heuristics for bidding a job?

THe first thing I would do is to get a precut price from your metal supplier to see if it is worth the aggrivation of cutting the stuff. The bandsaw cuts from a commercial saw need little deburring. Precutting makes handling the material much easier.

On a recurring job you got to put in the contract the posibility of increasing prices of raw materials.

Only you know the time its going to take you to make the product. Your estimate on time will probably be low. Also consider the time ordering the materials, handling the materials and the cost of delivering the product. The incidentials will pick your pocket.

The cost of running your mig machine would be estimated too. Gas, wire, consumables (tips, guides, tip dip, etc.) all have to be considered. Id figure at least 10 bucks an hour just for running the machine.

John

I am no expert, so won't offer much help, but as I tried to think about this, I came up with a couple of questions:

How much will the steel cost you? My guess is a dollar a foot = $36 per cube. If I am not mistaken, tubing comes in 20' lengths, so you get six 3' pieces per 20' length, thus you lose 10%, i.e. two 2' scrap pieces per cube, so at $1 a foot, it is really $40 per cube. Do these really have to be made of 1"x1" tubing? Rebar is a lot cheaper, if it is going to be buried in concrete. I think material is going to be your biggest cost, so I would really push them on thinking about alternatives.

This might come down if you could buy bigger quantities, so the second question is how many of these do they want? At what rate? I would think differently about this if it was 100 units at one time versus 5 per week for

What does their jig look like? A square welding table with corner clamps would allow you to make a bunch of 3'x3' sides at once, then adding the other four pieces later which I think would be easier than making a complete cube before starting the next one.

Grinding always seems to take me the longest time, (probably as a function of my gorilla welds), so a job with no grinding sounds pretty nice. Is this assumption true?

Do you have a truck or trailer to deliver these? They won't nest at all, so a pickup might only be able to carry four cubes at a time. This might be an issue depending on how many they want per week or whatever - multiple trips just to deliver would be a pain to me, especially with my 9 mpg gas hog.

A while ago I posted a similar question here about making 2 nine foot gates. After lots of suggestions, calculating, and a lot of thinking, I came up with a very detailed bid of $1000, only to find out that the local gate guy just bids a straight $50 per linear foot. I guess my point is not to overthink this if you think the competitor might just toss out a $50 each bid.

I am very interested in this issue, so am looking forward to the responses!

I base labour for guestimating at $ 1 per pound for heavy work or $1 per inch of weld for light tube for one off or short runs which ever is greater, for thin wall requiring TIG it is what ever the market will bear . Your project has about 64" if fully welded. Distorsion will be your enemy.Materials extra, welding supplies and consumables are generally included but some jobs require surcharging. Shop door rate is $ 90 /hour,

You don't have to debur edges that will be welded, only those that show in the finished job.

In this case the burr would interfere with the jig, or perhaps some would remain to present a slicing hazard to workers handling the part. Anyway, the customer cuts the tubing with an abrasive chop saw and then deburrs every cut before assembly, and they want the pieces deburred and it's their nickel.

I was wrong by the way about this getting buried, nor is the actual piece as simple as a 3' cube. I only asked guys to bid a 3' cube because it is pathologically simple and thus wouldn't be much work to figure up. No numbers yet forthcoming, alas ..

GWE

When I was learning to quote, I used to go talk to the "expert" in each department. I would ask them how long a job would take, then I'd double it. That usually got me pretty close.

For a recurring job, I always give 3 prices. The first I call a fixture price. It only happens one time. It covers the cost of building any fixtures, writing programs and that kind of thing. The 2nd is a set up charge. That covers changing over the equipment, setting TLO's and stops ext. The final charge is for the part. It covers material cost, disposables, and labor. I've found if I don't quote that way, the customer will ask me to quote a price for 1000 pc lots, then order 25 at a time.

If you have the luxury, why not get set up and build a part. You can base your price on the actual time it took you. The more you do, the faster you'll get.

They could be nested during assmembly!

:^)

Jim

It perhaps needs saying that it should be spelled out, explicitly or implicitly, that customer does not (or does) own the fixtures or the programs. Calling it a "setup charge" or something like that may clarify things sufficiently if you don't intend them to be able to take your work and shop it around.

Best regards, Spehro Pefhany

There is a simple "trick". Imagine you building that thing and estimate how long it takes for every step:

- getting material (ordering, delivering)

- setting up machines (cutting, fixtures, rearranging shop)

- every single cut takes x seconds

- every single weld takes x seconds

- remove welding splutter

- consumables (gas, wire, electricity, grinding disks, saw baldes)

- deburr

- clean?

- moving things around in your shop. If you have 100 of those cubes, where will they go?

Then, I would multply the number you got by two. There is always something missing. If it is an easy job, make one piece off to see how long it takes. Have a stop watch and time every step.

Nobody is gonna see if it was deburred or not if there is a weld. Sometimes it is faster to deburr before welding, sometimes faster after welding (reachability).

HTH, Nick

Good plan. I tend to figure hours to do it fast with everything going right and then multiply by 4. There's always something that mucks up and eats time. For the most part, it tends to come out pretty close on the onsies and twosies jobs.

And don't forget that it takes time to get out the tools needed as well as clean up and put tools away after. The amount of time to un-make one's fabrication mess is generally a lot more than is expected.

Koz

One approach is simly to list each task and detail the materials( steel, welding wire, gas, etc), labor, machine time for each task.

Then add your calculated overheads, rent, insurance, heat, light, etc for the number of hours the job takes. That time includes picking up materials, delivering the product, thinking about it, bathroom and cofee breaks etc.

You can get the times pretty close if you actually make one and record everything.

You need to quote higher than the above method to account for any downtime. That is if the job takes a week and only say 30 hours you need to charge overheads for 40, unless you have another job to fill in.