Very Light Weight, Very Powerful 2 x 72 Sander | ONLY 52.5 Pounds

[BelnapCustomKnives]

I posted a couple of months ago about the Spindle motor powered sander. Had many valuable comments. At that time I was beginning testing of that motor and drive. Last year I had also begun testing some new frame components. A couple of weeks ago I went ahead and put all of the components I had been testing into a complete machine. The results have been very nice. As mentioned in the video a maker brought his Pheer 454 to me for some modifications. He carried the frame with motor only in and it was all he wanted to carry. I walked with him holding the VFD. When he picked up my entire machine he was nearly sick at how much lighter it was. Then he saw it perform like nothing he has seen before.
The specs:
Model: Heretic H1
Total machine weight 52.5 pounds (includes motor, VFD, frame, platen)
Welded aluminum frame.
3 HP motor with VFD
7200 SFPM plus belt speed
Lots of power for even the very heaviest removals.

 

[Maelstrom78]

Pretty neat. I like all of the features. For me "light" doesn't thrill me either way unless I needed something to be portable. It gets clamped or bolted either way.

Really cool though.

 

[Ken H>]

Looks like it's running smooth at full speed. How slow will the belt run in SFPM? I use my 2X72 grinder in the 300 SFPM range a fair amount. It has to function for fine grit belts doing critical grinds as well as high speed profiling grinding.

Your toolarm clamping looks very interesting - I see you are only using one clamp now, did you decide the two clamps were not required?

 

[Stacy E. Apelt - Bladesmith]

Is that slot along the tool arm going to have a problem with fine dust and grit getting in it and then getting inside the tool arm channel?

 

[BelnapCustomKnives]

Is that slot along the tool arm going to have a problem with fine dust and grit getting in it and then getting inside the tool arm channel?

Excellent question. One I also considered. I have been testing this clamp for over a year and no dust issues encountered. I have used it with slot on the bottom as well during testing. Have never put the slot on top.

 

[BelnapCustomKnives]

Looks like it's running smooth at full speed. How slow will the belt run in SFPM? I use my 2X72 grinder in the 300 SFPM range a fair amount. It has to function for fine grit belts doing critical grinds as well as high speed profiling grinding.

Your toolarm clamping looks very interesting - I see you are only using one clamp now, did you decide the two clamps were not required?

Thanks. I did a penny test yesterday after a maker mentioned one that was done on an Esteem machine at 6000 sfpm. Mine was done at over 7200 sfpm. I have a minor buzz in my frame and am pretty sure it is from a drive wheel that was machined .0015" under sized for the bearing and it bounced around in there a little. I am having a new wheel made to proper spec and will see how that does for the buzz.

I was previously using a 12" clamp tube during testing and decided 8" is enough. I put two places for clamps but it seems to only require one at the 8" length. So it was either the tube length of the clamp being positioned near the end that made the difference. The 12" was in the center. That will save because those orange handles are expensive plus making and welding those tabs.

It will slow way down in feet per minute. I have the low end programed so it is arond 300 sfpm I think. I will run it with the laser tach on slow speed and report the speed. With that super tiny wheel I get about 3" belt travel per revolution.

Also I had the first drive wheel crowned because I did not know better. I also have a crowned tracking wheel. Going forward tracking is perfect. Reverse not very good. The next drive wheel will be flat. See if that corrects reverse tracking.

Those seem to be the remaining issues to work out then should be ready to make them. In the video it was 52.5 pounds. The next day I removed more than 5 pounds to 47 pounds 3 ounces.
https://youtu.be/tm50iw5OH2o