Author Topic: Convert stock Benbox laser unit to higher power diode.  (Read 10904 times)

Lob0426

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Convert stock Benbox laser unit to higher power diode.
« on: September 22, 2016, 04:06:51 PM »
Opening thoughts;
It took 5 days for me to get the stock "host" out of the heat sink. My host is aluminum. I had to soak it in finger nail polish remover. And I only was able to remove it with snap ring pliers. Even then it took some work to get that first movement, then it came out relatively easy. Those were suggested by a fellow forum member @kn4ud. The pliers probably would have worked a couple of days before.

This unit was a 500mw stock laser diode/host/heat sink. The stock laser diode was 3.8mm sized package (TO38). I intended to use the lathe to open the host up for a 9mm (TO5) diode. After I removed the host I knocked out the diode. I saw that there was a brass adapter from 5.6mm (TO18) down to 3.8mm. I knocked that adapter out and it exactly the right size for a 5.6mm diode.  There are a number of diodes in this size from 1W to 2W. And these are inexpensive to buy.

I have decided to use one of the M140 2W diodes in this housing. There are two reasons for this change. One is the host is aluminum. The higher powered NDB7875 (3W) needs more cooling. The fact that this will give those with these low powered unit a path, that does not need machining, for a major power upgrade. This should be true of many of the stock units.

I have a 1.8A Super-X Drivers to use with the M140 diodes.

If you have disassembled a stock Benbox laser unit, or another kit laser unit, please report on the diode size, host material (aluminum, copper, brass) and wattage. This will help others to know what they can do to upgrade their units. See link below if you need help in figuring the size.
http://www.us-lasers.com/images/5.6mm%20laser%20diode%20pkg%20size.jpg

I will post some pictures later. I hope this will help others upgrade their units for better performance.
« Last Edit: September 22, 2016, 05:27:15 PM by Lob0426 »
Richard
A5 2.5W w/homing switches on L7
A5 2W diode self upgraded from stock 500mw
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Agastar

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Re: Convert stock Benbox laser unit to higher power diode.
« Reply #1 on: September 22, 2016, 04:47:28 PM »
Thanks! I have the 500mW diode as well and I was wondering if my m140 diodes would fit. If mine has the adapter as well then I may just be in luck too.

I can share my experience here as well.

Lob0426

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Re: Convert stock Benbox laser unit to higher power diode.
« Reply #2 on: September 22, 2016, 05:20:19 PM »
Thank you Agastar!

I hope you see the same thing. After removing the lens you could see the silver "can", of the diode, and a brass border around it. The threaded host was Aluminum. You should be able to see the same thing if you remove the lens.

The quality of the Heat sink looks good on the outside. But the bore shows that it was bored from both ends and the bores were not quite in line. But then what should we expect from these inexpensive components. The Super X drivers are really small. They fit into the rear compartment of the 12mm host modules. I may just build an aluminum heat sink to mount it in the Laser assembly. Maybe drill a couple of holes to allow some air to pass through above the host.

There is an O-ring on the lens but it is not thick enough to steady the lens assembly. I will see what I can do about tightening that up before re-assembly.

Any thoughts on this people?
« Last Edit: September 22, 2016, 05:29:14 PM by Lob0426 »
Richard
A5 2.5W w/homing switches on L7
A5 2W diode self upgraded from stock 500mw
Printrbot Play. Ext bed, integrated tablet control.
Printrbot Simple Metal
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Agastar

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Re: Convert stock Benbox laser unit to higher power diode.
« Reply #3 on: September 22, 2016, 05:51:01 PM »
Yeah I think you just described mine. Mine also has the O-ring and it wiggles around. Sad part is I think it sits off center too because when I move it around the dot actually gets sharper. This might explain why it's only reading 300mW on the power meter too.

My M140s came in today and I'm tempted to do it but until my driver is ready I would be without a laser lol.

Lob0426

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Re: Convert stock Benbox laser unit to higher power diode.
« Reply #4 on: September 22, 2016, 06:11:24 PM »
The stock lens is a single acrylic lens. I found the DTR Laser lens package fits into the stock Host. It is a three glass element lens unit. Basically the stock lens works, that is about all you can say for it.

I wish you had one of the DTR's lens. It would be interesting to see if the brightness went up or down. Also remember that the diodes do not always meet their rating. Some are low and some are high. Then there is a loss as all lenses have some inefficiency.

The SuperX drivers are adjustable, I just do not have the stuff to adjust them. They have a pot but I do not have a way to measure the amps out. Mine, for the M140's, are set to 1.8A by DTR. I do not know If I would trust putting the NDB7875 into the stock Aluminum host. I could drill out the host then make a brass press in to fit the NDB into but is it worth the work?

I will be putting it together soon. Still cleaning the white crap out of everything! My host threads are completely full of the stuff.
Richard
A5 2.5W w/homing switches on L7
A5 2W diode self upgraded from stock 500mw
Printrbot Play. Ext bed, integrated tablet control.
Printrbot Simple Metal
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Agastar

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Re: Convert stock Benbox laser unit to higher power diode.
« Reply #5 on: September 22, 2016, 06:32:56 PM »
I had 3 of the 12mm host and 3rlement glass lenses in my shopping cart but I traded them for more of the $20 used M140 diodes instead.

I thought the aluminum would not be as good too but after reading DTRs website and why he switched to aluminum back halves on his hosts I'm not so sure now.

I'll see if I can find the page that mentioned this.

Agastar

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Re: Convert stock Benbox laser unit to higher power diode.
« Reply #7 on: September 22, 2016, 06:41:12 PM »
And here is a page with heat transfer rates for different materials.
http://www.physicsclassroom.com/class/thermalP/Lesson-1/Rates-of-Heat-Transfer

So copper is better than aluminum and brass is worse than either of those. I guess he is using aluminum to save on cost but netting a total gain over hosts made of brass.

Lob0426

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Re: Convert stock Benbox laser unit to higher power diode.
« Reply #8 on: September 22, 2016, 06:45:30 PM »
Here is a pictures of the new components I am going to install.

Price;
M140 diode from DTR Laser     $34
Super X driver from DTR Laser $26 no wires
Three Element glass lens        *$8.60
                                             
Note: I could not find the 3 Element lens by itself so the price is for a module with the lens. A "pulled" diode would have been $20.

EDIT: I found the lens, it does not have the knurled ring on it that the others have.

The Aluminum back half's do not worry me too much. Mounting the Diode in Aluminum does a bit, in the higher wattages. The copper moves heat faster than Aluminum. I bought some of the copper back half's as they were only $6 for 3. Just more heat sump area to soak up the extra heat.

I think the M140 will be fine in the stock host. But the NDB7875 costs more so I want a little more insurance when it comes to transferring the heat away!
« Last Edit: September 22, 2016, 07:03:26 PM by Lob0426 »
Richard
A5 2.5W w/homing switches on L7
A5 2W diode self upgraded from stock 500mw
Printrbot Play. Ext bed, integrated tablet control.
Printrbot Simple Metal
USA

Lob0426

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Re: Convert stock Benbox laser unit to higher power diode.
« Reply #9 on: September 22, 2016, 07:19:09 PM »
A little more for you. I was able to remove the knurled focus ring from the DTR lens package. I also was able to remove the stock lens knurled ring. I then swapped them around. So the Laser module will look stock when it is completed.

This means you can buy the bare 3 element glass lens package and use the knurled knob from the stock unit!
Richard
A5 2.5W w/homing switches on L7
A5 2W diode self upgraded from stock 500mw
Printrbot Play. Ext bed, integrated tablet control.
Printrbot Simple Metal
USA

Agastar

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Re: Convert stock Benbox laser unit to higher power diode.
« Reply #10 on: September 22, 2016, 07:31:45 PM »
Nice work! So how does the DTR lens assembly fit without the O-ring?

Lob0426

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Re: Convert stock Benbox laser unit to higher power diode.
« Reply #11 on: September 22, 2016, 07:40:14 PM »
About the same as the stock one, loose. I think this is a call for Teflon tape! LOL

That should tighten it up and center it. It should turn smoothly. Some thin Kapton tape may work well also.
« Last Edit: September 22, 2016, 11:27:33 PM by Lob0426 »
Richard
A5 2.5W w/homing switches on L7
A5 2W diode self upgraded from stock 500mw
Printrbot Play. Ext bed, integrated tablet control.
Printrbot Simple Metal
USA

Agastar

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Re: Convert stock Benbox laser unit to higher power diode.
« Reply #12 on: September 22, 2016, 07:42:52 PM »
Teflon tape sounds like a winner to me.

Lob0426

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Re: Convert stock Benbox laser unit to higher power diode.
« Reply #13 on: September 22, 2016, 07:44:40 PM »
I don't know about you Agastar!

One day you are digging deep into scoping signals the next you are whole hog Red Neck repair!

LOLOLOLOLOL!!!!
Richard
A5 2.5W w/homing switches on L7
A5 2W diode self upgraded from stock 500mw
Printrbot Play. Ext bed, integrated tablet control.
Printrbot Simple Metal
USA

Agastar

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Re: Convert stock Benbox laser unit to higher power diode.
« Reply #14 on: September 22, 2016, 08:00:25 PM »
Ah shoot, you haven't even seen my use of duck tape lol