Jeep2003 has your answer Karen, you take a block of steel and bore a hole the same size as your tubing diameter in the exact center then split the block at the hole so you end up with two identical blocks and then you use em with a press to smash the tube. Sounds easy but it's not, you have to guide the two pieces together with the tube centered while pressing. Ask Jeep, he'll go over it with ya I bet. A dedicated punch press that does it and punches the hole is ideal, I've considered buying dies but they are high rent and I'd maybe ever use em a few times. I have pondered buying a pocket rocket bike and using the components to build myself a Tom Thumb, I would likely use square tubing and build a mini Hound Dog. Gotta get the 7 project minis built or sold first, I'll likely buy even more and never got to it but it's nice to dream. For now I'll watch your build, anxious to see what engine you use. I know a guy who has a bunch of O&R powered drills and other small gas powered tools with O&R engines but shudders when I talk of robbing one off a drill or auger to use for a minibike. There are some high rent Fuji hobby engines out there in 24cc to an 86cc twin, Phil's Hobby Shop sells em.:thumbsup:
TOM THUMB by MANCHESTER
- Thread starter manchester1
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After Ace posted about those dies Jeep2003 uses, I got to thinking if there are any commercially made ones. So I did a Google search. Found this site along the way.
Dies for tube crimping or flattening? - OFN Forums
Dies for tube crimping or flattening? - OFN Forums
That is similar to what I'm talking about if not exactly, very cool tool to have there. I like the other ones too how they guide the blocks, if there were two reliefs in it to radius it I believe it would look better. I'd love to have a Tubing Shark and a punch press, I'd start building many things but minibike frames would be 1st.:thumbsup:
Karen, I had a bunch of O&R engines when I built my Tom Thumb bike. They do not have enough power to push the bike to 15mph. The other problem is that you have to find one with the correct output shaft for the clutch and it seems like the ideal output shaft is hard to find. I ended up using an Italian Blata engine. It puts out 3.3HP at 11,000RPMs and pushes my bike about 30MPH. I looked at a lot of engines and the biggest problem was that they were too tall to fit in the frame. :doah:
I hate to say it but just Google "pocket bike engines". Start asking sellers questions about dimensions, carbs, pipes, and parts availability. I looked a long time for something that was short enough to fit in my frame. A new high quality european engine with carb and pipe is probably going to be over $800 and a Chinese clone with carb and pipe should be under $200. But, there are plenty of good european engines on ebay for decent prices. Keep in mind that a decent 49cc engine will easily put out 3+HP. 