Small Turning Job

This forum is for those individuals or small business to solicit requests for Service from those members of our group. Machining, Foundry work, Sheet Metal work etc. This site makes no guarranty of work or represenation by the users of this site. It merely attempts to provide a place to allow individuals the opportunity to meet and discuss needs and capabilities.

Moderator: Harold_V

Russ Hanscom
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Joined: Wed Mar 15, 2006 11:10 pm
Location: Farmington, NM

Post by Russ Hanscom » Wed Nov 11, 2009 8:24 pm

Yes, determining where you want to end up is essential before going too far on the journey.

Harold's ideas will get you there in first class. Other methods may be appropriate if cost becomes a major consideration. Some times the procedure is dictated by the tools that are available - not necessarily optimum ones for a single shot effort.

Interesting, I thought most bikes had nuts on the axles to adjust the bearings, at least the ones that I have do.

Weld beads ground down are definitely a low tech, low accuracy approach.

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Joined: Sat Nov 07, 2009 10:16 pm
Location: Tucson, AZ

Second Version with Drawing

Post by bikenstock » Wed Nov 11, 2009 10:37 pm

Hello again, all:

Here is another version of the axle. In this one, the axle is solid 4130 Crmo. The center is .5" thick and two .5" wide flanges take us out to 20mm to ride inside the axle tube (bore) of the hub. Again there is a slot on the short end for a C-clip.

In the drawing, the part I am requesting quotes on is in yellow. I will need two, or four if they are the right price. (Please click on the drawing to enlarge it.)

This part should be able to be pressed in to the piece welded to the kingpin. So Harold, would you say the main diameter should be .505 to press into the welded piece's .5" bore? I think it can be bored after welding, and if it is a little small, I can always grind it out with a flap disc (that's a joke, all). :D

Again, (though I'm sure this will change in minor details as some of you real machinists and engineers peruse it), please e-mail me at with your quotes. Thanks again to all helping out from conceptualization to execution!

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Location: Onalaska, WA USA

Re: Second Version with Drawing

Post by Harold_V » Thu Nov 12, 2009 2:52 am

bikenstock wrote: So Harold, would you say the main diameter should be .505 to press into the welded piece's .5" bore?
.005" press for a small diameter is hugely over limits.

I'm going to assume that you will machine the weldment, so you have a straight and round bore in which to press the axle. That being the case, I'd shoot for no more than a thou. That's a serious press fit. However, if the wall is thin enough, you may get by with a little more, especially if you use heat for the assembly. If you preheat the housing and chill the shaft, you can assemble them without a press, and use .002" interference for the fit. That type of assembly will be far superior to a press fit, yet can be dismantled if necessary, using a press.

It was kind of Russ to comment on my suggested methods as getting you there in first class. He's a top notch individual with considerable talent, to say nothing of an engineering degree. My background is the aero-space and defense industry, so I see everything as being a part of a missile.

It's quite interesting to me to read that some of these trikes are being built with hand tools, using what I'd consider very primitive methods.

I confess, my first reaction was that this trike would be powered by an engine. It was for that reason I started tightening my recommendations.

After reading the speeds at which you expect yours to run, I believe I'd stick with them. The cost difference in construction wouldn't pay for the trip to the emergency room should you experience a failure due to design. That's what was motivating my thoughts. The added bonus would be a very well built assembly, assuming the design is sound.

Keep us posted on your progress!


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