Routing and Finishing Sign Foam

[city_graphics]

I have only been Botting for a few months and have a custom job to do. With the cost of sign foam, there is no room for a mistake.

Can anyone advise on the proper feeds and speeds of a simple V-Carve with the background cut-away to a flat depth?

Also how about painting?
6276

[joe]

Rodney,

There isn't much concern with feeds and speeds with HDU unless your using thirty pound or up. The question is what feed and speeds gives you the smoothest cuts on soft materials.

I'm not of the opinion that HDU is expensive. I make a large portion of my living with it. I'm more that willing to help folks learn how to route signs, but selling commercial HDU signs with absolutely no experience or knowledge of the materials, boggels my mind.

[erik_f]

Gotta start some where, right Joe? I bought my first PRT when I was 26. No major wood working, cad, cam, or sign foam experience. Why would it boggle your mind that someone with a CNC router would try to sell signs made out of materials they have never used before? That boggles my shizel up yo.

[scottbot]

Even those who are experts at working with sign foam had their first time using it.

Rodney, I wish I could help you but I've never used it before either. I'm sure some one on this great forum will help you out though. Good luck with the job.

[sevans]

Hello. I route sign foam quite frequently. I usually run the spindle at 12,000 RPM's with a move speed of 1.5 and end up with immaculate cuts. Over and Out, S.E.

[ernie_balch]

I have been using sign foam since the mid 90's and as Joe said for the 10 to 18 lb sign foam range speeds and feeds are not critical. You can use any design cutter, even make your own. Sign foam is very easy to cut, it is mostly air and has no grain. You can have a chip that is dust or you can move faster and make shavings, the sign foam does not care. You do have to turn on your spindle, the cut is very ragged if you forget to spin the bit (ask me how I know).

To make a smooth surface you can prime it with a high build primer or you can use an epoxy resin.

It is compatible with all paints that I am aware of.

Go to the sign foam web site for detailed info.

ernie

[joe]

The techniques for cuting and surfacing all HDU under the brand names, Sign Foam, Precision Board, Duan, etc has been posted on for years. Do a search.

[rc_woodworks]

You know what I have noticed that makes me leery to even ask a question, is the response from one person. I too am new to my Shopbot. Matter of fact I still have not been able to assemble it as of yet, due to health reasons. But when I do I know I will have question on sign making.

I just hope those who are helpful respond, I don't see how arrogance (as an excuse for experience )helps anyone.

[harryball]

Rick,

Ask all the questions you want, don't worry about flames. If you couch Joe's statements properly along with a grain of salt (maybe a big grain) you can find very prudent advice from someone who has been there and is still there. Take THAT advice and ignore the flamey bits and you'll be way ahead of the game.

As for cutting foam or HDU, I learned (from this forum no less) to crank it up to max RPM and then bring up the move speeds until I got the results I wanted. I did all this for myself on test material and personal projects or developing spec ideas for products. I personally would not sell anything I didn't make one of first. In other words, if I wanted to make HDU signs before I sold the first one I would show my customer one I'd made for myself and already finished (thus learning curve flattened a bit).

But I'm kind of weird, I don't take deposits on anything I do or make. I don't like it, won't do it. I want the full amount when I finish and if I can't fund the project myself it's too big for me to accept. In my mind that leaves me free to change my mind (which I've never done) to terminate the project. I might get sick or just fed up, either way I don't owe anything financial. Peter didn't get paid so I can't rob him to pay Paul and Peter's creditor can't get upset and take his truck.

/RB

[ray_skaines]

Rick, I understand what your sayin'. True Shopbotters and Letterheads are folks that enjoy helping and encouraging those who want to learn. Shoot, we were all born naked. I was young and dumb too but soon found out it was easier to ask than to learn from my own hardknocks. So I encourage anyone that yearns to learn post your questions. Just ignore the stuff that needs ignoring.

I wish you the best of health and hope your up and running soon.

[rc_woodworks]

Thanks RB and Ray, I have been making signs by hand for 28 years and CNC use is all new to me! I appreciate the fact that I have other Shopbotters to ask question. That was one of the main reasons to buy my Shopbot. I try every chance I can to help others and give patience to those who are in need of help.

Funny thing I read the original poster asking about HDU, thus trying to learn about the product before making a sign!

RB I agree I experiment before selling too, again the OP sounded like he was making this sign for a friend and not a customer. I am not sure if he is charging this friend, but doesn't sound like it to me! I know I have a hard time charging close
friends.

Again thank you for the encouragement, I have 2 CNC, my Shopbot and a smaller K2 CNC and I haven't been able to use anyone of them. It sucks having a new SB just the frame assembled and it being a year old!

Time will tell when I can be a Shopbotter rather then just an owner! I will continue to visit and learn!

Rick

[city_graphics]

Hi All;

Thank you so much for your support in this matter. I cut the sign yesterday and it went PERFECTLY thanks to all of your advice.

We have been in the sign business for 40 years and this particular sign is for a custome who sends me so much work, it was a free-bee. They have a fleet of 100 ambulances which I have lettered all of them in vinyl and before that mmy dad lettered all of thier rigs by hand.

We decided to go CNC because we love to turn concept into reality.

I feel Sign Foam is expensive and did not want to ruin a sheet just for practice.

We also have a lathe and a mill for metal working just as a hobby we make live steam locomotives and I know one thing for sure, IT IS ALL ABOUT SPEEDS AND FEEDS. That is why I wrote a thread about HDU so I would not ruin the material, machine, or tool stock.

Regardless, the sign trned out beautiful. THANK YOU SO MUCH TO ALL WHO HELPED ME WITH POSITIVE REPLIES.


Rodney Leggero

[rc_woodworks]

Rodney, I am so glad to hear the sign went well! I agree with you HDU is expensive when you are buying one sheet at a time! I use reclaimed old growth redwood. That I buy rough cut, so I make it into S4S and then cut it into sign blanks. Oh not to mention driving 6 hours one way to pick it up! So after all that when I screw up a sign I want to cry! Yes I misspell a sign or two the good thing is I can use it as a display.

I am sure I will give HDU a whirl on a smaller scale. The last time I checked the price for 20# HDU was $300.00 a sheet. Of course less for more you buy!

I hope you don't mind if I ask you for advice when I am ready to try it myself? Shoot I don't have a clue of the speeds I need for redwood for either of my CNC's!

Still glad to hear it all worked out the first time. It is a good feeling!

Rick