Panel Building

[padees]

357WH12 Self Drilling Screw, Washer Head, 8Gx12mm

What do you do with the metal chips that are bound to get stuck in the works, and potentially work their way into the electronic hardware?

I think those may be meant for other tasks, and not in control panels.

 

[brendan.buchan]

What do you do with the 'metal chips' when you drill and tap?

I do the same..

Edit: Smart-arse mode disengaged:

These are used for mounting ducting and din rail. It is easy to vacuum, blow-off or sweep up any swarf at this stage.

For mounting things like heavy drives, transformers, etc. our standard is to drill and tap.

This type of self drilling screw is used very commonly in Australia for control panels. It seems you yanks love to drill and tap everything. Don't get me started on slotted head screws and imperial thread sizes.

 

[Boorabee Parker]

What do you do with the 'metal chips' when you drill and tap?

I do the same..

Edit: Smart-arse mode disengaged:

These are used for mounting ducting and din rail. It is easy to vacuum, blow-off or sweep up any swarf at this stage.

For mounting things like heavy drives, transformers, etc. our standard is to drill and tap.

This type of self drilling screw is used very commonly in Australia for control panels. It seems you yanks love to drill and tap everything. Don't get me started on slotted head screws and imperial thread sizes.

The reason yanks drill and tap everything is for earth bonding. In oz as you know we have a earth bar, but have a look at a yank panel and there is none.

Pearson packaging (USA) build there machines like this, and this is how they end up installed in oz.

I use button techs, but old school panel builders in oz will drill and tap. This is usually specified or used to by public works departments.

 

[Tharon]

The reason yanks drill and tap everything is for earth bonding. In oz as you know we have a earth bar, but have a look at a yank panel and there is none.

Pearson packaging (USA) build there machines like this, and this is how they end up installed in oz.

I use button techs, but old school panel builders in oz will drill and tap. This is usually specified or used to by public works departments.

I'm pretty sure that we are not allowed to use mounting screws as grounding paths. I have a ground bar located in the corner of each of my panels. And use either galvanized back panels or remove the paint beneath the mounting location of the grounding bar and underneath one of the mounting locations of the back panel to the panel.

The reason I drill and tap all of my back panel mountings is because if I ever have to remove something, drilled and tapped fasteners remove a heck of a lot easier than a self tapper which stops about 1/8 to 1/4" (3-6 mm) from actually being removed and I then have to grab it with a pair of pliers and wiggle it out of the hole. I did meet one person who used self-tappers, but after he mounted everything, he went back behind the back panel and cut off all the drill tips of the self tappers... not sure how well that worked out of him.

I always felt that self-tappers on a back panel were a (not to offend) "lazy" route. Like when I go to remove a bracket from a machine and find that the maintenance crew welded it in place... they didn't want to take the time to do it "right" and drill and tap instead.

Measure/Mark all the holes, drill, a quick, light chamfer to remove any burrs, tap the holes. Usually use 10-32 screws. I prefer them over the coarse thread, a bit more bite. Pan Head, Phillips. Don't think I own any slot screws.

 

[Epy]

The reason yanks drill and tap everything is for earth bonding. In oz as you know we have a earth bar, but have a look at a yank panel and there is none.

Pearson packaging (USA) build there machines like this, and this is how they end up installed in oz.

I use button techs, but old school panel builders in oz will drill and tap. This is usually specified or used to by public works departments.

Though I have yet to put an earth bar in any of my personal boxes, us yanks do use them. Control panels built at Diamond Power in Ohio (used to work there) use them, for one.

I make pretty small boxes and I've gotten fond of using the 3-level ground push-in terminal blocks from Phoenix Contact. I'll bunch them up and use that as the star point.

 

[Boorabee Parker]

I'm pretty sure that we are not allowed to use mounting screws as grounding paths. I have a ground bar located in the corner of each of my panels. And use either galvanized back panels or remove the paint beneath the mounting location of the grounding bar and underneath one of the mounting locations of the back panel to the panel.

The reason I drill and tap all of my back panel mountings is because if I ever have to remove something, drilled and tapped fasteners remove a heck of a lot easier than a self tapper which stops about 1/8 to 1/4" (3-6 mm) from actually being removed and I then have to grab it with a pair of pliers and wiggle it out of the hole. I did meet one person who used self-tappers, but after he mounted everything, he went back behind the back panel and cut off all the drill tips of the self tappers... not sure how well that worked out of him.

I always felt that self-tappers on a back panel were a (not to offend) "lazy" route. Like when I go to remove a bracket from a machine and find that the maintenance crew welded it in place... they didn't want to take the time to do it "right" and drill and tap instead.

Measure/Mark all the holes, drill, a quick, light chamfer to remove any burrs, tap the holes. Usually use 10-32 screws. I prefer them over the coarse thread, a bit more bite. Pan Head, Phillips. Don't think I own any slot screws.

I agree self drillers / tappers are the lazy route. I use them, but mark out all equipment / duct first, pull it all out then drill and clean up any swarf before reinstalling.

We are not allowed to use the panel as an earth path, but it has to be earthed.

 

[Boorabee Parker]

Though I have yet to put an earth bar in any of my personal boxes, us yanks do use them. Control panels built at Diamond Power in Ohio (used to work there) use them, for one.

I make pretty small boxes and I've gotten fond of using the 3-level ground push-in terminal blocks from Phoenix Contact. I'll bunch them up and use that as the star point.

Yes I should have said the American panels I have come across. The English panels are earthed similar to ours.

 

[AustralIan]

Any metric fastener should do it.
Did you draw a panel layout with mounting hole locations in cad?
If so print it out real size ($1 at your local print studio) and duct tape it to your panel. Drill and tap.

 

[BryanG]

This self taps but does so by rolling the thread rather than cutting, so no metal bits to worry about. They are threaded to the end and so are easy to remove. And as the name mentions they are 'tite', no washers or glue required to keep them in place. Drill the right sized hole, screw these in and the job is done.

http://www.taptite.net/taptite/product.asp

 

[BITS N BYTES]

We ALWAYS use screw and lockwasher. BUT the lockwashers have a tendency to get lost [i.e. fall or get lost into nasty places likee cooling slots in drives, power supplies etc.].
We now use a variety of sizes of combination Steel Pan Head Machine Screw With Narrow Conical Spring Lock Washer. Washer NEVER falls off.

 

[Phil Buchanan]

Don't use self tapping screws as they get loose and are hard to remount in the same hole and make them hold well if you ever have to move the rail for any reason.

IMHO the self tapping screws do not look professional.


I use 10-24 or 10-32 (depends on panel thickness) button head screws with an Allen head so you need a T-Handle Allen wrench to install.

I use the Black oxide coated type for normal steel panels and the stainless type for stainless panels.

If you search the forums there is an old thread that has a mountain of good tips for panel building that many members contributed to so that may be a great resource for you.

 

[BryanG]

Don't want to start a fight here, but..... Do use self tapping Taptites they will save you a lot of time and can be unscrewed and re-screwed as often as you like.

 

[Phil Buchanan]

At the end of the day it's about what your customer wants. Some people use self tapper but I never would and I would not accept a panel from a panel builder who did.

They would find themselves doing a lot of rework.

 

[jraef]

"Machine screws" are called that because the threads are designed to resist backing off under vibration. Sheet Metal (self tapping) screws are not.

There are self tapping machine screws, that's what I use. The first few threads are tapered and somewhat hexagonal with little slots cut into them for the swarf. You still have to drill the hole first, but not tap it and the screws stay in.

That said, I use Tek Screws for duct all the time. it's not subject to vibration as much as heavier and "clunking" devices in a panel.

 

[Boorabee Parker]

Any metric fastener should do it.
Did you draw a panel layout with mounting hole locations in cad?
If so print it out real size ($1 at your local print studio) and duct tape it to your panel. Drill and tap.

A great idea, but I could have the panel built by the time I did the drawing and drove the 70 kilometer round trip to our local print shop.

If I ever move into the city away from my country customer base I will give it a try.