Skate boards

[magic]

A customer wants me to cut out 42 inch long skate boards made with various hard woods epoxied together with the end grains mostly at the long ends. 2D only nothing fancy.

Let's assume that I'll use a .25 bit and the board is .65 thick. I thought I could make the first pass at .2 / 40 ipm - the second at .3 / 30 ipm and the bottom pass .2 / 40 ipm

Do those speeds and depths seem reasonable?

The bit I'll probably use is an upcut because the customer will round-over the edges themselves (his choice)... OR should I use a down cut on the first pass then the upcut, the rest of the way

[mrdovey]

I'd use an upcut for all passes, and I'd feed at 1.5 inch/sec and bump that up until a saw some rough cutting - and then back the speed down.

Epoxy is had on cutting edges, and a slow feed just provides aggravation (and shortens the edge life by overheating).

Having said all that, let me also say that I've managed to stay from epoxy fairly well.
Time for someone who's done this to chime in.

[magic]

So, you think my cutting speed is half of what you would use?

[mrdovey]

Yes, but that's just my opinion. I like to keep the feed speed up to avoid overheating the bit. I do almost all of my cutting with solid carbide end mills and they seem to last noticably longer with higher feed rates.

The 0.2" to 0.3" depth of cut shouldn't present any challenge, so try a test cut with a 1.5"/sec feed - and then adjust up (or down) according to what you experience.

[magic]

thanks

[knight_toolworks]

even do it in one pass offset and the second pass a finish cut. I can get away with .5 with a 1/4" endmill at 1ips in solid tropical woods. but I would do a cleanup after that if I wanted a good edge.

[dingwall]

I'd recommend a 3/8" or 1/2" compression spiral to keep from splintering the top.

Most skate boards have a bull nose profile on their edges. You might have to do a tool change or have a manual template for a router table.

[magic]

These are flat, mostly decorative 42 inches long.
i told the customer i wanted 20 a board and he thought it should be 10 or under because he can have his workers cut out the shapw by hand on a band saw then use a belt sander to finish them.

Silly customer... is 20 too unreasonable for a 42 inch skate board board in a run of only 10 pieces, including programing and no set up charges? I ask you.

[knight_toolworks]

well it sounds like at most it will take you 10 minutes each including loading and removing. if you don't think it will take anymore then that for each board 10.00 each is not bad it's 60 a hour.
but I would charge expenses if you need to buy a bit.
I would do it for that because I bet it does not take more then 3 minutes per board.

[magic]

Here's the rub. he wants the boards to be a copy of the shape he's using now which will require measuring and node editing. i think it will be an extra hour to program. So i figure 4 minutes a board times 10.. 45 minutes and an hour which equals 145 minutes not including tool change (and broken bits, if any) and zeroing.

So would a better option be to charge him 50 dollars for the programing then 8 dollars a board? Sounds better.. then the next time it will just cost him 8 a board, yes?

[knight_toolworks]

Try taking a good picture of it importing it tracing it and checking it for fit. that may get you pretty close. if the lines are jaggy just use the draw polyline it will conform to the vectors pretty well. but yes that sounds good. once you have it it's a no brainer.

[magic]

Thanks

jay

[knight_toolworks]

for something that long you may get distortion on the picture. I do wacky pieces of cardboard templates and the longer ones get messed up. I would make a cardboard template paint it black and cut it in have crosswise and take the two pics and connect them.

[magic]

Really

I just plan to measure the width every 2 inches, Make an oval and use the node editing to fit. I've made lots of pieces this way and it goes pretty quick. The other method I rely on is to make illustrator files on my Mac and export them as an EPS. Sounds like I'm missing something.
How do you import a picture into partwizard? OR scan a flat object and get into partwizard?

[knight_toolworks]

partwizard can't vcarve can do it. sorry about that.but you can do it with illustrator. you can get vectors from a picture from it.

[wiese]

When taking a picture to use for importing and tracing, I back away from the object being pictured then zoom in. This reduces the amount of perspective distortion resulting in a more orthographic view of the object. Do I sound like a drafting teacher, or what?

[magic]

yes.. but how to import same into partwizard. I know about Streamline, a adobe product that I believe can make a B&W image into an EPS, but haven't used it in a while.

[knight_toolworks]

here is how to get a eps file from illistrator

- Opened it in Illustrator
- Used Live trace to trace it as a high resolution logo
- Expanded the result into shapes
- deleted shapes that duplicated the main shape
- combined remaining shapes into a single shape
- Saved it as an EPS in version 8 format

[jhicks]

I love the 10 minute logic and hope it works for you. After you cut the 20, ask yourself how much time you spent designing parts, buying material,picking up material, bits, and equipment costs, then the time to design pilot, fixture build, cut, remove, replace, unload, stack, pack,clean up the shop, invoice, phone time, forum time, etc, etc, etc.
I would submit that your cutting time will be least of your time spent, and your planned $200.00 invoice at $60.00 / hour will evaporate right before your eyes.
Hey better to train on someone elses money for break even so its not a total loss.
Hope it turns out better than a negative $ training transaction event but would be interested in your final conclusion after they are done.
Good Luck

[robtown]

Please avoid the temptation to engage in a race to the bottom. If you can't do it for less than 20.00/pc... then don't. Let him walk. Don't compromise or be afraid to let piecework walk, ever. My experience with piecework is such that I won't even talk to anybody about it anymore. If someone starts talking cutting parts, I'm not interested.

It's a double whammy, the customer beats you down to 10.00/pc, most likely promising you that they will abide by your schedule and allow you to "fill in" gaps with this work. Then once they get the toe in the door, they start hounding you for thier pieces, regardless of what they promised you initially. Suddenly the onus is on you to get them thier 10.00 pieces to keep them in business, and, here it comes..., then they start trying to get you to come down on your pricing, to increase thier profits. It's NEVER worked out for me. There are those who claim success, but I doubt if any of them ever really look at the cost of piecework.

I had one customer want to come in with a stopwatch and "observe" the cutting of parts for an afternoon, what the piecework customers fail to grasp, is that if you hire me to cut 100 parts, there is a lot more involved than the time the router is actually cutting.

Basically those who want piecework are only interested in you making them money, not you making money for you. If they can find a sucker to do it, they don't need to invest the time or money to make it happen on thier own.

I'd rather make $100.00 on a single job, than $1.00/ea on 100 jobs.

[Brady Watson]

You said it, Rob! Great insight. I've had customers try to schedule 'stopwatch time' in my shop - which is a strong antecedent to promptly throwing them out!

People - you have to keep in mind a few things...You may love doing this type of work, but you MUST be paid for it. Your shop needs to have a MINIMUM charge before you even turn on the machine to cut. This will weed out the riff-raff and make room for legitimate business to business customers. I do not do jobs for the general public. If you are not a business, we cannot do business.

The biggest point I'd like to make is that, you should not be making excuses for your work - in other words, don't give it away as if they are doing you a favor by using your services. Some customers are completely out of touch with what is involved with CNC, feeding their reasoning with some fantasy that 'you just push a button' and you're just 'hanging out' in the background sipping pink lemonade on the beach. We all know how much is involved...If it feels like you are being beat or beat-up, you probably are. Walk away. It is doubtful that they will get what they need at a better price than you, especially at such small quantity. You need to have minimums...

A small piece order like that just isn't worth the time to deal with, unless your gut truly feels like it will turn into something larger AND you feel that you will actually want to do the work when it does come in. You should price the small runs as 'prototyping' at a much higher rate, let's say $45 ea and you tell the customer
that when you get a purchase order for X number of units, he'll get a quantity discount. That's the only way to do business & make money and to provide an incentive to the customer to sell more units. You don't get wholesale pricing by buying onezies & twozies...

-B

[robtown]

Not to flog a dead horse here... but two more comments...

Before I ever turn the key in the deadbolt of the front door every morning, I'm in debt for $120.00 or so (rent and overhead). If you aren't making the rent AND your paycheck for that day, then you are losing money. (this applies to all of us, even those working out of thier garages).

AND..., you will NEVER get a piecework job to allow you to increase the pricing per pc. once you've set the bar on your pricing it becomes a cat and mouse game with your customer. They will do anything in thier power to get you to drop that price, but THEY WILL NOT let you increase it.

Stick to your guns, get your price or move on lest a real opportunity pass you by as you negotiate pennies...

I know this is hard to stomach if you are new to all of this, none of us are in business to say "no", but sometimes you have to say no to stay in business.

OMG... am I waxing philosophic here??? ... I've got to get back to my lemonade before the ice melts, I hate it when my lemonade gets all watered down...

[waynelocke]

I would probably charge my hourly rate to do the computer work, jig up and cut 2-5 boards and then give a unit price at that point. They should pay all of your R & D. Also if they don't pay for the design time, you may get into an almost endless round of meaningless tinkering with the design. Paying helps the client clarify and decide. If moving that line is going to cost $50 in consultation and computer time it is often fine like it is.

Are you gluing up the boards or are they? If they are providing them, what state are they going to be in? Are they going to be flat and true off of a jointer or just glued up as they come from the yard with epoxy filling the gaps from poor joinery? To me those issues really need to be crystal clear. If they are not flat and accurately sized you may have to fiddle with each one on the SB to hold it down.

[cnc_works]

On bidding piecework, if the job is not clearcut, I will always make my customer clear that my bid is only for the initial order (a reasonable number that I can live with if the bid is too low). I will then reassess and the bid may go up or may even go down.

Donn

[magic]

Points well taken

This is my neighbor. He glues the boards, runs them through a planer, then the table saw so they are all the same size. He will leave the boards with me and I can cut them when I want.

However I do appreciate all the advice because there are a lot of "Time Vampires" who want to look over your shoulder and make a one hour job into a three hour job.

And thanks Steve, I'll get Live Trace.