machine skate prototype

Groundhog

Groundhog

Registered
Registered
Joined
Jan 20, 2016
Messages
1,011
Awhile back I thought I was going to give myself a lathe DRO for Christmas. I will have to move the lathe to install the DRO (I want to move it anyway). Unfortunately I am not able to get the DRO just yet. Several things came up (dentist, bearings in mill spindle, air compressor overhaul, to name a few). But since I had already started on a prototype for a cheap machine skate I thought I would finish it. Keep in mind that I just have an Asian 12x36 lathe on a steel tube stand. My guess is that without unloading the storage shelf maximum weight will be less than 2,000 lbs.
I don't have any idea if this design will work. The rollers might collapse, flat spot or just not roll. Won't know until I try them. I figure I can always turn the axles to accept cheap bearings and go that route. I am just hoping to spare the expense of bearings using these bushing type of rollers.
When I designed the stand for the lathe I made sure that the lifting leg attachment for my port-o-power can raise the lathe to get the skates in place.
Today I will weld the frames (after a little TIG welding practice) and give them a try.
As for finish I haven't decided if I will paint, powder coat or just let them rust. Tolerances are close so powder coat is not likely.
If they work (or even if not) I have PDF and CAD drawings I would be glad to share. If they do work I think I can pack them in a small USPS box if anyone wants to borrow them.
Skate D blow out Drawing v1-1.png 0496.jpg The skate on the left has just the axles installed, the skate on the right has the rollers and spacer installed. Just need to weld them up. Chamfers cut for welding.

0503.jpg Bottom side.

(pictures are thumbnails - click to enlarge)
 
Last edited:
Groundhog, They look nice, have one thought, as the steel on steel. is there any way to oil or grease them. Help keep the wear and possibility of galling down.
 
kvt,
There is enough slop between the axle OD and the roller ID (0.010"+) to squirt some oil into anytime or to smear a coat of grease on before you bolt the axle in place. I thought about incorporating a grease zerk and channel in the axle but it seemed like a lot of trouble for something that might not work and something I am likely to use less than once a year.
 
Get some graded bolts with a big shoulder, or precision ground bolts. that way one is hardened, and one is soft teflon liquid will make an excellent lube.
Nice job, pics when you are done welding. BTW if the tolerances are that close, it's too close. Give yourself a little more wiggle room on the rollers. Last thing you want is a lockup from heat or galling on the sides. Brass (shim/washer) on the side is a good idea too. You want enough room to be able to lube and roll freely.
 
woodchucker,
Not sure what you mean about the bolts. The axles are bolted solid (do not rotate), the rollers spin around the axles. And, I doubt they will be going fast enough to worry about heat - I can't run that fast! :steamroller: The 0.010" clearance sure feels like it is plenty of room to allow for oil (teflon is a good idea) or even grease. There is about 0.010" of end play for each end of each roller and spacer or a total of 0.060" for the 3 parts. I'm hoping the polished ends are good enough not to need soft bushings. After all, I only need to move the lathe about 10 feet (on a very smooth concrete floor) out and back in (after DRO installation).
Thanks for the suggestions. They are things I will consider if this crude skate does not work.
By the way, I found some 1" OD bearings I can use (re-machine the axles and a few spacers) for about $80 (2 at each corner) if worse come to worse. Or I could just go to the garage and get my engine hoist!!
 
So I understand the bolts are bolted solid. It's not the fast, it's the weight and mild steel on mild steel. That weight is enough to create the friction to gall it. So a properly hardened bolt is hard, to mild. not perfect, but better than mild to mild.
yea, .010 seems like enough, you said tolerance were tight, so I thought you were real tight.

BTW even though it's a smooth floor, see if you can put some 2x4 outriggers on low, to prevent the lathe from tipping over if it gets out of control. just to keep it from going over, not on the ground. They are top heavy.
 
OK, I understand about the hardened bolt now. I'll try it this way- it should a lot less than 500 lbs on each skate. Maybe it will work, maybe not!

Hadn't thought about outriggers. My feet are wider than the front to back depth of the lathe but I will sure keep that in mind. I don't have any idea how stable it will be.
 
Wouldn't take much to add some grease channels and holes couple grease fittings .
 
You must log in or register to reply here.
Back
Top