Reparing damaged metal frame of HP 6186C - Page 1
Forum section: electronics / general

author: uoficowboy
author_rank: Regular Contributor
timestamp: May 30, 2013, 07:27:01 am
content: I recently acquired an HP 6186C. When I purchased it, they mentioned that one of the knobs was loose. Turned out that the "knob" was the earth banana jack - and that some of the plastic part of it had snapped, allowing it to move around pretty freely. I removed the jack (which was impressively tricky, due to the damage) and have epoxied it back together. I'm letting it cure overnight - and hope to have it back to normal tomorrow.However, they failed to mention the fairly significant frame damage. I've attached a photo. The frame consists of two plates that are on the right and left sides of the device. Essentially everything is attached to them - so they are very important. One of these plates has a large break in it, as seen in the photo. I'd love to fix this. Any suggestions? Both of these plates were also somewhat bent, but they were fairly easy to bend back into shape by hand.There's also the matter of the voltage limit light not working. I haven't looked at that yet.

author: Paul Price
author_rank: Super Contributor
timestamp: May 30, 2013, 08:51:58 am
content: Beautiful pictures.The frames seem to be made out of pot metal, so a weld would be difficult. You could try taking this piece it to an automotive machine shop or the like, and they might have some ways of fixing this at a reasonable price. I have had some luck with machinists at a local car motor machine shop who enjoyed the challenge and liked to help out people who can appreciate their fine skill.It may seem more trouble than it's worth, but you could also take two thin(width-wise and thickness-wise) small rectangular (steel or aluminum or brass) flat pieces of metal to bridge the gap(the gap itself epoxied together)on each side of the screw holes. Then, by drilling two to four small holes though the added plates on each side of the screw holes, you will be able to then attach the plates securely with small self tapping or screws and nuts. This might brace this frame back into a reasonably funky but workable shape. If you can find copper stock, it can be cut with a scissors, yet could be architecturally strong enough to overlay the brace and hold it together.Be aware that the pieces attached to this brace themselves can hold this broken brace together so that a few drops of superglue may be all that is needed if you don't bounce this power supply around too much.This metal brace idea worked well for my broken arm in which I broke both bones below the elbow. Know any orthopedic bone surgeons?A second choice would be to take some steel, copper or aluminum stock and cut or have it cut to the right shape, drill the holes to match to make another. It is not impossible.Another choice is to find another broken power supply of a similar model and take from two to make good one.

author: robrenz
author_rank: Super Contributor
timestamp: May 30, 2013, 12:49:21 pm
content: I would suggest a slot between the flange on the left and the countersunk hole on the right whose depth is about half the thickness of the frame and about .75 inch long on either side of the break. I would mill it but you could do it with a dremel tool and a decent carbide burr. I does not need to be precise. Then get some unidirectional carbon/graphite strip stock to fit the slot and epoxy it in with a high quality epoxy while the frame is clamped flat.

author: eKretz
author_rank: Frequent Contributor
timestamp: May 30, 2013, 02:38:50 pm
content: That sounds like a good way to do it. I might try TIG brazing or those aluminum "soldering" sticks if it were mine.

author: edavid
author_rank: Super Contributor
timestamp: May 30, 2013, 03:51:27 pm
content: Quote from: Paul Price on May 30, 2013, 08:51:58 amIt's aluminum.

author: ddavidebor
author_rank: Super Contributor
timestamp: May 30, 2013, 04:13:46 pm
content: Aluminium can't broke this way.

author: grumpydoc
author_rank: Super Contributor
timestamp: May 30, 2013, 04:26:47 pm
content: QuoteI think cast aluminium can fracture like this - but I suspect it is cast zinc.robrenz's suggestion for fixing sounds good.

author: SeanB
author_rank: Super Contributor
timestamp: May 30, 2013, 04:32:26 pm
content: Quick one is a 2 part metal loaded epoxy, and apply pressure to it during cure. Works well for me to epoxy LED modules to the heatsinks.

author: edpalmer42
author_rank: Super Contributor
timestamp: May 30, 2013, 04:41:55 pm
content: I had to do a similar repair to the frame of a Dell laptop. I used a Dremel to cut a slot across the break, dropped a piece of steel rod into the slot, and then used JB Weld epoxy to hold it together. I also used JB weld to fix other cracks in the same laptop. Everything's still holding together after a couple of years. I can't say enough good things about that epoxy.Ed

author: Len
author_rank: Frequent Contributor
timestamp: May 30, 2013, 04:46:51 pm
content: Quote from: grumpydoc on May 30, 2013, 04:26:47 pmThere's one way to find out, but afterwards you have to run naked through the street shouting "Eureka!"

author: G7PSK
author_rank: Super Contributor
timestamp: May 30, 2013, 05:43:26 pm
content: That looks like mazak to me so it wont weld as it contains a high level of zinc. The best bet is to drill small holes into the fracture faces such that you can insert pins and the glue it with epoxy resin, not the fast set type as that is weak but the old fashioned slow set one, heat it in an oven at around 120 deg C to get a fast cure, this will also give the greatest strength, I have fixed all sorts this way including drive pulleys and not had a subsequent failure of the item.

author: robrenz
author_rank: Super Contributor
timestamp: May 31, 2013, 02:25:08 pm
content: Linkto McMaster-Carr page with carbon fiber bars. The .125 x .325 x 12 is only $7.38