Off road tyres driving me INSANE

[alexapc]

By the way both my forks have outer threads but the bases are different, narrow and wide

[Burgerman]

take out old steel ones. Measure inside, outside, thickness, then search ebay for "stainless sealed bearing"...

If they are proper food grade ones as used in industry, they have blue rubber side sheilds so they can be spotted if one falls into food... Those are the ones to get.

[JOEY]

These items were purchased from Martin O, bolt holes dont line up , allen screws are 2mm and the allen key size to screw them in is 1.5mm, centre bore on spacer is to big for the hub so you could get the wheels to not be central on the spacer and weeble and wobble
we paid Martin O £143 for this junk + a trip from norfolk to hove. MARTIN YOU ARE A

[Burgerman]

Its supposed to fit flush and neat with coutersunk stanless cap screws like the ones on here: http://www.wheelchairdriver.com/BM-MK3- ... uction.htm -- Certainly no big ugly nuts and bolts, because that looks like an industrial factory! And no spacers.
And as we have discussed here before those allen screws will not be good enough for reversing loads, even if everything fitted.

Dont get confused though. There are 2 types of adapters here. The alloy ones fit the cheap trailer wheels. Which I no longer use. The steel ones are welded on, fit the Hegar type aircraft/karting wheels. Dont miss the 3 pictures further down the page...

[JOEY]

I understand bm, but how can you fit the hub on the shaft that has a 6mm keyway buy using a 2mm screw that leaves 4mm of keyway left to rattle around in and how tight would you get a 2mm screw with a 1.5mm allen key ????
the spacer is countersunk on both sides but where the holes are to fit the spacer to the hub, the bolts dont line up. where the spacer has a centre bore to fit over the centre hub spigot the spacer hole is too large so you would have a job fitting the spacer to the hub so that it was central, it is like a cock in a top hat, that is why it is like a weeble. The whole lot martin supplied seems to be a prototype that went wrong, but he still sold it to me knowing it was wrong. and i stand by what i said martin is. let us hear what excuse and bullshit he comes up with now. joey

[Burgerman]

spacer is countersunk on both sides

Only supposed to be one side, so the wheel fits totally flush to that adapter. The taper and the coutersunk bolts are what is supposed to centre it like a cars wheel. You cant use nuts and bolts! And it IS a spacer, it isnt supposed to have more spacers. Mine was designed for the groove motors. But the thickness will not be the same on the F55 motors.

Send it back to him, its unsuitable. It would still never stay tight even if the allen screws were 6mm. The contact area is too small. Even full length flat keyways wear out on f55s...

[LROBBINS]

The only way I've seen what you brits call grub screws used successfully with a keyed shaft was to have a key in the keyway and then the set screw at 90 or 180 degrees around the shaft. The grub screw isn't actually load bearing, it is just used to take out the slop. I've seen this on 1/4 hp motors running ca. 300-450 RPM in reversing applications on a belt drive, but I don't know if could hold up on a a high torque direct drive. Just using set screws in place of a Woodruff key is BAD. Ciao, Lenny

[Fulliautomatix]

Just using set screws in place of a Woodruff key is BAD. Ciao, Lenny

It'd shear off in about 2 minutes flat!
He was originally describing it as 6mm grub screws...which might stand some chance of working.

[ex-Gooserider]

The way I've seen setscrews used in such an application is to have two, and use a key... One screw sets on top of the key and drives it into the slot, taking up any slop in the fit between the parts, and the second was a lock screw going into the shaft at 90* to the keyway.

Don't know how this will work on reversing loads, but I certainly saw it on a centrifugal clutch for my leaf shredder, which has a 5hp gas engine and definitely gets severe shock loading...

I definitely agree that setscrews into a keyway is poor design at best - seems kind of Disney (as in Mickey Mouse...)

ex-Gooserider

[Burgerman]

If you are going to use f55 motors you need to use either the latest hubs that are similar to the groove and these only come with a set of wheels, or you need to use the taperlock pully made into a hub. Noting else will work properly unless it has the key slot machined into it too.

[Fulliautomatix]

or you need to use the taperlock pully made into a hub. Noting else will work properly unless it has the key slot machined into it too.

I note that the 20mm bore 1210 and 1610 bushes have a 6 x 3mm keyway as standard. Taperlock + key = absolutely bombproof solution.
The only advantage to making a bespoke hub would be to eliminate the wheel spacer - errr...which hasn't been done.

[alexapc]

Question again about F55 caster fork assembly, what is the PERFECT set up? 2 bearings, a bolt, are washers essential to stability? Top or/and bottom washers? What about the bolt, does thickness matter?

[Burgerman]

Bolt? At the bottom? I use a straight through 10mm axle and countersunk m6 stainless bolts. Washers?

[alexapc]

Not that, I mean the bearing assembly that connects the fork shaft to the frame

[woodygb]

http://www.sunrisedice.com/asset-bank/a ... /11602.pdf

page 8

[alexapc]

Great thanks, so there's a washer and a shim? What's the shim for? How is it different to the washer?

I see here you have 2 diagrams, are they for caster or shaft bearings? viewtopic.php?f=2&t=1068&p=13157&hilit=+bearing#p13157

[woodygb]

These two ...
are supposed to be the WHEEL and axle.

[woodygb]

SHIM:-

A shim is a thin and often tapered or wedged piece of material, used to fill small gaps or spaces between objects.[1] Shims are typically used in order to support, adjust for better fit, or provide a level surface. Shims may also be used as spacers to fill gaps between parts subject to wear.

I'd go with the red part of the definition.

[alexapc]

So what is this shim? Where can I get one?

[alexapc]

Yeah I know what a shim is! I have one of them only on one side, took it to hardware stores couldn't find one, only a washer with same inner hole 1/2 inch but wider outer diameter