Horizontal Band Saw Machine (copyleft?)

[vesema3]

Regarding the assembly procedure.

To assemble all the parts, we need holes in the back side:

Actually the eyebolts, which are seen at the images are 2 mm longer, than the ones you have in your 3D model. In any case you will have to chamfer a little bit the thread after the shortening . Also with a long-hole instead of 13 mm hole, it will be even more easy to mount the second eyebolt at an angle .
The assembly is done in the following sequence:
1. Build the vertical distance stacks (DIN433+DIN988), so the bearings' outer raceways don't touch (around 0,1 mm clearence is enough) and you have the desired band-saw gap. It would be way easier if you have whole precise distances at hand, but that would require machining, which we tend to avoid.
2. Assemble (eyebolt)+(ver. dis-ce stack (put the DIN988 at the bearing side))+(0,1 mm filler-blade half circumference piece (or use original thin sheet for the purpose ))+(a bearing above it)+(0,1 mm DIN988 (optional, only if the DIN6340 frictions over the bearing)+(as mentioned, DIN6340). All of this mount together into the 12 mm hole. Try to angle it, with the most chamfered lenght of the thread end, towards the hole - maybe a weak hammering would be required .
3. Because with 12m6 pin you will create interference fit with the vertical bearing, you can use 12h8, but you will make even greater clearence with the 12H9 eybolt holes. So with 12m6 you will need some kind of d12,5xD18 pipe piece as an "anvil". Make the pin extend from the bearing not more than (1x side dis. stack + 1 mm). Put both side dis. stacks with the DIN988 lying over the bearing and all of this mount, with the more extended end of the pin, into the already inserted assembly from point 2.;
4. Mount the second eyebolt assembly (p. 2) following the same procedure and with the help of the "anvil", placed under the second eyebolt head, hammer the pin until it goes equal between the heads of the eyebolts.;
5. Now you can mount the rest DIN125 + DIN985 and push on fixers for the pin.
Well that's it .

BR
Martin

[roerich_64]

Hi Martin,

for that 3D puzzle it needs a Video with the real parts from you to see how should it go

Ok. i will close the holes

I am waiting for the next steps

BR
Walter

[vesema3]

Hi Walter,
about the video, don't know, maybe sometime later in the project .
If you wish, you could make an A2p assembly similar to the "MainBeam" assembly I showed earlier, I think there is enough info, just needs to be more precisely dimensioned. I'm saying this because we have to model the following 'GuideSupportAssembly" also:

GuideSupportAssem-sketch1.jpg (50.08 KiB) Viewed 2399 times

This is welded assembly. The middle part is again 60x40x3 and the top profile is equal L 90x6 - L=100 mm. There are some holes, that we shall add to the 90x6 profile later. Changes to some of the already stated dimensions are also possible.

Here are the flat-bars I've promised. You can remodel them if you want (it was more easy for me, than making explanations with drafts) .:

GuideAssem_FlatBar2.FCStd

(33.69 KiB) Downloaded 57 times

GuideAssem_FlatBar3.FCStd

(32.47 KiB) Downloaded 60 times

The ...FlatBar3.FCStd is the one defined into the sketch above!
I consider this "GuideSupportAssembly" as the first weak point of the design, because of the aligning feature, that it incorporates, but I think its absolutely necessary with that amount of hand work and welding .

P.S.: I'm not very happy with the PartDesign->Hole feature. Are there any improvments in it with the latest released stable version of FC?

BR
Martin

[chrisb]

I cannot find the sketch shown in GuideSupportAssem-sketch1.jpg in any of the two models.

But you may be interested in how to center a rectangle more easy the using all this construction geometry with equality and parallel: You can use symmetry on diagonal corners with the center in the middle (see https://owncloud.gwdg.de/index.php/s/HS ... I/download if you're interested in some details).

[vesema3]

This sketch is only a draft section of the next assembly we should model. The uploaded files are used in it. On the sketch at the bottom there is a "section" of 40x8x120 mm flat-bar, which is infact the GuideAssem_FlatBar3.FCStd file.
Thanks for the hint, I already found the symmetry constraint and you can see it into the posted picture. I will check your file later, looks very well written . I've red, that there are some requests for middle point constraint, is it existent already?

BR
Martin

[vesema3]

Hi all,
I think this thread should be moved to the "Open discussion" forum, because it seems there are going to be a lot of technical matters involved, and really this "Users Showcase" forum is for presenting stuff, that is already done. So, if any of the current participants don't mind, can we move this thread?

BR
Martin

[chrisb]

I don't think it's that wrong here, and it is more than what we usually discuss in Open discussions.
You are very right, usually we see here ready made results of models or real objects. However, we have here a complete project from the beginning to a model, which would fit here quite well.

If we get some more votes we can move it nevertheless - and delete the discussion containing the votes.

[vesema3]

The problem is, as I mentioned in the beginning, that this project is not fully completed, and at some stage, those who wish to try it, would have to go on their own, but I hope this is not a big deal .
Don't know if Walter is on vacation, but I guess he wouldn't mind to take his work further by sharing the guide support assembly :

GuideSupportAssem.zip

(116.45 KiB) Downloaded 54 times

GuideSupportAssem2.zip

(132.68 KiB) Downloaded 62 times

GuideSupportAssem-test1.jpg (32.21 KiB) Viewed 2156 times

The equal L 90x7 is according EN 10056-1:1998 and its root R is 11 mm. I saw the actual standard - other sources say that root R should be equal to the thickness t of the legs - don't know for sure . The outer R of the square 70x5 main beam profile can be 7,5 mm (hot-formed) and 10 mm (cold-formed). In either case you will have to angle-grind or the equal L root R, or the square 70x5 outer R, because its obvious, that there will be a collision (just to clarify - this assembly is mounted to the main beam underneath and clamped from above with L-bended 8 mm rod, threaded at its ends - or more easy -> bended cut-outs from M8 thoroughly threaded rod ).
A hint regarding the cutting of the 60x40x3 profile - I think to cut one 97 mm piece, draw perpendicular lines (over the 40 mm sides) at 18 mm from each end, diagonally, and connect their vertices over the 60 mm side, so when you cut through (along the lines!) you will end up, hopefully, with two identical parts .

BR
Martin

[roerich_64]

No, i am not in the vacation

i am waiting for parts to assemble it:

Pic_08.jpg (74.59 KiB) Viewed 2141 times

What is with the MainBeam you wrote here:
https://forum.freecadweb.org/viewtopic. ... 10#p314873

Is it ready to assemble it?

BR
Walter

[vesema3]

Hi Walter,
first I want to mention, that there is a mistake in the assembly I uploaded. I'm working on repairing it
Second, please insert between the two assemblies shown on your picture, a third one including the GuideAssem_FlatBar2.FCStd I've uploaded earlier. The conical holes should face the support assembly. Also in this third assembly we will need two studs mounted into the M10 threads -> I will show you exactly how later. There is a second way using DIN 912 bolts, which I think to implement, but it is not really recommended!
About the "MainBeam" assembly, actually I thought, that we will proceed like we did with the guide assembly - I showed something, you model it really fast and last was to set the real dimensions. I can do it also, but as you can see I'm kind of slow with FC

P.S.: Please check my previous post for the repaired assembly. The equal L is changed from 90x6 (no such according to the standard ) to 90x7, and so the height of the rec. profile. But, when we come to the band saw rollers, dimensions may change again .

BR
Martin