Bearing / Linear Motion Design?

Design of structural and load bearing framework.
User avatar
beermkr
Posts: 55
Joined: Mon Dec 06, 2010 3:42 pm

Re: Bearing / Linear Motion Design?

Postby beermkr » Sat Jan 15, 2011 5:50 pm

In my case there is a threaded rod that puts side to side tension on the bearings. If you were to use v-groove bearings then you could keep the entire bottom clear. I think that a better option for doing dovetails is to allow the router to hang off of one end of the table and clamp the board being dovetailed there.
Mike Pensinger
Chief Brewer, The River Company Brewery, Radford, VA

User avatar
beermkr
Posts: 55
Joined: Mon Dec 06, 2010 3:42 pm

Re: Bearing / Linear Motion Design?

Postby beermkr » Sun Jan 16, 2011 11:20 pm

The way I fixed the flex issue I was having on the non drive side.
Attachments
100_0868.JPG
100_0867.JPG
Mike Pensinger
Chief Brewer, The River Company Brewery, Radford, VA

User avatar
Awesomeness
Posts: 107
Joined: Thu Dec 02, 2010 7:29 am
Own CNC?: Yes
Location: Colorado
Contact:

Re: Bearing / Linear Motion Design?

Postby Awesomeness » Tue Jan 18, 2011 10:28 pm


User avatar
larry104
Posts: 36
Joined: Wed Dec 08, 2010 1:29 am
Location: Bay Area

Re: Bearing / Linear Motion Design?

Postby larry104 » Thu Jan 20, 2011 7:35 pm


User avatar
Awesomeness
Posts: 107
Joined: Thu Dec 02, 2010 7:29 am
Own CNC?: Yes
Location: Colorado
Contact:

Re: Bearing / Linear Motion Design?

Postby Awesomeness » Thu Jan 20, 2011 9:35 pm


User avatar
beermkr
Posts: 55
Joined: Mon Dec 06, 2010 3:42 pm

Re: Bearing / Linear Motion Design?

Postby beermkr » Thu Jan 20, 2011 11:48 pm

I think we need to look at it in another light... how many people build an entry level machine and scrape the money together to do it, then turn around and build a bigger machine later? I know I am one.

I think that if the first machine had the speed and capacity from the beginning I may not be building the second one. That translates to a significant savings in the long run.

R/
Mike Pensinger
Chief Brewer, The River Company Brewery, Radford, VA

User avatar
dinki
Posts: 6
Joined: Tue Dec 07, 2010 6:34 pm

Re: Bearing / Linear Motion Design?

Postby dinki » Fri Jan 21, 2011 1:49 am

I can tell you that I started building my book machine with the false expectations of using the bill of materials at:

http://buildyourcnc.com/billmaterials.aspx

Total price of $341. I later found out that the motors listed really couldn't be used to drive the book machine. Had I known that the machine would actually cost twice as much and then some then I probably would have passed on the whole thing.

What you say is valid, but I know that I'd rather have a lower cost entry point and upgrade later if the need warrants. If my book machine proves to be useful and I can make some money doing projects for others (which I've already gotten a few people wanting me to cut things for them), then I can use that money to justify the expense of the upgrade.

I think Awesomeness is right in saying the machine should be designed for low cost entry for beginners and not to build the end-all beat-all machine unless it can be done for the same amount of money.

User avatar
Awesomeness
Posts: 107
Joined: Thu Dec 02, 2010 7:29 am
Own CNC?: Yes
Location: Colorado
Contact:

Re: Bearing / Linear Motion Design?

Postby Awesomeness » Fri Jan 21, 2011 4:18 am


User avatar
Awesomeness
Posts: 107
Joined: Thu Dec 02, 2010 7:29 am
Own CNC?: Yes
Location: Colorado
Contact:

Re: Bearing / Linear Motion Design?

Postby Awesomeness » Fri Jan 21, 2011 7:27 am

What about a cable drive? Might be a very cheap option.

User avatar
beermkr
Posts: 55
Joined: Mon Dec 06, 2010 3:42 pm

Re: Bearing / Linear Motion Design?

Postby beermkr » Fri Jan 21, 2011 2:20 pm

I thought about that also. I was worried about a couple things:

Slippage on the drive drum translating to lost steps

If you used some kind of rubber on the drum, the the wear factor on the drum material changing the diameter.

Otherwise cable may be one of the cheapest ways to go. I liked the thought of single side belt drive and using cable connections to pull the other side along.

R/
Mike Pensinger
Chief Brewer, The River Company Brewery, Radford, VA


Return to “Structural Design”

Who is online

Users browsing this forum: No registered users and 3 guests