Drawing Arches 2 - Segmental Arch

[@danoking69]

If you guys happen to forget stuff easily like myself, I recommend replicating this process on paper dozens of times along with re-watching this great content from a true trade hero. Wish everybody the best!

[@markdwyer100]

That brought back some memories drawing out and learning all the terminology tidy job do rob

[@SteveAndAlexBuild]

It’s all coming back watching these vids Rob , thanks 👌🏼🧱👍🏼

[@robsonger1]

Sorry about the quality of the resolution. They are all in HD but as soon as they upload they lose quality. I may re-upload later

[@SteveAndAlexBuild]

rob songer . I have the same problem rob . We film on a go pro 8 black in 4 k but KZbin spoils the quality when it’s uploaded 🙄🧱👍🏽

[@ensen89]

@@robsonger1 thanks. it is really hard to watch. I think this might have to do with youtube cutting on video quality because of corona crisis to take some load of the internet. on the other hand there a videos on other channels just uploaded some hours ago in 4k. very strange.

[@robsonger1]

@@ensen89 yes, I'm finding it very frustrating...the quality on my iMac is good HD...

[@MattBlacInc]

@rob songer great Tutorial. Top Notch Work.. Always.

[@danielmcsorley4765]

Love the drawings great work 👍

[@seanogk9]

You should do your own book rob 👍

[@matthewbishop6556]

Hi rob, Love you’re work,could you tell me if a segmental arch is self supporting would it need a bigger rise,I saw an architect discussing this and he talked about 1/8 rise,do you think that’s correct

[@robsonger1]

a segmental arch needs a rise of 1/6th of the span.

[@onthatilengomane7065]

​@@robsonger1 is it always 1/6 th?

[@mariannemerkus4642]

Greetings from a bricklayer from Holland Jan

[@timgrenz7472]

Rob you are a master. Do you have any advice/resources for building a perfectly circular brick wall. I've been asked to build a hip-height raised garden bed either from stone or brick. Curious if you have advice about how to do that. She wants what is called a keyhole garden, which has a cut out so you can access the center. Kind of like a pacman.

[@robsonger1]

Yes Tim, the staircase we built recently was circular, please look in the Community section on the main page here, there are a few pictures that might help, then ask me any questions you might have and I will try to help.

[@m101ist]

Must keep in mind, the 10mm mortar bed joints. 😳

[@davidlange-smith7967]

Great video Rob, i teach and setout a little different than you mate. I don't finish the top of the extrados to finish to courses .The reason is that the arch looks flat on the crown (top) and it eliminates the two small cuts at the crown ,I love your work mate keep it up ,cheers from Australia

[@chick262]

Can you explain a little more in detail how you get rid of the small cuts please

[@jynnandtonnyx]

When will the Rob Songer limited edition autographed arch drawings be available for purchase???

[@robsonger1]

I've actually thought about that!

[@brandonagius143]

How can I divide the arch into equal parts with a brick in the middle . Is there a formula I can use?

[@robsonger1]

It depends whether you are doing a rough arch or an axed/gauged arch. With a rough arch you need to set out on the intrados, on axed & gauged arches you'd set out on the extrados. Either way, set you dividers to c70mm and start centre of a brick at the centre of the crown and lightly trace the dividers to the springing point, adjust as necessary (always going smaller) until the tracing around fits. Then trace and mark each brick/voussior and draw in the joints by radiating to the striking point.. I hope that helps.

[@chick262]

How do you minipulate the rise if say the opening is 1200 and you divide by 6 it gives you a figure that is not gauge what then

[@robsonger1]

hi Butcher, I'd have to watch it again but I'm sure I talk about this in the video, if not then its definitely in the Three Centred Arch video. I hope that helps.

[@harry.godwinson1]

in the chess world rob the equivalent to you would be a grand master

[@robsonger1]

Haha..Haaarry... thanks

[@chrisnunn9596]

Gday Rob. I love watching your channel. I’m learning my trade over in Australia.i have a question for you. After I’ve drawn up this arch to scale on paper, to work out the actual size of the voussoirs do I just minus a joint I.e 10mm. I only ask this as when I get to the key brick I still need another joint to get it to fit. Sorry if it’s a dumb question.

[@harveysmith100]

No dumb questions Chris. The top of the key brick (the centre voussoir) should be the same height as the last course of bricks that need to be cut over the arch. So if you have your coursed marked up on a profile either side, pull your line across on your marks and the key brick should just meet the line. On a side note, I think your bricks are a slightly different size to ours, so ignore our measurements in the UK.

[@chick262]

Is it always 1 ,6th of the span the fourmula

[@robsonger1]

1/6th is the ideal ratio but i slightly adjust that if i have to do that the top of the arch is correct with the bed joint.

[@danielfite6761]

Rob Songer, what tools are you using to make your drawings? I see a couple compasses and rulers. Could you possibly list them off? I'd like to have a go at trying some drawings.

[@robsonger1]

sorry Daniel, I've only just read this! I use various size double pinned dividers, a scale rule, fine leaded retractable pencils, 0.1 and 0.3 pens, and 30 & 45 degree set squares... oh, and a rubber

[@samsung7888]

Very nice, thanks.

[@moisesisaiasmunos7548]

Saludos desde ayotlan jalisco mexico ánimo 👍✌👌

[@HarryWarren1]

keeping 75mm gauge on the extrados you would have 10mm joints, I remember you saying joints must be 4-6mm, does this not apply here?

[@robsonger1]

Yes, this is true. You will see on the video when I come to build these how I set them out on the extrados. In the meantime you can see it being done on the video '4 centred arch' Thank you for watching

[@HarryWarren1]

@@robsonger1 thanks for answering Rob, if you could answer one more I have that would be great. The arch has a rise of 150 over a 900 span which works for brickwork but because the axed soldier is dry that with give you 365 overall leaving you with a 20mm bed over the crown? If thats correct would you bump up the rise to 160 to accommodate? thanks again

[@robsonger1]

@@HarryWarren1 Yes, exactly right. Well noticed. It will be shown when I video the setting out and building of it.

[@HarryWarren1]

@@robsonger1 Glad I'm on the right wave length, looking forward to you building these at the farm, especially the Florentine Arch. Thanks

[@garethjones5624]

@@robsonger1 hi Rob , just wondering if you had time ? Could you make a video on how to set out or draw tumbling in ? Would be much appreciated ,G

[@doubleportraitartist9053]

视频真棒，感谢您的分享！

[@NoluvoDladla]

Please draw with bold line I don't see those faint

[@tendimatloha8418]

bad quality and the drawing is light i cant really see anything