Tire tread engraving

[Steve Paul]

Here are a couple pictures of Hoosier tire treads that have been engraved into slicks designed for 1/8 scale nitro sprint car racing. My 45W Helix was set to 18 to 22 speed, 100 power, 600 dpi. Tread depth was between .040" and .050" depending on the speed everything else held the same. Time for a rear slick was 25 minutes and a front tire was 17 minutes. Not really economical but cool none the less. I need to try this at 300 dpi to see if I can reduce the time but I fear I will reduce the depth.


I practiced on sheet neoprene glued down to the table. That allowed me to fine tune for the depth needed. These belted tires are hand made and the racers usually hand carve their tread pattern (rotary grinder). The tires being made out of race rubber engraved identical to the neoprene sheet. This saved some experimenting with the expensive tires.

I taped the tire than ran the file at reduced power in order to fine-tune the drawing size to the tire OD. The tape picture shows the cut. A lot of test time getting the drawing sizes right. For each tire OD I made a pair of jig wheels to ride on the rotary attachment rollers.


Even though the engraving is not economical, when you compare how much time it takes to hand carve the tread this may be an optional plan. When I handle the tires after cleanup it is amazing how many cutting edges you feel. This has to be more functional than the hand carved setup. I need to send some sets up to Chicago area where they race indoors all year long.


The 1 thing I didn’t adjust was the ppi. I left the setting at the default for the epilog print driver (I think it was 2500). This might allow me to speed the process up. There were small flames coming off the tire when engraving and I now know to use the air assist but I did the tires without. Ahh, the effects of being a newby.

Steve Paul

[Gary Hair]

Steve,
With the pattern you are using I would suggest vectoring the tires instead of rastering. To get the width you need simply copy the lines so that they overlap and result in the width you need. As small as they are you could probably cut your time down to just a couple of minutes instead of 25.

Gary

[Steve Paul]

Gary,
That is a good idea but I worry about crossing over previously cut lines and creating deep spots of engraving. The belted tire is only about an 1/8" thick. Also I need to get this in 1 rotation of the tire on the jig. This is why I like this forum; great ideas and new ways at looking at solutions. If I could get this to work, this could actually be marketable. If I charge only $100 per hour of run time I still end up with more money in the engraving than the cost of the tire not counting the many hours in developing the drawings. The drawing uses line weight to control the groove width. I need to try more PPI to see if that would speed up the process. If I could half the time I would consider doing this for what little market there is. Thanks again!
Steve

[Ross Moshinsky]

Definitely look into dropping the dpi to 300. I've done testing and 600dpi vs 300dpi will cut engraving in essentially half. So 2500dpi to 300dpi will cut engraving time on the 25 minute tire to about 3 minutes. As you mentioned, depth may become an issue but you can always tweak that with power and speed. The changing of the resolution will make a huge impact compared to a small tweaking of the speed. I also don't think there is any need to engrave at a high resolution. 300-400dpi would work perfect.

I'd also think you probably could do this with vectors but considering you could get engraving time down to 3-5 minutes per tire, I don't think thats worth all the work to R&D the new design.

[Martin Boekers]

Cool!

But are those tread patterns copyrighted or patented? (just Kidding!:p)

You could etch a name or an Escher-like pattern on them.

I like the creativity here!

Marty

I can see Rodne making some custom treads for his Vette! (if he figure a way to fit it
in the laser!!!)

[Steve Paul]

Martin,
Before I did this I contacted Hoosier and talked to them about what I was doing. They sent me files and links on there site to work with.
Steve

[Martin Boekers]

Martin,
Before I did this I contacted Hoosier and talked to them about what I was doing. They sent me files and links on there site to work with.
Steve

Isn't it great that they did that and even helped!

Rare in this time and age!

[Kim Vellore]

Paul,
They look awesome, as for the DPI if you reduce to300 the depth of engraving will also go down. I would go 1200DPI and increase the speed, It will give you the same time but sharper definition, give it a try.

Kim

[Gary Hair]

Gary,
That is a good idea but I worry about crossing over previously cut lines and creating deep spots of engraving. The belted tire is only about an 1/8" thick.

With the amount of potential time savings it would be worth drawing the lines so that they don't cross over each other.


[SIZE=2] Also I need to get this in 1 rotation of the tire on the jig.

That's the advantage my rotary attachment has over Epilog type, mine is fixed and could rotate all day long, back and forth, without any problems. I understand you need to work with what you have, but it might be worth exploring a modification to your rotary fixture to resolve the problem. Again, the time savings could be well worth it. I can't tell you how many jobs I have done where I have spent a fair amount of time creating fixtures or optimizing things and have saved countless hours because I spent more time up front.

Gary

[Steve Paul]

Ross,
Setting the frequency from 2500 to 5000 might allow me to run the dpi at 300, in fact it might allow the speed to increase also. I mistakenly called it PPI in the first post. I will try this mod on some neoprene sheet to see if it will produce favorable results.
Kim,
When I test run the drawing on the tape I do that at 300 dpi and it looks more than exceptable.
Martin,
When I talked to Hoosier I was needing a picture of their logo for creating a stencil to spray paint the name on the side of the tires. They sent me the logo in several formats for copying in CorelDRAW. The individual was trully interested in what I was trying to do. I did some work on this file but haven't cut it yet.
Steve

[stan kern]

well done, its amazinga laser can do tire threads

[Bill Cunningham]

In a similar project.. I have a 15 year old digital printing press that I used to run millions of paper tags, QSL Cards, and fliers on.. Eventually the rubber on the paper feed friction rollers wore out, just like an old tire tread. The Manuf. no longer stocked the part, and I sure didn't want to scrap the machine because everything else was running fine. I took off the four rollers, put them in the lathe and cut them down 1/4 inch diameter, then used the laser to cut some new 'retreads' out of a sheet of rubber stamp 'rubber' to wrap around the old turned down rubber rollers and secured them on with crazyglue. I've put another 1/2 million impressions on the machine since then, and the retreads are holding up fine.. If new rollers had been available from the manuf. they probably would have cost me 100.00 each.. See, you can not only make tire treads, you can make re-treads too:p

[GLENN BRADDY]

That is very cool....