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We are in the process of building some gearboxes for our new heavy but need some ideas for attaching the gear to the shaft of our Bosch 400. We don't have the tools to use a keyway and even if we did there isn't enough material on the gear to do it.
We are thinking of putting a pin through the gear and shaft and then welding it in place is this the right way to go or can anyone suggest something better?
Just weld it. Problem solved.
Merlin has always used a 5mm roll pin, never failed yet.
dead easy,
2 spot welds on the end, never fails.
if you want to change it, you grind the weld off, and then knock off !
:proud:
Another vote for welding it...just be careful to get no spatter in between the teeth or you'll have to get a needle file in and file it out.
Bodgers!
Just a word about following Jonno's advice. We did just that at barnsley and the weld actually snapped on the gear.Quote:
Originally Posted by roamingrobots
It works but we stuck in a 5mm bit of silver steel held in with some araldite too just for a bit more security and you can still take it off.
Glue :roll: lol
Or you could wrap some gaffa tape round it but we wanted to do a prefessional job :rofl:Quote:
Originally Posted by roamingrobots
And yes, glue just make sure you get some meths or white spirit on a cotton wool bud to take the grease off first and then it sticks like **** to a blanket. :proud:
I have also had a gear sheer in half, think I probably put too much heat into it as I TiG welded that one. Also had a shaft break off after welding twice on the same motor.
What size of gear, and what axle?
9 t kart sprocket same size hole just weld on
Ok after the welding gear on we remembered we hadnt done the magnet retaining ! Also after another weekend at Maidstone burning out another set of 400w mobility scooter motors, Will and I decided to try and fit the Bosch 400s originally intended for the new heavyweight (now superceded to 750s) into Maelstrom....with a bit of metal bending and plumbing and some mods to the gearboxes we might just be able.
So gear removed OK (ish), removed brush housing OK but the armature seems to be catching at the fan on the magnets. Followed tecnobots guide for removal / fitting their retainers (when they were available) and the armature should come up reasonable with a bit of force overcoming the magnets.
But seems to me its definetley hitting something preventing the armature to come out.
So any ideas ? Can you get the magnets out with armature still in place ? Just dont want to risk cracking a magnet.
Cheers, Ian
The magnets shouldn't be in the way of anything, normally it wont come out due to a bur or something on the shafts and not being able to slide through the bearing. You should be safe to give it a 'tap', if it still doesnt go, knock it back and you should be able to see marks on the shaft where its tight.
Thanks Alan...but defintely mechanical hitting...check for burrs etc but somethings hitting somewhere...Can you release the magnets with armature in place ?
Cheers, Ian
probably, never tried it, might be abit of a faff though! Got to be careful not to damage the spring clip things.
Allan../ Jonno you were right....was just binding on the bearing...hit it with bit of wood and came out soon after !
Broke 2 of the retainers (the middle clip ) - copied the magnet retaining method off Adrian (Eruption) so the magnets wont shift. So will probably araldite the clips in just to make sure the dont drift out and hit the fan.....might even consider a small nut and bolt to hold them in (thru the clips that are missing !).
So I feel like a proper roboteer now having modided my 1st Bosch ! 1 more to go on Maelstrom before total rebuild of the back end as they will stick out 1/2 more than the old littons and also new 1st stage gearing to take the new motor shafts.
Good experince before doing the 2 new 750s for the new heavy.
Busy weekend me thinks.....but as the team principal at Uni (ant weights in bristol i think ?) so wont having anyone telling me how it should be done.
Cheers Ian.
With regard to fitting sprockets or gears to shafts I use the method of drilling along the shaft so half the hole is in the shaft and the other is in the sprocket then tap the hole and fit a cap head (hex-socket) screw in with some stud lock.
As you can imagine with Saint with all that forwards and backwards movement the drive takes a hammering, most other methods would eventually fail.
And to remove the sprocket you just undo the bolt!