Hi, Bruce,
Wouldn¡¯t that be fixable by a larger gear on the encoder, reducing the ratio? Or would it require redoing the mount?
Yes, that would reduce the maximum frequency, but at the cost of resolution.? As I am not sure how critical the resolution is to the application, I would tend to preserve the resolution.? If a lower resolution works with the rest of the ELS system, then the larger gear, as you suggest, would be a perfectly fine solution.-- Regards, Charlie New Jersey, USA
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I had a single y axis ELS system with a tachometer and a hall effect magnet for the encoder. The system worked alright to a degree but was getting skipping issues. So with a great help from Richard Edwards I am going with the modified Russian ELS greatly improved and in English. Initially I was going to adopt the y axis system only but on reflection there not a lot of more work to do the? crossfeed x axis system as well. Almost finished the mechanical side using a? 600 p/r encoder geared 1 to 1 and a nema 23 fixed to the tailstock end 1 to 1 and a nema 23? for the crosslide again 1 to 1 only? the latter is a short version about 55mm long and less torque. Waiting for some more parts and meantime hopefully modifying the arduino sketch for my leadscrew? 2mm pitch and crosslide thread pitch 1mm? and the 600 p/r encoder. t
The spec states? Pulses:600p/r(Single-phase pulses P/r, Two phase 4 frequency doubling to 2400 pulse . Not sure about this should I set the encoder to 2400 in the sketch?
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Ralph,
Regarding my ELS purchases¡
?
I bought the encoder pulleys from SDP in Hicksville, NY.? I do not recommend them.? They are quite expensive.? I ended up paying a total of $40 in shipping for items with virtually no weight because they were broken up into three shipments.? What you need is two timing belt pulleys, one 16 tooth and the other 48 tooth, as I recall, with a 2.5 pitch.? The 16 tooth should have double-flanges; the 48 tooth does not need them, as you will make your new spindle spacers wide enough to act as flanges.? Both of these pulleys will have to be bored out; the large one to be a precision fit on the spindle, the small one a precision fit on the encoder.? When boring, then need to be held by the peak surface of the teeth; the flanges are not necessarily concentric.? I can get you more info when you are ready.? The specific pulley part numbers I bought were A 6A32M016DF0603 and A 6A32M048NF0606.? I bought three different length timing belts, but ended up using the longest one, A 6T32MF106060.
?
I bought the Arduino Mega 2560 Rev 3 board direct from the Arduino Store.? I could have bought it cheaper elsewhere, but wanted to make sure that I got the ¡°official¡± unit so it wouldn¡¯t be a problem.
?
I bought the aluminum for the motor mounts locally; you will use your own source.
?
I bought the stepper motors, which are bigger than they need to be, (especially for the cross-slide!) from Stepper Online, Model No. 23HS45-4204S.
?
I bought a via Amazon.
?
I bought three via Amazon.?
?
I bought a Signswise 600p/r Incremental Rotary Encoder Dc5-24v Wide Voltage Power Supply 6mm Shaft encoder from Amazon. ?John uses an encoder with identical specs, but I am a little more hesitant.? The maximum frequency response seems a bit limited, (see discussion with Richard above) but John has had no trouble.
?
I bought the two different sized couplers from Banggood; and .
?
For some items, I bought multiple quantities so I have spares; encoder, belt, pulleys (in case I screwed up machining them!).
I hope this helps.
-- Regards, Charlie New Jersey, USA
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Hi, Richard,
I ended up using an 600 PPR encoder that has identical specs to John's.? The mechanical speed is not an issue; maximum spindle speed with the gear reduction is 1250 RPM; at a 3:1 gear ratio, that's a maximum encoder mechanical speed of 3750 RPM.? What I was concerned about was the frequency response.? 600 PPR x 3750 RPM / 60 min/sec = 37.5 kHz, whereas this encoder is specified with a maximum frequency of 20 kHz.?
Wouldn¡¯t that be fixable by a larger gear on the encoder, reducing the ratio? Or would it require redoing the mount?
--? Bruce Johnson
"Wherever you go, there you are." B. Banzai, PhD
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Hi, Richard,
I ended up using an 600 PPR encoder that has identical specs to John's.? The mechanical speed is not an issue; maximum spindle speed with the gear reduction is 1250 RPM; at a 3:1 gear ratio, that's a maximum encoder mechanical speed of 3750 RPM.? What I was concerned about was the frequency response.? 600 PPR x 3750 RPM / 60 min/sec = 37.5 kHz, whereas this encoder is specified with a maximum frequency of 20 kHz.? Since it's already installed mechanically, I am going to stay with it for now and check how it affects ELS operation after the electronics is installed.? My alternative would probably to buy a 600 PPR encoder with a faster frequency response.
I spend 30+ years working for a German company, and one of our primary products was rotary shaft encoders.? I was involved in defining the specs needed by the product to the R&D team, writing the manuals, specification sheets, etc.? Of course, these encoders had prices in the several hundred dollar area.
--
Regards,
Charlie
New Jersey, USA
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Thanks John, have have a lot of Nema 23 motors on hand, I do not know the specs on any of them.
If I ever get to my shop I'll start looking at mounting them. I have relatively speaking a lot of room (30' x 20') but it is crowded but I have room around my lathes and mill.
Ralph
On Mon, Aug 19, 2019 at 3:04 PM Richard < edelec@...> wrote: Apologies for replying to my own post but to overcome the problem I
outlined it is possible to buy an 1800 p/r encoder E6B2-CWZ6C via
Aliexpress this unit is rated at 100Khz and 6000 rpm.
Obviously drive this at 1:1 spindle speed.
Richard
On 19/08/2019 08:45, Richard wrote:
> Bear in mind that the 600 line encoder was used as I had one. Ensure
> you check how your top spindle speed relates to the lines, ratio and
> max encoder revs from its specification! Typically a 600 line encoder
> driven at 3:1 with top rpm of 5000 should not be used on a machine
> that will run at 2500 rpm.
> Richard
>
--
Clausing 8520, Craftsman 12x36 Lathe, 4x12 mini lathe, 14" Delta drill press, 40 watt laser, Consew brushless DC motors and a non working 3D printer
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And while we are on the subject of 3D printing, here's a couple of useful and inexpensive projects for drying and keeping your filament dry.
Food Dehydrator as filament dryer:?
Drybox for keeping filament dry while printing:?
I worked for a medical device manufacturer with 44 injection molding machines. There were no plastics that were molded there that were not dried first.
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STEP and IGES files are pretty much universal among the CAD programs, with STEP being the preferred format, IMO.?
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Apologies for replying to my own post but to overcome the problem I
outlined it is possible to buy an 1800 p/r encoder E6B2-CWZ6C via
Aliexpress this unit is rated at 100Khz and 6000 rpm.
Obviously drive this at 1:1 spindle speed.
Richard
toggle quoted message
Show quoted text
On 19/08/2019 08:45, Richard wrote: Bear in mind that the 600 line encoder was used as I had one. Ensure
you check how your top spindle speed relates to the lines, ratio and
max encoder revs from its specification! Typically a 600 line encoder
driven at 3:1 with top rpm of 5000 should not be used on a machine
that will run at 2500 rpm.
Richard
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Hi Ralph. Playing catch up on e mails. Phew !!!! I used a 3:1 ratio,the 6 mm dia? encoder spindle 10T and the driver off the spindle 30 T. 2.5 mm pitch and belts accordingly. I believe Charlie procured through STP/SL? There is a some work to be considered in modifying the original lathe to accept the 30 T encoder, it becomes part of the preload spindle bearing spacers, but lets take it step by step, first procure the stepper motors, install, and we can move on after that. This first step should not impede any normal manual lathe operations during the conversions. I bought my steppers from Steppers on line,?? Nema 23 for the Z axis, Nema 17 or 23 for the X axis.your call to suit your machine. We can discuss procurement of drivers as we go along.? I am sure Richard will assist in selections.
I have stayed with the Nema 17 for the X axis, works OK and also I have space limitations ( back of the lathe to my building wall) for a Nema 23. it gets close.My workshop measures 6 feet x 6 feet, that?s it, includes a lathe, mill, pedestal grinder and off hand grinder. cupboards etc. Richard will tell you, it?s clorasephobic. LOL But if? the X slide gibs are set and working as they should, (if not modify as we have recently discussed) a Nema 17 will be OK. Pleny man enough.
John ?
Charlie, how did you get the timing belt for the encoder on the spindle?
Ralph
On Mon, Aug 19, 2019 at 3:45 AM Richard < edelec@...> wrote:
Bear in mind that the 600 line encoder was used as I had one. Ensure you check how your top spindle speed relates to the lines, ratio and max encoder revs from its specification! Typically a 600 line encoder driven at 3:1 with top rpm of 5000 should not be used on a machine that will run at 2500 rpm. Richard
On 17 August 2019 8:50:16 pm "CLevinski" <clevinski@...> wrote:
Hi, Ralph,
A 600 PPR quadrature rotary shaft encoder, coupled directly to the spindle with a timing belt with a 3:1 ratio.??
--
Regards,
Charlie
New Jersey, USA
--
Clausing 8520, Craftsman 12x36 Lathe, 4x12 mini lathe, 14" Delta drill press, 40 watt laser, Consew brushless DC motors and a non working 3D printer
--
John
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Talking about DXF, DWG, STL, Iges, Parasolid etc etc. I use M Cam (old prog ) for drafting, does all I need but limited to the above to export files.
Cheers
John
On Mon, 19 Aug 2019 at 20:45, Fast Eddie < epinnell@...> wrote: John, that is indeed good news!
Sharing and file transfers? I assume you are talking beyond the group's Files section. Do you intend to make this exclusive to all members, some members, or the public in general? What are your thoughts?
--
John
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John, that is indeed good news!
Sharing and file transfers? I assume you are talking beyond the group's Files section. Do you intend to make this exclusive to all members, some members, or the public in general? What are your thoughts?
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Members, have we struck gold or what.?
Robert Furmanak, we? have been friends for over 6 years.
We lost contact as he moved from PA to FL.a few years ago.
He was my mentor to allow me to move forward on the Gear Reduction for the Real Bull lathe. A brilliant electrics and practical engineer.
Robert designed and put together the original gear reduction for the Sieg type lathe.differences were I needed a idler gear
for normal anti clockwise motion, he did not need this, also the method of attaching the GR bracket to the end of the motor is different.
Sieg versus real Bull lathe motors are different.
He happens to have most of the information and I am in the process of preparing to 3D print of the Sieg bracket.
His knowledge of 3D printing, I did not know about.?WOW.
Anyway, I am sure we are starting to add on some big guns to the forum.
For example, Richard UK has assisted me in installing Power feed, ELS, CNC to the
mill and lathe,another what I call a genius.?
I am in the process of welcoming Robert into the digitalhobbyist family, I am sure he will assist when his time permits.?
Almost got the GR Real Bull off the3D printer, some tinkering required.
We need to discuss sharing and file transfers. Lets as a group see if can come up with common denominators.
Thanks
--
John
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Charlie, how did you get the timing belt for the encoder on the spindle?
Ralph
On Mon, Aug 19, 2019 at 3:45 AM Richard < edelec@...> wrote:
Bear in mind that the 600 line encoder was used as I had one. Ensure you check how your top spindle speed relates to the lines, ratio and max encoder revs from its specification! Typically a 600 line encoder driven at 3:1 with top rpm of 5000 should not be used on a machine that will run at 2500 rpm. Richard
--
Clausing 8520, Craftsman 12x36 Lathe, 4x12 mini lathe, 14" Delta drill press, 40 watt laser, Consew brushless DC motors and a non working 3D printer
|
Bear in mind that the 600 line encoder was used as I had one. Ensure you check how your top spindle speed relates to the lines, ratio and max encoder revs from its specification! Typically a 600 line encoder driven at 3:1 with top rpm of 5000 should not be used on a machine that will run at 2500 rpm. Richard
On 17 August 2019 8:50:16 pm "CLevinski" <clevinski@...> wrote:
Hi, Ralph,
A 600 PPR quadrature rotary shaft encoder, coupled directly to the spindle with a timing belt with a 3:1 ratio.??
  
--
Regards,
Charlie
New Jersey, USA
|
Re: Gear reduction 3D printed bracket.
#3D
#GR
Hi Greg.
Thanks for the post.
In this first trial I am using PLA. and see how it all works out.
ABS is stronger but can also become brittle ( I think) over periods of time.
Heat will not be an issue as the bracket is only in point contact (6 pointed grub screws) around the profile
that engage onto the motor casing, and is seeing air flow from the motor fan.
Strength again is not a major issue, the whole GR system is driven by the motor using plastic gears.2 x 16 T and 1 x 32 T
Without the adequate tools in place, the manufacture of the ally bracket can be difficult,
this maybe a good cheap option. But we shall see .
?
BLDC motors are good, but can suffer with lack of toque at the lower RPM spectrum, ? but I am
not an expert in these matters. we can pass this over to other members for discussion who are a bit more "savvy" than me
on motors.
?
A good test of adequate torque is to cut for example a? 40 mm dia x 2 mm pitch thread. This requires low RPM?
and sufficient torque when coming up to full depth.
The automatic "hands free" screwcutting module of the ELS demands the threading tool moves directly in the X axis direction.
No compound slide at 29.5 degree moves.
Not a problem as the number of roughing and finishing passes are pre set.and can also be changed if cutting brass versus steel.
At the end of the cuts, the ELS automatically backs out the tool " called rebound" and travels to the original starting point and feeds back in and cuts.
In manual ELS screwcutting this adopts the same X axis "IN" move, but naturally depth of cuts and tool retraction are controlled by the operator.
In automatic mode, a predetermined backlash setting is applied in the firmware. so no fear of the tool not clearing the thread profile on?
automatic returns.
?
Many thanks for your interest.
Keep posting.
-- John
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Re: Gear reduction 3D printed bracket.
#3D
#GR
Looks good, and sounds like a good plan. What filament are you using? Is heat resistance or strength a major consideration? I have a MicroMark with the BLDC motor, and am satisfied with the torque, but nonetheless I find your project interesting. ? Greg ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of John Lindo
Sent: Sunday, August 18, 2019 9:07 PM
To: [email protected]
Subject: [digitalhobbyist] Gear reduction 3D printed bracket.? Just preliminary working on a 3D plastic Real Bull motor bracket.
I cannot see why it would not work, this would remove the process of machining from aluminum billet.
The bearing bores x 2 would be finished by fine boring to size and position.
I will keep the forum regularly posted of my progress.
B est regards
--
John
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Gear reduction 3D printed bracket.
#3D
#GR
Just preliminary working on a 3D plastic Real Bull motor bracket.I cannot see why it would not work, this would remove the process of machining from aluminum billet.The bearing bores x 2 would be finished by fine boring to size and position.
I will keep the forum regularly posted of my progress. B est regards-- John
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Hi John, yes thank you! Of course I have two lathes (4x12 mini and 12x36 Craftsman) to do plus I want to do my Clausing 8520 mill. As late as I am getting into any machining I think I am going need a lot of help and anything I can automate? has to help. That plus my eyesight is showing it's age.
Ralph
Hi, Ralph,
An Arduino?Mega 2560 Rev 3.
I recently emailed a friend in Australia a list of most of the items I have purchased for ELS so far, along with sources.? I can copy and paste this list for you, if you wish; just let me know.? John is right, though, that the motors and couplings are the first things, as they get mounted first.
--
Regards,
Charlie
New Jersey, USA
--
Clausing 8520, Craftsman 12x36 Lathe, 4x12 mini lathe, 14" Delta drill press, 40 watt laser, Consew brushless DC motors and a non working 3D printer
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Re: Constant Surface Speed for mini-lathe
#CSS
Oh... sorry, I should have explained...
As I am sure you all know from your own experience, when a part is spinning at a fixed RPM rate, the surface speed of the moving part is greater the farther you get from its centerline.? Its speed is actually zero exactly at the centerline.? Our cutting tools work best at a certain range of surface speeds.
When turning a part, this makes no difference, as you set the RPM a little faster as the diameter gets smaller.? But when facing, the surface speed is highest at the outer edge and decreases as the cutting tool moves towards the center, and you can't really adjust it constantly.? (If I am using a sharp, HSS tool, and am right on the centerline, I can actually see the chip slowly peel off when I am almost to center, because the surface speed is so low.)? This creates an issue with getting the best performance from our tools and getting a good finish, especially when dealing with larger diameter parts.? Bigger lathes deal with this by having Constant Surface Speed systems that will automatically increase the RPMs as you near the centerline.? The system described above was intended to provide a similar function for the mini-lathe.
Sorry, I should have explained that before describing what the CSS system does!
--
Regards,
Charlie
New Jersey, USA
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John Lindo