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I am going to do my best to make a copy of GT Power Series 3 piece cranks.

I bought a set here on the museum for $55. Here is some pics with what I started with.

I tig welded the Logo. I preheated the arms to 400 degrees. Then tig welded. Post heated at 400 degrees to stress relieve.The brown color is the coating burning off. There was no coating by the logo.Very easy to do.

Last edited by Boersck (2012-03-29 7:33pm)

LooseNut · 2012-04-03 8:33pm

xtremevert · 2012-04-03 9:07pm

I did the same thing. it works great.

here's the link to see how mine turned out.

http://bmxmuseum.com/forums/viewtopic.php?id=100461

Boersck · 2012-04-05 2:58pm

Next I ground the weld smooth, Then media blasted them, followed by a few hours in a deburring tumbler. This was the results.

Dirty Habits · 2012-04-05 3:01pm

Nice, Now The Decals!

Boersck · 2012-04-05 3:08pm

I have noticed as I looked at other Primo cranks people have done that the outside profile looked wrong. I am a Model Maker by trade, so I went ahead and measured these. In the picture below the red line represnts the outside shape of the Primo's. The white line is original GT Power Series cranks. They are slightly different.

Another print out in black and white. I will be using this geometry to cut right to the line in a CNC Machine.The profile will be exact.

Last edited by Boersck (2012-04-05 3:27pm)

Boersck · 2012-04-05 3:13pm

So what could I do to make these look exactly the same As Power Series? I would have to cut the outside. But first I would have to add a little material by the square, before I cut it. I want these to look as close to originals as possible.

Blasted weld. Check them out. The weld is way more than what I need. I will cut most of it off.

Last edited by Boersck (2012-04-05 3:28pm)

LooseNut · 2012-04-05 3:19pm

Now we're talking!

BmxRacer4 · 2012-04-05 6:31pm

DAMMM Those Look So Nice

xtremevert · 2012-04-05 9:35pm

should of left them man. no one would ever notice the 1mm difference. how are you going to get them perfect? are you going to do some machining or just sand them to look how you want them?

LegoMyDayGlo · 2012-04-05 9:54pm

Wow!! You diiiid that! Awesome! Xtreme has point too man, I think you was really close already see what happens , looks like you have some skills!

Boersck · 2012-04-05 10:40pm

You guys have to have some faith, I 3d machine every day for a living. I am making a fixture to hold these, then they are going into a cnc machine to get cut.

LegoMyDayGlo · 2012-04-05 11:04pm

damn, sounds like you do have this under control. Can't wait to see how you finish them

Gustafa · 2012-04-06 6:37am

This is pretty dope! I have a job for you if interested! Not bmx related, but pretty dope.

getmoney · 2012-04-07 6:55am

Looking forward to seeing this completed, should be awesome I'm sure. Will you be removing the extra aluminium from the backs of the arms I guess on the non-drive arm too make it as close to the GT non-drive arm?

JOHNNY P · 2012-04-07 7:49am

This site has some extremely gifted people.

Boersck · 2012-04-07 11:15am

The plan I have on these is to machine the profile, then use the fixture to machine the backs to replicate power series.

kbillan · 2012-04-07 10:17pm

Impressive, Boersck.

I have a bench top CNC mill I play with. do you have a shop? work at a shop?

Open to commissions? screw it.. PM..

astroidbeltwalker · 2012-04-08 8:20am

to get the weight down (not strenght) could you drill an cap the cranks. drill some holes, instead of refilling with a light
material just cap the holes top & bottom with weld or another material.

Boersck · 2012-04-10 1:47pm

I am in the process of getting quotes for a 3D scanned image of the outside shape of Power Series arms. Once I get that it will be easy to machine these into exact replicas.

The fixture is almost done.

Gustafa · 2012-04-10 1:55pm

Boersck wrote:
I am in the process of getting quotes for a 3D scanned image of the outside shape of Power Series arms. Once I get that it will be easy to machine these into exact replicas.

The fixture is almost done.

Or make some crank replicas from a block? hmmmm? LOL

Boersck · 2012-04-10 2:16pm

With a model anything is possible, I want to see how the conversion works first. It would be nice to be able to use primo's bottom bracket with arms that looked exactly like Power Series.

I know the spindle bolt is different too, I have plans for that also.

Boersck · 2012-04-10 4:46pm

Got my first quote for a 3D Model. $700. I think I may need to look around more:(

astroidbeltwalker · 2012-04-10 5:09pm

whats a 3d model

wired · 2012-04-10 6:30pm

I think you already went above and beyond with your weld as they really look awesome.

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Making GT Power Series out of Primo Powerbites

Making GT Power Series out of Primo Powerbites

#2 2012-04-03 8:33pm

Re: Making GT Power Series out of Primo Powerbites

#3 2012-04-03 9:07pm

Re: Making GT Power Series out of Primo Powerbites

#4 2012-04-05 2:58pm

Re: Making GT Power Series out of Primo Powerbites

#5 2012-04-05 3:01pm

Re: Making GT Power Series out of Primo Powerbites

#6 2012-04-05 3:08pm

Re: Making GT Power Series out of Primo Powerbites

#7 2012-04-05 3:13pm

Re: Making GT Power Series out of Primo Powerbites

#8 2012-04-05 3:19pm

Re: Making GT Power Series out of Primo Powerbites

#9 2012-04-05 6:31pm

Re: Making GT Power Series out of Primo Powerbites

#10 2012-04-05 9:35pm

Re: Making GT Power Series out of Primo Powerbites

#11 2012-04-05 9:54pm

Re: Making GT Power Series out of Primo Powerbites

#12 2012-04-05 10:40pm

Re: Making GT Power Series out of Primo Powerbites

#13 2012-04-05 11:04pm

Re: Making GT Power Series out of Primo Powerbites

#14 2012-04-06 6:37am

Re: Making GT Power Series out of Primo Powerbites

#15 2012-04-07 6:55am

Re: Making GT Power Series out of Primo Powerbites

#16 2012-04-07 7:49am

Re: Making GT Power Series out of Primo Powerbites

#17 2012-04-07 11:15am

Re: Making GT Power Series out of Primo Powerbites

#18 2012-04-07 10:17pm

Re: Making GT Power Series out of Primo Powerbites

#19 2012-04-08 8:20am

Re: Making GT Power Series out of Primo Powerbites

#20 2012-04-10 1:47pm

Re: Making GT Power Series out of Primo Powerbites

#21 2012-04-10 1:55pm

Re: Making GT Power Series out of Primo Powerbites

Boersck wrote:

#22 2012-04-10 2:16pm

Re: Making GT Power Series out of Primo Powerbites

#23 2012-04-10 4:46pm

Re: Making GT Power Series out of Primo Powerbites

#24 2012-04-10 5:09pm

Re: Making GT Power Series out of Primo Powerbites

#25 2012-04-10 6:30pm

Re: Making GT Power Series out of Primo Powerbites

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