Thread: Speed Control

Originally Posted by DSEL74

Is there any benefits to have speed control to the moitor on a woodworking designated bandsaw?

The speed of the blade is generally fixed and you adjust the rate of feed (how fast & hard you push) manually.


Obviously if you mixing material there is a need to slow the blade down for plastics, non ferrous metals and super slow for steel.

I think you have pretty much answered your own question

My bandsaw has two pulleys so can change the speed, I tried making It faster but vibrated so much that the rubber tyres came off blade and all

I also tried a slower speed but that was pretty useless too, was like using a nail file.

I have been meaning to upgrade for ages as it is so loud and vibrates so much I fear it will fall to bits every time I use it, the 3/4 hp motor is quite inderpowered for a bandsaw too.

I may have answered my own question but it is theoretical guess work n my behalf, so looking to find real world verification for those with actual experiance.

Originally Posted by DSEL74

Is there any benefits to have speed control to the motor on a woodworking designated bandsaw?

The speed of the blade is generally fixed and you adjust the rate of feed (how fast & hard you push) manually.


Obviously if you mixing material there is a need to slow the blade down for plastics, non ferrous metals and super slow for steel.

There are benefits... ramp up/down starting/stopping, braking, various programmable functions, changing blade speed with the twist of a knob, all good things that improve the functionallity of the machine.


Pete

Originally Posted by pjt

There are benefits... ramp up/down starting/stopping, braking, various programmable functions, changing blade speed with the twist of a knob, all good things that improve the functionallity of the machine.

Yep, there are advantages to be had from additional functions. They all come with a cost. What you have to work out is if the cost is worth it in your own situation..

For example, last weekend I got my 21 inch bandsaw going again after several months of having the blade out, table off and blade guides removed. I took great delight in noting that the wheels kept turning for nearly two minutes after I turned of the power after each cut. To me it showed that my setup was great, with very little friction from the guides on the blade and all other aspects of the setup being pretty good. In a commercial shop they may see that as 2 minutes downtime they cannot afford and regard braking as a necessary feature.

You need to work out what is important for you and pay for what you need.

Cheers
Doug

Originally Posted by DSEL74

I may have answered my own question but it is theoretical guess work n my behalf, so looking to find real world verification for those with actual experiance.

Well in that case I do have experience as I work with wood and metal.
I can see no real benefit In changing speeds when cutting wood, but metal is a completely different issue as heat builds up rapidly and aluminium for example becomes "sticky" at certain temperatures clinging to the blade and tyres.The same applies to thermoplastics.

Depends how complicated you want to make it calculating cutting speeds, feed rate, also material thickness and blade types tpi etc.Probably just as well most wood bandsaws are 1 or 2 speed and there are dedicated bandsaws for cutting metal.

Originally Posted by doug3030

Yep, there are advantages to be had from additional functions. They all come with a cost. What you have to work out is if the cost is worth it in your own situation..

For example, last weekend I got my 21 inch bandsaw going again after several months of having the blade out, table off and blade guides removed. I took great delight in noting that the wheels kept turning for nearly two minutes after I turned of the power after each cut. To me it showed that my setup was great, with very little friction from the guides on the blade and all other aspects of the setup being pretty good. In a commercial shop they may see that as 2 minutes downtime they cannot afford and regard braking as a necessary feature.

I see the "running on" for 2 minutes as a bit of a safety issue.
The problem with my BS is that while its free wheeling like this 's is so quiet that sometimes I don't even know it's running and my hands have come close to the blade. This is why I fitted a footbrake that turns the power off and stops the blade in about 2 seconds. I could stop it even quicker but I'd be worried about the forces being generated.



More grimy detail here - https://www.woodworkforums.com/f27/bobls-bandsaw-brake-182752

Pete, Those features assume being controlled via a VFD?

Doug, I get what your saying, although it probably could be a safety issue depending on who else gets in your shed. I'm also thinking in terms of a 32" saw.

Bob, You never cease to amaze me with the little additions in your shed.

Originally Posted by DSEL74

. . . . .Bob, You never cease to amaze me with the little additions in your shed.

Yep, it's amazing what one can achieve working for about $5 an hour

Originally Posted by DSEL74

Pete, Those features assume being controlled via a VFD?

Yes, there are other types of speed control but I was thinking specifically a VFD.

When you say 32" I assume you mean wheel diameter, that sounds like a large machine for the average woody shop, high inertia forces to overcome when starting DOL (direct on line), high start currents, big cable, lights dimming, etc., for those reasons alone a ramped start (gradual speed up) via the VFD would be worth giving a VFD careful consideration to get around some of those start issues.

Is this machine in use or a soon to be installed?



Pete

Well maybe neither or to be installed. I bought the machine which has now been narrowed down in date to be a 1904 32" Crescent bandsaw made in USA. It was a bit rusty from storage but in otherwise great condition with fresh professionally done babbit bearings and a dozen blades.

However as post in another thread, the seller decided to load it with a forklift and no sling and toppled the old girl breaking several castings. I have paid for the machine already and am still waiting on hearing back from him regarding the machine having been repaired and what the compensation will be in terms of a discounted price with the difference refunded to me. I have made contact with a guy in the USA that may have parts available but shipping will be excessive.



If/once it arrives I will need to convert for single phase. So new motor or VFD. It has been suggested a diesel genny might be the go also.

Originally Posted by DSEL74

. . . . If/once it arrives I will need to convert for single phase. So new motor or VFD. It has been suggested a diesel genny might be the go also.

If that's the case I'd definitely be going VFD. Generators are usually a last resort thing.

Originally Posted by DSEL74

Well maybe neither or to be installed. I bought the machine which has now been narrowed down in date to be a 1904 32" Crescent bandsaw made in USA. It was a bit rusty from storage but in otherwise great condition with fresh professionally done babbit bearings and a dozen blades.

However as post in another thread, the seller decided to load it with a forklift and no sling and toppled the old girl breaking several castings. I have paid for the machine already and am still waiting on hearing back from him regarding the machine having been repaired and what the compensation will be in terms of a discounted price with the difference refunded to me. I have made contact with a guy in the USA that may have parts available but shipping will be excessive.



If/once it arrives I will need to convert for single phase. So new motor or VFD. It has been suggested a diesel genny might be the go also.

That's a whole lot of dissapointing there, Why should you be doing any sort of chasing of parts? the seller farked up so he should be the one chasing parts!



Pete