 350 watt motor off of a Sieg
Mini Mill, appears to run equally well in both directions.
Robert
From: 7x12minilathe@... [mailto:7x12minilathe@...]
On Behalf Of Roy
Sent: Sunday, May 19, 2013 9:19 PM
To: 7x12minilathe@...
Subject: [7x12minilathe] Re: Gear reduction for real Bull lathe.
Some of the controllers are set up to add a speed limiting resistor in
reverse. That's supposedly because the brushes are advanced a few degrees to
improve efficiency when the motor is running in the normal direction. In
reverse, the benefit becomes a loss.
Roy
--- In 7x12minilathe@...
<mailto:7x12minilathe%40yahoogroups.com> , Jerry Durand <jdurand@> wrote:
On 05/19/2013 12:14 AM, John Lindo wrote:
My arrangement differs as an idler gear has to be incorporated into
the the assembly so as the spindle rotates in the normal anti clockwise
direction without having to have the machine set in reverse.For some
reason,Real Bull lathes have a common problem of slower RPM when in
reverse.
Why not just swap the + and - wires to the motor so it runs the other way?
--
Jerry Durand, Durand Interstellar, Inc. www.interstellar.com
tel: +1 408 356-3886, USA toll free: 1 866 356-3886
Skype: jerrydurand
|
That is my experience, too.? In my mind, advancing the timing of the brushes is not logical, for what is happening inside an electric motor is essentially happening at the speed of light.? Advancing spark timing in a gas engine is logical, because it takes time for the flame front to propagate through the combustion chamber. ?But advancing timing in an electric motor? I can’t see it. ?However, I can’t say that it has never been done, either. ? Robert ? From: 7x12minilathe@... [mailto:7x12minilathe@...] On Behalf Of Robert Francis
? I've heard time and time again, the motors being set to run in the"main" direction, but never have I seen it documented by the equipment manufacturer. I think it's an old wives tale!
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On 05/19/2013 08:19 PM, Roy wrote: ? Some of the controllers are set up to add a speed limiting resistor in reverse. That's supposedly because the brushes are advanced a few degrees to improve efficiency when the motor is running in the normal direction. In reverse, the benefit becomes a loss.
Roy
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Mid-production Sieg lathes using the FC250 control boards had an extra set of switch contacts that would intentionally reduce the speed of the motor when the machine ran in reverse. If your board had this 'feature' it would have a P4 terminal connected to the directional switch, in addition to P1-P2-P3 going to the speed pot.
This was removed on later production boards, and as far as I know was never re-instated on the 'XMT' series of boards. Whether Real Bull decided to add this feature back in I can't say, but I have never received newer boards in for repair that included this function. My understanding is that it was supposed to be a safety feature.
--
Pete Brush (Olduhfguy)
web :
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gerry waclawiak
OldToolmaker
Warren LeMay