How do you make clean cutouts for HMI?

strantor

Member
Join Date
Sep 2010
Location
katy tx
Posts
401
When cutting square holes in an enclosure to mount an HMI, what method do YOU use? I've tried Jigsaw, angle grinder with abrasive cut-off disc, plasma, etc. and all of them damage the surrounding paint in some way. Is there a "trick of the trade" to do it cleanly? My best results have been obtained using a jigsaw, cutting against duct tape applied to the panel. The duct tape is about 75% effective in preventing the expelled chips being ground against the paint by the jigsaw platen.
 
Jig saw and tape the template on with blue painters tape. The blue painters tape is transparent enough to see through to the template but tough enough to keep the jig saw from marring the enclosure. Set the enclosure on an angle and cut from the top down. The vibration of the saw along with the angle of the enclosure will allow the chips to run off away from the saw base. This keeps the chips from damaging the enclosure.
 
If using a jigsaw if possible, cut from the inside as the blade cuts on the up stroke, not perfect but better.
Also, the bed of the jigsaw often marks the surface so cutting from the inside reduces this but again masking tape over the whole area where the jigsaw bed will travel is a must
I have also had success with a nibbling tool but you have to remember that it takes out quite a large area i.e. 4-5mm compared to 1mm of a jigsaw blade.
 
Mark the cutout with a fine tip sharpie. Drill the corners with a small (1/8") bit. Drill a larger hole (bigger than the width of a jigsaw blade) in opposite corners near the edge Apply multiple layers of painters tape just outside the cutout so you can see the line. Cut carefully. Hit the rough edges with a flapper disc to deburr it.
 
I think Jig Saw is the best, as it is easier to control, the downside is chips and jagged edges that you have to debur. I have also used Angle Grinders and Die Grinders with cut off wheels you get a clean cut but you have to be careful not to get the metal too hot and also to control the blade and not let it over shoot.


really though I have always wanted to try a hand held plasma cuter with some remade template guides.
 
I always use a cut-off wheel on a hand grinder. I get good results.

On the cosmetic side I always cut out before painting the panel (if it is getting painted) otherwise stainless and powdercoated panels clean up pretty good.

If it is a behind-the-plate installation of a monitor I always use push on edging from McMaster Carr
 
Metal cutting circular saw:

https://www.milwaukeetool.com/Products/Power-Tools/Metalworking/Metal-Cutting/2782-20

Gives a clean edge that looks machined. Way faster than jig saw or side grinder. BUT.... not for the faint of heart. Can be dangerous by kicking back if you attempt to pull backwards.

If you have a couple weeks, you can send Saginaw Controls (maybe others vendors too) a CAD drawing and they will give you a quote for them to machine cut before being painted. Better than any option and not too expensive.

A new method I recently tried for smaller holes was to machine a plastic guide plate, then use a 1/4" end mill in a router. Although the cut was clean and straight, I do not recommend because it is loud and slow.
 
Last edited:
Depends on how deep your pockets are (and how many a year your doing) but a water jet will give you the best and cleanest edge, there are companies that will also do it for you if you have a cad layout, I have used a plasma cutter many times and if its setup right you will not have any slag and very minimum paint issues.... I use plastic enclosures now :D
 
+1 on the waterjet, GIT. I found a small but very well-equipped fab shop locally the has a waterjet table. Gave them an AutoCAD drawing of the panel, with all the holes laid out (switches, pilot lights, meters as well), IIRC I took it in on one day and picked it up the next, and cost less than $100. Very clean and accurate. I used to do it with the Metabo grinder and a metal-cutting wafer disc, but as Archie says, it is definitely NOT for the faint of heart.
 
Last edited:
We do it with a plasma cutter. Made an aluminum jig for our most common sizes that is oversized to accommodate the bushing on the cutter. Welder just whips them out. Shop used to do them with the jig saw or on a mill when the panel would fit. They always get scratched even with good amount of tape.


Cheers
 
When cutting square holes in an enclosure to mount an HMI, what method do YOU use? I've tried Jigsaw, angle grinder with abrasive cut-off disc, plasma, etc. and all of them damage the surrounding paint in some way. Is there a "trick of the trade" to do it cleanly? My best results have been obtained using a jigsaw, cutting against duct tape applied to the panel. The duct tape is about 75% effective in preventing the expelled chips being ground against the paint by the jigsaw platen.

Laser, but then gain we do custom build all our enclosures !

In a previous life i just used use masking tape on the door, mark for the size, drill the corners then jigsaw and cleanup with a file.
 
+1 on plasma cutters. If you are getting too much burning of the paint at the edge of the cut, you need more practice. I practiced on scrap for a while before I figured out the right balance between heat and line speed to achieve no more than about 1/8 inch paint burn back along the edges. I also made aluminum templates for repeat installs and the aluminum helps to keep the burning in check. Water jet was good too, but has accessibility to that technology changed in the last 20 years? When I got out of the panel building biz, water jet cutting systems were big huge expensive CNC machines. If someone makes one now that is as portable and cheap as a plasma cutter, I’d go for it.
 
Water jet was good too, but has accessibility to that technology changed in the last 20 years? When I got out of the panel building biz, water jet cutting systems were big huge expensive CNC machines. If someone makes one now that is as portable and cheap as a plasma cutter, I’d go for it.

I think water jets are going to be like 3d printers someday in the near future this one is a little on the smaller side but looks nice https://www.wazer.com/

There is a video on it here https://www.youtube.com/watch?v=PGiXRvXYuGQ and they show their software interface if you scroll down on the right, looks easy

You can buy a large plasma cutter dirt cheap now, well compared to what they were and I think the water jets will get cheaper in time.
 

Similar Topics

Curious if anybody has any documentation or input on what this exactly does . Many times when I have a problem it is one of the first things tech...
Replies
3
Views
2,313
Hi All, I was assigned a project to help to reduce cup scrap during a clean out process. The cups travel on four conveyors prior entering robot...
Replies
21
Views
5,196
Hi all, The plant I work in seems to have a lot of contamination that affects our Ethernet connectors on all of our control panels. We are...
Replies
3
Views
1,595
I've probably been to a dozen different tube/hose, and wire/cable extrusion plants and they all have in common a haphazard arrangement of...
Replies
7
Views
3,009
Because of the COVID19 issue, people are ore obsessed with cleaning. Recently , we had a problem on a machine and traced it back to an operator...
Replies
24
Views
4,937
Back
Top Bottom