The 2 the Max Project

[JackM]

The above two posts serve as a good reminder to all of us who use tools on a regular basis. Its so easy to become complacent. You only have two eyes. Same goes with hearing protection. I developed tinnitus (ringing in the ears) a few years ago, and have to blame it on using chainsaws, weed trimmers, guns etc, without ear plugs in. Thanks

[Hydraulic Jack]

Max,

Looking at the design pieces, I am going to predict that the foot rest arm, the part that will bolt through your spacer with two small bolts, is going to flex inward toward the wheel when you push against it with your foot. I would add a third bolt at a minimum on the opposed side of the swingarm pivot housing so that there will be three bolts in a uniform triangle around the swingarm boss. This would require welding a tab and making the arm a bit larger around the swingarm boss. Even then the footrest arm may bend inward unless it is quite stout. If that happens you may need an additional tab behind the swingarm boss on the frame downtube, with an additional bolt or two there.

[hodakamax]

We are still kicking this pipe around with no results. It looks quite acceptable from the top but the bottom is awful. All the dent pullers are shaking their head and willing to try but with no guarantees. I tend to agree with them. Today the clever guy who built the Day One project and I decided that it was time to roll a new cone and do it right. This guy does good work on such things and I have complete confidence all will be well.

By the way, my second Dewalt 1/4" bit also broke while drilling the frame on the other side. Scary, I had a face shield on this time and it did stay in just two pieces rather than the tree of the other one.

A small but non-the-less report from the Cycle Shop.

Max

[matt glascock]

Hey Maxie, Do you think that chamber might be a candidate for filling with water, capping, and freezing or were you thinking of cutting out and welding in new divergent cone?

[Bill2001]

Oooch, that is unusual. I rarely, if ever, break a larger "Letter" drill. Smaller "Number" drills, all the time. Don't 'spose it's a bad run of the bits?

One of my design criteria revolves around repairability in the event of a mishap.

[Bullfrog]

I agree, some sort of "hold down" in front of the swing arm pivot bolt would be a good thing for the peg plate.

On the pipe, there are guys who use heat and controlled air pressure to "blow" pipes back into shape. Seems like a procedure to NOT try at home . . . but they securely plug the pipe ends and provide for a means of metering air into and out of the pipe. They heat the deformed area to red (pliable) hot and basically "inflate" the deformed area back into shape. Sorry, I have no leads on where to get that service now - knew a guy once who did it.
Ed

[hodakamax]

A long, long time ago we had a guy on our racing team who built pipes. A local sheet metal shop would cut out and roll the cones and our man would piece them together. The hard part was fitting and turning corners with cones. In this case we have a simple truncated cone to replace and we have an original cone to compare to. We can draw out the cone on construction paper and even fit it precisely before cutting out the metal piece by wrapping the pattern around the original. I'll cut the mounting bracket out of the cone so the fabricator can get a really good fit." What could go wrong?" I always say.

As for the foot peg plate needing more strength at the swing arm pivot has been considered and addressed. The plate will fit over the swing arm boss with a somewhat precision fit as does the spacer. This prevents any rotation. Contact points on the really stiff plate will be 100% on the spacer, near 100% on the swing arm boss and tightly along the frame down tube. Most forces should be rotational and not lateral. All should be well if not over engineered. What could go wrong?

Maxie

[hodakamax]

Here's a quick prototype idea just cut out from floor tile to show the concept. I still haven't figured out the exact position for the peg and it could even have different holes for different positions. The final will be constructed from 1/4" aluminum.

Max

[Bill2001]

I like it. The OCD part of me says "it'll be twisty and bendy" but the Practical part of me says "try it and see". Maybe you could run a secondary stay from the footpeg area down to the lower frame tube. Triangulation is spiritual.

I'm having my own obsessive-compulsive episode m'self. Upgrading to a heavier trailer hitch so I can mount a bumper carrier for the Hodie (got a DiscountRamps-dot-com "BlackWidow" 600 pound carrier in case I need to rescue my Beemer or a friend's bike). The hitch is a NAPA universal fit that is giving me fits.

Ah, the pipe cone. I remember an exercise in drafting class in high school where we'd draw a side view of a trunc cone and by projection "unroll" it to make a pattern. Holler if you need help.

[Bullfrog]

Thought I'd offer up an illustration showing my concern about the peg mount. It IS a difficult problem to "cure".

Weld a stud sticking out sideways ahead of the swing arm pivot? Weld a nut on the frame ahead of the swing arm pivot to accept a bolt where indicated? Other? Leave as currently envisioned, use washer under Allen head bolt and check tightness often?

Decisions, decisions . . .
Ed

[hodakamax]

Whoa! Good illustration Ed! Yes, I considered welding on a tab for third bolt but this thing is rock solid. With the stiffness of the plate and the circular contact with the boss this thing feels like part of the frame. The washers you mentioned will help even more. These are not even stand-on pegs due to the seating position. Meanwhile I've built a less fat prototype plate and put a bit more drop on the peg. Hey, this is fun stuff!

Maxie

Hmm, It just occurred to me that the final plate will be flush with the swing arm boss and a washer could be put both ends of the swing arm bolt insuring flat contact with the frame via the spacer. More to come as I try this.

[Bullfrog]

Maxie! That's a slick idea for positively clamping down the front of the peg plate!
Ed

[Hydraulic Jack]

Max,

First of all, you are doing prototype experiments here, so try whatever comes to mind. Why not.

But..... don't do the two or three hole design on the legs. All this does is make weak points where the arm will bend. Quarter inch aluminum isn't structurally sound material to begin with. Creating flex points will just make it easier to bend. I can bend quarter inch aluminum by hand if one end is clamped down, as your extensions will be.

The other bend point will be at the down tube because this will be the fulcrum under the lever that is the extension arm.

No, you won't be standing on them. I got that. But you will be bracing yourself against them, and on a motorcycle you can't always be gentle on the foot pegs.

Bolt one up, sit down, push back with a foot and watch the extension arm. If it flexs enough for you to see it flex, it will eventually fail. That would be ugly at 100mph. I think you will eventually need some sort of three dimensional backbone on the extension arm to resist flexure, and the backbone will either need to be attached to the downtube, or pushing against it firmly so that tendency to bend is transmitted into the downtube at a right angle. I would draw a picture, but don't have the photoshop tools Ed has.

[taber hodaka]

Wear pointed toed shoes, as to theory you will go faster. Use two stirups from a small saddle, thrown over the fender as they adjust and are made for a little flex Did you get the Van Tech?-----Clarence

[hodakamax]

Wear pointed toed shoes, as to theory you will go faster. Use two stirups from a small saddle, thrown over the fender as they adjust and are made for a little flex Did you get the Van Tech?-----Clarence

Whoa! The Van Tech thing got out of control! I was out early after testing the waters. I was going to go a couple of hundred but that didn't last long. They would have been cute on the Day One Project. Somehow I've already got too many projects started at once.

Max

[hodakamax]

A couple of items of note. I don't know the grade of this aluminum plate but It seems to be exceptionally stiff and tempered. Hole drilling lightens and exhibits design but can weaken parts. All holes in the two prototype pieces have at least 5/8" of material surrounding them. Of course the final test will be to build a final and see if I can make it fail. All part of the process. Advice helps, I'm not a certified engineer, but I do study something in depth before risking life and limb on it. Projects like this certainly are educational (and fun), again all part of the process. Thanks for everyone's interest!

Maxie

[Bill2001]

Max, google "rear sets rearsets" and review what others have done. And even at add-on passenger pegs. This will at least give you an idea of what worked before.

The Van Tech caper on eBay went bonkers!! This was my first serious auction and I pursued it strongly. I'm convinced that one other bidder used an auto-bidding program. He responded too-instantaneously with counter-offers.

I'm still looking for a set of Van Techs. Holler at me, Clarence.

[taber hodaka]

E bay bidding is auto, if the other bidder bids less than you, you win for the $$ of his last bid plus the increment. Trying to raise the bid in the last second does not work. Bid the amount you would be willing to pay. -----------Clarence

[hodakamax]

[quote="Bill2001"]Max, google "rear sets rearsets" and review what others have done. And even at add-on passenger pegs. This will at least give you an idea of what worked before.

Hey Bill, Yes, I've Googled, E-bayed and Amazoned this subject to the max so to speak. Hours probably. By using this plate, I'd like to have the control shift and/or brake shaft go through the plate in a mounted bearing with the crank on the inside of the plate. Most of the ones I see have a bolt on footpeg with the lever and pivot arm on the outside. The good and expensive ones have the arm angle adjustable to any degree. Just studying the situation. Once I get the plates in position I can get a bit more serious on the mechanisms. Here's one in the cart that looks to be a possibility. $80, USA, adjustable pivot arms. Check it out.

Max

[Hydraulic Jack]

I don't know the grade of this aluminum plate.........All holes in the two prototype pieces have at least 5/8" of material surrounding them.

Maxie

Max,

There is a formula for determining the amount of force needed to bend aluminum stock. Two of the variables in that formula are the tensile strength of the stock and the width of the material to be bent, multiplied together. Since we don't know the tensile strength of your aluminum stock, we can only demonstrate the relationship between full flat stock versus stock with holes drilled for lightness, rather than actually computing the true result, but really, the only question raised here is just how much drilling reduces strength, all other things being equal. So, all you need to do is measure the width of the stock as drilled versus what the full width is at the point it is drilled, and create a ratio.

For example, let's say that at the point your stock is drilled, it is three inches wide, and after drilling the hole, the total width of remaining stock is 1.125" (5/8" times two). The relative difference in strength regardless of the alloy or temper is the same: 1.125" / 3.0" = 0.375. With these dimensions, the resistance to bending after drilling the hole is roughly one third (0.375) as strong as it was before drilling. No matter how stiff the stock may seem, drilling lightening holes greatly reduces its native strength, while at the same time reducing weight by only a negligible amount. I would not give away two thirds of the strength of the stock just to save a quarter ounce of weight, or to make the part look artistic.

[Bill2001]

You have certainly read up and researched the subject adequately. Give it your best shot and if it breaks, improve it. All these niggling details can drive one nutso, but it is so nice to look at the product years later.

[hodakamax]

Thanks Jack. I think we all agree that holes weaken parts. I admit that if I want to reduce weight, the quickest way is to put the rider on a diet. I could easily give up five pounds rather than weakening parts grams at a time. Art is part of this project so I'll have to design the part to meet requirements rather than to be as strong as possible as in overkill. A fine line sometimes. I find aircraft an interesting design and challenge for the designer. It must be strong, light and aerodynamic. Lotsa holes are drilled to meet the weight requirement. It all adds up. Or a spacecraft where grams are big money in launch costs and/or payload limits. I guess what I'm saying is that I have the problem, I'm trying to build this project with some parameters. In this case it is like an aircraft. Requirements are similar, light, aerodynamic, strong, fast, hopefully safe and should look good with innovations. I don't know if I can meet all these requirements. Projects like this are a challenge, a game to me, a giant model or piece of art. All quite entertaining I might add!

Just rambling and being philosophic this rainy day. I always appreciate your and others advice. Part of the game is to please the Gang!

Max

[viclioce]

I've always liked the design aspects of your drilling and lightweight creating effects, Max. You did a similar design & function with the previous chain guard on the last project. It was fun to watch! Again with this piece, it DOES have a rather aerodynamic aircrafty (pun intended) look to it. And I'm assuming you'll use the same design but reversed for the other side? And then there will be the relocation of the brake pedal as well! Good luck & I can't wait to see the final results for both sides! ,Victor

[Bill2001]

Art is part of any project. Verily so.

One rule of thumb on RC aircraft built for competition, which have to be light and strong: make the part lighter and lighter til it breaks, then strengthen it so it doesn't break.

[hodakamax]

Hmm, I haven't had to construct a cone for several decades but I took on the challenge. This project is supposed to be educational. Home-made does't mean hiring it out. After I got the mounting bracket cut off, I did remember that a cone is part of a circle. Two rulers determined the angle and radius and my stick compass marked the circles. Now the fab guy can play with the cut-outs before cutting the piece out of metal. Fun.

Maxie