Freerails Home 
Home Search search Menu menu Not logged in - Login | Register

Because of non-railroad abuse of the site, new members MUST use their first names (at least) to join NO EXCEPTIONS!

Radio Control
 Moderated by: W C Greene Page:  First Page Previous Page  ...  105  106  107  108  109  110  111  112  113  114  115  Next Page Last Page  
New Topic Reply Printer Friendly
 Rating:  Rating
AuthorPost
 Posted: Wed Apr 12th, 2017 03:55 am
  PMQuoteReply
1091st Post
Michael M
Registered


Joined: Thu Jan 26th, 2017
Location: San Bernardino, California USA
Posts: 168
Status: 
Offline
Si,

The car cost about $25.00 including postage.  Picked it up off of eBay.  I haven't had a chance to start pulling it apart yet, but I'd say the car is about 18 inches long.  But, of course, I'm just interested in the electronics.  It has a 7.2 500 mAh battery, and the controller takes a 9 volt.  From what I can initially tell it should fit in my 35n2 critter.

http://www.ebay.com/itm/172430813664?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Only time will tell if I made the right decision.



____________________
Michael
Back To Top

 Posted: Wed Apr 12th, 2017 06:01 am
  PMQuoteReply
1092nd Post
Michael M
Registered


Joined: Thu Jan 26th, 2017
Location: San Bernardino, California USA
Posts: 168
Status: 
Offline
Here are some pictures of the car.







Big problem.  That 7.2 battery will NOT fit in my little critter.  So, do I build a trailer car to hold everything (something I really don't want to do), or do I replace it with a 7.4 volt LiPo battery?  There can't be much difference between 7.2 volts and 7.4 volts, right?  What's the difference of 0.2 volts?  Will have to head off to the local hobby store that sells R/C and find out what a 7.4 volt LiPo plus charger will cost.  Either way I'm sure I'll make it work.




____________________
Michael
Back To Top

 Posted: Wed Apr 12th, 2017 12:11 pm
  PMQuoteReply
1093rd Post
Bob R
Registered


Joined: Thu Nov 20th, 2014
Location: Papillion, Nebraska USA
Posts: 240
Status: 
Offline
Lipo is the only way to go in my opinion.  A 7.4v Lipo 2S battery is significantly smaller and lighter.  You will find they are available in many sizes in the same capacity (mah).  Most of my critters are running with 300mah cells.  I run single cells with a step up regulator.  There is an effeciency loss but I still get 1 to 1 1/2 hour on a charge.  With a 2 cell you would do better.  A two cell 300 mah battery is 7/8" x 1 3/8" x 1/2".   Cost is about $9.00.
Bob

Attachment: 20170412_070510_resized.jpg (Downloaded 42 times)

Last edited on Wed Apr 12th, 2017 12:12 pm by Bob R



____________________
Bob
Back To Top

 Posted: Wed Apr 12th, 2017 12:22 pm
  PMQuoteReply
1094th Post
Rod Hutchinson
Registered


Joined: Fri May 8th, 2009
Location: Mooroolbark, Australia
Posts: 313
Status: 
Offline
I would endorse Bob's comments. I buy mine on ebay preferably with the PCM connected to the terminals. The ones in R/C shops are normally too large for model railways. The current value of battery can give a rough indication of the physical size.

Just find ones that suit. If you wire up your own 2S cells ensure you really do understand how to wire them correctly, and charge them with a balance charger.



____________________
Rod Hutchinson
Mooroolbark, Australia
Back To Top

 Posted: Wed Apr 12th, 2017 12:23 pm
  PMQuoteReply
1095th Post
Rod Hutchinson
Registered


Joined: Fri May 8th, 2009
Location: Mooroolbark, Australia
Posts: 313
Status: 
Offline
I would endorse Bob's comments. I buy mine on ebay preferably with the PCM connected to the terminals. The ones in R/C shops are normally too large for model railways. The current value of battery can give a rough indication of the physical size.

Just find ones that suit. If you wire up your own 2S cells ensure you really do understand how to wire them correctly, and that you charge them with a balance charger.



____________________
Rod Hutchinson
Mooroolbark, Australia
Back To Top

 Posted: Wed Apr 12th, 2017 12:33 pm
  PMQuoteReply
1096th Post
bobquincy
Registered


Joined: Sun Jan 27th, 2013
Location: North Carolina USA
Posts: 157
Status: 
Offline
After comparing Li-ion, LiPo, and NiMH it looks like the main advantage of lithium is the light weight.  For total energy per volume NiMH compares well with lithium chemistries but at a greater weight.  The advantage of NiMH is availability and ease of charging.

For airplanes and race cars lighter weight is a big deal, for trains maybe not so much.



____________________
Monorail modelers have a one track mind.
Back To Top

 Posted: Wed Apr 12th, 2017 02:26 pm
  PMQuoteReply
1097th Post
W C Greene
Super Moderator


Joined: Fri May 4th, 2007
Location: Dallas, Texas USA
Posts: 7298
Status: 
Offline
Li Polys can be had in small packages and room is easier to find. A 2 cell 7.4 volt 160MAH job would be fine (I have these in my Porters). On the wires & connectors, I VERY CAREFULLY cut off the big red & black wires and connector and replace them with MINIATRONICS 2 pin connectors which are wired with 18 GA wire. I have used these for 15 or so years and have such a plug on my charger also. Just be careful and they last a long time.

Woodie



____________________
Go ahead, make my day!
Back To Top

 Posted: Wed Apr 12th, 2017 04:29 pm
  PMQuoteReply
1098th Post
Bob R
Registered


Joined: Thu Nov 20th, 2014
Location: Papillion, Nebraska USA
Posts: 240
Status: 
Offline
I have been using micro JST 1.25 connectors with good success.  On fleabay you can buy 10 pair (10 male/10 female) for $2.18 with free shipping.  Your LHS charges about $3 each.  That is what is pictured in my prior post.
Bob

Last edited on Wed Apr 12th, 2017 04:30 pm by Bob R



____________________
Bob
Back To Top

 Posted: Wed Apr 12th, 2017 05:07 pm
  PMQuoteReply
1099th Post
bobquincy
Registered


Joined: Sun Jan 27th, 2013
Location: North Carolina USA
Posts: 157
Status: 
Offline
I agree with you (mostly) and use LiPo in my smaller models where there is no room for AA batteries or voltage converters.  For larger models that have space for 2xAA or more I have not found any 14 x 50 x 28 mm LiPo that have greater energy density than Eneloop Pro (1.2 V @ 2450 mAH).

boB

W C Greene wrote: Li Polys can be had in small packages and room is easier to find. A 2 cell 7.4 volt 160MAH job would be fine (I have these in my Porters). On the wires & connectors, I VERY CAREFULLY cut off the big red & black wires and connector and replace them with MINIATRONICS 2 pin connectors which are wired with 18 GA wire. I have used these for 15 or so years and have such a plug on my charger also. Just be careful and they last a long time.

Woodie



____________________
Monorail modelers have a one track mind.
Back To Top

 Posted: Thu Apr 13th, 2017 05:09 am
  PMQuoteReply
1100th Post
Michael M
Registered


Joined: Thu Jan 26th, 2017
Location: San Bernardino, California USA
Posts: 168
Status: 
Offline
Thanks to everyone for their suggestions and input.  I definitely will go with LiPo batteries once I make a little progress.

I got the body off the car, and found that all the wiring was made with little connectors.  So it's just a matter of unpluging everything.  The board is 1 3/4 by 2 1/8 inches.  Should just fit into my little critter.

The wiring is pretty straightforward; red and white to the motor, red and black to the on/off switch; red and black to the battery.  I'm just going to dump the battery into a trailing ore car until I can pick up a LiPo.



____________________
Michael
Back To Top


 Current time is 12:58 pm
Page:  First Page Previous Page  ...  105  106  107  108  109  110  111  112  113  114  115  Next Page Last Page  

Top



UltraBB 1.172 Copyright © 2007-2016 Data 1 Systems