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View Full Version : How to attach items to shaft/pipe for transferring torque (mobile base build)



Tyler Keniston
10-28-2016, 8:27 PM
Yup another mobile base! Bet no-one's ever built one of those before :rolleyes:

But its time I do it... I am building one for a PM 140 bandsaw.
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I am planning on putting a hardwood frame around the exterior with corner angle brackets to catch the corners of the base (with leveling feet on each corner of the external hardwood frame to hit the floor). I would ideally like to make the mobile part inside the base to keep it low profile, but since its an enclosed base this eliminates many design options. My plan is to more or less build the mobile part similar to what's depicted here: https://www.youtube.com/watch?v=aMdKdglWMHo

A lever that activates 2 cams on the inside of the base pushing down hinged wheel assemblies. My drawing gives an idea but has some mistakes that make it so it doesn't really quite make sense...
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The heart of my question is this: How would you attach items (the actuating lever/handle and the cams) to the pipe to withstand rotational force and how would you set up the bushings/bearings and end stops/retainers? My limited experience with this stuff involves the use of keyways on motor shafts and stop collars on router bits. As far as pipe, I don't know what's out there to do those sorts of things (to provide a bushing and retention such as a stop collars would, etc). Only idea I currently have is to send bolts through a drilled hole in the pipe's diameter. Wasn't sure if there was anything more elegant or effective. As far as a bushing, I can only think to use the wood itself, maybe with some nylon washers as spacers.

Thanks for any thoughts

Tyler

Frederick Skelly
10-30-2016, 7:58 PM
"The heart of my question is this: How would you attach items (the actuating lever/handle and the cams) to the pipe to withstand rotational force and how would you set up the bushings/bearings and end stops/retainers? My limited experience with this stuff involves the use of keyways on motor shafts and stop collars on router bits. As far as pipe, I don't know what's out there to do those sorts of things (to provide a bushing and retention such as a stop collars would, etc). Only idea I currently have is to send bolts through a drilled hole in the pipe's diameter. Wasn't sure if there was anything more elegant or effective. As far as a bushing, I can only think to use the wood itself, maybe with some nylon washers as spacers."

Hi Tyler,
A couple thoughts. First, I wouldn't get sucked into buying bearings, stop collars, etc. Remember that you can buy a ready made JET mobile base that handles 28" x 28" and 600# for $79, and a bigger one for $140. Unless you just plain enjoy crafting your own stuff, I'd keep those in mind as upper limits on your spending. (I have both bases and like them.:) )

With that said, I don't think this is too tough. If I understand your questions, here's what I'd do if it were my bandsaw:
* Go to a home center and buy "black pipe". Pay them to cut it to your desired lengths and thread the ends. You can but screw on end caps for that pipe. I'd personally put a BIG washer between the end cap and the wood, but you could use other things.

* On the handle side, screw a "T" on the end of your axle and screw your handle into that.

* To attach the axle to the cams, I think you're right - it looks like the guy just rand a long bolt through the cam and then through a hole in the axle. That would be elegant enough for me. (Remember you can buy a good base for $79. Don't overthink this.)

* Again, personally, I wouldnt use bearings. I'd drill a hole for the axle through the wood. (Double-up the material where you are going to make the hole.) Then put some wax in there with a candle, and call it good.

I hope this helps at least a little.
Fred

Tyler Keniston
10-31-2016, 8:09 AM
Thanks Fred that definitely does help.

I did consider buying a base, but for whatever reason I felt the need to build it so its 'just the way I want it.' That said, I would also like to build it for cheaper (or at least no more) than I could buy such bases as the ones you mentioned.

I may give the threading a try. I didn't realize they could thread cut pipe right at the store. My only concern with the handle is making sure the force applied to raise the base is counter to the threads (doesn't unscrew it). Suppose I could either make sure it activates with a tightening (clockwise) motion or lock it up with some thread lock type stuff.

Thanks again
Tyler

Paul F Franklin
11-01-2016, 12:09 AM
Another option is to use a roll pin (sometimes called a spring pin) through a drilled hole to pin two pieces together. Advantage over using a bolt is that it doesn't extend out of the parts, so it won't interfere with anything. So it would be ideal to pin the cams to the pipe, or the handle, for that matter.

Agree with Fred on skipping any sort of bearing or sleeve in this application...unless you plan to move the bandsaw 10 times a day.

John Ziebron
11-01-2016, 12:32 AM
Tyler, you might get some ideas from this video:

https://www.youtube.com/watch?v=7TTnb3TyH5Y

Tyler Keniston
11-06-2016, 5:53 PM
thanks, those are the sorts of ideas I was looking for. I might try out some roll pins.

I like the little brass / wood handle shown in that video for his rod activated tool cabinet.

Brian Brightwell
12-04-2016, 4:29 PM
Tyler, I have a mobile base that came on a Delta table saw you can have. I don't know where you live, I live in Milltown In.