[CraigLam]

Delray, that was excellent advice. I made a v-groove set up, like the picture shows, with a c-clamp. I got a hole saw, but, the pilot bit doesn't go out the other end all the way. It wobbles. However, it still did a good job. I still have to clean them up on the grinder, but, not that much. I drill down about half way, turn the tube over and then drill the other side. It works really good. I'll still have to buy a good mandril. No problem. If you look at the bottom photo, it's not quite in the center.

[delraydella]

Nice! Glad to hear that it worked! These center finder gauges ( pictured below) work great . They are about $10 (+/-) and should be available at industrial supply or machinist supply stores.

An easy way to get center......take a scrap piece, lock it in the v-block , start the drill press and bring down the drill bit til it just touches the tube. If the bit starts to wander or bend as you apply pressure, you know you are off center and can adjust your v-block accordingly. Keep doing this until you hit center. The bit won't wander or bend on dead nuts center.

(edit)....check to make sure your table is level and square to the drill bit too.

Other Steve

[weldin mike 27]

Hey there,

Thats a beautiful fit up. Nice work. Hope it was easy enough to make for you to make many of them for your mini bikes.

Mick

[NorCalWelding]

I just got done with some modifications of a mini bike frame. The customer wanted a bigger fuel tank so he's removing the tank from the engine. I put a long tank under the seat made from aluminum.

[Otto Nobedder]

Slick!

How close is the tank to the cylinder head? Will you need a heat shield or air deflector to keep that thing from getting warm?

Steve S

[NorCalWelding]

Slick!

How close is the tank to the cylinder head? Will you need a heat shield or air deflector to keep that thing from getting warm?

Steve S

Not sure. The customer is putting the motor in himself. I haven't seen it.

[CraigLam]

NorCal, that is a super nice set up. It looks like an Azusa design. Mine will be the Taco 100B. After a lot of research, the 100B was the best choice for selling mini bikes.
Anyway, I wanted to let everyone know that the my Takas Bender is finally finished. I went to HF and picked up the air/hydro bottle jack and it worked fabulous. Here are the photos.


One thing that I added was the legs which you can barely make out. That's so the air assist chamber wont hit the ground. Also, I need to use my large compressor. My small pancake compressor doesn't have enough reserve to keep the piston moving. This Wed. I'm picking up the material to start the 100B. Now, I'm going to clean up all the welds, finish a few that I missed, prime and paint. Gloss black. I'll keep the photos coming so you can see my progress.

[TamJeff]

Very nice indeed. You have me wanting to build mini bikes! What a great project with the bender. Our pro tool notcher doesn't use the drill bit with the hole saw. Is there a reason why you need it with your setup?

[Otto Nobedder]

That "notcher" is a drill press, and is not secure/solid enough in attachment or spindle accuracy to notch without a pilot bit.

I think at one point in the discussion I mentioned the "Ol Joint Jigger" as a brand of notcher used in the homebuilt aircraft market for 4130 tubing; I think this is the most economical choice I've seen for the accuracy, but it can be done in a drill press, with a center-finder, center punch, pilot bit, and lots of patience and cutting oil.

It's apparent he can do it well enough for mini-bikes with that set-up.

Steve S

[delraydella]

The v-block/ drill press method of notching does work pretty good if you're in a pinch , need a couple of quick notches and don't want to lay out the $$$$$'s for a better quality one, but it should not be used for any production work or anything that needs close tolerances. Unless you can lock down everything on the drill press 6 ways to Sunday, theres always going to be too much vibration, something will slip off center, etc, etc.

Harbor Freight sells a halfway decent notcher for about $50 (+/-) but it's only suitable for light work and it takes about half a day of shimming and adjusting just to get it to cut close to center.

The biggest problem with the hole saw notchers is that you are limited to what size pipe you can notch by the depth of the hole saw. The high end notchers use either an end mill or an abrasive belt.

These guys pretty much wrote the book on quality notching machines.... http://metal.baileighindustrial.com/met ... ?limit=all

[Otto Nobedder]

I had some thoughts on a drill-press as a light duty notcher.

Replace the pilot bit with 1/4" drill rod, and locate a drill bushing at the BDC of the v-block jig, so the spindle is locked to the pipe centerline above and below. For larger tube, grind rough v-grooves in the pipe to be notched, to fit around the drill rod.

If the v-block is secure enough, this could be as accurate as any of the low-buck notchers.

Just two cents from letting my mind wander.

[delraydella]

That sounds like it could work, the table would need to be dead nuts level and square to the drill rod so it wouldn't bind. The v-block would need to be fairly precision for the same reason, no warp or cant and ground flat on the bottom.

I can see something in my mind that might work, a precision v-block bolted to a modified 1-2-3 block might just do it.....

[TamJeff]

I made one for our drill press. I used an annular cutter instead of a hole saw. I made the frame go all the way across the table with the V on that and it is held with 4 r11's. I used a pipe above it the size of the broach to center it with reliefs cut out at the business end so the swarf can clear. The only problem with it is I rarely cut 90's. It was more of a jig for one run of a couple hundred parts and come to think of it, I haven't seen it in awhile.

I put 1/4 SS rod in my hole saws for freehand cutting. I weld them in on the chuck end. Someone was always swiping the set screw bits and that cured that.

[CraigLam]

There are some great ideas and advice for notchers. The Baileigh notcher looks great. But, they're all so expensive. Tomorrow is the day I actually buy the 7/8" tube. I did the layout on the parts I will be making. Most of it will be hands on for the final production.

I spoke to T.J. at Azusa parts today and he was super helpful. I now have about 6 standing orders for mini bikes. I asked him if he would help me to price the bike when I'm finished. I will keep every receipt and log all the hours and even the gas I use for my van to calculate the cost of making the bike. I also asked him if I was misunderstood about the popularity of these mini bikes. He said not at all. These mini bikes are very popular. I checked the sales records on ebay and the new ones seem to sell very well. I will take good photos to record the progress.

[TamJeff]

That's awesome that you have orders for things that are actually fun to build. Those notches are actually pretty nice that you have there. I saw what looked to be a streetable version of a big boy's mini bike today. That would be a fun way to get around.

One thing about the pro tools notcher. The bearings in the spindle portion of it get worn and the hole saw shaft wanders by as much as a 1/4" at the saw. They have a large Milwaukee 1/2" reduction drill in ours and I have seen it tweak some wrists for the unsuspecting. Perhaps they have evolved as this one is 15 yrs old. But comparatively, I bet your drill press one can be turned into a better one than ours at least.

[Otto Nobedder]

http://www.jointjigger.com/

The base model is about $175, the "deluxe", $225.

Can be powered by a half-inch drill, or a drill press (assuring wrist safety).

Steve S

[TamJeff]

I went into the shop one day and saw that the cord was wrapped around the drill on the notcher about 6 times. I knew what had happened. I had warned and warned that he had better hold onto the drill tight enough to stop it when using it. His arm was black and blue like he had gotten in a fight with a ninja with nunchucks. . . .and lost.

It's best to make sure the leading edge of the slots in the hole saw are below flush. If they are proud in the direction that the saw turns, they can snag the sharp edges of the cope, causing what I described above. Not only that, it can strip the threads in the hole saw or the shaft that it screws onto. DAMHIKT, lol

Whenever I attach a new hole saw to the notcher, I tap that catchy side of the slot down with a hammer ever so slightly slightly.

[CraigLam]

I was so P O'd today. The only place that had 7/8" tube was Tell. Everyone else was out. So I bought some. I thought that the surface rust was light. When I wet sanded one of the tubes, it was pitted really bad. I called Phillips and they ordered some and will be in tomorrow afternoon(God Bless 'em). I'm gonna use the crappy stuff for templates. I'm getting use to using the bender. I have a simple angle finder that works really well. I'm gonna take some pictures and show how I did it.

[TamJeff]

That's all I use is a simple angle finder and a speed square.

[CraigLam]

Phillips finally got some tube in today, so, I went and pick up some up. I'll probably work in the shop tomorrow all day since the wife will be cleaning up for the big game. I need the bender to be level when I bend pipe and I was using blocks of wood as shims. That sucked. So I went to a surplus nut and bolt store and pick up some hardware to make some adjustable feet.



The bolt side sits up inside the leg for more adjustment. I've made a few more bike parts, but, wont take pictures until tomorrow.

[mikewalker11]

I've used sand inside brake lines to form them. Works Awsome. Building your own tools is great and they end up working better than store bought poop.

[CraigLam]

So, I'm at OSH and I'm talking to Franco, one of my friends that work there, and a guy, about my age, comes up and says that he overheard that I was making mini bikes. I asked what bender he was using. He said the one from HF. I said, "Oh". I told him about the Takas bender. He said he never heard of it. There's nothing wrong with the HF bender. But, it doesn't make the "perfect" bends like the Takas, especially when it comes to the really tight bends. I don't know what kind of mini bikes he's gonna make, but, I wish him luck.

[CraigLam]

Today, I bend. The first real day I started the mini bike project. Every step of the way is recorded. Angles, bends, degrees of bends, everything. I'm not sure when I start selling these, to sell them complete, which is the best, or as kits. Some companies sell these as kits that people weld them together. That's nice, but, too much can go wrong. It's better to sell them already complete and you just assemble the parts. I'll figure out the plan when I make a few units.

Here you can see the angle finder. Simple, but, it works good.

Fork pivot with bearings instead of just a 5/8" bolt.

I've made the side frames. They are a compound angle. This took some layout. The back and the bottom rails are to be parallel. But they angle in at the fork pivot. The next step is to notch them to fit into the pivot tube. After this is the fork plates.

[mikewalker11]

That is killer! That bender looks like it works way better than mine! I wanna make one. What an Awsome set up.

[CraigLam]

Mike, got a photo of your bender? This Takas bender you have to build. They're not hard to build, you just have to take you time. The tube comes out so perfect, it's hard to see the transition point where the bend begins and ends. I looked and looked and saw alot of do it yourself benders on the web and none of them came close. There was one that looked really good from Pro-Tools, but, the jack was on the top not underneath. Hence, you couldn't do 180 deg. The best feature about this bender-it's small in size. All the other mandrel benders mount on a table thus making it impossible to bend in a small area. You need a good compressor one with a good recovery @125 p.s.i. Send a personal message and I'll give you the address. I used all scrap steel. About $150+$80 for the HF air/hyd bottle jack. Then shop for the radius bending die you want which will depend on the project you select. Remember, this bender will bend .120 tube steel-no problem.