Making jig for welding front part

I have never used jig to make python. But this time,I need it.

That's simple construction. Rectangular pipe has screw and angle of 90 degrees.






Then set front parts on it.





After taking, I took off the jig and welding. I should not do it.



My welding becomes better.

I set the front part to the jig. Then I noticed it lost balance.

The center of folk and BB isn't much and a edge of the BB was high than the other one.
I thought about solution. At last, I cut the narrower pipes then with cramping BB and front fork, I welded them again.


Next task was welding pipe for front deraileur on the BB.

Around here, my welding didn't work well.

I welded two pipes between the front fork and the pipe for front deraileur.

This is front part. To check the position of handle, I need welding rear dropouts and making seat.

Preparing for next job

I cut some pipes and a one of them was cut like fish mouth.

And two of them were bent a little.

I ride my new pink python. It's comfortable than normal bike.
I noticed one problem about shift lever. They are too near seat.

Welding drop outs

I welded dropouts to the edges of front fork.
At first, their edges were covered.

Then, right drop out was welded.

The other side.

Next, I checked the position of left drop out.

Maybe good, I think. I'm not sure this way is enough.

At last, some small parts for bike are needed. I took them from my own designed first python.

This means one of my python can't be ridden. That's ok. I checked my welding skill during breaking it. That's needed to make better bike,I think.

Tension of spokes and data of wheels

The following word "front hub " means rear hub for normal bike.
"Rear hub" means front's.
Because the python drives by front wheel.

Rim Kinetix 24 inches
ERD 473 mm
Hub Kinetix
Distance of flange from the center
Front
Right 19.5mm
Left 34.3mm
Rear
Right 32.7 mm
Left 22 mm
PCD 58 mm
Hole diameter 2.5 mm
Spoke length for 3 cross
Front
right 225 mm
Left 227mm
Rear
right 231mm
Left 230 mm
Front
Right ( chain side ) 173 kg
Left ( disk side ) 107 kg
Rear
right ( non disk side ) 153 kg
Left (disk side ) more 173 kg

The other pair
Rim Alexrims ACE-20 24 inches
ERD 489 mm
Hub Sram 506
Distance of flange from the center
Front
Right 20.15mm
Left 34.45 mm
Rear
Right 33.2 mm
Left 22 mm
PCD right 45 mm left 58 mm
Hole diameter 2.5 mm
Spoke length for 3 cross
Front
right 235 mm
Left 235 mm
Rear
right 236 mm
Left 233mm
Front
Right 120 kg
Left 70 kg
Rear
Right120 kg
Left 153 kg

These measurements of tension measured by TM-1 Park Tool.

The tension is too high ?
I don't have any ideas about that.

Lacing wheels

I got spokes. The length is ordered. The spoke for 24 inch wheel is very rare.

The hub and rim were bought as completed wheel. But the balance of tension of spokes were bad. So some spokes were broken at my second day of riding new python.

I chooses 3 cross lacing. It's tough.

We can see many sources about lacing on the net. I found one for front wheel for MTB with disk brake.








Then,


It took 4 hours by here.
The lacing for rear wheel is different with front 's.









Today's total work time is 11 hours. I enjoyed too much.

Making front fork

I cut some parts like this for welding. I don't know whether this way is better. To know that, I have using this.

Next, I welded steering pivot. To keep the hole, I used brass round bar.

Then the steering pivot and the rectangular tube were welded.



This time I can check my welding from inside.

The back side was sanded to get flat.

They were put along the drawing then tacked.

I tried to change the voltage. From left to center, high power. From right to center low power. This part had 90 degrees angle and one side is edge and the other is surface. In this case, high voltage is better.

We can see the form like fork.




Today's last shot.

I can't leave beautiful bead yet.

Making main frame

I started cutting steering plate.

Then main tube was cut.

They are combined like this.

They were tacked and welded.

The edges of the main tube are bent to cover steering plate and welded.
after that, they were cleaned.

The main frame are bent.

But in this time, I cut it and combined them.
Then, tacking welding.

This zig zag frame and rear fork were welded. I used this connecting way like wood.

The edge of the main frame was cut like when the steering plate was welded.

The edges of rear fork were covered.





Some dust is left inside of the tube. How can I avoid this ?
That's last shot.