Bruder Delta loader conversion

[jerry56]

Ok I built a little dump truck but have no way to load it.... so it's time to do the obligatory Bruder Delta loader conversion..
It looks like it's been 10 plus years since the first one of these was documented on here so clearly I'm not breaking any new ground, I want to thank everybody that has done one of these for a well defined road map of how to get this thing done.
Being a newbie it's kind of daunting to but a new $30 plastic toy and as soon as you get it start tearing it apart, my main fear was cutting away something I shouldn't and turning my new toy into spare parts.... but again this build has a really well documented history...
Ok I got carried away and started tearing this thing apart before I took any pictures, so to anybody new here thinking about it just take you time and look at the little clips around the bottom and pull/tug/pry gently until you get it apart...once it's apart you end up with this...sort of



most of this is going to get gutted cause there ain't much room in this thing...
the first step for me was to get the Tamiya gear box in it.
This is the first problem...the loader is only 52mm or so wide and the gear box is 54.


and the gear box



So I took the gear box to the old sander and made it 51 and change


Now the sides look like this.



So we started with this


And ended up with this


And it fits nice and snug...


and that was the easy part lol...

[frizzen]

That's off to a nice start. Doesn't Bruder do a *really* good job of keeping toys together?

I've been wanting to build one of these for a while, but somehow ''IndyJerrys'' Dozer is in line ahead of it to cross the bench.

[jerry56]

LOL yes they do keep them together....just starting , this one might take a while since the weather here in the mid-Atlantic is cooling off I have a ton of stuff to do outside before winter gets here and it gets to cold to be in the yard..
Not sure what an "IndyJerrys" dozer is but can't wait to find out...

[jerry56]

OK this is the gear box I used, I went with the 115:1 option since it seemed to be the one that has worked best for people in the past.

Again from folks that have done this in the past I swapped out the 3v Tamiya motors for these slot car motors


I got them here https://www.professormotor.com/product-p/jkm7.htm
They are a a 48k motor at 12v so they will be fine at 7.2v.

I made a simple cardboard template to drill some mounting hols in the loader. The transmission fits snug in the body I used some plastic tubing to make some small 1/8 in spacers where the bolts go thru and it pulls the sides in straight and keeps everything solid.

The axles are a hex shape and to small for the bruder plastic wheels so first I knocked off the edges on it then put them in my drill and spun them against a file to round them out and cut them to about 3mm. Now I have to figure out how I'm going to mount them to the wheels. I have some brass tube just need to work out the details.....

[jerry56]

Ok .. I got the drive wheels done...ish I used the hole in the nut trick that RC Modder uses in his Bruder conversions and it seems to work pretty well. I drilled a roughly 2.5mm hole on the flat side of the nut and tapped it for a 3mm set screw.




Now the axle holes in the wheels are to big ...of course so I bought a set of copper tubing that all the pieces telescope into each other and I took the piece I needed to get the correct inside diameter to match the turned down axle shaft on the Tamiya gear box and then used the next size up to get an outside diameter to match the Bruder wheel.




The fit was snug but not tight so I used some JB weld on each piece and the inside of the wheel and let it set up overnight....it seems like it's on solid piece.
The nut is 5/16 and it screws onto the wheel, it's a tight fit and actually cuts some shallow threads in the plastic. once I had it flush I drilled a 2.5mm hole using my threaded nut as a guide thru one side of my wheel then ran my 3mm tap thru it again to thread everything. I left a lot of burrs inside the wheel but a little work with a tiny round file and it as all cleaned up. I used a long set screw and put a flat side on the axle shaft and it tightens down really well.

Now time to get the wheels ready for the 9 drive pins you need to add so the tracks to grab. Here I just marked where I wanted the hols, Bruder uses every other notch in the track so you drill accordingly....


This is my 2x4 block with a hole drilled in it deep enough to let the wheel sit flat while I drilled the holes..


I just need to drill these out and figure out some pins....

[jerry56]

I thought I had pictures of the pins in place but I don't...I used coat hanger for my pins it's about 1.9mm and easy to cut. I drilled the holes at 1.7mm so it as a snug fit then super glued the the back side to hold them in place then I mixed some clear epoxy I got at Hobby Lobby and poured the back almost full. Now I have a solid wheel. that pretty much finishes up the drives for now I did a quick function test to make sure the motors work and that my mix in the radio did what I hoped and everything seems to be ok, For the mix I mixed channel 1 and 2. In mix 1 I made channel 1 the master and channel 2 the slave and made the values 100%, for mix 2 I made channel 2 the master and made the values -100%, neither had any offset... it works... . I'm using the cheap $8 10a ESCs I combined the battery leads and the switch so essentially I have a poor mans dual ESC. these are small enough to slip underneath the battery at the bottom of the loader which is good cause space is limited...
Next I worked on my lift servo I used a HiTecD954sw https://www.servocity.com/d954sw-servo/?sku=36954S00
I think this was the single most expensive piece of this build....I also got a DPC 11 servo programmer https://www.servocity.com/dpc-11-servo-programmer/ so I could maximize the servo, plus I'll need it for the bucket curl.
Since I don't have a 3D printer I made my rear servo mount out of red Oak...hey it was the strongest thing I had and is pretty easy to work with. Here it is from the bottom


I drilled a hole thru the back to hold it in place.. and a view from the top



For the other side of the servo I cut a piece of 1in square tubing to fit between the servo ears and the side of the loader then split it so I ended up with a "C" shapped piece then I tapped it for the servo and to mount it to the side of the loader... I tapped it so I didn't have to fiddle with nuts on the inside of this thing.. The servo is mounted now the scary part is figuring out what to cut away and figure out how I'm going to make the boom go up and down.....

[frizzen]

That's coming along really well!

Isn't it cool that $16 of speed control and some channel mixing makes you not need to get the $$$ dual-channel tank control esc

For the lift-linkage, i think the slickest setup i've seen someone do for this would have your servo arm point forward, with an adjustable linkage going up to a crossbar that spans between both sides of the lift frame you still have attached to the machine. (Sorry i'm not giving due credit, i forget whose idea i stole)

[jerry56]

I know right....those little 20a ESCs can be hit or miss sometimes I had one just go up in smoke one me, one worked for a couple weeks in my tonka then just quit, and a third worked then stopped...then started working again...then stopped ..lol... but other than those I've had pretty good luck with them..
I haven't seen that method of lifting the boom but bears looking into, it might be on the site that is currently down..

[frizzen]

Yeah, scale4 and sparks are both down so it's getting harder to find source material. Plus many things happened before Photobutt broke the internet. (I know the rule...pics or it didn't happen)

You might want to look here at bruders by SmallHaul or ScottyK or Aash.
https://rctruckandconstruction.com/s...ghlight=Bruder
https://rctruckandconstruction.com/s...ghlight=Bruder
https://rctruckandconstruction.com/s...ghlight=Bruder

Also i believe someone pointed out another helpful mix to slave Curl to Hoist so the bucket stays flat during lifts until you move curl.

[jerry56]

I know I noticed both of those sites are down, scale4 had build threads for the D5 and the smaller wheeled skid steer. There are a ton of threads now without pictures because of photobutt... and sometimes I just need to see what they're talking about or describing...
I've watched smallhaul videos and read his build threads...they are a great help...I've seen hints of the curl hoist mix but never seen the exact set up, I'll have to play around with that

[jerry56]

I realized I need to get the bucket curl done before I finish the lift, This is a plastic toy after all and I don't want to snap the pieces on and off any more than I have to just to be on the safe side. I want to get the bucket curl done and the wires routed so it's done when I get to the lift assembly.
I went with these servos for the bucket curl again because people smarter than I figured out they work well, and again I'm pretty new at this so I'll stick with what works.




It took me a little bit to wrap my head around how these servos have to mount. I didn't want to cut away anymore than I had to but I couldn't get the curl to work smooth the way I was doing it, it's hard to line the servos up with the bucket hinge location perfect enough to make it not bind. Then I figured out you don't need to .... it has to be close but you cut away the inside of the arms so the servos fit in nice and snug and use the servo horn as the lever that slides up into the arm. Then I ran a 2.5mm bolt down thru the arm so the horn is "trapped", it can slide up and down just a few mm but can't slide all the way out this accounts for any offset in the hinge point
Sorry for the blurry picture...
I went to my go to red oak and made up a mount for the curl servos and painted them black I'll have to get a picture of them mounted and the bolts thru the arms...the mounts were just kind of trail and error, and the oak is kind of heavy so I cut it down as much as I could and still maintain it's strength

I used a dremel to open up a channel down each arm then cut the connector off and fed them thru the arm ...just have to take your time, the cables on the servos were to short so I used an extension cable and soldered it together in the middle after I ran the cut ends from opposite directions... then I made a "Y" cable to tie them together.



now this is the part that most people forget, take your servo programmer (I got the Hitec DPC-11 and hooked it to one of my laptops since it works with Windows 10) and first widen the deadband as wide as it will go, then program the end point so the are as close to matched as you can get them take your time...the deadband being opened up will help here. Just set and test...set and test ...when you get them were they aren't fighting each other at the endpoints I cut the speed by 70% I know it seems like a lot but they work really smooth and it looks way more scale they don't jerk as much. Remember it's the speed not the power that is reduced... I thought I had more pictures but I don't so I'll try to get a few of how the wires are run and what the curl mount looks like....if anybody needs to see them....once I get these done I'll mount the arm and work on the lift servo.. the servo programmer is on sale right now (8 Oct 2020) for $16.99 at Servo City just FYI...

[jerry56]

Sorry these are still a little blurry, my cheapie camera doesn't like to focus up close... this shows the 2mm bolt and flat washer that keep the servo horn trapped in the lift arm the bolt goes down along side it so the horn can slide a little to account for the offset in the mount location


This one shows the bolt head on top of the arm....not to obtrusive


And this one just shows the servo horns laying inside the lift arms, you have to cut away the plastic from the inside of the arms almost all the way up to the first cross bar... once done you can't see it and the servo horn and bucket help strengthen it a little



It's coming along pretty well so far but again it's a pretty well documented build....

[frizzen]

That looks pretty slick.

Thanks for the tips on setting up the digitals, i've never messed with those

It's gonna be moving material before ya know it

[jerry56]

Thanks Frizzen !
Well SmallHaul mentioned it it one of the old threads from like 2009, that you needed to match the endpoints and open the deadband way up so they don't tend to fight each other and hey when he talks I listen LOL.... Using digital Servos and the programmer it lets you fine tune them ...I like the results.... I hope to have it wrapped up by the end of the month. Right now I'm trying to get my shop insulated and wall panels up before it gets really cold....once cold weather sets in I'll be able to spend more time on builds....I got a bunch waiting...

[jerry56]

Ok I got back to this a little bit.... I ran the servo cables down the inside of the arms, I just used a dremel with a little ball shaped cutter to open up a hole in each one of the arm supports so the wire stays in and out of the way. I took it out the back and down each side in the cavity on each side of the loader and will just hot glue the connectors in there so they don't flop around


Now I have to get the lift working .... this part of the build has worried me the most 'cause a wrong cut means buying another loader for a new set of lift arms...Turns out it wasn't as bad as I thought.
First I guess I was a little rough getting my loader apart because the cross bar was cracked on one side so it had to be cut anyway.... I didn't want to go all the way thru with a nut or bolt on the outside but it just seemed to be the simplest and strongest way to do it.


I used a piece of 3mm threaded rod then covered it with apiece of 7/32 plastic tube. The threaded rod fit perfect in my little airplane control rod thingy so I cut the tubing and used that to keep my lift rod from sliding around. Then I cut a small slot in a piece of 9/32 tubing for the lift rod to slip into then slipped the whole mess over the control rod..


Held it in place and slipped my threaded rod thru then put a nut on each end, I used locktite on one end to act like a bolt head so far it's been working...

I was a little concerned the piano wire wouldn't be strong enough so I built a heavier, adjustable version. If I have to use it I'll just modify my cross bar



Getting the length on this was a little tedious if I got it to seat good and tight then I was a little shy on the total lift...it was only a tiny bit shorter but I was trying to maximize it as much as I could... so I went with it not seated as tight but with max lift.... The heavy duty lift rod is adjustable the wire one isn't.... I'm going to run it this way for a while once it's done and see how I like it, then I may change it just to see how it does then..
Frizzen suggested I use an arm on the front side of the servo that goes straight up and down, it involved adding another cross bar which I was nervous to do... but I was already kind of committed to this method. I think if I do another one I may go that route it looks smoother over all.... or I may change this one....I'm learning as I go....At least I haven't ruined the toy yet LOL

[frizzen]

Could that linkage length be compensated for with cranking on your radios EPA for lift channel?

Even if you do 'ruin' the toy, it just means you need to "remove more of its weakness". Misdrills can be scuffed up and filled with styrene or epoxy. If it cracks, cut out the crack, stabilize the joint, add epoxy, sand flush, (make weld detail if you're truely crazy) paint to match. Longer cure time epoxy sets harder than short time.

[jerry56]

I tried messing with the end points.... and will continue to play with them .. the issue is when it seats all the way down the servo horn is below the servo center causing the piano wire to bend around the center....if I move it up so it doesn't bend then it doesn't seat....if I shorten the rod then I don't get full height.... I think there is a very small window to get both full seat and full height I just haven't found it yet. That's why I'm liking your idea on turning the horn to the front and adding a cross bar.. I was trying to keep it as original looking as possible but I'm thinking I can make the second bar look ok...
I'm trying to avoid major brakes and miss drills...LOL I didn't know that the longer curing epoxy cures harder....I am learning that there are ways to fix these if you screw up which makes me a little less afraid of ruining them.... I'm really enjoying this hobby even though I'm just starting out...

[frizzen]

If the linkage will hit on stuff, it needs to have a curve bent into it for clearance around whatever. (Steering link on my narrow-front tractor looked almost like a "?") Adding the curve will use up more rod length than when it was straight, and it's not quite as strong as a straight rod.

I think we all *try* to avoid mistakes. They happen, and on toys like these it's usually fixable. Knowing some fixes helps it be less scary to tear into converting old / rare / expensive toys.

For strength I generally like the 24-hr cure epoxys, or metal-reinforced stuff that can be drilled & tapped. 2-part mix and the putty you knead together both have their uses.

[jerry56]

I do have a slight bend in it, I'll have to see how it does when I actually start lifting stuff..
I know it says JB weld can be drilled and tapped... but in reality can it be, and is it reliable

[frizzen]

Drilled yes. Assume not reliably tapped for hardware at this scale. I just suggested that type because it tends to become harder, denser, and can form a pretty good mechanical bond.

Sorry to keep derailing your build thread.