How to measure radius of curved corners?

[MarcosD]

Ok I know there’s a lot of smart people in here. I need to figure out the radius of curved corners in the eurobrace opening so I can get a lid custom made. John says the opening is 41.75”x18”. He says the eurobrace is 4”. I don’t think I’ll be able to figure it out based off those numbers and picture but when I get the tank delivered, what measurements/tools do I need to figure it out? I’m lost

 

[Turkeysammich]

I always ask chatgpt. Then I double check my math. Hopefully there’s a starting point.

 

[MarcosD]

I always ask chatgpt. Then I double check my math. Hopefully there’s a starting point.

I’ve never used ChatGPT before but that did it. It gave me a few options for tools to measure radius, going to be ordering them so I have on hand when the tank gets delivered. I’ll make a temporary diy lid while the custom is being done so my clowns don’t jump. Thank you for the lead!

 

[PjFish]

Make a template

 

[MichaelB]

I’ve never used ChatGPT before but that did it. It gave me a few options for tools to measure radius, going to be ordering them so I have on hand when the tank gets delivered. I’ll make a temporary diy lid while the custom is being done so my clowns don’t jump. Thank you for the lead!

With something so precise. Lets say its ceramic you were cutting to make that curve you would make a peice out of card board as one option, in real life you bring the peice outside make small adjustments back and forth to the saw until it fits.

With custom lid you probably only have one shot at measuring it. Maybe get some foldable canvas or something than can be folded a few times, cut out precise shape of it, and mail it to the lid company?

Unless you can make the curves with 100% precise measurements it's risky. And ur a big diyer so you know how many times you have to typically cut a piece to make the perfect curve lol. (Often even then it's never perfect it's merely good enough where we can live with it lol.)

I only worry with a lid a little off you may have a gap or maynot fit flush

 

[PjFish]

Measure the old fashioned way with framing square! But if the radius is not cut perfectly or looks funny then toss the framing square out and make a template which would be an 100% match then send template in unless you digitize the template into a file and email..You can cut templates in half also just have straight cuts..7 bucks at Home Depot template material

 

[MichaelB]

Plus one to a template ***

 

[MarcosD]

With something so precise. Lets say its ceramic you were cutting to make that curve you would make a peice out of card board as one option, in real life you bring the peice outside make small adjustments back and forth to the saw until it fits.

With custom lid you probably only have one shot at measuring it. Maybe get some foldable canvas or something than can be folded a few times, cut out precise shape of it, and mail it to the lid company?

Unless you can make the curves with 100% precise measurements it's risky. And ur a big diyer so you know how many times you have to typically cut a piece to make the perfect curve lol. (Often even then it's never perfect it's merely good enough where we can live with it lol.)

I only worry with a lid a little off you may have a gap or maynot fit flush

Measure the old fashioned way with framing square! But if the radius is not cut perfectly or looks funny then toss the framing square out and make a template which would be an 100% match then send template in unless you digitize the template into a file and email..You can cut templates in half also just have straight cuts..7 bucks at Home Depot template material

Ooh good ideas! Thank you!

 

[richiev]

I always ask chatgpt. Then I double check my math. Hopefully there’s a starting point.

If we created a ChatGPT bot to respond to forum threads, we likely wouldn't need anyone to respond to anything. That's a pro and a con,

I’ve never used ChatGPT before but that did it. It gave me a few options for tools to measure radius, going to be ordering them so I have on hand when the tank gets delivered. I’ll make a temporary diy lid while the custom is being done so my clowns don’t jump. Thank you for the lead!

These tools and the template suggestions are good. As one more possibility, once you get the dimensions you can try and have someone 3d print or CNC a piece to match the measurements, and test that.

I did that when trying to design a custom lid setup for my frag tank. Goal was to do a combo of a mesh lid using standard AL hardware store frames plus 3d printed or CNC'ed pieces for the round corners. I ended up being happy with the basic AL rectangle frame so abandoned it, but making the pieces was helpful.

The 3d printed version has an issue that filament shrinks a bit when printing, but CNC'ing a piece of acrylic wouldn't have that problem. If you figure out dimensions I have a CNC and could attempt to do a test piece if you get a cheap thin piece of acrylic to me.

 

[MarcosD]

If we created a ChatGPT bot to respond to forum threads, we likely wouldn't need anyone to respond to anything. That's a pro and a con,


These tools and the template suggestions are good. As one more possibility, once you get the dimensions you can try and have someone 3d print or CNC a piece to match the measurements, and test that.

I did that when trying to design a custom lid setup for my frag tank. Goal was to do a combo of a mesh lid using standard AL hardware store frames plus 3d printed or CNC'ed pieces for the round corners. I ended up being happy with the basic AL rectangle frame so abandoned it, but making the pieces was helpful.

The 3d printed version has an issue that filament shrinks a bit when printing, but CNC'ing a piece of acrylic wouldn't have that problem. If you figure out dimensions I have a CNC and could attempt to do a test piece if you get a cheap thin piece of acrylic to me.

Thank you for the offer! I might take you up on that, will pm you if that time comes. I’m going to try a mix of the two tools I’m ordering, the template, and framing square method first since those are easy enough to do. If I can get the same radius between all those methods, I’ll feel comfortable with the final number I get. Would be a lot easier if John had the DXF or similar CAD file for the eurobrace part that he was willing to share so I can get the specs off that but I’m not sure if that’s sensitive info.

 

[richiev]

Thank you for the offer! I might take you up on that, will pm you if that time comes. I’m going to try a mix of the two tools I’m ordering, the template, and framing square method first since those are easy enough to do. If I can get the same radius between all those methods, I’ll feel comfortable with the final number I get. Would be a lot easier if John had the DXF or similar CAD file for the eurobrace part that he was willing to share so I can get the specs off that but I’m not sure if that’s sensitive info.

I think the radius of a curve wouldn't be sensitive

 

[MarcosD]

I think the radius of a curve wouldn't be sensitive

Haha that’s what I’m thinking but you never know. I asked for either the file or if he knew the radius and gave me the measurements from front:back, side:side. I told him I needed to know the radius of the curve for the lid and he said he thinks it’s 4”… which isn’t right. At this point I’d feel more comfortable getting my own measurement than having them measure for me. I can understand them not having the file being that the pieces had been previously cut for another build and maybe they just don’t know which file it was. Although, looking through their IG 48x24” with a 4” eurobrace is pretty common, I’m willing to bet they use the same curve radius on their tanks with the same footprint and eurobrace size.

 

[tribbitt]

Take pic from the top, put it into solidworks and adjust radius of some corner until it looks like it fits lol

i am sure there’s a smarter way

 

[H2OPlayar]

Measure the straight part, subtract from the total length, that is the diameter of your circle.

Measure both length and width and average the diameters to make sure you are accurate.

Other ways. Roll a piece of paper into a circle until it fits in the arc, then measure the circle, or flatten the paper out and measure the circumference and divide by pi.

Edit, reading above, I feel good for my future job security as a mechanical engineer...jk

 

[RandyC]

Amazon.com

 

[MarcosD]

View attachment 61599

Amazon.com

Do you mean use this to get the shape of the curve, outline it on a paper, and then get the radius of that?

 

[RandyC]

Do you mean use this to get the shape of the curve, outline it on a paper, and then get the radius of that?

I’d measure all four rounded corners too to make sure they’re the same.

 

[MichaelB]

Last min thought, You also want it like a 1/8th or a 1/16th smaller than the total dimensions so it drops in place easily, not 100% exact or it will be to tight of a fit. You don't wanna have to shove it in or pry it out.

 

[MarcosD]

Last min thought, You also want it like a 1/8th or a 1/16th smaller than the total dimensions so it drops in place easily, not 100% exact or it will be to tight of a fit. You don't wanna have to shove it in or pry it out.

Usuallt I just give them the dimensions of an opening and theyll do the math for the tolerances. For example this is the file for the low boy lid

 

[MichaelB]

Usuallt I just give them the dimensions of an opening and theyll do the math for the tolerances. For example this is the file for the low boy lid

Cool never had anything custom made, i suppose that would definitely have to be on their check list to avoid having lids sent back everyday.