how do you guys make holes in metal cabs. is a hand held drilling machine enough for this. How do you get rid of the excess metal that will probably appear on the other side of the hole. How do you tap holes for screws/nuts etc. Is there a diference in handling steel vs aluminium, or sheets vs heatsink. i need to handle this shortly.
DIY: Pass F5 turbo v2 initiated
- Thread starter omishra
- Start date
Drilling method follows - punching dot for bit at centre of the hole position using hammer and punch. Then drilling with required bit under water droplets at that positions. For removal of burr at other end, I used double sized bit under stopping momentum of drill machine with mild force. This give smooth finish. For tapping positions I drilled 1 mm less diameter to max length. Then tapping done with oil applied over tapping head. This action done inline to hole and three turns forward and backward each time removing burr and replenishing oil. Used tool 1,2 & 3 from set for each size of hole. I used 4T engine oil and drill machine at normal drill, no hammer drill.
Working with aluminum is easy but SS is hardest and requires special bits. MS is okay till 1-2mm thickness.
Audiodoc
Well-Known Member
@ Captian. You are right. Hot air being lighter rises and holes on the bottom / sides helps to fill the resulting low pressure by sucking in cold air. This is a efficient non active (no fans needed) means of cooling.
The same principle holds true for vertically aligned heat sinks (Black ones are preferred, those having higher surface area i.e longer fins with serrations perform better).
The same principle holds true for vertically aligned heat sinks (Black ones are preferred, those having higher surface area i.e longer fins with serrations perform better).
To add to what omishra said above:
1) center punch is very critical to get exact drilling position. A punch is nothing but a high speed steel with one pointy end. Mark the point to be drilled with a pencil or marker and punch at this point with a hammer blow to the center punch.
2) drill the hole with a drill bit which is smaller than the final size.
3) repeat the drilling with correct drill bit size.
4) High Speed Steel hand tap like this is more than sufficient to tap the screw thread upto 10-12 mm inner diameter on mild steel plate. Aluminium or brass should be much easier, but stainless steel will be quite a struggle. Make sure that the hole drilled is smaller than the tap by one size.
5) when drilling on mild steel or aluminium, the more critical factor is the force you are putting on the drill bit than the rpm of the bit. Put more force at lower rpm. Higher rpm at low pressure simply heats up drill bit and is not effective.
1) center punch is very critical to get exact drilling position. A punch is nothing but a high speed steel with one pointy end. Mark the point to be drilled with a pencil or marker and punch at this point with a hammer blow to the center punch.
2) drill the hole with a drill bit which is smaller than the final size.
3) repeat the drilling with correct drill bit size.
4) High Speed Steel hand tap like this is more than sufficient to tap the screw thread upto 10-12 mm inner diameter on mild steel plate. Aluminium or brass should be much easier, but stainless steel will be quite a struggle. Make sure that the hole drilled is smaller than the tap by one size.
5) when drilling on mild steel or aluminium, the more critical factor is the force you are putting on the drill bit than the rpm of the bit. Put more force at lower rpm. Higher rpm at low pressure simply heats up drill bit and is not effective.
My cabinet is shaping up @ Om Labs:
Any further progress? Eagerly awaiting the outcome.
What are the dimensions of the cabinet? I'll use it as reference to finalise the dimensions of mine.
+1. Please share dimensions of the cab, if possible with some rough outline drawing as there tends to be confusion with the terms Width, Length, Height.
Box measures externally ~20" (W) X 12" (D) X 6" (H) including heatsinks.
Usable internal dimensions are 11" (W)X 12"(D) X 6" (H) with +-1mm tolerance.
Top and bottom plates overlap heatsinks 12mm as well as front plate (6mm), back plate (3mm).
Mounting scheme - single toroid of 1KVA mounted at shown in picture and other PS PCBs over it by some aluminum support extended from bottom plate to cover that transformer with ~1/2" spacing. (This is not in the picture)
GeorgeO
Well-Known Member
An interesting and unconventional F 5 build from a friend, using MDF
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GeorgeO
Well-Known Member
He initially planned to get a sheet metal chassis but the fabricator backed out, so he went for an alternative solution!
We will be drilling holes for RCA, binding post, IEC socket, power switch, PCB and trafo mounting over this weekend, and hope to give it for anodizing by Monday which in-turn would take around 3 days, it should take around a week after that for biasing and calibration based on the heat generated.
The dimensions are:
Internal WxDxH - 11 x 12 x 6 in.
Outer WxDxH -18.15 x 12 x 6 in.
The 6mm faceplate I got is 6" in height, it should be around 7" so that it could cover the top and bottom plate, I plan to change that in future when I find one with the proper height.
Regards,
sann'
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Since you are not using any frame for fixing the heat sinks and relying on the screws for fixing the cabinet walls, it may be a good idea to use reinforcements at the appropriate places.
This is how Silicon Ray cab has been made: -
Yes, there is reinforcement. Please see those 2 aluminum angles in bottom near heatsink. It will be fixed in such a way that each bottom corner of heatsink will have 3 bolts from 3 directions of X, Y and Z axis. One bolt from front(or back), another from bottom and third from inside towards fin through angles. Also those angles will be bolted to bottom plate (2 at each side) to share some weight of transformer and overall load in bottom plate. Also I feel this should save some life of threading inside heatsink.
Yes any one could be used for speaker and for return use PGND/away from input ground.
couldn't do black
Same heatsinks as Om but 500mm in length (pre cut stocks at local vendor), Monoblocks will be vertical orientation. I cheaped out, got the cabs made form MS rather than aluminium.
The plan is to build the first channel without P3 and the second channel with P3 (see how much i can tweak) and adjust the first accordingly.
I am not in a hurry, am so happy ravaging me Aleph J
The plan is to build the first channel without P3 and the second channel with P3 (see how much i can tweak) and adjust the first accordingly.
I am not in a hurry, am so happy ravaging me Aleph J
I think the heatsink is the same one that Omishra is using.
Edit: Looks like my post has crossed that of Kroyin.
I'm ordering trafos today. Would there be any difference between a single 800 va vis a vis 2 x 400 va trafos?
What are the pros and cons (if any)
Edit: Looks like my post has crossed that of Kroyin.
I'm ordering trafos today. Would there be any difference between a single 800 va vis a vis 2 x 400 va trafos?
What are the pros and cons (if any)
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