last Jig or Weld Fixture Design blog<\/a> we talked about different ways to locate a round rod or tube.\u00a0\u00a0 One of the more common ways is with a v-block.<\/p>\nToday we will discuss some of the questions that help you decide the material, modeling method using Pro\/E\u00a0 4.0, and fastener locations.<\/p>\n
1)\u00a0\u00a0\u00a0\u00a0\u00a0 MATERIAL \u00a0—<\/strong><\/p>\nFirst decide what material you will need the v-block to be.<\/p>\n
How much will the fixture be used?<\/strong>\u00a0\u00a0\u00a0 That means knowing what the product is made of because we need the v-block to be strong enough not to wear down too quickly.\u00a0 We want to be able to produce lots of product before we have to replace any of the parts in the fixture.\u00a0\u00a0\u00a0 The more the fixture is going to be used the harder you need to make the v-block relative to the product tube or rod.<\/p>\nDo you need to plan for weld splatter?<\/strong><\/p>\nIf the v-block is located near the weld joint, you will need to consider using a metal that the weld splatter will not stick to as easily, or using a weld splatter shield.\u00a0 Remember that like metals stick better.\u00a0 So if you are welding steel, you may want your v-block to be Ampco 18 bronze or a hardened steel such as 4140 PH or A2. \u00a0\u00a0If you are welding aluminum, hardened steel may work just fine.<\/p>\n
2)\u00a0\u00a0\u00a0\u00a0\u00a0 TOLERANCING \u2013<\/strong><\/p>\nIs the location of the rod or tube critical?<\/strong><\/p>\nIf the tube or rod needs to be located in just the right spot in order to work or assemble easily to the rest of the product parts, then you will want to design in adjustability with shim packs.\u00a0 You will need to look at the product drawing and also know your customer\u2019s preferences.<\/p>\n
At Rentapen we design for many different customers.\u00a0 So we have to consider the standards and preferences of each customer when we design.\u00a0 Some of them love to shim every locator in a fixture.\u00a0 Some of them don\u2019t like to shim at all.\u00a0\u00a0 If you are a CAD drafter, you may be working under more than one designer.\u00a0 Each designer may have their own preferences.\u00a0 But it is up to you to look at the product drawing and then advise them when you think shims will be needed to meet the tolerances of the product drawing.\u00a0\u00a0 Then do what they say, they are your customer.<\/p>\n
If it is a rough location, you may be able to use a purchased V-block from somewhere.\u00a0 Do you have a favorite model or brand you would like to share?<\/p>\n
3)\u00a0\u00a0\u00a0\u00a0\u00a0 FASTENERS \u2013<\/strong><\/p>\nOnce you have decided if your v-block will have shims to fine-tune its location before going into production, you can decide about the location of the fasteners.\u00a0 If the tube or rod location is critical, you will need to use dowels to lock in the location.\u00a0 If it is rough, you can just fasten the v-block directly to the base plate with screws.<\/p>\n
4)\u00a0\u00a0\u00a0\u00a0\u00a0 MODELING —<\/strong><\/p>\nLocating the Vee in the v-block.<\/p>\n
Here is how I model in the Vee cut.\u00a0 Click on the video to see my method using Pro\/E\u00a0 Wildfire 4.0.<\/p>\n