4D Maglite ROP with sub-c cells

[Mjolnir]

I have been considering making an ROP mod with a 4d maglite, but I have been unable to find all of the info that I need. It seems that people have been able to do it with 6 sub-c cells (like a custom stuck from cheapbatterypacks.com).
However, will 6 sub-c cells fit in a 4d maglite without modification (in other words, are they too long?)?
I don't actually have a 4d maglite; only a 3d, so I don't know the length of the battery compartment in a 4d. Also, if I get a stick with a wire and plug for charging (is there any other way to charge it?), will the stick still fit inside the light? How much difference is there between the diameter of the battery stick and the inner battery tube diameter?
If anyone has done this mod this way I would appreciate the help.

 

[Mjolnir]

No one has any ideas? I know that tons of people have made this mod. Most have probably used AA's, but I know some have used sub-c's or other larger rechargeables...
Any suggestions would be appreciated (they can be vague and don't have to be from first hand experience).

 

[swampgator]

The 4D/Six Sub C was Kevin's original ROP recipe, if my memory is correct. According the CBP webpage a Sub C ranges in length from 43.14mm (Elite 3300 & 5000) to 43.94 (Elite 4000), so for sake of argument just say 44mm each. Total 264 mm. Now a D cell is roughly 58mm so four would equal 258mm. Making the six Sub Cs longer.

So short answer is yes, a pack of six Sub Cs will work in a 4D. Going from memory you may need to tweak the spring to make contact.

You won't need wires, just a pack. However you will need a charger capable of charging a pack at once.

 

[Mjolnir]

What chargers can charge a pack all at once?
In other words, what type of contacts should the charger have to be able to attach to the ends of the battery pack?
Also, if I get it from cheapbatterypacks.com, should I get the cells soldered together?

 

[swampgator]

There are some "pack" chargers on CBP. If you choose that route, you could attach the positive terminals and negative terminals to the pack with magnets.

I'd opt for keeping the cells separate. That way if a single cell begins to fail, you only have to replace that cell as opposed to the whole stick. A multiple bay charger is available here. You can get a four cell charger relatively cheap or opt to have all six charge at once in a more expensive model.

Note: I've never dealt the site listed and it is listed only to give you an idea of what's available.

 

[ktafil]

Here is my 4D --> 6Sub-C ROP
Maybe the pics can help out a little.

A very used 1990 4D maglite
A glass magcharger lens (had that already in before the ROP)
A medium orange peal reflector
A ROP - HI bulb
A 'low resistance fix' on the switch
6x 5000mAh sub-c cells
A PVC pipe to fit the Sub-C size cells in the D-tube
A customised original tailspring

This is how far the Sub-C's will stick out of the 4D!

 

[ktafil]

Also, if I get a stick with a wire and plug for charging (is there any other way to charge it?)
I would appreciate the help.

I just charge them in an universal scharger.
But since the Sub-C's are quite flat i need to put on a little magnet for the battery to reach the contact in the charger. :twothumbs
you will need to take off the magnet when you put them in the 4D otherwise the total batery pack becomes too long.

 

[Mjolnir]

So I would have to use a modified shorter tail spring to fit the cells in?
Also, what are the dimensions of the pvc pipe you used?

 

[ktafil]

So I would have to use a modified shorter tail spring to fit the cells in?
Also, what are the dimensions of the pvc pipe you used?

I used a 32mm PVC plumming pipe. this is a standard size here in the Netherlands. It fits nicely in the 4D and the Sub-C's fit nice as well.
I guess there must be some like that in the US.

For the spring I cut the original spring to fit and turned it upside down in the tailcap.
Unfortunately I don't have photo's of that in different stages.

I cut the top of the spring and the curl in the end of the spring.
I turned the spring around and bent the inside up a little to apply some pressure on the bat's.
You will have to fidle a little to get it right.

 

[SimpleMods]

Hi, I'm new here and this is my 1st post.
I was wondering if someone could point me too the parts needed to make 8c batteries fit into a 6d m@glite, i have the m@g & the batteries and know that the cap closes with NO spring in it.

I have put tin foil in there but it isn't great, please could someone tell me how to do this perminantly and reliably I have read about PVC pipe and shortened tail springs above.
I know this isn't entirely relevent to this thread but like i said this is my first post and i couldn't find a more relevent thread... :mecry:.

EDIT:
I think the width of the pipe i need is 26mm (on the inside) to house the c's snuggly and then use rubber gaskets to stop it all rattling, does anyone know where to find this? I have been looking.

Thanks, SimpleMods.