PhillipM
Member
- Messages
- 3,036
They are on a lot of dampers, one it keeps weight down, and two making the shaft hollow reduces the oil displaced so the dampers run cooler, are more sensitive and generally have less hysteresis.
- Thread starter PhillipM
- Start date
They are on a lot of dampers, one it keeps weight down, and two making the shaft hollow reduces the oil displaced so the dampers run cooler, are more sensitive and generally have less hysteresis.
Bullet2012
Member
- Messages
- 5,292
- Location
- on average about 200 miles from the ISS.
He is still on here, latest project. https://www.mig-welding.co.uk/forum...fountain-a-really-really-big-fountain.127212/
hi Stuvy
not much to report really life got in the way just like with everyone else, i sold or gave away most of my buggies, only left with 2 or 3 now, this Chinese one which although its very flimsy and i certainly wouldent want to roll it as the roll cage would probably just fold up
it has however had the cheap and cheerful Chinese 2 cylinder engine replaced with a nissan mirca engine and box doubling its capacity and power, its also road legal which is really the main reason i have kept it as one day i would like to biuld a copy of it with suitable sized and specced tubing along with my vw/Audi turbo engine and box, would be fun fetching the shopping in that
so that's buried in a shipping container waiting for me to get round to it, the only other one i sometimes work on is a suzuki jimny based buggy, jimny chassis and axles standard jimny suspension, both diffs welded up solid, the back one you have to live with the front you can disconnect either hub since they are vacuum operated so you can have 2 3 or 4 wheeldrive, engine and box is a pug 306 diesel with its diff welded up too, although that may come back out in favor of a metro engine as its all aluminum ,
i havent started the roll cage yet but it will be something like the red one, all curves
and that is more or less it
apart from 5 excavators and a few lorries lol
Proper buggy racing...Oh, I do have some good news, for you guys anyway. We didn't have time to fit it yet but we do have an in-car GoPro now....
PhillipM
Member
- Messages
- 3,036
Okay, a little progress after collecting more parts and a bit of machining fun all day today, trying to correct most of the problems with the hubs/bearings - a few of these I should really have spotted, I was wary about the seals these use from the very start but assumed a big racing firm that made them for a lot of £100k+ rally cars must have had things running well enough that I should just use them how they came (well, apart from our own uprights in the centres of them, anyway).
Bit of a mistake, obviously, and I've since learnt that other teams that used to or are still running these have all had similar problems with dirt and water ingress and damaged bearings.
Now as I said before, I found about 5-6 areas that had issues, either the seals themselves, machining stackup tolerances or just outright poor practice on picking fitup clearances generally. I'd normally go into more detail as you guys know on exactly what and why - but I'm going to keep it relatively sparse I'm afraid at the moment, as the firm that bought up the old business that originally made these doesn't seem to know how to fix them, doesn't really want to sell us spares as they want them for their ongoing customers who are having issues (so we can't even get one spare barrel and bearing housings to be able to make ourself a spare corner up with the extra upright we have already) and I know a few of the guys from the racing read here too
So there might be a bit of work on there fixing old sets and I don't really intend to give away my findings, apologies, but I will still show what's being done anyway, just without specifics of why
First up the bearing casings got re-machined due to some design clearance issues:
Some new bearing lock rings/seal retainers were made up, slightly thicker material, different sizing, and thoroughly chamfered, deburred, etc, which was quite a long job for 6 plates with all those holes to countersink from both sides on the drill press...
And some pre-load rings for the bearings were made up to correct an issue there, originally they don't run any:
I also knocked off the bearing face and outer sealing face from the hub barrels, so I could clean up and machine those due to some silly choices on tolerances there too - you can see just how much water made its way into the barrels here between the bearings just from the surface staining:
While I was at it I filed and chamfered the threads on the barrels where the cutouts are for the lockring, as the partial threads where they were machined through had distorted and made getting the threaded preload rings off a nightmare. I've cleaned the barrels up with some abrasive nylon brushes since this but I'm half tempted to bead blast them back clean completely.
Speaking of those threaded rings:
Even after a quick cleanup with emery on the old bottom one there you can see the damage from the debris caught in the seal. So newly machined ones instead are replacing them, which also have some modifications to sizing because the old ones also had some machining or tolerance errors - or perhaps deliberate choices to try to fix the water ingress issues - and appear to have melted the bigger inner seals in spots...
The inner rings I knocked off the barrels above got remachined too as you can see.
And finally some different sealing methods - the original seals they used in these were some machined down things that they'd clamped in a fixture and narrowed down to fit. That mean the seals twisted in the housings as they were no longer stable or round enough after machining. These new seals fit full width with no messing around machining them, meaning they're much stiffer axially and shouldn't suffer from that again. They should also be far more effective at keeping dirt out than the originals do to some changes in fitting, something I wish I'd changed when I saw the problem with the originals to start with.
I will explain this one though as I expect people will ask - the black ring is a modification made to prevent the spring that energises the lip seal (you can just see it on a standard seal in the background there) getting knocked out by debris. It's a form of sealant that actually foams into a sponge so it's very soft and doesn't affect things too much.
Not something you'd ever usually bother with as it changes the sealing effectiveness slightly - but it's necessary for all the dirt/mud/rocks things get exposed to in this type of racing.
Anyway, need to let that foam up and cure for a day and then start putting things back together with some redesigned gaskets, seals, grease, etc.
Bit of a mistake, obviously, and I've since learnt that other teams that used to or are still running these have all had similar problems with dirt and water ingress and damaged bearings.
Now as I said before, I found about 5-6 areas that had issues, either the seals themselves, machining stackup tolerances or just outright poor practice on picking fitup clearances generally. I'd normally go into more detail as you guys know on exactly what and why - but I'm going to keep it relatively sparse I'm afraid at the moment, as the firm that bought up the old business that originally made these doesn't seem to know how to fix them, doesn't really want to sell us spares as they want them for their ongoing customers who are having issues (so we can't even get one spare barrel and bearing housings to be able to make ourself a spare corner up with the extra upright we have already) and I know a few of the guys from the racing read here too
So there might be a bit of work on there fixing old sets and I don't really intend to give away my findings, apologies, but I will still show what's being done anyway, just without specifics of why
First up the bearing casings got re-machined due to some design clearance issues:
Some new bearing lock rings/seal retainers were made up, slightly thicker material, different sizing, and thoroughly chamfered, deburred, etc, which was quite a long job for 6 plates with all those holes to countersink from both sides on the drill press...
And some pre-load rings for the bearings were made up to correct an issue there, originally they don't run any:
I also knocked off the bearing face and outer sealing face from the hub barrels, so I could clean up and machine those due to some silly choices on tolerances there too - you can see just how much water made its way into the barrels here between the bearings just from the surface staining:
While I was at it I filed and chamfered the threads on the barrels where the cutouts are for the lockring, as the partial threads where they were machined through had distorted and made getting the threaded preload rings off a nightmare. I've cleaned the barrels up with some abrasive nylon brushes since this but I'm half tempted to bead blast them back clean completely.
Speaking of those threaded rings:
Even after a quick cleanup with emery on the old bottom one there you can see the damage from the debris caught in the seal. So newly machined ones instead are replacing them, which also have some modifications to sizing because the old ones also had some machining or tolerance errors - or perhaps deliberate choices to try to fix the water ingress issues - and appear to have melted the bigger inner seals in spots...
The inner rings I knocked off the barrels above got remachined too as you can see.
And finally some different sealing methods - the original seals they used in these were some machined down things that they'd clamped in a fixture and narrowed down to fit. That mean the seals twisted in the housings as they were no longer stable or round enough after machining. These new seals fit full width with no messing around machining them, meaning they're much stiffer axially and shouldn't suffer from that again. They should also be far more effective at keeping dirt out than the originals do to some changes in fitting, something I wish I'd changed when I saw the problem with the originals to start with.
I will explain this one though as I expect people will ask - the black ring is a modification made to prevent the spring that energises the lip seal (you can just see it on a standard seal in the background there) getting knocked out by debris. It's a form of sealant that actually foams into a sponge so it's very soft and doesn't affect things too much.
Not something you'd ever usually bother with as it changes the sealing effectiveness slightly - but it's necessary for all the dirt/mud/rocks things get exposed to in this type of racing.
Anyway, need to let that foam up and cure for a day and then start putting things back together with some redesigned gaskets, seals, grease, etc.
slim_boy_fat
Member
- Messages
- 29,532
- Location
- Scottish Highlands
PhillipM
Member
- Messages
- 3,036
That's one together, after a little more machining work, also, a bearing with Pot Noodle for scale. Highly scientific units those:
And yes I was hand packing bearings with grease. No it's not advisable. Yes I still did it.
Here you can see where the barrel goes and the bearings and seals sit a bit easier:
And then torqued up, new modified lockplates fitted:
And all assembled and ready to go:
And yes I was hand packing bearings with grease. No it's not advisable. Yes I still did it.
Here you can see where the barrel goes and the bearings and seals sit a bit easier:
And then torqued up, new modified lockplates fitted:
And all assembled and ready to go:
PhillipM
Member
- Messages
- 3,036
And all back together, gotta put the floor and under armour back on the car before we can test it though. They feel much smoother and far less tight than initially, which is good, you needed a fair bit of strength just to spin them before given the size of the seals dragging, etc.
PhillipM
Member
- Messages
- 3,036
Well, the good news after a test run up and down the lane here, everything bedded in nicely, bearings are running much cooler than previously, noticably less drag too. Also the car rides much smoother from the damper work, and the turn in is a noticeable chunk better, whether it's a little too flighty remains to be seen but better that than another season of fighting understeer.
Bad news, it blew a front brake line out leading to squeaky bum time and a dent to the workshop wall...luckily the car is okay, and even better is at least it happened now. Not quite sure how it looks like it's split clean across, the theory at the moment is either a rogue stone strike or a faulty crimp that damaged the hose, every other line looks fine.
New brake lines fitted, front circuit rebled and she's ready to go again, just needs a bit of testing, so hopefully this time we actually make it to the racing. It's up at the Parkwood Offroad Centre in Tong/Bradford this weekend if anyone is up that way!
Bad news, it blew a front brake line out leading to squeaky bum time and a dent to the workshop wall...luckily the car is okay, and even better is at least it happened now. Not quite sure how it looks like it's split clean across, the theory at the moment is either a rogue stone strike or a faulty crimp that damaged the hose, every other line looks fine.
New brake lines fitted, front circuit rebled and she's ready to go again, just needs a bit of testing, so hopefully this time we actually make it to the racing. It's up at the Parkwood Offroad Centre in Tong/Bradford this weekend if anyone is up that way!
Typical . . . just down the road . . . except I fly to Seattle Saturday . . .
stuvy
Member
- Messages
- 9,304
I used to grass track race a mini and was lucky to be in front of everyone and not get pelted
PhillipM
Member
- Messages
- 3,036
Haven't really updated much as I've been busy rebuilding a Merc engine and now a Yamaha, but Eddy sorted new bearings and washing everything out while I was busy, got it all together and took the buggy to Minehead today, along with the new rear springs to match to the previous damper changes - and it's just ended up 6th.
It had enough pace to be in the top 3 if it hadn't been for some steady morning runs (which lost about a minute or two) to make sure the engine was all okay, 4th place was literally only a couple of seconds away, pretty happy regardless!
And it was at Minehead where we blew our diff once, broke down another and slid into a tree once when I wasn't there (ill in bed with flu at the time) - so it's broken a streak of bad luck there. Not a great event for a 2wd usually either as there's a lot of loose rocky uphill scrambles from low speeds.
Pretty happy!
It had enough pace to be in the top 3 if it hadn't been for some steady morning runs (which lost about a minute or two) to make sure the engine was all okay, 4th place was literally only a couple of seconds away, pretty happy regardless!
And it was at Minehead where we blew our diff once, broke down another and slid into a tree once when I wasn't there (ill in bed with flu at the time) - so it's broken a streak of bad luck there. Not a great event for a 2wd usually either as there's a lot of loose rocky uphill scrambles from low speeds.
Pretty happy!
