Fit brake to Startrite 352 bandsaw?

[Chris152]

Is it possible and if so, is it difficult and what's it likely to cost?

Thanks

Chris

 

[Ttrees]

If you dont have a bandsaw yet, you could get a VFD with built in braking capacity for a 3 phase (dual voltage) saw, (internal capacity or have an outlet for a simple braking resistor)
The VFD's for 100 quid have internal capacity but it might not be a good idea to make them stop, say within three seconds due to cheap parts.
I haven't checked the cheapest VFD you can get which has components for a working braking resistor...
I haven't checked the Isacon/askpower drives, although it has a nice big terminal for one...
IIRC, I might have read that these are also best suited to spindles and the likes.

I can check about this in the VFD's parameters in a few days if you, or someone else likes
Tom

 

[Chris152]

It's a friend's but I get to use it in a shared workshop if we can sort a brake. It's 3 phase. And I know diddly squat about electrics - can you just install the vfd to the existing setup? Sorry if that's too naive for words!

 

[Ttrees]

I think the law is for it to stop under 10 seconds,
Clarification needed !
If so, a hundred quid or less inverter will do it seems, providing its a three phase machine, with 240 on the nameplate (delta triangle symbol, household, low voltage)
and then you specify what phase you want in.
I know nothing of 3 phase IN inverters as I only have used 13 and 16 amp plugs before..so single phase IN.

A stop and a start button depending if you go with the Isacon/askpower VFD's you wont have a noisy annoying fan going off constantly, but that means you wont have the
ability for a "button station" without buying a relay for it to work £4 or something....
I need to get a link for one actually as I have a lightswitch, which is terrible, and I at least need a throw style switch to get me by.
When you have a start and also a stop button.... the relay goes inbetween making it "three wire control" .
..for under a fiver, togther with the stop and start switch @£2 pound each and a bit of wire." so about a tenner for switches and installation all in all.
These Isacons are the newer looking like the huanyangs and have similiar tech like what Jack Forsberg speifiys with his VFD range he seems to be getting made up
(Jack english machines)
I cant guarentee the VFD I have is the best but it probably will be
You will need to make a box out of tin for it to protect it from dust and damage
You will see both for sale, so spec what phase supply you want IN.

 

[Lons]

I know it's not electric or automatic but my ancient 352 has a foot brake pedal which stops the machine pretty quickly, I thought they all had it. :?

 

[Chris152]

Thanks Tom, I understood some of that but not all of it - but found this as I tried to decipher the terms:
http://www.hse.gov.uk/pubns/wis38.pdf
(hse guide on retrofitting brakes on woodworking machines).

I know it's not electric or automatic but my ancient 352 has a foot brake pedal which stops the machine pretty quickly, I thought they all had it. :?

Yes, it does have one of those, and the hse guide lists these methods:

The main ways of providing braking are to:
■ replace the existing unbraked motor with a
braked motor;
■ use an electrical braking solution by fitting a
variable speed drive (VSD), or a direct current
(DC) injection braking device to the existing
unbraked motor;
■ fit a power-operated mechanical brake;
■ fit a manual or foot-operated brake.

so maybe the foot brake is sufficient to meet hse guides. Failing that, a vsd fitted.

 

[Ttrees]

So your saw has a three phase motor on it?
And you can see 220 or 240v on the motor nameplate, which you should as with any I've seen....providing the motor wasn't swapped out.
It seems, from glossing the first paragraph...it states that a brake is required to stop a bandsaw in 30 seconds.
I would get an Isacon/askpower drive, for the job personally, and depending if you enjoyed your time working sheet metal
making/ finding another box of some sort for mounting either a plain toggle switch,
or go all fancy and get a nice big red button, and separate green start button...for the fancy switches you need an additional
part called a relay...
link requested for a cheap suitable relay anyone?

I can easily stop my 24" bandsaw in that time...with the VFD rated for 3hp/2.2KW motor...which is what machine has.
I haven't found much info on these , so unsure if the cheaper priced 1.5HP rated Isacon can do this as well
You can use a more powerful rated VFD than the motor you have, provided you enter the correct values.
This might be advisable as there's only probably 20 quid in the difference.

It seems there's a bit of cobbling to do regardless if you make a brake or make up a tin box for the VFD/inverter....
(no-one calls e'm VSD's)

I am unsure if the cable from the motor going to the VFD needs to be protected/shielded...
This could be done easily, a multitude of ways.

I dont know of any other cheap VFD which has the auto shutoff fan, which I find nice.
Maybe a foot brake is more sensible, but I looked in to making one for my machine years ago, and decided not to.
Could it be bought cheaply?
Tom

 

[Ttrees]

It seems you may also need have to have an isolator switch to be able to turn off power to the VFD aswell as the stop button?
There's also talk about 10 seconds.
I'm not sure if the HSE folks would be OK with you turning your machine off with two switches, in an emergency situation one applied about 4 or five seconds after the first?

 

[Ttrees]

It seems Sawmill Creek is the place to get an answer on the VFD part ?
I can never find any links on the archive.
Tom