The Murphy Builders Site

Ive been looking for an oval inspection/access cover template for my cabin floor to no avail.
Does anyone have an oval cover that is preferably still at #40 they could scan; then I can print to use as a template?
I want my covers symmetrical so that they are interchangeable. if not I'll have to get the geometry set out.

Thanks
Monty

Monty,
I don't have a template but you could make a symmetrical covers by making 2 oval shapes and drill one quadrant with holes and then flip the one plate about long axis , drill the mirror half then flip about the short axis and drill the bottom half of holes.

For my normal round templates in the floor I ended up making a 3/16" steel template with both a 6 hole and a 5 hole pattern. The template also a the center hole so I could locate the hole saw on it and I drilled screw holes prior to cutting out large hole since it would be registered about the center.

So you have the other cover to use as a template? This is just about the easiest thing for any human to make. Kids do things like this in art and craft class. I like to use cardboard for free form design. But in your case you want to start with a rectangle with hard easy dimensions. Think round numbers. Draw it out on paper with a ruler or scale to size then make the proper size radius on the ends. Find something in your house that is close or often times the exact size. Like a coffee can or lid from the pantry. If there are bolt holes in the floor. Cut out this design. And fit it to the floor and mark the holes by using a pencil shade on the top side or have someone poke them through from the bottom. Then make a hard template out of cardboard from this paper cut out. Dial it in real nice. There are thicker and thin cardboard types, choose what works best. Make another if you need or as many as it takes. Its super fun and easy. There are tons of metal working videos out there or I can make one and show you. Hell if you're close to me I'll come do it. You'll maybe want to step up and put some type of sticky foam gasket tape on the back side to keep the rattle down and if you really want to get fancy try and roll a bead into it and a raised emboss center shape. All kinds of ideas. But first draw and cut

Thanks,
I took drafting in univ while studying engineering so drawing the template is not an issue. I just wanted covers punched from a CNC so they were interchangeable north south top bottom and with each other. No matter how accurate I draw; the holes will shift some so wanted to remove that step. The folding method may give that repeatable accuracy. I also like the rolled lip idea.

I havent used autocad in many years but
I might have cheat and download Google sketchup.

Spent yesterday mocking up firewall so I can build cowl.
I need to modify stand so it has a bigger footprint and is more stable.
Monty

There are other ways to get a perfect hole spread without cnc or even drill press equipment say you start with the part envelope. The entire cut part before you put on the radius. You can do what's called layout. Paint the part where the holes are going to be with sharpie or dykem. The use a set of dial calipers to mark a + in the x and y axis. Take the top and left side as zero so the top left corner is (0,0) in the Cartesian plane. The set your calipers to the desired hole placement in the x axis say 4.250 inches. Next take one end of the calipers on the flat zero side and the other open end set at desired dimension is used to scrib a line in the paint. Now do the same to the y dimension, say .750 in from the top edge so now you have a + at exactly (4.250, -.750) +/-.005
Lay out all your holes this way then use a punch to dimple them for your drill. This is

Another way is to use whats called tranferpunches. All of this stuff can be bout at big box or hf but I'd get some quality stuff off marketplace or Craigslist

If you want a CNC part you could talk to Perry at Velocity (www.velocitymachining.ca) in Burnside and have it water jet cut. The office sends them parts all the time. They need a .DXF or STEP model to work from. All you would need would be the dimensions of the cover/hole pattern to make the model/drawing.

Otherwise when I want to make something that precise in my shop I print the part drawing 1:1, tape the print to the raw material and centre punch the hole locations, just put crosshairs at the hole centres in your drawing. It's way more accurate than I can do by doing a layout on the part.

If you're an EAA member you can download the full Solidworks suite (3D Professional CAD, finite element stress analysis, fluid flow analysis (CFD) etc.), free as an EAA benefit. It's an education license so the drawings will be watermarked but it's the full Professional package otherwise.

Cheers,

Dave

monty777er wrote: ↑

Fri Sep 18, 2020 4:33 am

Thanks,
I took drafting in univ while studying engineering so drawing the template is not an issue. I just wanted covers punched from a CNC so they were interchangeable north south top bottom and with each other. No matter how accurate I draw; the holes will shift some so wanted to remove that step. The folding method may give that repeatable accuracy. I also like the rolled lip idea.

I havent used autocad in many years but
I might have cheat and download Google sketchup.

Spent yesterday mocking up firewall so I can build cowl.
I need to modify stand so it has a bigger footprint and is more stable.
Monty

Hey Monty

Lance here. if you can pm me or let me know exactly what you want either i can draw it in cad for you or even cut one out.

Lance
613-five 6 1 -8seven 2 8

Thanks Lance that's quite the offer. I'll figure out what I need and let you know.

Today after assembling and disassembling the door posts forward 10s of times and having put project on hold in 2004 with half the gear box upgrafe and belly strap completed i finally riveted the front together.
My proseal that expired in 2001 was hard as a puck so used a marine sealant on belly strap. So yes proseal does expire.