Working to Tenths with Economy Tooling

[erikmannie]

erikmannie, If you are at all serious about what you want to do, let's analyze the process.

1. The tools and equipment that you have may already be sufficient to make a prototype. Think Wilbur & Orville in a bicycle shop. Your "inferior" tools are light years ahead of what was available at the time.
2. Make a good CAD drawing.
3. Hire a lawyer. You need to check for existing patents and also what DOT requires to be allowed on the road.
4. Get an engineer to certify your material properties. Flexibility being very important. Tires are only round off the vehicle. He should also be able to advise thickness and maching tolorences.
5. You can start machining the prototype. You will need to work within the limitations of your machine. To prove the feasibility of the idea, machining to a thousand or 1/2 thousand may be fine. Other option is to find a company that has the capability to make the prototype for you. The next option is to spend some really serious money to get machines with the tolerances you want. At the least you will need a good surface plate and dial indicators to check the machined item. Or one of them fancy digital touch probe measuring machines.
6. Find a really, really rich investor or business to partner with. A business
7. Home-brew test the tire to see if it works at all. Riding down the street isn't a good idea. If the prototype fails you may need an engineer to determine why and suggest alternatives. If the tire lives, make a couple for destructive testing.
8. Have a lab test and certify the results. DOT may require this.
9. Get a ton of insurance and farm out the manufacturing to a reputable company or buy the equipment and start your own. Better still, partner with a company and just get a royalty.

Can you do? Absolutely! A lot of work and headache. The reward is that you may become a millionaire if your idea takes off. Who knows,we might be bloging with the next Elon Musk! However, if the machines you have can't handle the material you specified down to say, one hundred thousands of an inch, then buying all the micrometers and gauge blocks to measure one ten thousands won't really get you any where. You might really need one ten thousand accuracy for public use, but I would end up there, not start there.

Good Luck and keep us posted! Charles

I am 53 years old and all I like to do is go to school and work in my shop. I have a good union job (I work for UPS at the Oakland Airport) that will allow me to pay my bills, go to school and work in my shop for the rest of my life.

I have never had any interest in sales, marketing or becoming wealthy. If I were wealthy, I would still work at the same job, go to school and work in my shop.

My tire armor idea is very much open source. I hope that somebody does bring it to market, but it won't be me because that could take me away from my classes or shop.

My prototype steel plates do the job for my purposes; I only need to find a more elegant way than duct tape to attach the plates to (the inside of) the tires. The plates move independently in all axes. I don't mind fabricating the plates (in fact I enjoy it), but mass production of the plates would call for a streamlining of the production process.

I will start a thread on this when I have time; until I do, here are some important considerations:
(1) Great fitup makes the welding go a lot faster and easier,
(2) .050" Grade 5 Ti in precut 5" X 5" squares is not expensive because you can buy second hand drops. The ERTi-5 is expensive, and of course a lot of Argon is used.
(3) I use a hydraulic press to bend the material,
(4) I have only tested these at 19-20 psi tire pressure, and
(5) There are many simple ways (e.g. powder coating) to protect the material from cutting the tube (if using a tube) or tire.

Here are the CAD drawings for a single plate for a 26" X 5.05" tire. If anybody is interested, you may adopt the idea as your own.

 

[erikmannie]

I did additional testing, this time inside my 70 degree F home with Starrett 0-1” and 1-2” micrometers in addition to the Shars digital electronic mikes mentioned in the OP. This time, the Shars gauge blocks tested fine in relation to the Starrett mikes.

I think the Shars digital electronic mikes were the source of the confusion. So now I use the Shars mikes for roughing cuts.

 

[Nogoingback]

I think there's another reason for having quality tools besides the fact that they are more accurate or do the job better.
A good tool is a pleasure to use, and makes the task more enjoyable, which, after all, is why we have hobbies. I imagine all of us have tools that we particularly enjoy using: perhaps passed down from a relative, because they just feel "right"
in the hand or because we've used them for years and enjoyed making things with them. In my experience, poor quality
tools rarely fall in that category.

If you aren't happy with the Shars mics, for whatever reason, get rid of them and buy something that you'll enjoy.
There are lots of quality tools in good condition out there at good prices. You don't need to buy new or spend a huge sum of money.

 

[erikmannie]

I think there's another reason for having quality tools besides the fact that they are more accurate or do the job better.
A good tool is a pleasure to use, and makes the task more enjoyable, which, after all, is why we have hobbies. I imagine all of us have tools that we particularly enjoy using: perhaps passed down from a relative, because they just feel "right"
in the hand or because we've used them for years and enjoyed making things with them. In my experience, poor quality
tools rarely fall in that category.

If you aren't happy with the Shars mics, for whatever reason, get rid of them and buy something that you'll enjoy.
There are lots of quality tools in good condition out there at good prices. You don't need to buy new or spend a huge sum of money.

Great points. After I posted that, I sat down again with the same materials and played with them for a few hours. My tentative conclusion was that these Shars mikes would be able to get me to a thou at best, and the gauge blocks seem to be accurate to about 5 tenths. This is just my experience.

 

[mattthemuppet2]

I am trying to develop plate armor for the inside of tires for an electric bike.

The material for the plates is .045” Grade 5 Ti. The prototypes and fixtures are mild steel.

These bikes can travel up to highway speeds, so it can be a matter of life and death if the wheel assembly is out of kinetic balance. Safety always comes first.

I wouldn't sweat the metrology stuff too much to start with. In my experience you find out as you go along which aspects of metrology you're deficient in and fix those as they come up. If you're struggling to get repeatable bore measurements and bearing press fits, you get better telescoping gauges or step up to bore mikes. If you're working to tenths on shaft diameters, you get a machinist level, lathe test bar and maybe a tool post grinder. It just depends.

As for the project, that sounds like something for the Department of Defense, like for a Mine Resistant Armoured Personnel Carrier! I can't see motorcyclists (or ebike cyclists) being all that keen on the extra weight of Ti plates for what is likely to be a marginal improvement in puncture resistance over steel or aramid belted tires. Just by rough calculation those plates come out to around 900g per tire. That will have a significant effect not just on acceleration/ deceleration but also on the gyroscopic effect in corners. I ride an ebike around 9000 miles a year, every working day, and I get perhaps a puncture every 3000 miles. On really crappy rarely cleaned roads. It's a neat engineering project for sure, just can't see much of an application for it.

 

[erikmannie]

I wouldn't sweat the metrology stuff too much to start with. In my experience you find out as you go along which aspects of metrology you're deficient in and fix those as they come up. If you're struggling to get repeatable bore measurements and bearing press fits, you get better telescoping gauges or step up to bore mikes. If you're working to tenths on shaft diameters, you get a machinist level, lathe test bar and maybe a tool post grinder. It just depends.

As for the project, that sounds like something for the Department of Defense, like for a Mine Resistant Armoured Personnel Carrier! I can't see motorcyclists (or ebike cyclists) being all that keen on the extra weight of Ti plates for what is likely to be a marginal improvement in puncture resistance over steel or aramid belted tires. Just by rough calculation those plates come out to around 900g per tire. That will have a significant effect not just on acceleration/ deceleration but also on the gyroscopic effect in corners. I ride an ebike around 9000 miles a year, every working day, and I get perhaps a puncture every 3000 miles. On really crappy rarely cleaned roads. It's a neat engineering project for sure, just can't see much of an application for it.

Recently, when I taking 3+ hours to install 28 prototype plates in a fat tire, I was thinking "I would so much rather be working on my lathe right now". Today, I spent most of the afternoon on the lathe (so fun!), and I was thinking "This is so much better than installing plates in a tire".

So there ya go. I am going to put the bicycle tire plate armor project on the back burner indefinitely and do what I like which is working on machine tools and welding. At some point, a guy just wants to have fun.

I'll bet that most people here like to spend time making stuff in their shop.

 

[pontiac428]

When I first started out, I needed some measuring tools to keep at the bench while running parts. I bought a set of 0-6" individually boxed Chinese micrometers with the odometer digits that read thousandths, and a vernier barrel for tenths. The tools were smooth and worked pretty well. I verified calibration with a span of gauge blocks to within .0001-.0002 using the torque clutch on the thumb wheel. I did the same for my Chinese dial calipers. The tools tested good. Now, twenty something years later, I'm replacing those mics with Suhl, Jena, and Helios pieces (there's a theme there). I am under no misconceptions that they will measure better, they just feel better. So I've spent more on good used German calipers than I did on my new, perfectly good Chinese ones, and all I really have gained is a better, seemingly more consistent feel, and in some cases (Suhl) the calipers have big, easy to read heads.

Now, I've never used Shars' measuring tools, but I have a pile of Shars stuff that I've been very happy with across the board. Shars was great before the tariffs, now it's pretty good even at a higher price. I don't think they have much more headroom to charge for imported, tariffed steel before people find other, more equitable ways to buy what they need. But at the end of the day, Shars stuff is definitely useable, and we're their market. I think the stuff you've already bought will serve you well if you can find confidence in it.

 

[westerner]

But at the end of the day, Shars stuff is definitely useable, and we're their market. I think the stuff you've already bought will serve you well if you can find confidence in it.

This is, after all, the HOBBY machinist site. If you are being browbeaten to produce parts to NASA spec in production level quantity, this is probably NOT your site.
I love the atmosphere here. "Practical Machinist", not so much. Mostly due to the fact I AM A HOBBY MACHINIST.

 

[erikmannie]

This is, after all, the HOBBY machinist site. If you are being browbeaten to produce parts to NASA spec in production level quantity, this is probably NOT your site.
I love the atmosphere here. "Practical Machinist", not so much. Mostly due to the fact I AM A HOBBY MACHINIST.

This forum is indeed very helpful and friendly. I understand that Practical Machinist doesn’t even allow people to discuss Asian machines (my machines are Precision Matthews).