# I'm confused on what I need for a 12 for top beam **URL:** \ **Category:** Frame\ **Created:** [June 15, 2020, 8:12pm UTC](https://forums.maslowcnc.com/t/im-confused-on-what-i-need-for-a-12-for-top-beam/13709 "2020-06-15T20:12:37Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![tater3000](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/tater3000/32/16760_2.png) [@tater3000](https://forums.maslowcnc.com/u/tater3000)\ **Post date:** [June 15, 2020, 8:12pm UTC](https://forums.maslowcnc.com/t/im-confused-on-what-i-need-for-a-12-for-top-beam/13709/1 "2020-06-15T20:12:37Z")
So I got my maslow kit, I got my area sorted for where I’m going to build it. I ordered 10 feet of extra chain but I can’t find any instructions for building a frame with a 12 foot top beam. I found one post that said just raises the top beam by a bit. What’s a bit? I’m a journeyman B pressure red seal welder. In my world a bit is 0.5 mm That doesn’t seem to be enough to change the geometry. Is a bit 300mm? Or a foot for those on the forum still using imperial. Half that? Help, haha. I’m putting together the frame this week and am trying to get together a material list. Thanks in advance. ---
**Author:** ![Orob](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/orob/32/16344_2.png) [@Orob](https://forums.maslowcnc.com/u/Orob)\ **Post date:** [June 15, 2020, 9:14pm UTC](https://forums.maslowcnc.com/t/im-confused-on-what-i-need-for-a-12-for-top-beam/13709/2 "2020-06-15T21:14:06Z")
There aren’t instructions, there are guidelines. Look [here](https://forums.maslowcnc.com/t/maslow-chain-geometry-spreadsheet/4308). The 4th post has a link to a google spreadsheet that allows you to change the numbers and get an optimal setup. ---
**Author:** ![tater3000](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/tater3000/32/16760_2.png) [@tater3000](https://forums.maslowcnc.com/u/tater3000)\ **Post date:** [June 15, 2020, 11:52pm UTC](https://forums.maslowcnc.com/t/im-confused-on-what-i-need-for-a-12-for-top-beam/13709/3 "2020-06-15T23:52:24Z")
OK ill take a look at it. I just figured that seeing as how the steadfast frame has hard measurements that the 12 foot would as well with how popular it seems to be. If I have any questions I’ll post. Thanks for your help. ---
**Author:** ![tater3000](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/tater3000/32/16760_2.png) [@tater3000](https://forums.maslowcnc.com/u/tater3000)\ **Post date:** [June 16, 2020, 12:03am UTC](https://forums.maslowcnc.com/t/im-confused-on-what-i-need-for-a-12-for-top-beam/13709/4 "2020-06-16T00:03:22Z")
OK I put in my own values. Now what? There is nothing in the description saying what an acceptable value is. I see the stock values but I want to build the 12 foot beam for increased accuracy, so what values do I need to shoot for? Is higher or lower max force preferable? Is there a range I should be inside, is there a range that will give me better accuracy than stock? I’m just looking for a known height above the work piece for the 12 foot beam that is known to increase accuracy. ---
**Author:** ![Printer\_V](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/printer_v/32/13135_2.png) [@Printer\_V](https://forums.maslowcnc.com/u/Printer_V)\ **Post date:** [June 16, 2020, 12:12am UTC](https://forums.maslowcnc.com/t/im-confused-on-what-i-need-for-a-12-for-top-beam/13709/5 "2020-06-16T00:12:57Z")
Check post “28” on the same page. There is a fairly good image posted of what is happening and what you are trying to accomplish by “stretching” the frame out. By its nature, the forces between the two chains varies considerably depending on the position of the sled. You are trying to move the highest and lowest force positions to beyond your cutting area. This will help with accuracy of the machine. The actual dimensions you make are not super critical as the machine will basically measure itself during the calibration procedure. > [@Maslow Chain Geometry Spreadsheet](https://forums.maslowcnc.com/t/maslow-chain-geometry-spreadsheet/4308/28): > > Perhaps overly simplified but I had played around with v-plot script on the [http://2e5.com/plotter/V/design/](http://2e5.com/plotter/V/design/) site and generated the PNG plot file. I then inserted the .png file as a canvas into Fusion 360 and did a calibration to the size of my current machine, this is a trick you can use to be able to sketch on top of a photograph at scale! My first attempt was done at my current machine dimensions at 10 ft top bar and sketched in a 4’ x 8’ board on top of the canvas. The problem areas are cl… ---
**Author:** ![tater3000](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/tater3000/32/16760_2.png) [@tater3000](https://forums.maslowcnc.com/u/tater3000)\ **Post date:** [June 16, 2020, 12:17am UTC](https://forums.maslowcnc.com/t/im-confused-on-what-i-need-for-a-12-for-top-beam/13709/6 "2020-06-16T00:17:07Z")
OK so 30 inches according to that diagram. The math for all of this is beyond me, I’m a tradesman not an engineer. I have no desire to understand why it works, just if it works. Kind of like my truck. I don’t care how the engine works, I just want to know how to drive it. Thank you for your help and simple explanation