Cobs Suck !!

Richard Drysift

Well-Known Member
I can say I’m very happy with my Timber COBs, they are vero29 @ 3500k. They outperform a 600w HPS eye hortiluxe. I admit they run hotter than expected but stay in the mid 80s even during the hot weather. Not really much cooler than my old HPS with a ducted hood. Just because you had a sucky thing happen doesn’t mean all cobs suck in general.
 

Southside112

Well-Known Member
I can say I’m very happy with my Timber COBs, they are vero29 @ 3500k. They outperform a 600w HPS eye hortiluxe. I admit they run hotter than expected but stay in the mid 80s even during the hot weather. Not really much cooler than my old HPS with a ducted hood. Just because you had a sucky thing happen doesn’t mean all cobs suck in general.
Agreed. Poorly worded thread. Cobs don't suck ive just had a lot of issues with mine.
 

RainDan

Well-Known Member
Just want to share my experiences with cob led's so far. So I have been running cobs in addition to other white led's for 4 years now.
Vero 29's to be exact. 4 years ago I bought a Timber 4vs which is a 400w 4 vero29 unit. I have replaced all 4 cobs already due to burning out and tonight 2 more burned out on me. 2 of the original cobs were replaced with graumaus pucks. So I have 2 pucks and 2 vero 29's on the unit. My current grow is in flower and stretching at the moment. I raised up my light like 6" tonight and got my par meter out. Turned up the power on the unit from like 60% power to like 80% power. Instantly smelled a burned electronic smell followed by flickering lights. Boom both cobs burned out and went dark. Took out the unit to much inconvenience as I have 4 flowering plants in my grow area. They were all burned up melted and black around the cobs.

Bottom line imo is cobs generate way too much heat in too small an area. 100w of cobs concentrated to an area the size of a key lime. Vero 29 cobs are the only ones to my knowledge that can run constant 100w most others run @ 50w. So this might just be a vero issue. But numbers don't lie. 6 burned out vero 29 cobs in 4 years.
I placed an order for 2 more graumaus pucks from rapid led tonight. So my unit will be a 400w 4 graumaus puck moving forward.

Never had an issue with the pucks or a 240w qb I have only cobs. So to anyone who reads this do yourself a favor and go the qb, strip or puck route. Save yourself all the hassles ive had to deal with. Thanks.
Hello @Southside112

I saw your post and would like to comment on your experience. We have done extensive testing on our current design, which has been in production for 4+ years with little/no change required to the design.

We have thousands of lights just like yours in service in a variety of different types of installations - I can recall no more than a handful that have had any issues, and most common amongst them were failed fuses. We very, very rarely encounter failed COBs as we source heat sinks that are designed, engineered and purpose built for the Vero29 operation @ 100 watts/COB.

While I do not recollect your actual issue, I have no doubt that you sent your lights to us and that we serviced them appropriately. It seems based on the (1) picture you posted that there are a variety of issues with the rebuild you attempted:

1. It appears the COB wires were cut rather than removed appropriately. This makes re-installation prone to error as the strip length of the wire must be correct to avoid shorts. Re-application of thermal paste is also critical - we recommend Arctic Silver 5 installed correctly for LED longevity and proper thermal management.

2. You are attempting to operate the GrowMau5 pucks in combination with the COBs, although they have different drive voltages. Additionally, per the picture it appears that the pucks are not mating correctly to the heatsinks.

3. Your light has a dimmer that is designed to operate with all (4) COBs running at the same time. Alterations to the design will also effect the performance of the light.

In the future it would be appreciated if you would contact us directly for any modifications, or assistance with changes to your light. This is not only for the performance aspect, but most importantly for your safety.

COBs continue to be a proven performer and have many attributes that mid power diodes do not - and vice versa. There is no one size fits all solution which is why the consumer has so many good options to select from in the marketplace today.

Have a good day.

Take care,
Dan
 
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Southside112

Well-Known Member
Hello @Southside112

I saw your post and would like to comment on your experience. We have done extensive testing on our current design, which has been in production for 4+ years with little/no change required to the design.

We have thousands of lights just like yours in service in a variety of different types of installations - I can recall no more than a handful that have had any issues, and most common amongst them were failed fuses. We very, very rarely encounter failed COBs as we source heat sinks that are designed, engineered and purpose built for the Vero29 operation @ 100 watts/COB.

While I do not recollect your actual issue, I have no doubt that you sent your lights to us and that we serviced them appropriately. It seems based on the (1) picture you posted that there are a variety of issues with the rebuild you attempted:

1. It appears the COB wires were cut rather than removed appropriately. This makes re-installation prone to error as the strip length of the wire must be correct to avoid shorts. Re-application of thermal paste is also critical - we recommend Arctic Silver 5 installed correctly for LED longevity and proper thermal management.

2. You are attempting to operate the GrowMau5 pucks in combination with the COBs, although they have different drive voltages. Additionally, per the picture it appears that the pucks are not mating correctly to the heatsinks.

3. Your light has a dimmer that is designed to operate with all (4) COBs running at the same time. Alterations to the design will also effect the performance of the light.

In the future it would be appreciated if you would contact us directly for any modifications, or assistance with changes to your light. This is not only for the performance aspect, but most importantly for your safety.

COBs continue to be a proven performer and have many attributes that mid power diodes do not - and vice versa. There is no one size fits all solution which is why the consumer has so many good options to select from in the marketplace today.

Have a good day.

Take care,
Dan
Thanks for the reply Dan. I'll be in touch.
 

Southside112

Well-Known Member
Dan is correct the graumau5 pucks are too large to fit the Timber heatsinks. They don't sit completely flush. Also I'm no electrician and did not know that installing the pucks would affect the cobs on the other side. Dan is assisting me with my issues and I will update the outcome. Thanks everyone that read and commented on this thread.

I also have a Timber 2vl so I definitely believed in Dans products and have used them to grow nice plants.
 

pich

Active Member
2. You are attempting to operate the GrowMau5 pucks in combination with the COBs, although they have different drive voltages. Additionally, per the picture it appears that the pucks are not mating correctly to the heatsinks.

I was thinking of doing something similar. Is it okay if wired in series with constant current driver?
 

Southside112

Well-Known Member
To be fair to myself I would never have installed the pucks in the first place had the original cobs not burned out. So there definitely had been issues with my unit.
Now that I recall I had to send the 2vl model back as well as the reflectors melted. Dan should at least acknowledge the melted reflector issues.
 

Southside112

Well-Known Member
2. You are attempting to operate the GrowMau5 pucks in combination with the COBs, although they have different drive voltages. Additionally, per the picture it appears that the pucks are not mating correctly to the heatsinks.

I was thinking of doing something similar. Is it okay if wired in series with constant current driver?
I'm having a private conversation with Dan now about using the graumau5 pucks on all 4 cob sites. Will see what he says.
 
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