Machinists Gazette

MANUAL MACHINES => Saws & Grinders => Topic started by: PJB on July 14, 2018, 01:07:19 PM

Title: Band Saw Downfeed Hacks
Post by: PJB on July 14, 2018, 01:07:19 PM
My Ramco RS-90P horizontal band saw works great in most respects except the down feed.  The saw originally came fitted with a pneumatic cylinder but it didn't work worth a darn.  Could be the piston seals shot I'm not sure.  So I modded it with a needle flow control in between both ports and filled it with way oil.  This helped a ton but now I have an annoying oil leak dripping to the chip pan and for some reason even with the valved fully closed, the saw still descends too quickly.  No doubt the oil is merely squirting past the piston seal which limits the effectiveness.   Until I either replace or rebuild the cylinder my "there I fixed it" hack is a heavy C-clamp.  It weighs probably 10lbs and clamped hand tight to the upper beam provides just enough counterbalance to fine tune the down feed.  Moving it slightly left or right varies the speed.

ps no be dissing my tape measure storage rack ok? ;D
Title: Re: Band Saw Downfeed Hacks
Post by: DeadNutz on July 14, 2018, 01:19:35 PM
On my old Johnson saws I used to lay a block of tool steel on the handle to help get faster cuts which helped with blade life and straightness of the cut. I like the c-clamp idea.
Title: Re: Band Saw Downfeed Hacks
Post by: Matt_T on July 14, 2018, 03:52:31 PM
Nice work on the cylinder. I've threatened to fix those things but never found the time to actually do it.

I've seen some saws with an adjustable weight on top. Like a slide hammer with the shaft ends supported by brackets.

Does that saw not have coolant or am I just overlooking it?
Title: Re: Band Saw Downfeed Hacks
Post by: 4GSR on July 15, 2018, 12:27:20 PM
You got enough tape measures there??? ;D

Find you a real brass needle metering valve to replace that piece of plastic and I bet your problem will go away.  Work the air out of the cylinder and lines, that should help too.

Ken
Title: Re: Band Saw Downfeed Hacks
Post by: Ulma Doctor on July 16, 2018, 08:46:09 PM
you can NEVER have too many tape measures!  ;D
Title: Re: Band Saw Downfeed Hacks
Post by: 4GSR on July 16, 2018, 09:50:35 PM
Yeah, I have no room to talk.  Have a stash of tape measures myself.  But they are not all at the saw!
Title: Re: Band Saw Downfeed Hacks
Post by: PJB on July 21, 2018, 12:25:12 PM
Ordered a new cylinder from Automation Direct that showed up today.  Was about $30.  I'll need to make a little bit different mounting bracket to accommodate the new cylinder but that will be another Sat project.   I may skip the oil and try simply using air.  Not sure if the rod seal is tight enough.   We shall see.
Title: Re: Band Saw Downfeed Hacks
Post by: gtermini on July 21, 2018, 01:38:32 PM
I read somewhere about using a porous foam insert or something in the top side to keep the cylinder full without dead space, since the volumes aren't the same on both ends, accounting for the cylinder rod.

Greyson
Title: Re: Band Saw Downfeed Hacks
Post by: PJB on August 07, 2018, 12:32:01 AM
Got around to making up the mounting bits, rod clevis end tonight.   Still need to cross drill for the clevis pin.  It does work with only air albeit kinda spongy so I'll likely fill it with oil both sides and bleed out the bubbles.  The flow control has a check in it to allow free flow raising up and metering on the way down.   
Next upgrade will be some sort of length stop.  I'm getting tired of having to kludge together makeshift stops like the one below every time I go to cut multiples...
Title: Re: Band Saw Downfeed Hacks
Post by: Carpenter84 on August 07, 2018, 06:07:23 AM
Uhg. I wish I had the room for a saw... Hell if I could find a saw cheap enough, I'd make room. I've been using a porta-band style Chinese princess auto saw for years. Saturday I had to chop up a 2.5" block of stock. I was standing at the vise sawing for nearly an hour.
Title: Re: Band Saw Downfeed Hacks
Post by: 4GSR on August 07, 2018, 06:58:12 AM
PJB,

That's a nice down feed mod you made there.  Thanks for sharing.

Ken
Title: Re: Band Saw Downfeed Hacks
Post by: chips and more on August 07, 2018, 09:43:10 AM
Yes very nice mod. But what happened to the dirt, grim and swarf? When I use my saw, it makes one hella mess  :D
Title: Re: Band Saw Downfeed Hacks
Post by: groundhog on August 18, 2018, 12:21:47 PM
Nice Job. Making a similar set-up for my saw has been on the top of my list for about 5 years! Seems I usually work on that list from somewhere around the middle.  :P