Note: If you’d like to play with G-Wizard Estimator, there’s a free 30-day trial available.
Thanks to all who participated in our Cost Estimation Survey, I think most of the feedback has been incorporated with this release.
Let’s go through what’s been added to this new release:
Feature Quantity and Fixed vs Variable Costs
A number of people suggested we add the ability to set a Quantity for each feature being added to the Estimate. For example, a single part may have a number of holes, all with the same dimensions. So there’s a new Quantity field right where you add CADCAM Wizard features to the Estimate:
You can specify Quantity of a feature to add to the Estimate as well as whether it goes under the Variable or Fixed Costs…
Cost estimate fixed and variable costs…
In addition, there is a checkbox so you can designate whether the cost is added to the Fixed Costs (up front or one-time costs) or the Variable Costs (per-part costs). When you use the Quantity field, multiple Op entries are created and they’re numbered (#1 and #2 in the screen shot) in the Description field so you can keep up with which is which, if needed.
The Variable Cost page is focused on the costs that are allocated per part and won’t change if quantities change. Here is the Fixed Cost page:
The Fixed Cost page. Cost types are selected via the tabs right above the cost schedule…
Fixed Costs are one-time costs such as:
– Programming: More on this one in a minute, but you’d typically do the g-code programming or CAM work up front and it would be a fixed cost for the job.
– Fixturing: If you decide to build a custom fixture for the job, you can use the CADCAM Wizards to estimate the cost to machine the fixture and have all those costs added to the Fixed Cost schedule.
In all likelihood the Fixed Cost schedule will change quite a bit as functionality is added to allow estimation of different volumes. Fixed costs are a big part of volume estimating. For example, at low volumes, it might be sufficient just to stick the parts in your vise(s) on your mill table. For higher volumes, it might make more sense to build a custom fixture that allows a lot more parts to be machined on the table.
For now, we tally up the statistics and costs separately for the Volume and Fixed Cost pages and we also export them separately to spreadsheets.
A scrap allowance is pretty import to have when estimating machine shop job costs.
The Scrap Allowance is found on the Estimator Tab, 4th line down, by the date. By default, it is set to 5%. The Scrap Allowance affects the overall estimate by assuming that parts are completed before being scrapped and that the Scrap Allowance percent of parts will be scrapped. It is therefore added to the overall cost of the part directly by increasing the value of Cost / Pc. In addition, the number of parts produced per time interval is reduced by the rounded up number of parts that will be scrapped.
For example, let’s assume we can produce 2 parts per hour and there is a 5% scrap allowance. The parts per time interval will be:
– 2 parts per hour (actually, 2.0 * (100% – Scrap%) = 2.0 * 95% = 1.9 which rounds back to 2.
– 8 Hours: 2 * 8 * 95% = 15
– 40 Hours: 2 * 40 * 95% = 76
– 160 Hours: 2 * 160 * 95% = 304
Ops are the cost line items used by CADCAM Estimator. Several new ones were added in this release, but the most interesting is the Programming Op.
Suppose you’re putting together an estimate for a tray similar to what we’ve shown in our CADCAM Estimator video:
Here’s what the features look like for our tray:
Features required to manufacture the tray. “Features” are just the machining operations…
It’s a simple part, so we have roughing and finishing passes needed for a pocket, profiling the outside edge, and face milling the top and bottom. That’s gets all sides machined and away we go.
What will it cost us to do the CAM programming for this part?
To find out, click the “Add Op” button and select the “Programming” op:
Programming Op is used to estimate the cost of CAM and g-code programming…
Note: Before clicking “Add Op”, be sure to select the Fixed Cost tab as we will need the programming just once and not for each part. Of course if you need to encounter for some kind of personalization like engraving each part, perhaps there would be some programming component on the Variable Costs.
The Programming Op works by counting up the features generated by the CADCAM Wizards. It knows, for example, that there are 6 features needed to make the tray. It then applies an amount of time to program each feature (default 10 minutes) and an hourly rate for programming ($30/hour by default). That all gets turned into the cost of programming and added to whichever (Variable or Fixed) schedule you have currently selected.
Components Op, Finish Op, and Coating Op
We added a bunch of new ops, or at least made them functional:
Components Op: Covers purchase of additional components that will be incorporated into the part such as Fasteners or Bearings.
Finish Op: For operations like running the part through your blast cabinet (bead blasting) or vibratory polisher (tumbling).
Coating Op: Covers the cost of things like powder coat and anodizing.
These simple ops all work the same way. There’s a combo box at top left that lets you select different options to go into the Op field. It’s just there to save you typing and keep things consistent. You’re free to add further comment to the op, but we encourage you to choose one of the canned options and put the further information into the Description field. Here’s the Finish Op, for example:
Additional Time and Cost Columns
Several in the survey commented they want to be able to add some additional time or cost to any line item. This is done via the Addl Time and Addl Cost fields.
Like CADCAM Estimator, it’s not finished yet, but we have started a Doc Page for Estimator that you can refer to.
Lots more substance in this release: CADCAM Estimator has come a long way. But it’s still very much a work in process and we need your feedback to help guide our efforts in the way that will make the most difference for you. Let us know what you think of it, your likes and dislikes. Much more to come!
PS If you haven’t already, check out our Cost Estimation article to get a good grounding in how we’re thinking about this problem.
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Bob is responsible for the development and implementation of the popular G-Wizard CNC Software. Bob is also the founder of CNCCookbook, the largest CNC-related blog on the Internet.