Front Panel Thickness
« on: January 04, 2017, 02:45:18 PM »
Is there a standard for the thickness of a front panel depending on size? I know thicker is usually better in terms of rigidity but I'm debating between 3mm and 2.5mm at front panel express. It's a 3RU panel so I'm worried about too much flexing. I'm also considering the cost and the 6.5 mm bushing length on the alpha pots I'm using. I think 3 is about as thick as I can go unless I add a cavity on the rear of the panel which increases the cost. But if its going to flex then it might be worth it.


What do you guys think?

I've attached a pdf of the panel layout. The shaded area are knobs and meter bezels btw.

Thanks!


ruffrecords

Re: Front Panel Thickness
« Reply #1 on: January 04, 2017, 03:03:34 PM »
If it is supported along the entire length of the top and bottom then it should be no problem at 2.5mm.

Cheers

Ian

Re: Front Panel Thickness
« Reply #2 on: January 04, 2017, 05:05:13 PM »
If it is supported along the entire length of the top and bottom then it should be no problem at 2.5mm.

Cheers

Ian

Hmm..unfortunately it's only supported at the four corners.  The price  difference between 2.5 and 3mm is not so bad but I'm starting think I should go thicker than 3mm.  Do it right or do it twice situation... Does 4mm seem overkill? What about 1mm cavities for the pots? Do you think that be necessary?
Panel with engraving will probably be close to $200 at this point for a one off.

ruffrecords

Re: Front Panel Thickness
« Reply #3 on: January 04, 2017, 05:47:41 PM »
Hmm..unfortunately it's only supported at the four corners.  The price  difference between 2.5 and 3mm is not so bad but I'm starting think I should go thicker than 3mm.  Do it right or do it twice situation... Does 4mm seem overkill? What about 1mm cavities for the pots? Do you think that be necessary?
Panel with engraving will probably be close to $200 at this point for a one off.

4mm thick will not be enough for nearly 19 unsupported inches. Even steel will flex over that length. If it is impossible to support at the top and bottom then you may be forced to go to the audophile thickness of 10mm.

Cheers

Ian

Re: Front Panel Thickness
« Reply #4 on: January 04, 2017, 06:17:48 PM »
4mm thick will not be enough for nearly 19 unsupported inches. Even steel will flex over that length. If it is impossible to support at the top and bottom then you may be forced to go to the audophile thickness of 10mm.

Cheers

Ian

I wouldn't say totally unsupported. There is a chassis behind it and against it. It's only secured at the 4 holes about 17" across and ~4" vertically.

ruffrecords

Re: Front Panel Thickness
« Reply #5 on: January 04, 2017, 07:12:42 PM »
I wouldn't say totally unsupported. There is a chassis behind it and against it. It's only secured at the 4 holes about 17" across and ~4" vertically.

OK, understood. Where it is secured does not matter too much from the bending point of view but where it is supported does. So if you have a chassis running along the top and bottom such that if you press the top middle of the front panel it pushes also directly against the chassis then it is supported in which case you are OK with 2.5mm. Basically if it is supported around its periphery it will be fine. Because it is only 3U high the maximum distance of any unsupported part from a support is 1.5U which is fine for 2.5mm aluminium.

Cheers

Ian

Re: Front Panel Thickness
« Reply #6 on: January 04, 2017, 09:13:21 PM »
OK, understood. Where it is secured does not matter too much from the bending point of view but where it is supported does. So if you have a chassis running along the top and bottom such that if you press the top middle of the front panel it pushes also directly against the chassis then it is supported in which case you are OK with 2.5mm. Basically if it is supported around its periphery it will be fine. Because it is only 3U high the maximum distance of any unsupported part from a support is 1.5U which is fine for 2.5mm aluminium.

Cheers

Ian

Okay that makes sense.
Thanks AGAIN for all of your help.

I could see how a panel only supported on the far ends would need to be very thick

ruffrecords

Re: Front Panel Thickness
« Reply #7 on: January 05, 2017, 03:19:57 AM »
I could see how a panel only supported on the far ends would need to be very thick

This occurs quite often with 19 inch panels that simply fit into a regular rack. They are supported at the left and right ends only and can flex easily in the middle. That is why they are usually made of steel. In one mixer I built I had a rotary pot aluminium panel made this way and it flexed a lot in the middle. I had to add extrusions to the top and bottom to stop it.

Cheers

Ian

johnheath

Re: Front Panel Thickness
« Reply #8 on: January 11, 2017, 10:37:51 AM »
I sometimes use a 15mm wide 2mm thick angle in aluminum that I bolt to the chassi "floor" and the bolt it to the front panel with a small stainless steel 3mm bolt.

That is if you can live with a small bolt in the frontpanel or not. I place it in the middle and make sure to use a good looking bolt that "blends in".

Best regards

/John
Nothing is impossible - It just takes some more time

Re: Front Panel Thickness
« Reply #9 on: January 11, 2017, 12:04:55 PM »
I've seen that done before. While obviously its not ideal it wouldn't have to be obtrusive. I think I'll be alright on this design with 3 mm panel. It's actually just over 3mm at  1/8".  I found a similar panel around the shop and it seemed  like it would be fine I could always add the angle later.

I did however remove the bezels around the edgewise meters and install PEMS on the back side. This allowed me to raise the Main Output knobs a good 1/4". It should be cleaner overall.


johnheath

Re: Front Panel Thickness
« Reply #10 on: January 11, 2017, 12:33:26 PM »
I've seen that done before. While obviously its not ideal it wouldn't have to be obtrusive. I think I'll be alright on this design with 3 mm panel. It's actually just over 3mm at  1/8".  I found a similar panel around the shop and it seemed  like it would be fine I could always add the angle later.

I did however remove the bezels around the edgewise meters and install PEMS on the back side. This allowed me to raise the Main Output knobs a good 1/4". It should be cleaner overall.

Yes… Sometimes when the situation admits it you can use a 15mm wide 1,5mm steel in desired length to make an angle and use a pot or switch to "bolt the front panel to the chassi floor… i.e no extra bolts in the front :)

Best regards

/John
Nothing is impossible - It just takes some more time