adrian
Flying Squad
So there I was a couple of weeks ago idly flicking through the latest entertainment from youTube when I saw Colin Furze's latest update
Replacing a mountain bike suspension with magnets which got me thinking - just how powerful are these little magnets that you can get and as I'm currently drawing up sprung W-irons,see alternative thread with Macaw F build, with guitar string, is the repulsive force sufficient for modelling purposes. A quick scan of ebay found various miniature sizes of magnets so a few different ones were ordered. The first to arrive were some 2mm diameter by 1mm height magnets.
Rather than start hacking a wagon kit I thought I'd draw and print a little test bed. So the plates have a little tube printed in each corner where the magnets are a push fit, the size is representative of a 9ft wheelbase 7mm scale wagon. The base plate has extended corners to hold the floating plate in the correct position above the other magnets.
The grey plate was the first effort with just one magnet in the base and the floating plate. First effort floated nicely and settled to a level position.
However adding a little weight (65g) significantly reduced the clearance - probably around 0.5mm
So the red version had slightly taller tubes so that each column could have 2 magnets.
This floated slightly higher and more importantly a slightly bigger air gap when the weight was added. I thought this was sufficient to start on trying it on a wagon kit.
In the stash I had a Parkside kit for a Conflat which seemed like a suitable test bed. The Parkside kits are nicely designed and allow for the axleboxes to float to a certain extent. I think most of us have devised different systems using either tiny coil springs or spring wire in various contortions to make them sprung rather than just floating.
So the Conflat was dug out of the cupboard and a quick check showed that it was feasible to drill a 2mm hole in the spring sufficient for magnet to be hidden.
So then to the axle boxes - slightly deeper hole for 2 magnets stacked. This illustrate the first huge benefit compared to using the little miniature coil springs. I bet every workshop has numerous little coil springs distributed all over. Not so with the magnets they stick like s**t to a shovel - or scalpel in this case. I've not lost a single one yet.
The downside is they also have a propensity to stick to each other!!
So a first effort to see if it works was to assemble the bare floor, buffer beams and sole bars. This was the first dip in enthusiasm as it didn't seem to settle very well, the axle boxes all seemed to have slightly different friction levels so it didn't settle very well and often ended up at a jaunty angle balanced on 3 wheels.
Trouble was I'd started so I cleaned up the axle boxes, added a little lubrication and have just finished off the kit as supplied.
At the end of the day it didn't work out too bad. With no weight added straight out of the box the kit is quite light (40g) and there is quite a gap between the spings and axle boxes.
Adding a little weight again made a big difference, adding the 65g so now a total weight of 105g settled the wagon quite nicely, it seems a reasonable weight for the wagon and pushing it through the turnouts it floated like on springs - or "air suspension". It's more settled and doesn't bottom out so quite pleased with the modification.
So now it's added to the paint shop road to join the other flat wagon.
So conclusions - yes it appeared to work. It's probably okay for plastic kits - open wagons. Not too sure about anything larger like box vans or heavier etched kits, however prototypes with larger "cube" axle boxes may allow larger magnets to be fitted.
It's been an interesting test for this wagon - and certainly a very easy spring conversion for Parkside Kits. I think I still prefer etched w-irons and guitar wire as suspension of choice for etched kits, however I will certainly look to using magnets again as it was easier than other Parkside conversions I've done.
Replacing a mountain bike suspension with magnets which got me thinking - just how powerful are these little magnets that you can get and as I'm currently drawing up sprung W-irons,see alternative thread with Macaw F build, with guitar string, is the repulsive force sufficient for modelling purposes. A quick scan of ebay found various miniature sizes of magnets so a few different ones were ordered. The first to arrive were some 2mm diameter by 1mm height magnets.
Rather than start hacking a wagon kit I thought I'd draw and print a little test bed. So the plates have a little tube printed in each corner where the magnets are a push fit, the size is representative of a 9ft wheelbase 7mm scale wagon. The base plate has extended corners to hold the floating plate in the correct position above the other magnets.
The grey plate was the first effort with just one magnet in the base and the floating plate. First effort floated nicely and settled to a level position.
However adding a little weight (65g) significantly reduced the clearance - probably around 0.5mm
So the red version had slightly taller tubes so that each column could have 2 magnets.
This floated slightly higher and more importantly a slightly bigger air gap when the weight was added. I thought this was sufficient to start on trying it on a wagon kit.
In the stash I had a Parkside kit for a Conflat which seemed like a suitable test bed. The Parkside kits are nicely designed and allow for the axleboxes to float to a certain extent. I think most of us have devised different systems using either tiny coil springs or spring wire in various contortions to make them sprung rather than just floating.
So the Conflat was dug out of the cupboard and a quick check showed that it was feasible to drill a 2mm hole in the spring sufficient for magnet to be hidden.
So then to the axle boxes - slightly deeper hole for 2 magnets stacked. This illustrate the first huge benefit compared to using the little miniature coil springs. I bet every workshop has numerous little coil springs distributed all over. Not so with the magnets they stick like s**t to a shovel - or scalpel in this case. I've not lost a single one yet.
The downside is they also have a propensity to stick to each other!!
So a first effort to see if it works was to assemble the bare floor, buffer beams and sole bars. This was the first dip in enthusiasm as it didn't seem to settle very well, the axle boxes all seemed to have slightly different friction levels so it didn't settle very well and often ended up at a jaunty angle balanced on 3 wheels.
Trouble was I'd started so I cleaned up the axle boxes, added a little lubrication and have just finished off the kit as supplied.
At the end of the day it didn't work out too bad. With no weight added straight out of the box the kit is quite light (40g) and there is quite a gap between the spings and axle boxes.
Adding a little weight again made a big difference, adding the 65g so now a total weight of 105g settled the wagon quite nicely, it seems a reasonable weight for the wagon and pushing it through the turnouts it floated like on springs - or "air suspension". It's more settled and doesn't bottom out so quite pleased with the modification.
So now it's added to the paint shop road to join the other flat wagon.
So conclusions - yes it appeared to work. It's probably okay for plastic kits - open wagons. Not too sure about anything larger like box vans or heavier etched kits, however prototypes with larger "cube" axle boxes may allow larger magnets to be fitted.
It's been an interesting test for this wagon - and certainly a very easy spring conversion for Parkside Kits. I think I still prefer etched w-irons and guitar wire as suspension of choice for etched kits, however I will certainly look to using magnets again as it was easier than other Parkside conversions I've done.
