ANy welders near derby?

[ricey3]

Morning all

I've got little frame made of 25mm sq box section i need welding up just after christmas. bench top sized job, imagine the size of a car wheel ramp.

Its actually a frame to hold a starter motor and a couple of rollers, which i'm then going to use to start my motorbikes. so needs to be accurate and neat, which is why i'm not attempting it!

Anyone in the derby area fancy a bit of beer money?

 

[Furry Freak]

Seems a little quiet in Derby there matey. If you get no better offers I am South side of Chesterfield, A38 and A61 straight to my door. I used to commute to Derby every day. I can certainly mig up a frame for you if you have everything cut and ready to go. I use a lot of box section for making ladders and towers etc, so not a problem for me.

Not offended if that is too far, but if you can't find anyone else, I'd be happy to help out for the cost of the wire and gas. I'm not a pro, just a hobbyist but if you check out my posts, you can see that what I weld won't fall apart.

FF

 

[pedrobedro]

I'm not much nearer but will say the same, I've built a few 25mm RHS items (car chassis mostly) and if you have a design and materials it sounds like a project.

 

[ricey3]

Guys, thanks both for the reply. Very much appreciated. As ff posted first I'll take up your fine offer mate.

And no not too far at all, i.m at alvaston so can jump on the M1 no problem and fly up.

Can you pm me your name and number and i'll get in touch, going to pick up the box from egglestons on xmas eve and cut it over xmas so will be a week or two before I need it doing and then will just work around your availability mate

cheers
brendan

 

[pedrobedro]

Quicker and easier to come up the A38

 

[daf45]

Any chance you could post plans and or pics of this project please?
It's something I've been meaning to make for ages - but working out things like how fast a starter motor spins compared to how fast the bikes wheel needs to turn baffles me.
Will you use belt or chain to drive the rollers? Knurled metal tube or gokart wheel for the rollers? Drive one or two rollers? what bearings? Any clutch / freewheel? etc etc etc?
Couple of mates racing classics last year and next, none of us can currently afford what the pro starters seem to go for and frankly I'm sick of pushing!
Any help would be much appreciated.

 

[ricey3]

Well without going too far because i want to make sure it works first before offering any advice! ha ha i'm basically using two aluminium rollers that i've turned up, sprockets bolted on the end of both and then a chain drive to a seat arosa starter motor. It is just running on standard roller bearings, no clutch, the shafts are fixed, not sure on the main switch yet, maybe foot operated, but i'm retaining the starter solenoid and using a switching relay. I've alos removed the bendix from the starter motor too.

It wont be perfect, may need some tweeking but it will work, the rollers are straight and it look like most have at least one with two tapers to centralise the wheel but i can take care of that if i find its a problem in the mk2 version, the rollers are bolted togeather so it will just be a case of make new tubes.

Rpm should turn the rear wheel and in turn the engine over at 1000rpm on my bike, which with the gearing works out about 7mph, which will be more than enough (think about how fast you run with the bike when bumping), TBH its the torque of the motor that most important and when you drop the clutch you want the motor to not have any problems, which a starter motor wont. the roller diameters and corresponding gearing were just worked back, a small amnount of educated guessing too.

heres a few picks of progress so far, like i say work in progress reckoning on £100 to build, luckily i have a lathe.

 

[brightspark]

if u have disreguarded the bendix and its a direct drive on to the rollers what happnes when the engine starts and runs the rollers faster than the starter motor. u cant dip the cluch that fast .??

 

[the snooper]

the motor would just be turned fast by the bike

 

[brightspark]

the motor would just be turned fast by the bike

at 3 times its speed as it would be geared up when driven by bike wheel instead of down by the motor

 

[the snooper]

look on the bright side brightspark the motor will only fly to bits once

 

[brightspark]

look on the bright side brightspark the motor will only fly to bits once

lol exactly

 

[the snooper]

i would use a centrafugal pully system like the scooters have so when the driven roller speeds up the pully disengages the motor

 

[daf45]

Looking good so far!

I thought gokart clutch but surely a centrifugal clutch will engage as bike fires and rpm rise NOT dis-engage. Hence the freewheel or one way bearing question / ideas.

Most other systems i looked at seem to use very similar double tapered rollers like you describe and I feel sure paddock starters wont be their only use - it's just remembering where else to find something suitable.

Not rocket science but like you said some fine tuning will be needed to get them working well (not self destruct) Lucky I dont have a lathe in a way cos in my head I'm already on the mark four design and I havent even scrounged a starter motor yet!

 

[ricey3]

Thanks for the replys guys,
yes the above has been a consideration, like i said in the first post its under development, I have the scope to re use the bendix albeit modified or something similar to allow overspeed if i need to.
I've become acustomed to using roller starters and you have to bear in mind what your trying to achieve, i dont rev the bike on the rollers, so hopefully the overspeed of the motor wont be quite a huge problem, you dont apply any throttle until you've pulled the clutch in and tick over of my bike with the choke out is lower than what the roller will turn the engine over at