| Author |
 Topic  |
|
BurleyJim
Fireman
Premium Member
|
 Posted - 02/08/2021 : 01:20:24 AM
|
After I made sure the electrical connection to the track was without problems. I sealed up the sides of the bridge with the sideframes that I built a few pages back. Afterward I had to tweak the track leveling again.
The bridge is now very rigid. The center of bridge rails are actually straight, a little lens distortion makes it look like there is a dip in the middle.
The drive servo finally arrived. I made coupler to connect the servo to the bottom of the turntable. I also made that mounting plate to secure the servo in place. Another bad photo, it's actually a square fit.
Here is the drive servo, fresh off the boat!
The servo mounted to the constructed platform.
It didn't take very long before I discovered that I had made quite an error in the selection of that servo. The primary purpose of the turntable was to ''turn' an engine around end for end. I had used hobby type servos for other projects. They all were 0 -> 180 degree units. I saw this 360 degree servo and jumped right on it. I also wanted the turntable to be somewhat autonomous. Microprocesser control 'sounded good at the time'. A 360 degree servo also goes under the alias as a 'continuous motion' servo. WAIT A MINUTE! Actually wait a few days, until I could figure out how to control the beast! There is no position control with forward/backward, CW/CCW in degrees. Just timing pulse widths to deal with. It was a lot of  action on this bench. I really should have used a 'stepper motor' to start off with. At least We could have calculated move in degrees, not number of pulse widths within a timeframe, and not had a spinning wheel. STEPPER MOTOR! I'll have to write that a thousand times.
Anyway, if you want to see how smooth and extremely quiet the turntable works right now...
https://www.dropbox.com/s/gf2ocjxku3lna68/IMG_2404.MOV?dl=0
Heading back on working with the roundhouse tomorrow (later today, actually)
Jim
|
| Take the red pill |
Edited by - BurleyJim on 02/08/2021 12:02:50 PM |
|
Country: USA
| Posts: 6163 |
 |
|
|
TRAINS1941
Engineer
Premium Member
|
Posted - 02/08/2021 : 08:21:07 AM
|
No problem your hired!!!!
Wonderful work Jim.
|
Jerry
"And in the end, it's not the years in your life that count. It's the life in your years." A. Lincoln |
|
Country: USA
| Posts: 13204 |
|
|
|
jbvb
Fireman
Premium Member
|
Posted - 02/08/2021 : 08:21:37 AM
|
Nice CB&Q geep, Jim.
|
|
Country: USA
| Posts: 6804 |
|
|
|
BurleyJim
Fireman
Premium Member
|
Posted - 02/08/2021 : 09:40:49 AM
|
Thanks Jerry.
James, I painted that locomotive probably 40+ years ago. I've re-engine'd and DCC'd it. One of my favorites.
Jim
|
| Take the red pill |
|
Country: USA
| Posts: 6163 |
|
|
|
k9wrangler
Engineer
|
Posted - 02/08/2021 : 11:44:48 AM
|
Dropbox won’t let me in.
That nice red engine sure got dirty sitting around 40 years..
|
Mega Dittos
Karl Scribner
Manistique, Michigan |
Edited by - k9wrangler on 02/08/2021 11:45:52 AM |
|
Country: USA
| Posts: 11903 |
|
|
|
BurleyJim
Fireman
Premium Member
|
Posted - 02/08/2021 : 12:07:10 PM
|
Sorry folks, here is the corrected link....
https://www.dropbox.com/s/gf2ocjxku3lna68/IMG_2404.MOV?dl=0
I thought it a little strange that James thought the engine was a Geep, when the moving model is an SD9.
That's what I get for posting at 0130. BTW, I painted both of the engines.
Jim
|
| Take the red pill |
|
Country: USA
| Posts: 6163 |
|
|
|
George D
Moderator
Premium Member
|
Posted - 02/08/2021 : 12:10:47 PM
|
Nice smooth operating turntable, Jim.
George
|
| Fly Army |
|
Country: USA
| Posts: 16785 |
|
|
|
Bernd
Fireman
|
Posted - 02/08/2021 : 1:00:31 PM
|
Pretty good Jim.
Engines look great too.
Bernd
|
| New York, Vermont & Northern Rwy. - Route of the Black Diamonds |
|
Country: USA
| Posts: 3949 |
|
|
|
BurleyJim
Fireman
Premium Member
|
Posted - 02/08/2021 : 4:26:18 PM
|
Thanks Bernd, I'm scrounging around for an old printer to snag a stepper motor out of. You know how the 'tinkering bug' bites.
Jim
|
| Take the red pill |
|
Country: USA
| Posts: 6163 |
|
|
|
Bernd
Fireman
|
Posted - 02/08/2021 : 4:46:31 PM
|
quote:
Originally posted by BurleyJim
Thanks Bernd, I'm scrounging around for an old printer to snag a stepper motor out of. You know how the 'tinkering bug' bites.
Jim
How about and old HP plotter pen holder motor? It worked when I dissembled the plotter.
Bernd
|
| New York, Vermont & Northern Rwy. - Route of the Black Diamonds |
|
Country: USA
| Posts: 3949 |
|
|
|
BurleyJim
Fireman
Premium Member
|
Posted - 02/08/2021 : 6:13:05 PM
|
Bernd,
I found one from an old dot-matrix printer that I'm going to see if it has enough torque to swing that bridge. I looked up that P/N on the Sigma you have, but can't find any electrical specs on it. I'll see if this one I recovered has enough to do the job.
Thanks Jim
|
| Take the red pill |
|
Country: USA
| Posts: 6163 |
|
|
|
Bernd
Fireman
|
Posted - 02/09/2021 : 10:23:13 AM
|
quote:
Originally posted by BurleyJim
Bernd,
I found one from an old dot-matrix printer that I'm going to see if it has enough torque to swing that bridge. I looked up that P/N on the Sigma you have, but can't find any electrical specs on it. I'll see if this one I recovered has enough to do the job.
Thanks Jim
Okay, I'll keep it around just in case you want it. Remember, I'm trying to clean the basement out.
Bernd
|
| New York, Vermont & Northern Rwy. - Route of the Black Diamonds |
|
Country: USA
| Posts: 3949 |
|
|
|
Frank Palmer
Fireman
|
Posted - 02/09/2021 : 10:25:21 AM
|
Wait a minute, pen plotter, dot matrix printer, you guys are talking "OLD" school.
Jim do you get much warping of the product from the printer?
Attsa' smooth. The turntable that is.
|
| Frank |
Edited by - Frank Palmer on 02/09/2021 10:28:56 AM |
|
Country: USA
| Posts: 6129 |
|
|
|
BurleyJim
Fireman
Premium Member
|
Posted - 02/09/2021 : 12:02:47 PM
|
Thanks for stopping in Frank.
Warping? I get very little if any. I use mostly ABS, but will probably
make the change to PETG. Warpage occurs with not having the print
starting off right on the build plate. There are a few factors that
enter into this.
Bed leveling - when you are printing with a .4 or .5mm nozzle,
that first layer will be .2 mm thick. Here is where a lot problems
start. If that first layer isn't locked on to that glass, it's downhill
from there. That, takes a 'heated' bed, and some experience with the
printer. Most of the 'trinket' printers out there, take a lot of time
horsing around with bed leveling. It's the smae as 'tramming' a vertical
mill. If it's wrong at the start, it ain't gonna get fixed at the end.
The 'hot bed' is the other bad start problem. The bed has to be hot
enough for that first layer to adhere to. Then it has to cool down for the
next number of layers to adhere to the previous layer without looking like
an overdone grilled cheese sandwich. That is controlled by the printer
mechanically, but the 'slicer' software plays a major part in getting that
info to the printer. That info is 'user configured'. There is some voodoo
involved in those settings.
Back to the bed leveling, On my printer, which is a 'delta' printer. It would
be very time consuming to ensure that the printhead is flat across the
entire surface. It's 300mm in dianeter. My machine is autoleveling, so if I
move it, there are temp changes, out in the shop, etc. It takes about 2 minutes
to run the 'autoleveling' macro (app ) to map the surface at 64 locations to
.02 mm accuracy. I do it about once a week, just to make sure it's done.
The next cause of warpage is not making that temperature transition from that
initial hot layer to the subsequent layers. If that bed stays too hot, the
'grilled cheese' keeps shrinking the upper layers just enough to distort the print.
Yet another cause is the material itself. There is a WIDE variation in material.
There must be some description of what mixture of components are in the generic
names of PLA, ABS, PETG, TPU, and whatever. But, I've bought PLA from 3 different
companies and the quality differences would turn anyone away from thinking this is
a good venture. This is clearly a 'get what you pay for' deal. I bought a roll of
TPU from Amazon (the stuff I made hinges out from for the roundhouse after the rebuild)
I ended up throwing that roll in the garbage. It was TPU in name only. I ended up
finding a meter of the original TPU I used and made enough to redo the hinges.
So filament quality is indeed a factor in the final product. I now only buy 'Atomic'
filament, made in the USA.
So, non-warpage is attained by good quality tools and materials, with experience and
some voodoo.
Jim
|
| Take the red pill |
Edited by - BurleyJim on 02/09/2021 12:05:56 PM |
|
Country: USA
| Posts: 6163 |
|
|
|
Terrell
Fireman
|
Posted - 02/09/2021 : 2:17:58 PM
|
Looking good, Jim!!
|
|
Country: USA
| Posts: 2351 |
|
|
|
Topic |
|
Home
Forums
Events Calendar
Sponsors
Guestbook
FAQ
