Volvo G990 Grader

[Stefan]

The recessed end portions were bent with a more sturdy fixture than used for other parts earlier in the build.











Thanks for looking.
Stefan

[9W Monighan]

Always fun trying to get the correct radius when bending around a mandrel like you are doing. If it's not right you have to keep turning down the mandrel diameter till the spring back is where you want the radius to be.
Sometimes when I bend 180deg bends , the mandrel needs to be maybe 1/4'' smaller diameter than my finished bend.

[Stefan]

Steve, in the figure I´ve tried to illustrate a piece of material which has sprung back after having been tightly bent around the mandrel. The next time you bend something you should note down the spring back ratio k=R/r of the material. This, in my experience, is a material constant. So thereafter you can easily calculate which D you need for the R you really want as:

D=2R/k-t

where, obviously, t is the material thickness.



Stefan

[Stefan]

I´ve some pics from modelling the lower edge of the moldboard blade. First, a 2 mm strip had a radius formed to it and was soldered to the back of the blade.





The heat caused some unwanted bending


Milling the forward side to replicate the recess. The strip enabled a good grip in the vice.




This is the first pass with the radius mill which took care of the concave radius of the S-shaped bend. There were a further two passes made to approximate the convex radius. I still have to remove (probably by grinding) the remaining material on the convex radius.


Thanks for looking.
Stefan

[Stefan]

Short update: Got the laser sinterered end pieces for the rear axle (works on blade has been put on hold). Needed a little machining, of course.

[Rimrock]

The laser sintered parts looks great. Is this Stainless steel + bronze? I am about to order some parts of that material, and have noticed it is very hard material. Is it difficult to tap threads into this material? I would guess that with smaller taps than M3-M4 there is big risk for the taps to break?

[Stefan]

Yes, it is stainless steel + bronze and it is indeed rather hard and tough. I use hard metal drill bits whenever possible. Even the HSS ones specially made for "normal" stainless wear much too fast. You are also right that it is very easy to break the smaller taps, because the torque needed is so large. Nevertheless, the smallest done so far was M1 for the screws holding the lid on the circle valve. The secret is to drill larger holes than the standard says, using high performance tapping grease and to make sure you tap straight. By the way, the tap you see in the last picture is an M3 thread former. I´m getting more and more fond of using formers since the day I managed to make 64 M1.6 threads in AISI 304 (1.4301 X5CrNi18-10) without breaking the tap (I did brake one or two drill bits, though). As you know, 304 is good for welding but hard to cut, since it cold hardens. In my experience, the stainless steel + bronze from Shapeways is even tougher than the 304.

[D8R]

Interesting way of manufactoring, Stefan. Didn't know that was possible. Hard to tell but what is the size of the valve?
/Dan

[jack van]

i do think we have a master craftsman at work this is an incredible build and i can not wait to see more of your work not just of this model do have any other master pieces that you have made plz send me pics my email .s jvan320@gmail.com

[Stefan]

@Dan: The size is 15,6 mm from bottom to top of the lid. The body diameter is about 8,5 mm.

@Jack: Thanks! I´m glad you like it. More pics will be coming.

/Stefan

[Stefan]

Finished the end pieces for the rear axle.





In it goes the planet gears carrier/output shaft from a cordless screwdriver.






Thanks for watching.
Stefan

[Stefan]

The outgoing drive shaft hub is finished, so here are some more pics:

























Stefan

[ihbuilder]

Very nice, Stefan

[Jared]

Those planetaries look great! Well, everything else does, too.

[Azonic]

Great job, this will be one **** of a model when done!

[titandigs]

Great work as usual Stefan

[RCLogger]

WOW Another work of art Stefan,
Thanks for keeping us involved in your build.
Greg

[Stefan]

Thank you guys for those words of appreciation.

Havent´t done much on the grader lately, but anyway I got the so called "anchorage" for the lift cylinders from Shapeways and started some machining.

[AbelVincze]

Stefan, can you tell me some words about these printed steel parts? Are comparable as hard/strong than a traditional molded steel part? (I would like to make my machine's axle housing this way, but it needs to be strong enough)

[Stefan]

For hardness/strength reasons I wouldn´t hesitate at all making an axle housing from it. Maybe from a price and machining points of view. It´s actually very tough. Drilling is as difficult as for normal stainless steel, if not worse. You´d better use high quality carbide grade tools.