precision hanger on a non precision baseplate?

[ewrestler305@gmail.com]

I thought the whole idea of precision components was that they fit together flawlessly with no room for error. basically they do exactly what you want them to. i've seen alot of people sticking precision hangers such as radikals on non precision baseplates such as the randel system. does this make that much a difference from a typicall R2 180 Hanger? it's at the same degree and would assume both hangers having the same pivot point. of course the radikal will be stronger and better built. but will it actually make a large performance difference if both truck components arent machined to fit perfectly together?

[stridey]

Deleted as double post

[stridey]

]The use of cast, mass produced baseplates can be down to a couple of things...cost being a major factor. Using a readily available baseplate can be difficult though, particularly with Randals. The pivot cup size is a difficult one to find as a replacement, and the Khiro Large size is just a bit too small and needs padding out with tape.

The problem with cast baseplates to my mind is accuracy to a small degree, and the difficulty of removing pivot cups if you need to. A custom CNC baseplate will solve this if designed to.

One other factor is that it is easier to sell a hanger as a 'replacement' upgrade to an existing baseplate from a known manufacturer. Riders will likely be more willing to try a custom hanger on a known manufacturers baseplate than try what is in effect an entirely new brand?

Also, if your design a CNC hanger to fit a cast baseplate you are likely merely copying angles and the distance from pivot to kingpin, and also pivot size to a certain extent and tat has to be a small compromise in design?

But a good cast baseplate would likely be very similar in feel to a cnc'd one in practice. Its the hanger where the bigest improvemnt would be made cnc'ing, unless your baseplate offers something different such as the adjustability of a GOG,[/QUOTE]

[Zach_Wolf]

Post I wrote a while ago on a different forum I dug up for you, to answer your question (with somewhat of an opinion) there isn't really much point unless you include some of the features detailed in the "On CNC/Milled" section. Hopefully this will also help some other people. Please note the tolerances are likely wrong, I was going off what a machinist friend of mine had told me a while back, if so please correct me. This is also purely my understanding of these things, take them with a grain of salt, I'm sure a few people would disagree with them.

On Precision and Precisely Made Trucks

Cast :
each cast degrades the mold and thus the tolerances of the truck, though tolerances are adjusted to counteract this, and molds are cycled, they do not retain the tolerances throughout the production run that a CNC cut truck does, due to the manufacturing process, as they aren't individually made. Casting also requires weaker aluminum, that is more prone to defects and stress which is why some designs cannot utilize this process.

CNC/milled:
Guided: Trucks are individually crafted (by hand, or Computer Numeric Controlled machine) instead of replicated, and made to originally designed tolerances, with negligible variation (0.001" - 0.0001"). Designed with spherical bearings to guide and prevent the hanger from deviating from along it's intended span (term?) and in my opinion, hold a more consistent line. An additional spherical bearing may replace the pivot cup, creating a static pivot, and largely reducing the effect of side loads on the geometric integrity of the truck, and allowing tight tolerances but smooth rotation in the pivot, along with ease of maintenance as you can pivot the hanger upwards to switch bushings, instead of removing it entirely as you must with some other higher tolerance designs without this feature. (a fancy and over-imagined way of saying it prevents the side loads from shifting parts around and effecting the integrity and operation of the mechanism, and allows the pivot to move freely in tight tolerance)

I have a feeling I'm going to get burned by the engineers on here for that one. Sorry guys.

Unguided:
Trucks are individually crafted (by hand, or Computer Numeric Controlled machine) instead of replicated, and made to originally designed tolerances, with negligible variation (0.001" - 0.0001")

On CNC/Milled
What I find more interesting than the accuracy to which CNC and milled trucks are built, is the design possibilities that open up with CNC or mill production. That's what the draw of "precision" trucks is to me; different axle placement (inline, split, offset), spherical bearings (in hanger and pivot), higher strength and more durable materials, ability to alter axle length and width/interchange them (JimZ, Radikal, Smokey), change baseplate angle (GOG), lowered height in some cases, and who can forget, anodizing them to make them cool colours?

They are heavy though.

[breamo]

The pivot cup size is a difficult one to find as a replacement, and the Khiro Large size is just a bit too small and needs padding out with tape.

Randal pivot cups are probably the easiest to find of all the brands. After checking other manufacturer websites, Randals are the only ones to offer them by themselves on their site, as well as many other online retailers, and they are also available in the Randal Tune Up Kit.

The problem with cast baseplates to my mind is accuracy to a small degree, and the difficulty of removing pivot cups if you need to. A custom CNC baseplate will solve this if designed to.

Yes, if the baseplate has the truck mounting holes cast-in then accuracy is a problem. This was the problem with the first generation 'older' Randals, and many other current baseplates. Now, Randal baseplate holes are punched and machined on a mill with CNC accuracy, so in effect there is little or no difference in accuracy between a good cast plate and a CNC, other than looks.

Also, the Randal R-II series incorporates a small hole at the bottom of the pivot cup for making removal a breeze by pushing it out from the bottom. (and not allowing air pressure to keep 'sucking' it in)

[stridey]

Randal pivot cups are probably the easiest to find of all the brands. After checking other manufacturer websites, Randals are the only ones to offer them by themselves on their site, as well as many other online retailers, and they are also available in the Randal Tune Up Kit.

Try that in the UK, Michael. The only place I could find that even sells them seperately does so in pairs.

And by the way, I sell Khiro singly.

one thing on the Randals, are the kingpin holes cast, or drilled? If cast, are the kingpins designed to be a press fit? If drilled, how can accuracy be up to CNC standard if the baseplate is a cast item?

And being able to poke out the pivot cup is an excellent move.

[breamo]

Try that in the UK, Michael. The only place I could find that even sells them seperately does so in pairs.

And by the way, I sell Khiro singly.

one thing on the Randals, are the kingpin holes cast, or drilled? If cast, are the kingpins designed to be a press fit? If drilled, how can accuracy be up to CNC standard if the baseplate is a cast item?

And being able to poke out the pivot cup is an excellent move.

You can buy from Randal.com in the UK. Shipping is only a couple bucks, and we'll sell them one at a time.

The kingpin holes, and pivot cup holes are milled. Therefore, essentially a CNC base. (just not the fancy looks, only milled in the parts that determine the geometry)

[stridey]

Hmmm.

Its good to hear you will supply those parts. Especially for the slalomers running Skandal modded Randals. You might want to check your site as currently its impossible to buy anything.

However, at a bit of a loss to see how milling into cast can be as accurate as CNC, as the casting would need to be held in exactly the same place and as you say the casting wander a bit over time. I'm looking at a baseplate right now and its obvious the kingpin is out by approx 2mm. This either means the kingpin is out by that much its whole length, or tilts. Neither is a good thing, compared to CNC.

But for Casting, they certainly are better than Randals of a couple of year ago.