When you tidy up the workshop....

[Stormbringer]

Wow mate thats some excellent progress 

[Juanmacine]

On 05/08/2021 at 13:40, Nitroholic said:

and you think...hmmm...that might work.

 

Was tidying my stock of Hyper parts up, seperating and putting together complete assemblies just to see what I had after I got everything unpacked following a recent house move.

Shocks, wheels, a load of parts... I also had my brushless converted one out on the table as I was thinking about a rework of it's component layout.

 

Was looking at the bits all together, comparing the steering setups.....

 

 

when I also found this....which I had put together a little while back. It's made up from 2 spare Hyper 7 diff cases, with the mating surfaces cleaned up, and a slice out for a shock tower. Basically...it's a pass through diff for a 6 wheel drive setup. I plan to make a tube to replace the driveshaft cups to link the pinions together...

 

 

Now I want to build this....

 

 

I mean...everyone should have a 6 weheel drive 4 wheel steer buggy.... right?

Wowww, looks like an ancient Tyrrell F1.

[Nitroholic]

Yup...the Tyrell P34 was my main inspiration

 

[Nitroholic]

Got some more done today.

 

Stripped and cleaned both the front diffs, and filled with 7k silicon diff oil. It's a quick and easy job to do, and I didn;t want to build up the project with grubby, dirty stuff.

So while I was at it...both front ends got completely stripped, all the plastics washed  and cleaned. One of the diffs still had the original grease in it, so that had to be cleaned out.

 

Stripping down one of the diffs was a breeze....the other...some idiot had used superglue on the nyloc nuts that held the diff housings together. This had run down the shafts ( it's thin....so it 'wicks' and gets drawn down the holes ) and getting the housings apart was a nightmare. I needed the long bolts, so I had to persevere....but I have no idea why people do stuff like that. Nyloc nuts don't need anything to stop them coming loose!

 

But....the front diff was all assembled, and bolted up.

 

The second diff with passthrough needed some minor work.

 

The front plate needed a little relieving so it would fit around the output shaft. If you look at a stock diff, the rear brace has a recess .... the front doesn;t...so I had to file a curved recess into the top so it would fit up snugly. I also needed to add  a couple of spacers to position the front plate where it needed to be.  I needed to cut about 2mm off the edge of the upper arms where they fit against the shock tower. The arms would bind if you forced them in.....and the lost material will not be a significant weakness. 2 bits of M4 studding were used to bolt through the cases at the top, as the stock bolts are way too short. The bottom ones fit fine!

 

 

Did hit one little snag.......annoying considering how many times I measured and checked stuff..... When I came to bolt up the second diff to teh chassis, the 2 front mounting screws didn;t line up....
I'd checked it time and again with a different diff.....and I had checked and measured and the diffs were 100% symetrical front/back. So it shouldn't matter.....but it did. When I bolted up the diff, I could see the front 2 holes were about 2mmaway from 'correct'. If I spun the diff 180' the front link was binding....

 

Dug out the verniers.....and the diff housing ....made up of 2 rear halves... 2 IDENTICAL MOULDINGS ... wasn't symetrical. They were fine when put together in terms of pin spacing and hole spacing....but for some reason, the drillings in the bottom for the mounting holes were different. Nothing for it but to oval out the holes in the chassis plate. Hate doing it...but I had no option. It was that or start again, and I don;t haveenough sheet metal for another try right now.

 

So.....with both front ends mounted up, squared off, and the suspension arms all moving freely and in line.... I got a consistent gap of just over 10mm between the front wheels, which was what I wanted. If the tyres ever balloon enough to contact...then they were rubbish tyres 🙂

 

 

I also checked the driveshaft is free and not binding.....and that the diffs are orienated to rotate the wheels the same way! The pass trhough diff reverses directions...so the diffs have to be set that way. I had to flip the front diff in its case...and originally, it was binding a little...until I realised I had left the shims where they were...and reversed it...so I had to reverse the shimming to sit the diff right on the pinion.

 

Next job is to mount the steering posts and rig up the linkages and servo mount.

[Stormbringer]

good grief it looks you wont take long to finish it mate 

[Nitroholic]

I have hooked up the steering this afternoon, but now need to make a new servo mount and battery tray. Will need to fire up the 3D printer for those.

Then I need to make up some top deck braces. I want to brace the front two diffs, and across to the centre diff....and then back to the rear diff. The ESC will sit on the rear brace.

 

I have a fun idea for that ...which might or might not work...

 

I also have to sort an issue with the row 2 axles. Both fronts have CVDs which is nice...but the second set needed to have more canber than htey should to sit the pins in the drive cups. They just look to be too short! ahubs on the left is a right hand one, upside down. Don't think thats really helping matters. I may have to remove the CVDs and swap them to dogbones and see what I can do. Looks odd with 2 different cambers....and I don;t want huge negative camber on all wheels.

 

Been thinking about the shell ....  got a few ratty Hyper 7 ones....so I might just cut up a couple and see what fits 🙂

 

[Nitroholic]

Well...what a faff!

 

My 2 'Hyper 7' front ends are not exactly what they should be! One is proper. 100% Hyper 7. The other is a mongrel!

 

The driveshafts don;t fit because the arms are actually about 3mm too long. They were made to fit by winding the top arms in to shorten the distance enough. The ends of the arms should be open...

But the second set are closed. The pivot point is off a bit. The moulding pattern looks identical, and the outer end is chunkier than the Hyper ST ones...but closed like them. No idea what model they are off, but I assume it's another Hobao...... It can;t be a Hyper 7 though, as the driveshafts just don't fit. The hubs are identical ( though I do need to sort an issue with the pivot bushes on one, as it was not done up tight, just locked with a ton of threadlock. The ferrule is binding. Will fix that easy enough with aplain shanked bolt that can be tightened without binding.

 

Meantime.... the 'rogue' arms are getting a mod. Drilled a fresh hole for the end pivot, and modded the plastic upright to clear by removing a bit of material from the inside of the cross brace. This lets the upright sit 3mm in from where it was. I have plugged the old hole with a nylon plug superglued in for good measure. I want to minimise stress and not create a weakspot with the second hole. I left the end closed......so really it ought to be strong enough. I might end up buying some proper arms at some point, but I will see how this goes. Don;t mind butchering these arms, as they would not have been ay good as spares anyway!

 

End result.... all 4 front wheels with sensible camber!

 

 

edit:

https://www.ebay.co.uk/itm/203255040551?chn=ps&mkevt=1&mkcid=28

 

Those are what I had. They are listed as Hyper 7 .... but the 2 setups while generally the same are not compatable completely.

Edited August 17, 2021 by Nitroholic

[Stormbringer]

bummer about the arms but cool you got it fixed 

[Tug]

You're not into big air Kevin Talbot style, but do you think this will take a jump or two?

[Nitroholic]

I suppose it would ... I mean...it's basically a Hyper 7!

 

Might be a bit nose heavy in flight. Not really looked at the balance in those terms

[Alex97]

On 15/08/2021 at 21:55, Nitroholic said:

Yup...the Tyrell P34 was my main inspiration

 

Try the FW08 B

 

 

Edit - for some reason I thought the 2 sets of wheels were at the rear and not the front.

Edited August 17, 2021 by Alex97

[Nitroholic]

The March 2-4-0 did the same thing, using 4 driven sheels.

 

I just fancied 4 steered wheels 🙂

[Nitroholic]

OK...got some more work done today.

 

Finsihed up the front braces, putting a brace for the front steering posts that also linked it to the rear steering bulkhead.  Then a second steering post brace behind to tie it all together.

 

 

Have done a test of both steering and drive on the bench. Got no mounts for battery or ESC, so it was a static run on blocks, as I don;t want to ruin anything!

Went pretty well, and the steering worked just as I hoped. For about as long as it took me to set up the EPA and get it all dialled in. Then it started getting glitchy. That was just for openers. Now the servo will not stop anywhere in the centre region. Go to full ock on either side....turn it slowly back...and it gets halfway toi dead ahead...then shoots right through to halfway the other side.

 

Yup...servo is FUBAR. It's a cheap old clone Tower Hobbies job, and its seen a bit of life, so no surprise. I have a decent Savox one in the spares pile, so that will go on. Bit overkill for this application, but...well...its been sitting there as a spare after I fried the throttle servo in the Baja running it in snow. Of course.....I never needed it.....

 

The batteries will sit on the side opposite the motor, and the ESC will sit up on the centre brace at the back when I make it. I also want to make a smaller receiver box, as the one I made before was a bit big for this application, and looked ugly. I want to make a properly compact RX holder that will look tidier. Might try and combine it with the ESC tray.

 

 

Hit another snag here..... cannot find the adaptor I need to plug the micro SD card into the PC to get the files out to the printer. Had to order one off E-Bay, which will take a few days. So that has put the brakes on.

Once I get the things here, I can print off a battery tray to bolt to the chassis, print a little shallow ESC tray and a receiver tray.

 

But...one thing I could do was think about the shell.

 

I got 4 beat up, grotty old painted on the outside, cracked and ruined shells.....so I figured I could cut one of those up to see what might work.  Cutting the front down, trimming hte sides to clear the steering, and generally slicing and dicing.....I got this:

 

 

Not final result....but....it's not half bad looking 🙂

If I patch up the holes, I could try and made a fibreglass version and extend the nose over hte front brace. I'm liking this oddball!

[walkbythesea]

Brilliantly bonkers 😎👌

[Juanmacine]

Wait for the last results when you run It.

[Stormbringer]

looking forward to seeing this finished mate 

[Redback]

Amazing! how did you get the driveshaft to the front? In the middle did you use 2 diff housing ouputs? did they fit together fine? did you have to flip the diff to retain correct rotation on the front?

Edited August 19, 2021 by Redback

[Kpowell911]

36 minutes ago, Redback said:

Amazing! how did you get the driveshaft to the front? In the middle did you use 2 diff housing ouputs? did they fit together fine? did you have to flip the diff to retain correct rotation on the front?

Have a read through he explains everything lol

[Nitroholic]

@Redback basically....the Hyper 7 diff housing is broadly symetrical. They front and rear halves key together with a ridge that runs around the join, fitting into a groove on the other side. I took 2 'backs', trimmed the joining ridge off, and bolted them up. That gives 2 output shafts. The diff in there does rreverse the rotation when the drive comes out....so the front diff is flipped over. Again, Hyper 7 housings don;t care which way round the diff goes....unlike Savage ones...where the case slopes and a diff only fits one way.  I then made up a very short driveshaft cutting, shutting and welding a sleeve over the join. The rest....is easy

[Nitroholic]

Got the 3D printer up and running, sorted the adapter....found my SD card was FUBAR too ...so that went in the bin and a new one replaced it. So, got things moving, and spent a couple of days churning out hte parts I needed.

 

First order was getting the battery tray in position:

 

 

Bolted to the chassis with 4 captive nutsand a strap each end ( when I can find the missing one... )

 

Then I could fit the ESC tray to the top brace, with one bolt through from underneath and the two rear centre diff screws locking it down. Recesses were left for the cable ties to run through and hold the bits in place

 

 

Receiver sits at the back with a built in channel to take the antenna.

 

 

Put it all together, and the electrics tested out fine. The steering servo is still not 100%.... but I stripped and cleaned it and threw some contact cleaner into the potentiometer. Settled it a bit, but it will be swapped out.

 

 

Need some double sided tape for the on/off switch, and I can tidy up the cabling a bit more once the servo is replaced. But....it seemed like a nice day, so a short test run was in order to see how it turned. My garden isn;t ideal for running a 1/8 on 4S with any speed....I don;t suppose many are!  But I wanted to see how it ran, check the driveline was smooth and not binding and to find out how well it turned. So...

 

 

 

Video is a bit shonky, as I was trying to hold the phone and point it while steering and looking where I was going. Screw this multi-tasking lark!

But you get the idea 🙂

[Stormbringer]

it appears to turn well 

3 minutes ago, Nitroholic said:

 

Video is a bit shonky, as I was trying to hold the phone and point it while steering and looking where I was going. Screw this multi-tasking lark!

But you get the idea 🙂

maybe you should have got the mrs to do it mate 

[Tug]

6wd and 4ws! Impressive! Bravo!

[khevolution]

Needs another 2 Wheels on the back 😁

[Nitroholic]

If I put 2 more wheels on the back....I'd have to add 2 more to the front....on principle! Don't have enough parts 🤪 Maybe next time.......

 

Going to try and adjust the rear steering angles to reduce the throw on turning to get a graduated turning effect. Currentrly, It's pulling the front sideways as much as turning, and I want to reduce that effect as under power...it can lose grip at the rear and crab. I reckon by moving the linkage pivot points I can reduce the steering movement while keeping it proportional.

 

I also need to tidy up my bodged shell a bit, and fabricate a front mount for it. If at some point I decide I want to buy a proper shell, I want to know exactly what modification it will need to fit right. A knackered overpainted shell is the perfect way to experiment!

 

Then...I can think about what I might mess with next.... might be time to see if I can make a swing-axle front end for a Baja....or if I can figure out how to make track brakes for a halftrack and some hub adaptors that would take a drive sprocket. I really need a lathe......