???Building XR can Light engines.???

:shrug:Ok. I am new to this whole thing. Can anyone help with a little information? I have spent some time searching threads but the info is a bit confusing.
1) When building an XR can LE do you HAVE to reflow solder the driver (GD variety)to the bottom lip of the XR can , or can you just AA it down? Does it need to be conductive with the XR can (solder) to work? or can you just glue it down?
2) I have read that only the Downboy converter has to be grounded using the VIN and a notch cut into the can with a wire leading fron the coverter to the can ? so the GD doesnt need this? If you can AA glue the coverter to the XR can does it then need to be grounded as opposed to soldering and no Vin ground needed?
3)do you need to apply a sodler blob to the outside of the GD to make contact with the battery?
4)also , does the PCB the led is attached to (MCPCB650?) have to be soldered tothe top of the XR can on that lip? or can that also be glued?

I have limited skills but was going to put together a LE to use in an Aleph empty head/body and figured it should be easy enough to do myself. Any help is greatly appreciated before I take the plunge.

Anyone? :sigh: nobody has thoughts?

I have epoxied an NG and a FLuPic converter into the cans. One an XR and the other an EScrew can. I did cut notches in them and soldered the ground wire to them. I have also epoxied emitters to the boards. I have a Downboy LE that came from the Shoppe and it does have the neg. wire soldered to the can.

Good questions, I have a couple more.

1. Do you have to buy a specific PCB for the Cree LEd??

2. Does the Shop sell the Crees mounted on the PCB ready for lead connections??


Also due to the rise in LE demand, specially for Cree ones, a tutorial / shopping list , would be great for us modder wannabes...

Thanx for the input Nake, but I dont know if your answers have confused me even more? Sof if you epoxy the board you have to ground and if you solder you dont? (except for the DB?):duh2::shrug:



I can answer one of those questions Cuso. There are a limited number ,last time I checked, of Crees mounted on a PCB650 on the Shoppe. I came across a thread about it with a link yesterday. I think this would make things a little easier in bldg. a LE since you wouldnt have to reflow solder the Cree?

litetube, I hope this post doesn`t end up adding to your confusion. :green:

OK, the link below is great for understanding an Aleph light engine build. That McGizmo guy so.... :thumbsup: Even though it is not an XR-can with a Cree, Don`s explanation with pictures and paying attention to the ground path that is required for the light to work should help you answer most of your questions yourself.
Battery (-) > tailswitch > battery tube > E-can or XR-can > converter > LED
Positive is isolated from the can and flashlight body.
Solder blob on the converter for battery (+) is a yes.
Solder MCPCB650 to the XR-can is a no. I believe the MCPCB is Aluminum.

Now, ignore my rambling nonsense above because but I think you will find the link quite helpful.

http://dmcleish.com/CPF/Aleph-LE-Build-Notes/index.html

litetube said:

Thanx for the input Nake, but I dont know if your answers have confused me even more? Sof if you epoxy the board you have to ground and if you solder you dont? (except for the DB?):duh2:

Click to expand...

Correct, if you epoxy you have to ground. I was just confirming what you read about the DB....looking at the one I have.

thanx Kenster and Nake. Still a bit of an open ended process it seems with the XRcan. I did find that thread on building the LE , and it definitley helps with the basic concept of doing it. I just wish there was an updated How To with the Xr can and the current generations of drivers and LEDs .

I still am not sure but it looks like I could reflow solder the Driver to the can bottom in my toaster oven and not have to VIN ground.

I hate being ignorant:duh2:

I still am not sure but it looks like I could reflow solder the Driver to the can bottom in my toaster oven and not have to VIN ground.

Click to expand...

I don't have oven reflow experience, but I do solder my drivers to the XR can with a small butane hobby torch...

Note: The XR can has a thinner lip, than the E can...

Hi TB. Thank you for the info. You use a blow torch to heat up the Can? Si I am assuming you put a "bead" of solder on the lip and heat the can till it melts and drop your driver in?

Do you Ground VIN ?

Thanx for any add'tl help!!

FWIW, I use a roughly 3 mm long bead of solder paste (Kester R276) between the perimeter ground ring of the board and the lip of the XR-can. I then crank up the iron to 800 deg. and apply localized heat to the can in the vicinity of the solder paste using a large screwdriver-type tip. Even at 800 deg., it takes about 20 seconds to heat sufficiently for reflow given the heat-dissipating mass of the can. I apply pressure from the component side while heating to secure a tight joint.

After cooling, I apply a few dabs of AA epoxy inside the can to fortify the union of the board and the can before fitting the wires. The solder joint can break while fitting other build components if not secured prior to potting.

I've got an idea for my next LE build. I made a small aluminum plate with handles that will go on a burner of my electric stove. With my IR heat gun I can determine when it gets to the temp I want and stabilizes. I will put solder paste on the lip of the can and place the board in it, then put it on the aluminum plate and watch for the solder to flow. I have used the paste to successfully solder an emitter to a small star. I didn't use the stove, but a small butane torch heating the bottom of the star. Like TB said you have to be careful with a torch, hard to get an even heat to what you're working on. Here's the paste I'm going to try it with.

http://www.solder-it.com/solderpaste.asp

Hey Nate. thanx for more thoughts. exactly which one of those solder pastes are you gonna get?

I have used the silver bearing solder so far.

Just to update for any other poor unsuspecting ignorant souls like myself who decide to undertake something like this,


YOU DO NOT HAVE TO GROUND THE LE VIA THE GND VIN TO A NOTCH IN THE XRCAN!!!!!!!!!!!!!!!!!!!!!!!!! with a GD coverter board.

At least not in MY application of this LE

I spent hours into days follwoing MISINFORMATION on how to do this DIY.

Trying to save someone else the headaches if they decide to do this 'cause there is way more MISINFORMATION on here than fact:shakehead

I dont know why this stuff is such a secretive mystery .

I put a few spots of solder on the ground ring of the GD750 first.
Then with flux between the board and can heated it on an electric stovetop on LOW.
The board dropped down flat and I slid it to the side, then lifted it onto a heatsink quickly.
I use the same process to "reflow" a cree onto a mcpcb650. A small even layer of solder on the pcb's 3 sections.
Then heat it and when the solder flows I drop the cree on, quickly center it and slide the pcb-cree off the hot area of the stovetop.
The same could be done using a hot plate and lifting the piece off to cool.

As to the ground path to XR can I've only noticed the GD and Wiz boards have the neg ring on the bottom edge. Madmax, BB, DB ??SOB?? all need to be grounded to the body off the led- as show in McGizmo's instruction link above. But do it below the lip the mcpcb650 sits on basically in the side wall.

A hole could be drilled into the side for this purpose below the threading and the ground wire inserted and soldered closed.

Hi Nein. Thanx for the add'tl info. That would make sense. I have had some experience with the DB in a longbow Mcapsule and in that application the capsule is anodized and isolated.

I used a GD500 in this project thus no need for the extra external ground . Its good to know if in the future I do another with a different board other than the GD or Wiz , I will have to ground to the can.

Thanx for the idea on mounting the Cree. I was thinking of doing it that way.