Archive for March, 2013

Title Bits

Arrrrr-gon, I was lacking a clever title so I thought I would tell one of my very own homemade pirate jokes. Here is another one. What do pirates take on vacation? an Arrrrr-V. Lets move on shall we?

I had taken on my CB160 cafe racer project as my main garage focus and continued to do little side projects in between. It would appear that my 65 Revive project is starting to become the side project as I continue to get side tracked with numerous project that seem to be taking up the majority of my time. Either way I continue to stay focused on the Honda build and still make progress using what little time I can find.

I decided it was time to tackle the exhaust. There was no reason why the exhaust was the next required step it was a decision based purely on what I felt like doing. I had already mentally designed the system and had ordered all my stainless steel mandrel bends from Columbia River Mandrel Bending as well as my muffler from Megs Mufflers. As much as I would have liked to just jump in and start seeing the system come to life there were necessary preliminary steps that needed to be performed before the `glory`work could commence.

The original header pipes had flanges bent into the tubing in order to allow for a gasket surface as well as a way to secure them to the cylinder head. I had played around with a few ideas as to how I would accomplish this on the new stainless pipes and had finally settled on machining some flange rings that would get welded onto the down pipes.

Another item that needed some attention before fabricating the entire exhaust were the factory cast finned flanges that secure the exhaust to the cylinder head studs. Since I was building a fully welded 2 into 1 exhaust system I needed to thread the flanges onto the exhaust downpipes before welding up the system. The flanges would be permanently installed onto the exhaust system therefore I needed to perform final finishing of the flanges.

So I`ll let the pictures walk you through the details. So far everything has worked out perfectly and I look forward to seeing the exhaust system take form.

OEM Downpipes

These are the factory downpipes for the CB160. You can see the pressed flanges that fit into the cylinder head. The orignal set up was a dual exhaust however I have opted to change things up to a 2 into 1. Using Megs Mufflers collector size chart I opted to feed the factory 1.250″ primary pipes into a collector with a 1.50″ outlet.

Machining ex flange

In order to get the flange I needed on the primary downpipes I decided to machine them up. Here is the finished machining except for the trimming to length.

Header pipes with rings

Here is a shot of the 2, soon to be, new downpipes with the freshly machined flanges ready for welding.

Press fit flanges

I machined the flanges with a very slight interference fit in order to help hold them in place while they get TIG’d on. The fit is fantastic.

Doin what I love

Laying down the molten.

Ex flange weld

All welded from the inside, no clean up required. I love welding staniless.

Powdered ex hold downs

Here is a shot of the factory finned exhaust collars that secure the header pipes to the cyclinder head. Since these flanges will be an integral part of the new 2 into 1 exhaust I needed to clean, glass bead blast, and powder coat them. I ordered in high temp powder coating just for this occasion.

Trimming mandrel bends

Trimming up all the mandrell bends on the bandsaw makes the fittment so nice, all the cuts are square and the joints fit up perfectly.

Argon feed

Thought I would show my stainless steel wedling set up. Since stainless “sugars” so badly on the back side of the weld it is important to back purge it when it welded. This simply means that argon needs to get pumped not only on the top side of the weld but also on the back side. I built my own back purge set up. I added a Tee fitting to my argon regulator and attached a ball valve plumbed with a 1/4″ pneumatic airline.

Back purge valve

I then run the 1/4″ pneumatic airline to a regulator and another ball valve. I made this little unit so I can clamp it to my wrok bench near by where I am welding therefore it is quick and easy for me to control the valve before and after the welding.

Pipe purge plugs

I use surgical tubing from the work bench mounted valve to a couple of silicone plugs. I stole the plugs out of my powder coating kit. I drilled holes through the center of the plugs and inserted an air needle used for filling up sports equippment. One plug acts as my inlet and the other is my exhaust.

Ex set for tacking

Here you can see the set up in action. I simply feed argon into the pipe and allow all the air to exit the other end. Once the pipe is filled with argon the welding can take place and sugaring of the welds backside is prevented. It uses up the argon a little more quickly however it is worth it considereing the weld quality it produces.

Mocking up 2 into 1

And here it is. All the prelimary leg work completed. It may not seem like much but it is a required step on my way to getting the complete system fabricated. Now I am able to get onto the actual forming of the sytem.


Title lathe cleanout

I perform a fair amount of side jobs that I never post since they are usually either too small to mention or they are not of much interest. I decided to post the following and even though it’s not that fascinating to look at it is still representative of what goes on in my garage.

A friend of mine who does carpentry work was in need of a solution for his router table. He has a Dewalt router that fits into a router base that is permanently attached to the underside of his router table. The issue he has is with the adapter that allows bolting of the router base to the table. The universal adapter plate is plastic and is attached to the aluminum Dewalt base using, what looks like, three 4mm bolts that hang on by 2.5 threads. The problem is that the small threads can only handle a light router load as my friend found out the hard way. Placing a larger load causes the threads to pull out from the router base and then bad things seem to start to happen.

He had asked if I could build an aluminum adapter plate and beef up the bolts that secure the base to the plate. Normally I don’t get very excited about projects like this however there is a part of me intrigued by the challenge associated with improving on a manufacturers short comings and making the result look pro at the same time. I am unsure who manufactures the plastic adapter plate, it may be the maker of the router table or it may be DeWalt. Regardles I figured I would see if I can show up the original designer with some home hobby metal work. Now mind you I understand that manufacturing costs play a huge role in the kinds of products companies turn out and that is most likely why the adapter plate is plastic however…it always feels good when the little guy can step into the octagon.

I’ll leave the narration to the pictures. You will be able to figure out the process as there really is nothing complicated. It was still a 10+ hour project for me but it not only produced a successful product but it also came with a decent level of satisfaction.

Factory plastic base

The plastic adapter plate to the left is what I am dealing with. The pressed in metal nuts are what bolts the adapter to the table. The plate is first bolted to the aluminum router base with 3 small screws.

Squaring router housing

I needed to re-drill the aluminum base to allow four .250″ to be used as the main load bearing fasteners. I squared the base up on the milling machine and then used the DRO to dial in 4 perfectly spaced holes.

Measuring bolt spacing

I needed to calculate the factory spacing of holes in the plastic adapter plate. Instead of using calipers to determine the spacing I decided I would use my DRO to perform the measurment. Turns out bolt spacing was exactly 118mm.

.375 6061 flat bar

I opted to plasma cut a rough aluminum adapter plate out of 8″ x 3/8″ 6061 aluminum flat bar. It is about .080″ thicker then the plastic base which will allow me some extra metal for machining.

Drill and tap base plate

I drilled holes on the adapter plate before I machined it. I needed to use the center of the plate to base all my calculations off of. Doing it before I machine allows for quicker machine set up as well as will allow me to bolt the plate to the base for machining. I added 6 holes, instead of the original 3, for mounting to the router table. This way the router base can be positioned in 60 degree increments to allow for ideal access for tool changes.

Router housing mounted

My lathe chuck is not large enough for me to mount a 7.5″ aluminum plate to. After standing and staring at the lathe for 10 minutes I finally figured out that I could mount the plate for machining by using the router base as an adapter. Worked out great.

Hogging out router base

Here is a shot of the rough machined adapter plate. I trimmed down the perimeter and then bored out the center to match the same dimensions as the plastic adapter.

Router base freshly machined

Here is what the plate looks like freshly machined.

Rough polish

I could have deemed the project complete at the point of final machining however I still wanted to “one up” the original design so I opted to anodize. I hadn’t anodized for quite some time so I figured I had better use this project as a practice oppurtunity. In order to get a good anodized finish I find it is nessecary to polish the aluminum first. This picture shows a very rough polishing as there are still many scratches evident however for anodizing this works just fine.

Router base anodized

After prepping and cleaning the new adapter plate recieved a 2 hour bath in a sulphuric acid solution.

Current control

Current was controlled at 2.75 amps for the 2 hour period.

Base in dye tank

After the anodizing process was complete the adapter plate recieved a 6 minute dunking in some warmed up Red Bordeaux dye.

Freshly dyed

This is what the dyed anodized plate looks like fresh out of the dye bath. Cool!

Sealing the base

All that was left was to seal the dye in by soaking the plate in boiling water for 30 minutes.

Finished router base 1

Finished product! Looks, and will perform, much better then the original plastic unit it will replace. You can see the 4 new .250″ bolts that will, hopefully. outperform the orignal 4mm bolts that were pulled out of the threads.

Finished router base 2

Finished router base 3

Title Petcock

So I was able to get back onto the CB160 cafe racer project. Building the monitor stand was a good break as it allowed me to regain some focus on the 65 Revive situation. I had got my way through the kick stand project and I was happy to have got that challenge over with. Building of the kick stand was a necessary step in the master plan in regards to the exhaust system.

Getting into position

Decided to flip the bike upside down to make the fab work a bit more accessible

The bike is going to get a full custom stainless steel 2 into 1 exhaust system. In order to accommodate the exit chamber for the CO I needed to clear room under the engine and frame. One factory component that needed to be removed was the center stand as it sits exactly where the exhaust will need to be routed. So with the side stand previously fabricated I was now able to start chopping up the factory frame.

Center stand has to go

This is the mess I am dealing with. I realize it is hard to decipher the details based on the picture however much of what you see needs to go.

With both the center stand removal and the future exhaust work required I had thought about raising the bike up onto a couple of saw horses. This would have required a second assistant but at the time I was ready to start work there was no one in sight. I figured the bike has no liquids in it, except for the shocks, so I opted to flip the bike upside down and rest it on the rear frame rails and the original handlebars. I am glad I did as it made the frame mods so much easier to execute.

Starting to clean up

I needed to get a better idea on where to chop up the frame so I started to cut tabs and supports off in order to gain a better perspective.

I had not previously brainstormed plans as to how I was going to accomplish the center stand removal and frame mods so I opted to just “wing it”. Obviously the first order of business was to unbolt the center stand. With the stand removed it was evident the number of extra tabs and mounts that were welded into the lower frame section. Part of building a cafe racer is all about cleaning up all the unnecessary equipment so the plan was to strip everything that wasn’t required off of the frame.

Chopping junks

No going back now! I fired up the plasma cutter and chopped up the side supports then I broke out the cut off wheel and trimmed up the center tube.

One of the things to consider before chopping up the frame is how the modifications will impact getting the bike, eventually, registered and insured. I am unsure of the rules in my local area concerning motorcycle frame modifications however it is my unofficial understanding that cutting and welding a frame is a big no-no unless you have the right credentials. Anything that could be considered a safety factor when modifying a frame is something I want to stay away from. In the case of the center stand frame supports there is nothing that would be considered structural therefore I felt confident in stripping away some of the unnecessary frame.

Shredded stand

Here is all the sacrificial metal stripped from the bike. Was able to shave off a bit of weight.

I started by grinding off the old center stand mounts, brake pedal pivot, and rear foot peg mounts so that I could get a better view of the extra frame section I was dealing with. Once I could see things in more of a 2D image was able to light the plasma up and chop off some unwanted frame section.

I had previously purchased some Moto-bits rear sets that use the mounts for the rear foots pegs. As I stared at the frame section that included the rear peg mounts I decided to clean it all up and make it look like the rear sets were not an afterthought.

Using a round section of .625” cold rolled steel I machined some 8mm threads into the ends in order to mount the rear sets to. I had already chopped off the factory rear foot peg mounts and planed to replace the supports with a solid, one piece, section of steel in order to mount the rear sets to.

New rear set support

Here is the mocked up support for the rear sets that will get welded and, in turn, add support back into the lower frame section.

So from here on in there is not much to say or exciting pictures to show. Basically the frame got chopped, the new section of machined steel for the rear sets was set into place and things were welded up. I think the frame mod came out very well since it really cleaned up the underside. People may never notice that the change was made however it is the small details that make the difference. Quite often it is the subtle highlights, the ones people can’t pick out, are what creates the visuals. So as uneventful as this task was it is, at least, completed and I can now move onto the exhaust fabrication.

Center stand gone

Mission accomplished! New support rod welded into place and the side frame members got rounded, cleaned up, and finished off to give a clean look. I suspect the modification will look good when the frame is blasted and painted.