Proof Of Concept Hydraulic Bandsaw Feed Rate Limiter

**rgsparber** · Feb 28, 2019, 11:13 AM

(title should read Pneumatic and not hydraulic!)
When sawing thin stock on a horizontal bandsaw, it is essential that the feed rate be slow. Otherwise, teeth start to shear off and the cut veers away from true. Plenty of nice homemade hydraulic feed rate controlling devices exist but, as usual, I wanted to find a different path.

This video shows a possible simple way to control the feed rate. This is just a proof of concept and needs more work before I make something to keep.

If you are interested, please see

Your comments are welcome. All of us are smarter than any one of us.

Thanks,

Rick

**mklotz** · Feb 28, 2019, 12:01 PM

Very clever, as usual, Rick.

For folks without sinus afflictions, probably the most commonly available bottle would be the ubiquitous two liter soda/water bottle. A 'calibrated' simple hole in the cap used in combination with the down pressure spring on the saw should provide the correct feed.

I have a tube from an HF 13" tire that already has a leak. I'll have to give that a try.

I wonder if something like modeling clay or duct seal could be used; varying the width of the piece being crushed could control the descent rate.

Oh, and you have good taste in bandsaws. Or I do. I have exactly that model Enco bandsaw. One of the most useful tools I ever bought.

**rgsparber** · Feb 28, 2019, 12:22 PM

Originally Posted by mklotz

Very clever, as usual, Rick.

For folks without sinus afflictions, probably the most commonly available bottle would be the ubiquitous two liter soda/water bottle. A 'calibrated' simple hole in the cap used in combination with the down pressure spring on the saw should provide the correct feed.

I have a tube from an HF 13" tire that already has a leak. I'll have to give that a try.

I wonder if something like modeling clay or duct seal could be used; varying the width of the piece being crushed could control the descent rate.

Oh, and you have good taste in bandsaws. Or I do. I have exactly that model Enco bandsaw. One of the most useful tools I ever bought.

Thanks Marv.

That bandsaw was the first machine I bought for my shop. Never had any trouble with it although am dismayed by the rising cost of blades.

I visited my local Home Depot and bought the Air Shim, gate valve, and a needle valve. I found the needed tubing in my junk box. I can get a nice, controlled feed rate with it but do have to use the attached squeeze bulb to pump it up. Not as handy as the plastic bottle where I just partially unscrew the cap.

I gave more thought to your suggestion of using a polycarbonate bottle. The bottle I use is polypropylene and designed to flex. The pop bottle will deflate nicely but will not spring back and will fatigue leading to cracks. I'm looking for an alternate to the nasal bottle.

Rick

**WorkerB** · Mar 1, 2019, 06:33 AM

Just a thought, how about using a screen door closer. The tubular pneumatic type with a larger knob for the closing rate instead of the supplied screw adjuster. Probably remove the spring too.

**rgsparber** · Mar 1, 2019, 07:57 AM

Originally Posted by WorkerB

Just a thought, how about using a screen door closer. The tubular pneumatic type with a larger knob for the closing rate instead of the supplied screw adjuster. Probably remove the spring too.

I mentioned John Herrmann's solution in the video. This is what he so masterfully did. It is a fine solution, just would not be a new one if I did it.

Rick

**WorkerB** · Mar 1, 2019, 02:40 PM

My bad. I didn’t watch the video

But hey, great minds and all that!!

**rgsparber** · Mar 3, 2019, 06:37 PM

My second prototype:

Rick

**RonRock** · Apr 13, 2019, 08:33 AM

Originally Posted by rgsparber

I mentioned John Herrmann's solution in the video. This is what he so masterfully did. It is a fine solution, just would not be a new one if I did it.

Rick

Nice thinking Rick.

Does anyone have a link to John Herrmann's hydraulic unit? I had no luck with several search's I tried. I did keep getting distracted with other various great ideas though. Hard to focus.

**rgsparber** · Apr 13, 2019, 08:55 AM

John published it in Home Shop Machinist.

Rick

**Peter Sanders** · May 15, 2022, 06:24 PM

While this a is a clever and quirky "outside the box thinking" solution, that does seem to work well, I don't see the point in any feed rate limiter.

My 6 x 4 bandsaw (probably the same factory different "brand"), has worked well for the last 8 years or so. I wound the spring tensioner to "limit" the feed rate (support the weight), but this spring has almost no effect on the feed rate. The weight of the whole mechanism is quite heavy but I consider some of the weight is supported by the spring.

So, for the last 8 years, I just place the blade on the material and let it cut. Provided I have my blade guides adjusted correctly I always get a straight cut.

Generally speaking, the bandsaw cut does not have to be that accurate as the cut usually precedes further machining or other processing (welding etc.).

Consider the use of the hand held hacksaw. Does the user work with "light" cuts? Unless there are "special cutting needs", normally no. The user usually "leans in to it" to make the cut. (Please don't take this statement too literally).

The user presses down quite firmly while cutting and this is what I allow my bandsaw to do. Eight years ago after fiddling with the spring tensioner, with no appreciable variation, I just let the bandsaw do its thing. I get quick and accurate cuts at the maximum speed the material allows. Cutting 1.6mm (1/16th inch) wall thickness stainless square tubing proceeds very quickly with no damage to the blade, no ripped off teeth etc.

A great idea Rick, for those that have the need.