Author Topic: Experience with PuHui T937/T937M or Charmhigh BTRRO-420 (reflow oven)?  (Read 2920 times)

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Offline Florian_

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Experience with PuHui T937/T937M or Charmhigh BTRRO-420?

At office we have a Madell SMD-2007 IR + hot air reflow oven. It works fine, but the seller margin is to high, so that the product gets to expensive for private use.

I am searching one for privat use. 1000 EUR ($) with duty and VAT are ok.
IR + hot air.

I have found PuHui T937/T937M or Charmhigh BTRRO-420 which should have IR + hot air.
Have someone else one of these ovens? How are your experience? Or an other one about 1000 EUR ($).

Best regards,

Florian
« Last Edit: March 24, 2017, 05:38:31 pm by Florian_ »
 

Offline krtkr

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Re: Experience with PuHui T937/T937M or Charmhigh BTRRO-420 (reflow oven)?
« Reply #1 on: November 05, 2017, 06:59:44 pm »
Hi Florian,

any luck in getting T937 or BTRRO-420 ovens? I am considering to try one of them. Any experience using them is quite interesting for me.

Regards,
krtkr
 

Offline Simon

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Re: Experience with PuHui T937/T937M or Charmhigh BTRRO-420 (reflow oven)?
« Reply #2 on: January 05, 2018, 09:01:17 pm »
I'm looking at these too, are they any good ? I am always nervous about what they mean by "effective soldering area" is it simply the drawer size of the actual area that will be properly heated for soldering. I have one of the small units that came out a few years ago that is 800W and it has two bulbs if you don't put the boards between them it does not work so only 30% of the draw area is actually useable.
 

Offline JPlocher

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I've had my CHM/BRTRO 420 for 2+ years now, and was planning on upgrading it with Blair's Blazing BRTRO board (https://github.com/bleckers/brtro-420-better-blazin/wiki), when the main controller died.  The symptom was that, after heating, one of the elements would no longer turn off - which made for a batch of broiled boards before I detected the problem  :-[

I took the system apart, and found a toasted driver mosfet with burnt traces - a sketchy board design at the least.  From Blair's blog on HAD, the controller uses an obsolete MCU, which reinforces the low cost driven nature of the machine.

In these two years, I've processed thousands of boards, and found a couple of issues/constraints:

The edges of the tray are IR shadowed, and don't reflow well.  While I can fit a 3x3 array of 10cm panels onto the tray, I got many failed reflows on the outer perimeter - so I now only do a 2x2 array in the middle of the tray.

I switched to GC-10 leadfree paste - and getting the oven dialed in to handle it was a pain - the UI for setting curve temps and times is a disaster, especially coupled with the poor thermocouple placement and accuracy.

Now that it died, I'm going to replace it with a T937M - the larger tray should let me go back to a 3x3 panel array AND leave enough slop around the edges to avoid the cool areas.

   -John

« Last Edit: March 31, 2021, 07:26:39 pm by JPlocher »
 


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